More than a third of the 30 biggest school districts in the United States are not using any math or English/language arts curricula that are rated highly for alignment to state standards, a new study from the Center for American Progress finds.

It is time to refocus on building competency-based schools that work over time rather than forcing top-down laws that end in superficial changes in policy and no change in student outcomes, says guest blogger Van Schoales.

This week, our resident cartoonist turned his pen on the Coronavirus outbreak, Bernie Sanders rising popularity in the United States and the battle for an SNP seat at Holyrood.

WHAT’S a little distancing between us? Go on, stick your nose closer to the page or screen. Let’s snuggle in a little closer.

Concerned that schools don't notice or nurture business skills, nonprofits are using the humble lemonade stand to foster entrepreneurship.

The 'Total Physical Response' method to learning vocabulary is beneficial for students, especially English-language learners, to break down and analyze the roots and endings of vocabulary words.

Instead of fixating on the word gap and other false language-skills dilemmas, focus on what's really hurting students, writes Olivia Obeso.

The current standard of care includes informing women about prenatal testing and newborn screening for cystic fibrosis and providing genetic counseling to parents whose child is referred for sweat-testing. Despite counseling, early data identified some persistent confusion about residual risk.

Prenatal discussions about carrier testing and newborn screening for cystic fibrosis are not routine. Parental anxiety about abnormal results from a screen is decreased after speaking to a genetic counselor when scheduling the sweat test. Despite counseling, residual risk continues to be poorly understood. (Read the full article)

Conduct problems, substance use, substance use problems, and depressive symptoms increase as black adolescents enter high school. Although family-centered prevention programs deter these problems during middle school, no such programs have been developed and evaluated for black high school students.

This study demonstrates that participation in a family-centered preventive intervention reduces conduct problems, substance use, and substance use problems among black adolescents by more than 30% compared with adolescents in an attention control condition across nearly 2 years. (Read the full article)

There is a perception among clinicians that methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and/or meningitis result in a greater burden of disease than invasive infections attributed to methicillin-susceptible Staphylococcus aureus (MSSA) among very low birth weight (VLBW) infants.

VLBW infants with MRSA and MSSA bacteremia and/or meningitis have equivalent morbidity and mortality. These findings suggest that allocation of resources for prevention and treatment of both MRSA and MSSA infections among VLBW infants should be comparable. (Read the full article)

Disparities in outcomes of ethnic minority children have been reported, and have been ascribed to having barriers to access to health care. Minority parents have indicated that difficulties in access are because of problems with transportation and being non-English speaking.

This population-based study of Texas infants with severe congenital heart disease reports that neither home distance from a cardiac center nor Hispanic children having a Latin American–born parent were risk factors for first-year mortality. (Read the full article)

Primary care settings provide an important venue for early detection of substance use and intervention, but adolescent screening rates need improvement. Screening and brief interventions appear effective in reducing adult problem drinking but evidence for effectiveness among adolescents is needed.

A computer-facilitated system for screening, feedback, and provider brief advice for primary care can increase adolescent receipt of substance use screening across a variety of practice settings, and shows promise for reducing adolescents’ use of alcohol and cannabis. (Read the full article)

Social and environmental risks related to substandard housing contribute to adverse health outcomes. Partnerships between the health care and legal systems can help families address such risks and help clinicians understand the legal context of health.

A medical-legal partnership colocated in a pediatric primary care setting identified and treated a large cluster of poor quality, substandard housing. Housing improvements were possible because of strong collaboration between clinicians, attorneys, community partners, and families. (Read the full article)

Autism spectrum disorders are characterized by heterogeneous severity. Previous latent variable analyses of longitudinal data have focused on trajectories of related features such as IQ, and not on changes over time in standardized, observational measures of core autism symptoms.

Autism Diagnostic Observation Schedule–calibrated severity scores allow comparisons of observational data from toddlerhood to adolescence. This first report of latent autism severity trajectory classes indicates that most children show stability in core symptom severity over many years; small groups improved or worsened. (Read the full article)

National asthma treatment guidelines include the recommendation that all asthma patients receive a written asthma action plan. No previous study has sought to examine the readability, suitability, and content of asthma action plans within a nationally representative sample.

Although variability was found across written asthma action plans, and improvements in readability, suitability, and content are needed, there were also many common elements that would support a move to a single universal standard action plan. (Read the full article)

Although the metabolic syndrome is associated with obesity, not all obese children have insulin resistance and metabolic syndrome, and nonobese children may develop these abnormalities. Associated factors have not been well described.

There was a 6.6% prevalence of nonobese children who were insulin-resistant, associated with a family history of hypertension. There was a 21.3% prevalence of obese who were not insulin-resistant, associated with a low waist circumference. (Read the full article)

Many US children aged 6 to 24 months who would be classified as low weight-for-age by the Centers for Disease Control and Prevention 2000 reference will be classified as normal weight-for-age by the World Health Organization 2006 standard.

Children who will be reclassified from low to normal weight-for-age using the World Health Organization growth standard are at higher risk of adverse health outcomes than children who are not low weight-for-age by the Centers for Disease Control and Prevention reference. (Read the full article)

Evaluating for elevations in alanine aminotransferase (ALT) is a common screening test for the presence of nonalcoholic fatty liver disease (NAFLD). NAFLD is less common among non-Hispanic blacks. Better predictors of NAFLD are needed to identify individuals in most need of screening.

Relative to other ethnicities, metabolic syndrome and insulin resistance performed poorly at identifying non-Hispanic black adolescents with ALT elevations. The presence of metabolic syndrome may therefore not be an adequate trigger for NAFLD screening. Triglyceride elevations performed similarly between groups in identifying ALT elevations. (Read the full article)

Phthalate exposure has been associated with insulin resistance in animal studies and cross-sectional studies of adults, but has not been studied in adolescents.

We detect associations of urinary phthalate metabolites in a cross-sectional study of US adolescents. The association is highly robust to multiple sensitivity analyses, and specific to phthalates commonly found in food. Further longitudinal study of dietary phthalate exposures is needed. (Read the full article)

Invasive methicillin-resistant Staphylococcus aureus (MRSA) in children is associated with high morbidity and mortality. Although reductions in health care–associated MRSA infection among adults are documented, it is unclear if a similar trend is occurring among children.

Data from population-based surveillance were analyzed to assess changes in invasive MRSA infection incidence over time. This analysis describes the epidemiology and trends of invasive MRSA infections among children in 9 US metropolitan areas and estimates national burden. (Read the full article)

There is a perception that Gram-negative bacilli (GNB) bloodstream infection is increasing in the NICU, and those infections caused by a multidrug-resistant (MDR) strain are a growing threat to hospitalized patients.

Exposure to broad-spectrum antibiotics is the most important risk factor for MDR GNB bacteremia, which is associated with higher mortality. Neonates with risk factors for bacteremia caused by a MDR GNB strain may benefit from empirical antimicrobial therapy with carbapenem. (Read the full article)

Recent studies have shown that participating in the Supplemental Nutrition Assistance Program (SNAP) is associated with improved household food security. With the exception of 1 descriptive analysis, studies have not examined how SNAP affects children’s food security.

This article estimates the association between