ria Multilevel Variation in Diabetes Screening Within an Integrated Health System By care.diabetesjournals.org Published On :: 2020-04-20T12:00:32-07:00 OBJECTIVE Variation in diabetes screening in clinical practice is poorly described. We examined the interplay of patient, provider, and clinic factors explaining variation in diabetes screening within an integrated health care system in the U.S. RESEARCH DESIGN AND METHODS We conducted a retrospective cohort study of primary care patients aged 18–64 years with two or more outpatient visits between 2010 and 2015 and no diagnosis of diabetes according to electronic health record (EHR) data. Hierarchical three-level models were used to evaluate multilevel variation in screening at the patient, provider, and clinic levels across 12 clinics. Diabetes screening was defined by a resulted gold standard screening test. RESULTS Of 56,818 patients, 70% completed diabetes screening with a nearly twofold variation across clinics (51–92%; P < 0.001). Of those meeting American Diabetes Association (ADA) (69%) and U.S. Preventive Services Task Force (USPSTF) (36%) screening criteria, three-quarters were screened with a nearly twofold variation across clinics (ADA 53–92%; USPSTF 49–93%). The yield of ADA and USPSTF screening was similar for diabetes (11% vs. 9%) and prediabetes (38% vs. 36%). Nearly 70% of patients not eligible for guideline-based screening were also tested. The USPSTF guideline missed more cases of diabetes (6% vs. 3%) and prediabetes (26% vs. 19%) than the ADA guideline. After adjustment for patient, provider, and clinic factors and accounting for clustering, twofold variation in screening by provider and clinic remained (median odds ratio 1.97; intraclass correlation 0.13). CONCLUSIONS Screening practices vary widely and are only partially explained by patient, provider, and clinic factors available in the EHR. Clinical decision support and system-level interventions are needed to optimize screening practices. Full Article
ria Facility-Level Variation in Cardiac Stress Test Use Among Patients With Diabetes: Findings From the Veterans Affairs National Database By care.diabetesjournals.org Published On :: 2020-04-20T12:00:33-07:00 Full Article
ria Bariatric Surgery in Patients With Obesity and Latent Autoimmune Diabetes in Adults (LADA) By care.diabetesjournals.org Published On :: 2020-04-20T12:00:33-07:00 Full Article
ria Cardiac biomarkers are prognostic in systemic light chain amyloidosis with no cardiac involvement by standard criteria By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Patients with systemic immunoglobulin light chain amyloidosis (AL) with no evidence of cardiac involvement by consensus criteria have excellent survival, but 20% will die within 5 years of diagnosis and prognostic factors remain poorly characterised. We report the outcomes of 378 prospectively followed Mayo stage I patients (N-terminal pro b-type natriuretic peptide <332 ng/L, high sensitivity cardiac troponin <55 ng/L). The median presenting N-terminal pro b-type natriuretic peptide was 161 ng/L, high sensitivity cardiac troponin 10 ng/L, creatinine 76 μmol/L and mean left ventricular septal wall thickness, 10 mm. Median follow up was 42 (1-117 months), with 71 deaths; median overall survival was not reached (78% survival at 5 years). Although no patients had cardiac involvement by echocardiogram, a proportion (n=25/90, 28%) had cardiac involvement by cardiac magnetic resonance imaging. Age, autonomic nervous system involvement, N-terminal pro b-type natriuretic peptide >152 ng/L, high sensitivity cardiac troponin >10 ng/L and cardiac involvement by magnetic resonance imaging were predictive for survival; on multivariate analysis only N-terminal pro b-type natriuretic peptide >152 ng/L (P<0.008, hazard ratio [HR] 3.180, confidence interval [CI]: 1.349-7.495) and cardiac involvement on magnetic resonance imaging (P=0.026, HR=5.360, CI: 1.219-23.574) were prognostic. At 5 years, 70% of patients with N-terminal pro b-type natriuretic peptide >152 ng/L were alive. In conclusion, N-terminal pro b-type natriuretic peptide is prognostic for survival in patients with no cardiac involvement by consensus criteria and cardiac involvement is detected by magnetic resonance imaging in such cases. This suggests that N-terminal pro b-type natriuretic peptide thresholds for cardiac involvement in AL may need to be redefined. Full Article
ria Appropriation of GPIb{alpha} from platelet-derived extracellular vesicles supports monocyte recruitment in systemic inflammation By www.haematologica.org Published On :: 2020-05-01T00:05:41-07:00 Interactions between platelets, leukocytes and the vessel wall provide alternative pathological routes of thrombo-inflammatory leukocyte recruitment. We found that when platelets were activated by a range of agonists in whole blood, they shed platelet-derived extracellular vesicles which rapidly and preferentially bound to blood monocytes compared to other leukocytes. Platelet-derived extracellular vesicle binding to monocytes was initiated by P-selectin-dependent adhesion and was stabilised by binding of phosphatidylserine. These interactions resulted in the progressive transfer of the platelet adhesion receptor GPIbα to monocytes. GPIbα+-monocytes tethered and rolled on immobilised von Willebrand Factor or were recruited and activated on endothelial cells treated with TGF-β1 to induce the expression of von Willebrand Factor. In both models monocyte adhesion was ablated by a function-blocking antibody against GPIbα. Monocytes could also bind platelet-derived extracellular vesicle in mouse blood in vitro and in vivo. Intratracheal instillations of diesel nanoparticles, to model chronic pulmonary inflammation, induced accumulation of GPIbα on circulating monocytes. In intravital experiments, GPIbα+-monocytes adhered to the microcirculation of the TGF-β1-stimulated cremaster muscle, while in the ApoE–/– model of atherosclerosis, GPIbα+-monocytes adhered to the carotid arteries. In trauma patients, monocytes bore platelet markers within 1 hour of injury, the levels of which correlated with severity of trauma and resulted in monocyte clearance from the circulation. Thus, we have defined a novel thrombo-inflammatory pathway in which platelet-derived extracellular vesicles transfer a platelet adhesion receptor to monocytes, allowing their recruitment in large and small blood vessels, and which is likely to be pathogenic. Full Article
ria Characterization of response and corneal events with extended follow-up after belantamab mafodotin (GSK2857916) monotherapy for patients with relapsed multiple myeloma: a case series from the first-time-in-human clinical trial By www.haematologica.org Published On :: 2020-05-01T00:05:42-07:00 Full Article
ria Risk Factors for Diabetic Peripheral Neuropathy and Cardiovascular Autonomic Neuropathy in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study demonstrated that intensive glucose control reduced the risk of developing diabetic peripheral neuropathy (DPN) and cardiovascular autonomic neuropathy (CAN). We evaluated multiple risk factors and phenotypes associated with DPN and CAN in this large, well-characterized cohort of participants with type 1 diabetes, followed for >23 years. DPN was defined by symptoms, signs, and nerve conduction study abnormalities in ≥2 nerves; CAN was assessed using standardized cardiovascular reflex tests. Generalized estimating equation models assessed the association of DPN and CAN with individual risk factors measured repeatedly. During DCCT/EDIC, 33% of participants developed DPN and 44% CAN. Higher mean HbA1c was the most significant risk factor for DPN, followed by older age, longer duration, greater height, macroalbuminuria, higher mean pulse rate, β-blocker use, and sustained albuminuria. The most significant risk factor for CAN was older age, followed by higher mean HbA1c, sustained albuminuria, longer duration of type 1 diabetes, higher mean pulse rate, higher mean systolic blood pressure, β-blocker use, estimated glomerular filtration rate <60 mL/min/1.73 m2, higher most recent pulse rate, and cigarette smoking. These findings identify risk factors and phenotypes of participants with diabetic neuropathy that can be used in the design of new interventional trials and for personalized approaches to neuropathy prevention. Full Article
ria A Variation on the Theme: SGLT2 Inhibition and Glucagon Secretion in Human Islets By diabetes.diabetesjournals.org Published On :: 2020-04-20T12:00:34-07:00 Full Article
ria Brief interventions for obesity when patients are asked to pay for weight loss treatment: an observational study in primary care with an embedded randomised trial By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 BackgroundA brief intervention whereby GPs opportunistically facilitate an NHS-funded referral to a weight loss programme is clinically and cost-effective.AimTo test the acceptability of a brief intervention and attendance at a weight loss programme when GPs facilitate a referral that requires patients to pay for the service.Design and settingAn observational study of the effect of a GP encouraging attendance at a weight loss programme requiring self-payment in the West Midlands from 16 October 2018 to 30 November 2018, to compare with a previous trial in England in which the service was NHS-funded.MethodSixty patients with obesity who consecutively attended primary care appointments received an opportunistic brief intervention by a GP to endorse and offer a referral to a weight loss programme at the patient’s own expense. Participants were randomised to GPs who either stated the weekly monetary cost of the programme (basic cost) or who compared the weekly cost to an everyday discretionary item (cost comparison). Participants were subsequently asked to report whether they had attended a weight loss programme.ResultsOverall, 47% of participants (n = 28) accepted the referral; 50% (n = 15) in the basic cost group and 43% (n = 13) in the cost comparison group. This was significantly less than in a previous study when the programme was NHS-funded (77%, n = 722/940; P<0.0001). Most participants reported the intervention to be helpful/very helpful and appropriate/very appropriate (78%, n = 46/59 and 85%, n = 50/59, respectively) but scores were significantly lower than when the programme was NHS-funded (92% n = 851/922 and 88% n = 813/922, respectively; P = 0.004). One person (2%) attended the weight loss programme, which is significantly lower than the 40% of participants who attended when the programme was NHS-funded (P<0.0001).ConclusionGP referral to a weight loss programme that requires patients to pay rather than offering an NHS-funded programme is acceptable; however, it results in almost no attendance. Full Article
ria Yonder: Oncogeriatrics, binge eating in black women, dissection, and podcasts By bjgp.org Published On :: 2020-04-30T16:04:41-07:00 Full Article
ria Caring for Rohingya Refugees With Diphtheria and Measles: On the Ethics of Humanity [Reflections] By www.annfammed.org Published On :: 2020-03-09T14:00:11-07:00 Hundreds of thousands of Rohingya refugees arrived in Bangladesh within weeks in fall 2017, quickly forming large settlements without any basic support. Humanitarian first responders provided basic necessities including food, shelter, water, sanitation, and health care. However, the challenge before them—a vast camp ravaged by diphtheria and measles superimposed on a myriad of common pathologies—was disproportionate to the resources. The needs were endless, resources finite, inadequacies abundant, and premature death inevitable. While such confines force unimaginable choices in resource allocation, they do not define the humanitarian purpose—to alleviate suffering and not allow such moral violations to become devoid of their horrifying meaning. As humanitarian workers, we maintain humanity when we care, commit, and respond to moral injustices. This refusal to abandon others in desperate situations is an attempt to rectify injustices through witnessing and solidarity. When people are left behind, we must not leave them alone. Full Article
ria Efficacy and Safety of Use of the Fasting Algorithm for Singaporeans With Type 2 Diabetes (FAST) During Ramadan: A Prospective, Multicenter, Randomized Controlled Trial [Original Research] By www.annfammed.org Published On :: 2020-03-09T14:00:11-07:00 PURPOSE We aimed to evaluate the efficacy and safety of use of the Fasting Algorithm for Singaporeans with Type 2 Diabetes (FAST) during Ramadan. METHODS We performed a prospective, multicenter, randomized controlled trial. The inclusion criteria were age ≥21 years, baseline glycated hemoglobin (HbA1c) level ≤9.5%, and intention to fast for ≥10 days during Ramadan. Exclusion criteria included baseline estimated glomerular filtration rate <30 mL/min, diabetes-related hospitalization, and short-term corticosteroid therapy. Participants were randomized to intervention (use of FAST) or control (usual care without FAST) groups. Efficacy outcomes were HbA1c level and fasting blood glucose and postprandial glucose changes, and the safety outcome was incidence of major or minor hypoglycemia during the Ramadan period. Glycemic variability and diabetes distress were also investigated. Linear mixed models were constructed to assess changes. RESULTS A total of 97 participants were randomized (intervention: n = 46, control: n = 51). The HbA1c improvement during Ramadan was 4 times greater in the intervention group (–0.4%) than in the control group (–0.1%) (P = .049). The mean fasting blood glucose level decreased in the intervention group (–3.6 mg/dL) and increased in the control group (+20.9 mg/dL) (P = .034). The mean postprandial glucose level showed greater improvement in the intervention group (–16.4 mg/dL) compared to the control group (–2.3 mg/dL). There were more minor hypoglycemic events based on self-monitered blood glucose readings in the control group (intervention: 4, control: 6; P = .744). Glycemic variability was not significantly different between the 2 groups (P = .284). No between-group differences in diabetes distress were observed (P = .479). CONCLUSIONS Our findings emphasize the importance of efficacious, safe, and culturally tailored epistemic tools for diabetes management. Full Article
ria Thank You, Reviewers and E-Letter Contributors! [Editorials] By www.annfammed.org Published On :: 2020-03-09T14:00:11-07:00 Full Article
ria Implications of the FAST Protocol Beyond Spirituality [Editorials] By www.annfammed.org Published On :: 2020-03-09T14:00:11-07:00 Full Article
ria Bioimpedance Guided Fluid Management in Peritoneal Dialysis: A Randomized Controlled Trial By cjasn.asnjournals.org Published On :: 2020-05-07T10:00:25-07:00 Background and objectives Bioelectrical impedance analysis (BIA) devices can help assess volume overload in patients receiving maintenance peritoneal dialysis. However, the effects of BIA on the short-term hard end points of peritoneal dialysis lack consistency. This study aimed to test whether BIA-guided fluid management could improve short-term outcomes in patients on peritoneal dialysis. Design, setting, participants, & measurements A single-center, open-labeled, randomized, controlled trial was conducted. Patients on prevalent peritoneal dialysis with volume overload were recruited from July 1, 2013 to March 30, 2014 and followed for 1 year in the initial protocol. All participants with volume overload were 1:1 randomized to the BIA-guided arm (BIA and traditional clinical methods) and control arm (only traditional clinical methods). The primary end point was all-cause mortality and secondary end points were cardiovascular disease mortality and technique survival. Results A total of 240 patients (mean age, 49 years; men, 51%; diabetic, 21%, 120 per group) were enrolled. After 1-year follow-up, 11(5%) patients died (three in BIA versus eight in control) and 21 patients were permanently transferred to hemodialysis (eight in BIA versus 13 in control). The rate of extracellular water/total body water decline in the BIA group was significantly higher than that in the control group. The 1-year patient survival rates were 96% and 92% in BIA and control groups, respectively. No significant statistical differences were found between patients randomized to the BIA-guided or control arm in terms of patient survival, cardiovascular disease mortality, and technique survival (P>0.05). Conclusions Although BIA-guided fluid management improved the fluid overload status better than the traditional clinical method, no significant effect was found on 1-year patient survival and technique survival in patients on peritoneal dialysis. Full Article
ria A Post Hoc Analysis of Statin Use in Tolvaptan Autosomal Dominant Polycystic Kidney Disease Pivotal Trials By cjasn.asnjournals.org Published On :: 2020-05-07T10:00:25-07:00 Background and objectives Tolvaptan is approved to slow kidney function decline in adults with autosomal dominant polycystic kidney disease (ADPKD) at risk of rapid progression. Because in vitro studies indicated that the tolvaptan oxobutyric acid metabolite inhibits organic anion–transporting polypeptide (OATP)1B1 and OATP1B3, United States prescribing information advises avoiding concurrent use with OATP1B1/1B3 substrates, including hepatic hydroxymethyl glutaryl–CoA reductase inhibitors (statins). This post hoc analysis of the pivotal phase 3 tolvaptan trials (Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes [TEMPO] 3:4 trial [NCT00428948] and Replicating Evidence of Preserved Renal Function: an Investigation of Tolvaptan Safety and Efficacy in ADPKD [REPRISE] trial [NCT02160145]) examined the safety of concurrent tolvaptan/statin use. Design, setting, participants, & measurements The trials randomized a combined total of 2815 subjects with early- to late-stage ADPKD to tolvaptan (n=1644) or placebo (n=1171) for 3 years (TEMPO 3:4) and 1 year (REPRISE). Statin use was unrestricted, and 597 subjects (21.2% overall; 332 [20.2%] tolvaptan, 265 [22.6%] placebo) received statins. Statin use (duration, dose change, statin change, permanent discontinuation), incidences of statin-related adverse events, and hepatic transaminase elevations were determined for subjects who received tolvaptan+statin, placebo+statin, tolvaptan alone, and placebo alone. Results No differences in statin use parameters between tolvaptan- and placebo-treated subjects were observed. No statistically significant increases in commonly reported statin-related adverse events (e.g., musculoskeletal disorders, gastrointestinal symptoms) were seen between subjects receiving tolvaptan+statin and placebo+statin. For example, in TEMPO 3:4, frequencies were 5.4% and 7.8%, respectively, for myalgia (difference –2.4%; 95% confidence interval, –11.2% to 6.4%) and 9.3% and 7.8%, respectively, for abdominal pain (difference 1.5%; –7.9% to 10.9%). In an analysis that excluded participants concurrently using allopurinol, the frequency of alanine transaminase or aspartate transaminase >3x upper limit of normal in the pooled study populations was 3.6% for the tolvaptan+statin group and 2.3% for the placebo+statin group (difference 1.4%; –2.0% to 4.7%). Conclusions Tolvaptan has been used safely in combination with statins in clinical trials. Podcast This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_04_06_CJN.08170719.mp3 Full Article
ria Darbepoetin Alfa in Patients with Advanced CKD without Diabetes: Randomized, Controlled Trial By cjasn.asnjournals.org Published On :: 2020-05-07T10:00:25-07:00 Background and objectives Large, randomized, controlled trials targeting higher hemoglobin level with erythropoiesis-stimulating agents for Western patients with CKD showed harm. However, the effect of anemia correction using erythropoiesis-stimulating agents may differ between CKD subpopulations. The Prevention of ESKD by Darbepoetin Alfa in CKD Patients with Non-diabetic Kidney Disease study, a multicenter, randomized, open-label, parallel-group study, aimed to examine the effect of targeting hemoglobin levels of 11–13 g/dl using darbepoetin alfa with reference to a low-hemoglobin target of 9–11 g/dl on kidney outcome in patients with advanced CKD without diabetes in Japan. Design, setting, participants, & measurements We enrolled 491 patients with CKD without diabetes, and an eGFR of 8–20 ml/min per 1.73 m2. Of these 491 patients, 239 and 240 were ultimately assigned to the high- and low-hemoglobin groups, respectively (12 patients were excluded). The primary outcome was a kidney composite end point (starting maintenance dialysis, kidney transplantation, eGFR≤6 ml/min per 1.73 m2, and 50% reduction in eGFR). Results Mean hemoglobin levels were 11.2±1.1 and 10.0±0.9 g/dl in the high- and low-hemoglobin groups, respectively, during the mean study period of 73.5±29.7 weeks. The kidney composite end point occurred in 105 (44%) and 116 (48%) patients in the high- and low-hemoglobin groups, respectively (log-rank test; P=0.32). The adjusted Cox proportional hazards model showed that the hazard ratio for the high- versus low-hemoglobin group was 0.78 (95% confidence interval, 0.60 to 1.03; P=0.08). Cardiovascular events occurred in 19 (8%) and 16 (7%) patients in each group, respectively, with no significant between-group difference (log-rank test; P=0.66). Conclusions Targeting a higher hemoglobin level (11–13 g/dl) with darbepoetin alfa did not improve kidney outcome compared with targeting a lower hemoglobin level (9–11 g/dl) in patients with advanced CKD without diabetes. Clinical Trial registry name and registration number Prevention of ESKD by Darbepoetin Alfa in CKD Patients with Non-diabetic Kidney Disease (PREDICT), NCT01581073. Full Article
ria Enhanced Immunogenicity of Mitochondrial-Localized Proteins in Cancer Cells By cancerimmunolres.aacrjournals.org Published On :: 2020-05-01T00:05:25-07:00 Epitopes derived from mutated cancer proteins elicit strong antitumor T-cell responses that correlate with clinical efficacy in a proportion of patients. However, it remains unclear whether the subcellular localization of mutated proteins influences the efficiency of T-cell priming. To address this question, we compared the immunogenicity of NY-ESO-1 and OVA localized either in the cytosol or in mitochondria. We showed that tumors expressing mitochondrial-localized NY-ESO-1 and OVA proteins elicit significantdly higher frequencies of antigen-specific CD8+ T cells in vivo. We also demonstrated that this stronger immune response is dependent on the mitochondrial location of the antigenic proteins, which contributes to their higher steady-state amount, compared with cytosolic localized proteins. Consistent with these findings, we showed that injection of mitochondria purified from B16 melanoma cells can protect mice from a challenge with B16 cells, but not with irrelevant tumors. Finally, we extended these findings to cancer patients by demonstrating the presence of T-cell responses specific for mutated mitochondrial-localized proteins. These findings highlight the utility of prioritizing epitopes derived from mitochondrial-localized mutated proteins as targets for cancer vaccination strategies. Full Article
ria Different Effects of Soil Fertilization on Bacterial Community Composition in the Penicillium canescens Hyphosphere and in Bulk Soil [Environmental Microbiology] By aem.asm.org Published On :: 2020-05-05T08:00:35-07:00 This study investigated the effects of long-term soil fertilization on the composition and potential for phosphorus (P) and nitrogen (N) cycling of bacterial communities associated with hyphae of the P-solubilizing fungus Penicillium canescens. Using a baiting approach, hyphosphere bacterial communities were recovered from three soils that had received long-term amendment in the field with mineral or mineral plus organic fertilizers. P. canescens hyphae recruited bacterial communities with a decreased diversity and an increased abundance of Proteobacteria relative to what was observed in soil communities. As core bacterial taxa, Delftia and Pseudomonas spp. were present in all hyphosphere samples irrespective of soil fertilization. However, the type of fertilization showed significant impacts on the diversity, composition, and distinctive taxa/operational taxonomic units (OTUs) of hyphosphere communities. The soil factors P (Olsen method), exchangeable Mg, exchangeable K, and pH were important for shaping soil and hyphosphere bacterial community compositions. An increased relative abundance of organic P metabolism genes was found in hyphosphere communities from soil that had not received P fertilizers, which could indicate P limitation near the fungal hyphae. Additionally, P. canescens hyphae recruited bacterial communities with a higher abundance of N fixation genes than found in soil communities, which might imply a role of hyphosphere communities for fungal N nutrition. Furthermore, the relative abundances of denitrification genes were greater in several hyphosphere communities, indicating an at least partly anoxic microenvironment with a high carbon-to-N ratio around the hyphae. In conclusion, soil fertilization legacy shapes P. canescens hyphosphere microbiomes and their functional potential related to P and N cycling. IMPORTANCE P-solubilizing Penicillium strains are introduced as biofertilizers to agricultural soils to improve plant P nutrition. Currently, little is known about the ecology of these biofertilizers, including their interactions with other soil microorganisms. This study shows that communities dominated by Betaproteobacteria and Gammaproteobacteria colonize P. canescens hyphae in soil and that the compositions of these communities depend on the soil conditions. The potential of these communities for N and organic P cycling is generally higher than that of soil communities. The high potential for organic P metabolism might complement the ability of the fungus to solubilize inorganic P, and it points to the hyphosphere as a hot spot for P metabolism. Furthermore, the high potential for N fixation could indicate that P. canescens recruits bacteria that are able to improve its N nutrition. Hence, this community study identifies functional groups relevant for the future optimization of next-generation biofertilizer consortia for applications in soil. Full Article
ria Prebiotics Inhibit Proteolysis by Gut Bacteria in a Host Diet-Dependent Manner: a Three-Stage Continuous In Vitro Gut Model Experiment [Food Microbiology] By aem.asm.org Published On :: 2020-05-05T08:00:35-07:00 Dietary protein residue can result in microbial generation of various toxic metabolites in the gut, such as ammonia. A prebiotic is "a substrate that is selectively utilised by host microorganisms conferring a health benefit" (G. R. Gibson, R. Hutkins, M. E. Sanders, S. L. Prescott, et al., Nat Rev Gastroenterol Hepatol 14:491–502, 2017, https://doi.org/10.1038/nrgastro.2017.75). Prebiotics are carbohydrates that may have the potential to reverse the harmful effects of gut bacterial protein fermentation. Three-stage continuous colonic model systems were inoculated with fecal samples from omnivore and vegetarian volunteers. Casein (equivalent to 105 g protein consumption per day) was used within the systems as a protein source. Two different doses of inulin-type fructans (Synergy1) were later added (equivalent to 10 g per day in vivo and 15 g per day) to assess whether this influenced protein fermentation. Bacteria were enumerated by fluorescence in situ hybridization with flow cytometry. Metabolites from bacterial fermentation (short-chain fatty acid [SCFA], ammonia, phenol, indole, and p-cresol) were monitored to further analyze proteolysis and the prebiotic effect. A significantly higher number of bifidobacteria was observed with the addition of inulin together with reduction of Desulfovibrio spp. Furthermore, metabolites from protein fermentation, such as branched-chain fatty acids (BCFA) and ammonia, were significantly lowered with Synergy1. Production of p-cresol varied among donors, as we recognized four high producing models and two low producing models. Prebiotic addition reduced its production only in vegetarian high p-cresol producers. IMPORTANCE Dietary protein levels are generally higher in Western populations than in the world average. We challenged three-stage continuous colonic model systems containing high protein levels and confirmed the production of potentially harmful metabolites from proteolysis, especially replicates of the transverse and distal colon. Fermentations of proteins with a prebiotic supplementation resulted in a change in the human gut microbiota and inhibited the production of some proteolytic metabolites. Moreover, we observed both bacterial and metabolic differences between fecal bacteria from omnivore donors and vegetarian donors. Proteins with prebiotic supplementation showed higher Bacteroides spp. and inhibited Clostridium cluster IX in omnivore models, while in vegetarian modes, Clostridium cluster IX was higher and Bacteroides spp. lower with high protein plus prebiotic supplementation. Synergy1 addition inhibited p-cresol production in vegetarian high p-cresol-producing models while the inhibitory effect was not seen in omnivore models. Full Article
ria Unexpected Abundance and Diversity of Phototrophs in Mats from Morphologically Variable Microbialites in Great Salt Lake, Utah [Microbial Ecology] By aem.asm.org Published On :: 2020-05-05T08:00:35-07:00 Microbial mat communities are associated with extensive (~700 km2) and morphologically variable carbonate structures, termed microbialites, in the hypersaline Great Salt Lake (GSL), Utah. However, whether the composition of GSL mat communities covaries with microbialite morphology and lake environment is unknown. Moreover, the potential adaptations that allow the establishment of these extensive mat communities at high salinity (14% to 17% total salts) are poorly understood. To address these questions, microbial mats were sampled from seven locations in the south arm of GSL representing different lake environments and microbialite morphologies. Despite the morphological differences, microbialite-associated mats were taxonomically similar and were dominated by the cyanobacterium Euhalothece and several heterotrophic bacteria. Metagenomic sequencing of a representative mat revealed Euhalothece and subdominant Thiohalocapsa populations that harbor the Calvin cycle and nitrogenase, suggesting they supply fixed carbon and nitrogen to heterotrophic bacteria. Fifteen of the next sixteen most abundant taxa are inferred to be aerobic heterotrophs and, surprisingly, harbor reaction center, rhodopsin, and/or bacteriochlorophyll biosynthesis proteins, suggesting aerobic photoheterotrophic (APH) capabilities. Importantly, proteins involved in APH are enriched in the GSL community relative to that in microbialite mat communities from lower salinity environments. These findings indicate that the ability to integrate light into energy metabolism is a key adaptation allowing for robust mat development in the hypersaline GSL. IMPORTANCE The earliest evidence of life on Earth is from organosedimentary structures, termed microbialites, preserved in 3.481-billion-year-old (Ga) rocks. Phototrophic microbial mats form in association with an ~700-km2 expanse of morphologically diverse microbialites in the hypersaline Great Salt Lake (GSL), Utah. Here, we show taxonomically similar microbial mat communities are associated with morphologically diverse microbialites across the lake. Metagenomic sequencing reveals an abundance and diversity of autotrophic and heterotrophic taxa capable of harvesting light energy to drive metabolism. The unexpected abundance of and diversity in the mechanisms of harvesting light energy observed in GSL mat populations likely function to minimize niche overlap among coinhabiting taxa, provide a mechanism(s) to increase energy yield and osmotic balance during salt stress, and enhance fitness. Together, these physiological benefits promote the formation of robust mats that, in turn, influence the formation of morphologically diverse microbialite structures that can be imprinted in the rock record. Full Article
ria CosR Is a Global Regulator of the Osmotic Stress Response with Widespread Distribution among Bacteria [Genetics and Molecular Biology] By aem.asm.org Published On :: 2020-05-05T08:00:35-07:00 Bacteria accumulate small, organic compounds called compatible solutes via uptake from the environment or biosynthesis from available precursors to maintain the turgor pressure of the cell in response to osmotic stress. The halophile Vibrio parahaemolyticus has biosynthesis pathways for the compatible solutes ectoine (encoded by ectABC-asp_ect) and glycine betaine (encoded by betIBA-proXWV), four betaine-carnitine-choline transporters (encoded by bccT1 to bccT4), and a second ProU transporter (encoded by proVWX). All of these systems are osmotically inducible with the exception of bccT2. Previously, it was shown that CosR, a MarR-type regulator, was a direct repressor of ectABC-asp_ect in Vibrio species. In this study, we investigated whether CosR has a broader role in the osmotic stress response. Expression analyses demonstrated that betIBA-proXWV, bccT1, bccT3, bccT4, and proVWX are repressed in low salinity. Examination of an in-frame cosR deletion mutant showed that expression of these systems is derepressed in the mutant at low salinity compared with the wild type. DNA binding assays demonstrated that purified CosR binds directly to the regulatory region of both biosynthesis systems and four transporters. In Escherichia coli green fluorescent protein (GFP) reporter assays, we demonstrated that CosR directly represses transcription of betIBA-proXWV, bccT3, and proVWX. Similar to Vibrio harveyi, we showed betIBA-proXWV was directly activated by the quorum-sensing LuxR homolog OpaR, suggesting a conserved mechanism of regulation among Vibrio species. Phylogenetic analysis demonstrated that CosR is ancestral to the Vibrionaceae family, and bioinformatics analysis showed widespread distribution among Gammaproteobacteria in general. Incidentally, in Aliivibrio fischeri, Aliivibrio finisterrensis, Aliivibrio sifiae, and Aliivibrio wodanis, an unrelated MarR-type regulator gene named ectR was clustered with ectABC-asp, which suggests the presence of another novel ectoine biosynthesis regulator. Overall, these data show that CosR is a global regulator of osmotic stress response that is widespread among bacteria. IMPORTANCE Vibrio parahaemolyticus can accumulate compatible solutes via biosynthesis and transport, which allow the cell to survive in high salinity conditions. There is little need for compatible solutes under low salinity conditions, and biosynthesis and transporter systems need to be repressed. However, the mechanism(s) of this repression is not known. In this study, we showed that CosR played a major role in the regulation of multiple compatible solute systems. Phylogenetic analysis showed that CosR is present in all members of the Vibrionaceae family as well as numerous Gammaproteobacteria. Collectively, these data establish CosR as a global regulator of the osmotic stress response that is widespread in bacteria, controlling many more systems than previously demonstrated. Full Article
ria A novel decision aid to help plan for serious illness: a multisite randomized trial By www.cmajopen.ca Published On :: 2020-04-28T01:30:11-07:00 Background: Recent studies have shown substantial deficiencies in the quality or quantity (or both) of communication and decision-making during serious illness. We evaluated the efficacy of a novel decision support intervention, the Plan Well Guide, in increasing completion of a standard medical order form for advance medical care planning and improving decisional outcomes in nonacademic primary care settings. Methods: We conducted a randomized trial in 3 primary care practices in Lethbridge, Alberta in 2017–2018. We recruited "patients at high risk" referred by the primary care doctor who required establishment or review of their Goals of Care Designation (GCD). Enrolled patients were randomly allocated to receive the Plan Well Guide, delivered by a trained facilitator, or usual care. Eight to 12 weeks after the intervention, a research assistant blinded to intervention assignment contacted the patients in both groups by telephone to do a final outcome assessment. The primary outcome was completion of GCD forms; secondary outcomes included decisional conflict scores and ratings of satisfaction. Results: A total of 123 patients (59 women [48.0%]; mean age 73.9 yr) were enrolled, 66 in the intervention arm and 57 in the usualcare arm; 119 patients completed the trial. After the intervention, GCD completion rates in the intervention and usual-care groups were 95.3% and 90.9%, respectively (risk difference [RD] 4%, 95% confidence interval [CI] –14% to 22%), and the rate of concordance between medical orders and expressed preferences on follow-up was 78% and 66%, respectively (RD 12%, 95% CI –7% to 30%). Significantly fewer patients in the intervention group than in the usual-care group had written medical orders for intensive care unit care and cardiopulmonary resuscitation (22 [34%] v. 33 [60%], RD –26%, 95% CI –42% to –8%). Patients in the intervention group had lower decisional conflict scores than those in the usual-care group (mean 30.9 v. 43.1, adjusted mean difference –12.0, 95% CI –23.2 to –0.8). Physicians considered patients in the intervention group to have lower decisional conflict than those in the usual-care group, although not significantly so (mean score 10.4 v. 14.9, adjusted mean difference –4.7, 95% CI –9.9 to 0.4) and spent less time with the former (mean 9.7 v. 13.2 min, adjusted mean difference –3.5, 95% CI –5.5 to –1.5 min). Interpretation: The decision-support intervention did not increase GCD completion rates but did seem to improve some aspects of decisional quality while reducing the physician’s time to accomplish GCD decisions. Trial registration: ClinicalTrials.gov, no. NCT01297946 Full Article
ria Analytical Performance Specifications for Lipoprotein(a), Apolipoprotein B-100, and Apolipoprotein A-I Using the Biological Variation Model in the EuBIVAS Population By academic.oup.com Published On :: Wed, 08 Apr 2020 00:00:00 GMT AbstractBackgroundWith increased interest in lipoprotein(a) (Lp[a]) concentration as a target for risk reduction and growing clinical evidence of its impact on cardiovascular disease (CVD) risk, rigorous analytical performance specifications (APS) and accuracy targets for Lp(a) are required. We investigated the biological variation (BV) of Lp(a), and 2 other major biomarkers of CVD, apolipoprotein A-I (apoA-I) and apolipoprotein B-100 (apoB), in the European Biological Variation Study population.MethodSerum samples were drawn from 91 healthy individuals for 10 consecutive weeks at 6 European laboratories and analyzed in duplicate on a Roche Cobas 8000 c702. Outlier, homogeneity, and trend analysis were performed, followed by CV-ANOVA to determine BV estimates and their 95% CIs. These estimates were used to calculate APS and reference change values. For Lp(a), BV estimates were determined on normalized concentration quintiles.ResultsWithin-subject BV estimates were significantly different between sexes for Lp(a) and between women aged <50 and >50 years for apoA-I and apoB. Lp(a) APS was constant across concentration quintiles and, overall, lower than APS based on currently published data, whereas results were similar for apoA-I and apoB.ConclusionUsing a fully Biological Variation Data Critical Appraisal Checklist (BIVAC)–compliant protocol, our study data confirm BV estimates of Lp(a) listed in the European Federation of Clinical Chemistry and Laboratory Medicine database and reinforce concerns expressed in recent articles regarding the suitability of older APS recommendations for Lp(a) measurements. Given the heterogeneity of Lp(a), more BIVAC-compliant studies on large numbers of individuals of different ethnic groups would be desirable. Full Article
ria Salivary AMY1 Copy Number Variation Modifies Age-Related Type 2 Diabetes Risk By academic.oup.com Published On :: Sun, 26 Apr 2020 00:00:00 GMT AbstractBackgroundCopy number variation (CNV) in the salivary amylase gene (AMY1) modulates salivary α-amylase levels and is associated with postprandial glycemic traits. Whether AMY1-CNV plays a role in age-mediated change in insulin resistance (IR) is uncertain.MethodsWe measured AMY1-CNV using duplex quantitative real-time polymerase chain reaction in two studies, the Boston Puerto Rican Health Study (BPRHS, n = 749) and the Genetics of Lipid-Lowering Drug and Diet Network study (GOLDN, n = 980), and plasma metabolomic profiles in the BPRHS. We examined the interaction between AMY1-CNV and age by assessing the relationship between age with glycemic traits and type 2 diabetes (T2D) according to high or low copy numbers of the AMY1 gene. Furthermore, we investigated associations between metabolites and interacting effects of AMY1-CNV and age on T2D risk.ResultsWe found positive associations of IR with age among subjects with low AMY1-copy-numbers in both studies. T2D was marginally correlated with age in participants with low AMY1-copy-numbers but not with high AMY1-copy-numbers in the BPRHS. Metabolic pathway enrichment analysis identified the pentose metabolic pathway based on metabolites that were associated with both IR and the interactions between AMY1-CNV and age. Moreover, in older participants, high AMY1-copy-numbers tended to be associated with lower levels of ribonic acid, erythronic acid, and arabinonic acid, all of which were positively associated with IR.ConclusionsWe found evidence supporting a role of AMY1-CNV in modifying the relationship between age and IR. Individuals with low AMY1-copy-numbers tend to have increased IR with advancing age. Full Article
ria Limitations of Animal Studies for Predicting Toxicity in Clinical Trials: Part 2: Potential Alternatives to the Use of Animals in Preclinical Trials By www.basictranslational.onlinejacc.org Published On :: 2020-04-27T11:00:20-07:00 Dramatically rising costs in drug development are in large part because of the high failure rates in clinical phase trials. The poor correlation of animal studies to human toxicity and efficacy have led many developers to question the value of requiring animal studies in determining which drugs should enter in-human trials. Part 1 of this 2-part series examined some of the data regarding the lack of concordance between animal toxicity studies and human trials, as well as some of the potential reasons behind it. This second part of the series focuses on some alternatives to animal trials (hereafter referred to as animal research) as well as current regulatory discussions and developments regarding such alternatives. Full Article
ria Design of the {beta}3-Adrenergic Agonist Treatment in Chronic Pulmonary Hypertension Secondary to Heart Failure Trial By www.basictranslational.onlinejacc.org Published On :: 2020-04-27T11:00:20-07:00 Combined pre-and post-capillary hypertension (CpcPH) is a relatively common complication of heart failure (HF) associated with a poor prognosis. Currently, there is no specific therapy approved for this entity. Recently, treatment with beta-3 adrenergic receptor (β3AR) agonists was able to improve pulmonary hemodynamics and right ventricular (RV) performance in a translational, large animal model of chronic PH. The authors present the design of a phase II randomized clinical trial that tests the benefits of mirabegron (a clinically available β3AR agonist) in patients with CpcPH due to HF. The effect of β3AR treatment will be evaluated on pulmonary hemodynamics, as well as clinical, biochemical, and advanced cardiac imaging parameters. (Beta3 Agonist Treatment in Chronic Pulmonary Hypertension Secondary to Heart Failure [SPHERE-HF]; NCT02775539) Full Article
ria Overdiagnosis of lung cancer with low-dose computed tomography screening: meta-analysis of the randomised clinical trials By breathe.ersjournals.com Published On :: 2020-03-18T06:44:39-07:00 In low-dose computed tomography (LDCT) screening for lung cancer, all three main conditions for overdiagnosis in cancer screening are present: 1) a reservoir of slowly or nongrowing lung cancer exists; 2) LDCT is a high-resolution imaging technology with the potential to identify this reservoir; and 3) eligible screening participants have a high risk of dying from causes other than lung cancer. The degree of overdiagnosis in cancer screening is most validly estimated in high-quality randomised controlled trials (RCTs), with enough follow-up time after the end of screening to avoid lead-time bias and without contamination of the control group. Nine RCTs investigating LDCT screening were identified. Two RCTs were excluded because lung cancer incidence after the end of screening was not published. Two other RCTs using active comparators were also excluded. Therefore, five RCTs were included: two trials were at low risk of bias, two of some concern and one at high risk of bias. In a meta-analysis of the two low risk of bias RCTs including 8156 healthy current or former smokers, 49% of the screen-detected cancers were overdiagnosed. There is uncertainty about this substantial degree of overdiagnosis due to unexplained heterogeneity and low precision of the summed estimate across the two trials. Key points Nine randomised controlled trials (RCTs) on low-dose computed tomography screening were identified; five were included for meta-analysis but only two of those were at low risk of bias. In a meta-analysis of recent low risk of bias RCTs including 8156 healthy current or former smokers from developed countries, we found that 49% of the screen-detected cancers may be overdiagnosed. There is uncertainty about the degree of overdiagnosis in lung cancer screening due to unexplained heterogeneity and low precision of the point estimate. If only high-quality RCTs are included in the meta-analysis, the degree of overdiagnosis is substantial. Educational aims To appreciate that low-dose computed tomography screening for lung cancer meets all three main conditions for overdiagnosis in cancer screening: a reservoir of indolent cancers exists in the population; the screening test is able to "tap" this reservoir by detecting biologically indolent cancers as well as biologically important cancers; and the population being screened is characterised by a relatively high competing risk of death from other causes To learn about biases that might affect the estimates of overdiagnosis in randomised controlled trials in cancer screening Full Article
ria The STELVIO trial, a game changer for bronchoscopic lung volume reduction in patients with severe emphysema By breathe.ersjournals.com Published On :: 2020-03-18T06:44:39-07:00 Chronic obstructive pulmonary disease (COPD) is characterised by persistent respiratory symptoms and airflow limitation, which is caused by small airway disease (bronchiolitis) and alveolar destruction (emphysema) [1]. Patients primarily suffering from severe emphysema are often limited in exercise capacity due to the consequences of hyperinflation [2]. Full Article
ria Lung cancer incidence and mortality with extended follow-up in the National Lung Screening Trial By breathe.ersjournals.com Published On :: 2020-03-18T06:44:39-07:00 Since lung cancer (LC) is still the leading cause of cancer deaths worldwide [1], early detection through screening represents an important opportunity to improve LC survival and is a priority area for cancer care. The National Lung Screening Trial (NLST) aimed to compare low-dose helical computed tomography (LDCT) with chest radiography in LC screening of current or former heavy smokers. The trial found a relative reduction in mortality from LC of 20% in those who had undergone LDCT screening. LC screening has regained prominence in the thoracic oncology literature with the completion of NELSON and other European trials, which support the role of LC screening in achieving early diagnosis and reducing mortality. A growing number of implementation pilots are providing an impetus towards organised, national programmes for LC screening, which are in need of long-term follow-up data such as those presented in this study. Full Article
ria Lung cancer incidence and mortality with extended follow-up in the National LungScreening Trial By breathe.ersjournals.com Published On :: 2020-03-18T06:44:39-07:00 A 78-year-old male presented at the emergency room complaining of dry cough, fever up to 38.5 °C and malaise for 1 month. He had visited a general practitioner and received amoxicillin 500 mg three times a day for 7 days for a presumed chest infection, without improvement. He had a history of diabetes and arterial blood hypertension, for which he was receiving metformin 1000 mg twice a day and amlodipine 10 mg a day for 7 years. He reported no alcohol abuse and was an ex-smoker of 20 pack-years (quit 30 years ago). He had no recent hospitalisations or any medical interventions. Full Article
ria Burkholderia cepacia Complex Bacteria: a Feared Contamination Risk in Water-Based Pharmaceutical Products [Reviews] By cmr.asm.org Published On :: 2020-04-15T05:30:10-07:00 Burkholderia cepacia (formerly Pseudomonas cepacia) was once thought to be a single bacterial species but has expanded to the Burkholderia cepacia complex (Bcc), comprising 24 closely related opportunistic pathogenic species. These bacteria have a widespread environmental distribution, an extraordinary metabolic versatility, a complex genome with three chromosomes, and a high capacity for rapid mutation and adaptation. Additionally, they present an inherent resistance to antibiotics and antiseptics, as well as the abilities to survive under nutrient-limited conditions and to metabolize the organic matter present in oligotrophic aquatic environments, even using certain antimicrobials as carbon sources. These traits constitute the reason that Bcc bacteria are considered feared contaminants of aqueous pharmaceutical and personal care products and the frequent reason behind nonsterile product recalls. Contamination with Bcc has caused numerous nosocomial outbreaks in health care facilities, presenting a health threat, particularly for patients with cystic fibrosis and chronic granulomatous disease and for immunocompromised individuals. This review addresses the role of Bcc bacteria as a potential public health problem, the mechanisms behind their success as contaminants of pharmaceutical products, particularly in the presence of biocides, the difficulties encountered in their detection, and the preventive measures applied during manufacturing processes to control contamination with these objectionable microorganisms. A summary of Bcc-related outbreaks in different clinical settings, due to contamination of diverse types of pharmaceutical products, is provided. Full Article
ria Intrathecal Antibacterial and Antifungal Therapies [Reviews] By cmr.asm.org Published On :: 2020-04-29T05:33:50-07:00 Intrathecal administration of anti-infectives is indicated in central nervous system infections by multiresistant pathogens when drugs that can reach adequate cerebrospinal fluid (CSF) concentrations by systemic therapy are not available. Antibiotics that readily pass the blood-brain and blood-CSF barriers and/or that have low toxicity allowing an increase in the daily dosage should not be used for intrathecal therapy. Intrathecal therapy is accompanied by systemic treatment. Antibacterials indispensable for intrathecal therapy include aminoglycosides, colistin, daptomycin, tigecycline, and vancomycin. Limited experience suggests the utility of the antifungals amphotericin B and caspofungin. Intraventricular administration ensures distribution throughout the CSF compartment, whereas intralumbar dosing often fails to attain adequate antibiotic concentrations in the ventricles. The individual dose is determined by the estimated size of the CSF space and by the estimated clearance from CSF. For moderately lipophilic anti-infectives with a molecular weight above approximately 1,000 g/mol, as well as for hydrophilic drugs with a molecular weight above approximately 400 g/mol, one daily dose is normally adequate. The ventricular drain should be clamped for 15 to 120 min to facilitate the distribution of the anti-infective in the CSF space. Therapeutic drug monitoring of the trough levels is necessary only in cases of therapeutic failure. Full Article
ria Plasma Thymidine Kinase Activity as a Biomarker in Patients with Luminal Metastatic Breast Cancer Treated with Palbociclib within the TREnd Trial By clincancerres.aacrjournals.org Published On :: 2020-05-01T00:05:36-07:00 Purpose: Thymidine kinase 1 (TK1) is downstream to the CDK4/6 pathway, and TK activity (TKa) measured in blood is a dynamic marker of outcome in patients with advanced breast cancer (ABC). This study explores TK1 as a biomarker of palbociclib response, both in vitro and in patients with ABC. Experimental Design: Modulation of TK1 levels and activity by palbociclib were studied in seven estrogen receptor–positive breast cancer cell lines: sensitive (PDS) and with palbociclib acquired resistance (PDR). TKa was assayed in plasma obtained at baseline (T0), after one cycle (T1), and at disease progression on palbociclib (T2) in patients enrolled in the "To Reverse ENDocrine Resistance" (TREnd) trial (n = 46). Results: Among E2F-dependent genes, TK1 was significantly downregulated after short-term palbociclib. Early TKa reduction by palbociclib occurred in PDS but not in PDR cells. In patients, median TKa (mTKa) at T0 was 75 DiviTum units per liter (Du/L), with baseline TKa not proving prognostic. At T1, mTKa decreased to 35 Du/L, with a minority of patients (n = 8) showing an increase—correlating with a worse outcome than those with decreased/stable TKa (n = 33; mPFS 3.0 vs 9.0 months; P = 0.002). At T2, mTKa was 251 Du/L; patients with TKa above the median had worse outcomes on post-study treatment compared with those with lower TKa (2.9 vs 8.7 months; P = 0.05). Conclusions: TK is a dynamic marker of resistance to palbociclib which may lead to early identification of patients in whom treatment escalation may be feasible. In addition, TKa may stratify prognosis in patients with acquired resistance to palbociclib. Full Article
ria KatG as Counterselection Marker for Nontuberculous Mycobacteria [Letters] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Full Article
ria Genomic Characterization of Neisseria gonorrhoeae Strains from 2016 U.S. Sentinel Surveillance Displaying Reduced Susceptibility to Azithromycin [Epidemiology and Surveillance] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 In 2016, the proportion of Neisseria gonorrhoeae isolates with reduced susceptibility to azithromycin rose to 3.6%. A phylogenetic analysis of 334 N. gonorrhoeae isolates collected in 2016 revealed a single, geographically diverse lineage of isolates with MICs of 2 to 16 μg/ml that carried a mosaic-like mtr locus, whereas the majority of isolates with MICs of ≥16 μg/ml appeared sporadically and carried 23S rRNA mutations. Continued molecular surveillance of N. gonorrhoeae isolates will identify new resistance mechanisms. Full Article
ria Activity of Plazomicin Tested against Enterobacterales Isolates Collected from U.S. Hospitals in 2016-2017: Effect of Different Breakpoint Criteria on Susceptibility Rates among Aminoglycosides [Susceptibility] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Plazomicin was active against 97.0% of 8,783 Enterobacterales isolates collected in the United States (2016 and 2017), and only 6 isolates carried 16S rRNA methyltransferases conferring resistance to virtually all aminoglycosides. Plazomicin (89.2% to 95.9% susceptible) displayed greater activity than amikacin (72.5% to 78.6%), gentamicin (30.4% to 45.9%), and tobramycin (7.8% to 22.4%) against carbapenem-resistant and extensively drug-resistant isolates. The discrepancies among the susceptibility rates for these agents was greater when applying breakpoints generated using the same stringent contemporary methods applied to determine plazomicin breakpoints. Full Article
ria Investigating the Effects of Osmolytes and Environmental pH on Bacterial Persisters [Susceptibility] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Bacterial persisters are phenotypic variants that temporarily demonstrate an extraordinary tolerance toward antibiotics. Persisters have been linked to the recalcitrance of biofilm-related infections; hence, a complete understanding of their physiology can lead to improvement of therapeutic strategies for such infections. Mechanisms pertaining to persister formation are thought to be associated with stress response pathways triggered by intra- or extracellular stress factors. Unfortunately, studies demonstrating the effects of osmolyte- and/or pH-induced stresses on bacterial persistence are largely missing. To fill this knowledge gap within the field, we studied the effects of various osmolytes and pH conditions on Escherichia coli persistence with the use of phenotype microarrays and antibiotic tolerance assays. Although we found that a number of chemicals and pH environments, including urea, sodium nitrite, and acidic pH, significantly reduced persister formation in E. coli compared to no-osmolyte/no-buffer controls, this reduction in persister levels was less pronounced in late-stationary-phase cultures. Our results further demonstrated a positive correlation between cell growth and persister formation, which challenges the general notion in the field that slow-growing cultures have more persister cells than fast-growing cultures. Full Article
ria In Vitro Activity of Ceftazidime-Avibactam against Isolates from Respiratory and Blood Specimens from Patients with Nosocomial Pneumonia, Including Ventilator-Associated Pneumonia, in a Phase 3 Clinical Trial [Susceptibility] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Nosocomial pneumonia (NP), including ventilator-associated pneumonia (VAP), is increasingly associated with multidrug-resistant Gram-negative pathogens. This study describes the in vitro activity of ceftazidime-avibactam, ceftazidime, and relevant comparator agents against bacterial pathogens isolated from patients with NP, including VAP, enrolled in a ceftazidime-avibactam phase 3 trial. Gram-positive pathogens were included if coisolated with a Gram-negative pathogen. In vitro susceptibility was determined at a central laboratory using Clinical and Laboratory Standards Institute broth microdilution methods. Of 817 randomized patients, 457 (55.9%) had ≥1 Gram-negative bacterial pathogen(s) isolated at baseline, and 149 (18.2%) had ≥1 Gram-positive pathogen(s) coisolated. The most common isolated pathogens were Klebsiella pneumoniae (18.8%), Pseudomonas aeruginosa (15.8%), and Staphylococcus aureus (11.5%). Ceftazidime-avibactam was highly active in vitro against 370 isolates of Enterobacteriaceae, with 98.6% susceptible (MIC90, 0.5 μg/ml) compared with 73.2% susceptible for ceftazidime (MIC90, >64 μg/ml). The percent susceptibility values for ceftazidime-avibactam and ceftazidime against 129 P. aeruginosa isolates were 88.4% and 72.9% (MIC90 values of 16 μg/ml and 64 μg/ml), respectively. Among ceftazidime-nonsusceptible Gram-negative isolates, ceftazidime-avibactam percent susceptibility values were 94.9% for 99 Enterobacteriaceae and 60.0% for 35 P. aeruginosa. MIC90 values for linezolid and vancomycin (permitted per protocol for Gram-positive coverage) were within their respective MIC susceptibility breakpoints against the Gram-positive pathogens isolated. This analysis demonstrates that ceftazidime-avibactam was active in vitro against the majority of Enterobacteriaceae and P. aeruginosa isolates from patients with NP, including VAP, in a phase 3 trial. (This study has been registered at ClinicalTrials.gov under identifier NCT01808092.) Full Article
ria Antibacterial Monoclonal Antibodies Do Not Disrupt the Intestinal Microbiome or Its Function [Experimental Therapeutics] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Antibiotics revolutionized the treatment of infectious diseases; however, it is now clear that broad-spectrum antibiotics alter the composition and function of the host’s microbiome. The microbiome plays a key role in human health, and its perturbation is increasingly recognized as contributing to many human diseases. Widespread broad-spectrum antibiotic use has also resulted in the emergence of multidrug-resistant pathogens, spurring the development of pathogen-specific strategies such as monoclonal antibodies (MAbs) to combat bacterial infection. Not only are pathogen-specific approaches not expected to induce resistance in nontargeted bacteria, but they are hypothesized to have minimal impact on the gut microbiome. Here, we compare the effects of antibiotics, pathogen-specific MAbs, and their controls (saline or control IgG [c-IgG]) on the gut microbiome of 7-week-old, female, C57BL/6 mice. The magnitude of change in taxonomic abundance, bacterial diversity, and bacterial metabolites, including short-chain fatty acids (SCFA) and bile acids in the fecal pellets from mice treated with pathogen-specific MAbs, was no different from that with animals treated with saline or an IgG control. Conversely, dramatic changes were observed in the relative abundance, as well as alpha and beta diversity, of the fecal microbiome and bacterial metabolites in the feces of all antibiotic-treated mice. Taken together, these results indicate that pathogen-specific MAbs do not alter the fecal microbiome like broad-spectrum antibiotics and may represent a safer, more-targeted approach to antibacterial therapy. Full Article
ria Meropenem-Vaborbactam versus Ceftazidime-Avibactam for Treatment of Carbapenem-Resistant Enterobacteriaceae Infections [Clinical Therapeutics] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 The comparative efficacy of ceftazidime-avibactam and meropenem-vaborbactam for treatment of carbapenem-resistant Enterobacteriaceae (CRE) infections remains unknown. This was a multicenter, retrospective cohort study of adults with CRE infections who received ceftazidime-avibactam or meropenem-vaborbactam for ≥72 hours from February 2015 to October 2018. Patients with a localized urinary tract infection and repeat study drug exposures after the first episode were excluded. The primary endpoint was clinical success compared between treatment groups. Secondary endpoints included 30- and 90-day mortality, adverse events (AE), 90-day CRE infection recurrence, and development of resistance in patients with recurrent infection. A post hoc subgroup analysis was completed comparing patients who received ceftazidime-avibactam monotherapy, ceftazidime-avibactam combination therapy, and meropenem-vaborbactam monotherapy. A total of 131 patients were included (ceftazidime-avibactam, n = 105; meropenem-vaborbactam, n = 26), 40% of whom had bacteremia. No significant difference in clinical success was observed between groups (62% versus 69%; P = 0.49). Patients in the ceftazidime-avibactam arm received combination therapy more often than patients in the meropenem-vaborbactam arm (61% versus 15%; P < 0.01). No difference in 30- and 90-day mortality resulted, and rates of AE were similar between groups. In patients with recurrent infection, development of resistance occurred in three patients that received ceftazidime-avibactam monotherapy and in no patients in the meropenem-vaborbactam arm. Clinical success was similar between patients receiving ceftazidime-avibactam and meropenem-vaborbactam for treatment of CRE infections, despite ceftazidime-avibactam being used more often as a combination therapy. Development of resistance was more common with ceftazidime-avibactam monotherapy. Full Article
ria Assessing Animal Models of Bacterial Pneumonia Used in Investigational New Drug Applications for the Treatment of Bacterial Pneumonia [Experimental Therapeutics] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Animal models of bacterial infection have been widely used to explore the in vivo activity of antibacterial drugs. These data are often submitted to the U.S. Food and Drug Administration to support human use in an investigational new drug application (IND). To better understand the range and scientific use of animal models in regulatory submissions, a database was created surveying recent pneumonia models submitted as part of IND application packages. The IND studies were compared to animal models of bacterial pneumonia published in the scientific literature over the same period of time. In this review, we analyze the key experimental design elements, such as animal species, immune status, pathogens selected, and route of administration, and study endpoints. Full Article
ria In Vitro Screening of the Open-Source Medicines for Malaria Venture Malaria and Pathogen Boxes To Discover Novel Compounds with Activity against Balamuthia mandrillaris [Susceptibility] By aac.asm.org Published On :: 2020-04-21T08:01:10-07:00 Balamuthia mandrillaris is an under-reported, pathogenic free-living amoeba that causes Balamuthia amoebic encephalitis (BAE) and cutaneous skin infections. Although cutaneous infections are not typically lethal, BAE with or without cutaneous involvement is usually fatal. This is due to the lack of drugs that are both efficacious and can cross the blood-brain barrier. We aimed to discover new leads for drug discovery by screening the open-source Medicines for Malaria Venture (MMV) Malaria Box and MMV Pathogen Box, with 800 compounds total. From an initial single point screen at 1 and 10 μM, we identified 54 hits that significantly inhibited the growth of B. mandrillaris in vitro. Hits were reconfirmed in quantitative dose-response assays and 23 compounds (42.6%) were confirmed with activity greater than miltefosine, the current standard of care. Full Article
ria Comparison of Treatment Outcomes between Analysis Populations in the RESTORE-IMI 1 Phase 3 Trial of Imipenem-Cilastatin-Relebactam versus Colistin plus Imipenem-Cilastatin in Patients with Imipenem-Nonsusceptible Bacterial Infections [Clinical Therapeutic By aac.asm.org Published On :: 2020-04-21T08:01:09-07:00 The RESTORE-IMI 1 phase 3 trial demonstrated the efficacy and safety of imipenem-cilastatin (IMI) combined with relebactam (REL) for treating imipenem-nonsusceptible infections. The objective of this analysis was to compare the outcomes among patients meeting eligibility requirements based on central laboratory susceptibility versus local laboratory susceptibility. Patients with serious infections caused by imipenem-nonsusceptible, colistin-susceptible, and imipenem-REL-susceptible pathogens were randomized 2:1 to IMI-REL plus placebo or colistin plus IMI for 5 to 21 days. The primary endpoint was a favorable overall response. Key endpoints included the clinical response and all-cause mortality. We compared outcomes between the primary microbiological modified intent-to-treat (mMITT) population, where eligibility was based on central laboratory susceptibility testing, and the supplemental mMITT (SmMITT) population, where eligibility was based on local, site-level testing. The SmMITT (n = 41) and MITT (n = 31) populations had similar baseline characteristics, including sex, age, illness severity, and renal function. In both analysis populations, favorable overall response rates in the IMI-REL treatment group were >70%. Favorable clinical response rates at day 28 were 71.4% for IMI-REL and 40.0% for colistin plus IMI in the mMITT population, whereas they were 75.0% for IMI-REL and 53.8% for colistin plus IMI in the SmMITT population. Day 28 all-cause mortality rates were 9.5% for IMI-REL and 30.0% for colistin plus IMI in the mMITT population, whereas they were 10.7% for IMI-REL and 23.1% for colistin plus IMI in the SmMITT population. The outcomes in the SmMITT population were generally consistent with those in the mMITT population, suggesting that outcomes may be applicable to the real-world use of IMI-REL for treating infections caused by imipenem-nonsusceptible Gram-negative pathogens. (This study has been registered at ClinicalTrials.gov under identifier NCT02452047.) Full Article
ria A Biosynthetic Platform for Antimalarial Drug Discovery [Chemistry; Biosynthesis] By aac.asm.org Published On :: 2020-04-21T08:01:09-07:00 Advances in synthetic biology have enabled the production of a variety of compounds using bacteria as a vehicle for complex compound biosynthesis. Violacein, a naturally occurring indole pigment with antibiotic properties, can be biosynthetically engineered in Escherichia coli expressing its nonnative synthesis pathway. To explore whether this synthetic biosynthesis platform could be used for drug discovery, here we have screened bacterially derived violacein against the main causative agent of human malaria, Plasmodium falciparum. We show the antiparasitic activity of bacterially derived violacein against the P. falciparum 3D7 laboratory reference strain as well as drug-sensitive and -resistant patient isolates, confirming the potential utility of this drug as an antimalarial agent. We then screen a biosynthetic series of violacein derivatives against P. falciparum growth. The varied activity of each derivative against asexual parasite growth points to the need to further develop violacein as an antimalarial. Towards defining its mode of action, we show that biosynthetic violacein affects the parasite actin cytoskeleton, resulting in an accumulation of actin signal that is independent of actin polymerization. This activity points to a target that modulates actin behavior in the cell either in terms of its regulation or its folding. More broadly, our data show that bacterial synthetic biosynthesis could become a suitable platform for antimalarial drug discovery, with potential applications in future high-throughput drug screening with otherwise chemically intractable natural products. Full Article
ria Novel Insights into Plasmodium vivax Therapeutic Failure: CYP2D6 Activity and Time of Exposure to Malaria Modulate the Risk of Recurrence [Epidemiology and Surveillance] By aac.asm.org Published On :: 2020-04-21T08:01:09-07:00 Plasmodium vivax relapse is one of the major causes of sustained global malaria transmission. Primaquine (PQ) is the only commercial drug available to prevent relapses, and its efficacy is dependent on metabolic activation by cytochrome P450 2D6 (CYP2D6). Impaired CYP2D6 function, caused by allelic polymorphisms, leads to the therapeutic failure of PQ as a radical cure for P. vivax malaria. Here, we hypothesized that the host immune response to malaria parasites modulates susceptibility to P. vivax recurrences in association with CYP2D6 activity. We performed a 10-year retrospective study by genotyping CYP2D6 polymorphisms in 261 malaria-exposed individuals from the Brazilian Amazon. The immune responses against a panel of P. vivax blood-stage antigens were evaluated by serological assays. We confirmed our previous findings, which indicated an association between impaired CYP2D6 activity and a higher risk of multiple episodes of P. vivax recurrence (risk ratio, 1.75; 95% confidence interval [CI], 1.2 to 2.6; P = 0.0035). An important finding was a reduction of 3% in the risk of recurrence (risk ratio, 0.97; 95% CI, 0.96 to 0.98; P < 0.0001) per year of malaria exposure, which was observed for individuals with both reduced and normal CYP2D6 activity. Accordingly, subjects with long-term malaria exposure and persistent antibody responses to various antigens showed fewer episodes of malaria recurrence. Our findings have direct implications for malaria control, since it was shown that nonimmune individuals who do not respond adequately to treatment due to reduced CYP2D6 activity may present a significant challenge for sustainable progress toward P. vivax malaria elimination. Full Article
ria Early Bactericidal Activity Trial of Nitazoxanide for Pulmonary Tuberculosis [Clinical Therapeutics] By aac.asm.org Published On :: 2020-04-21T08:01:09-07:00 This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 μg/ml; the mean NTZ maximum concentration (Cmax) in plasma was 10.2 μg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis. Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.) Full Article
ria Drug Effect of Clofazimine on Persisters Explains an Unexpected Increase in Bacterial Load in Patients [Pharmacology] By aac.asm.org Published On :: 2020-04-21T08:01:09-07:00 Antituberculosis (anti-TB) drug development is dependent on informative trials to secure the development of new antibiotics and combination regimens. Clofazimine (CLO) and pyrazinamide (PZA) are important components of recommended standard multidrug treatments of TB. Paradoxically, in a phase IIa trial aiming to define the early bactericidal activity (EBA) of CLO and PZA monotherapy over the first 14 days of treatment, no significant drug effect was demonstrated for the two drugs using traditional statistical analysis. Using a model-based analysis, we characterized the statistically significant exposure-response relationships for both drugs that could explain the original findings of an increase in the numbers of CFU with CLO treatment and no effect with PZA. Sensitive analyses are crucial for exploring drug effects in early clinical trials to make the right decisions for advancement to further development. We propose that this quantitative semimechanistic approach provides a rational framework for analyzing phase IIa EBA studies and can accelerate anti-TB drug development. Full Article
ria Whole-Cell Phenotypic Screening of Medicines for Malaria Venture Pathogen Box Identifies Specific Inhibitors of Plasmodium falciparum Late-Stage Development and Egress [Experimental Therapeutics] By aac.asm.org Published On :: 2020-04-21T08:01:09-07:00 We report a systematic, cellular phenotype-based antimalarial screening of the Medicines for Malaria Venture Pathogen Box collection, which facilitated the identification of specific blockers of late-stage intraerythrocytic development of Plasmodium falciparum. First, from standard growth inhibition assays, we identified 173 molecules with antimalarial activity (50% effective concentration [EC50] ≤ 10 μM), which included 62 additional molecules over previously known antimalarial candidates from the Pathogen Box. We identified 90 molecules with EC50 of ≤1 μM, which had significant effect on the ring-trophozoite transition, while 9 molecules inhibited the trophozoite-schizont transition and 21 molecules inhibited the schizont-ring transition (with ≥50% parasites failing to proceed to the next stage) at 1 μM. We therefore rescreened all 173 molecules and validated hits in microscopy to prioritize 12 hits as selective blockers of the schizont-ring transition. Seven of these molecules inhibited the calcium ionophore-induced egress of Toxoplasma gondii, a related apicomplexan parasite, suggesting that the inhibitors may be acting via a conserved mechanism which could be further exploited for target identification studies. We demonstrate that two molecules, MMV020670 and MMV026356, identified as schizont inhibitors in our screens, induce the fragmentation of DNA in merozoites, thereby impairing their ability to egress and invade. Further mechanistic studies would facilitate the therapeutic exploitation of these molecules as broadly active inhibitors targeting late-stage development and egress of apicomplexan parasites relevant to human health. Full Article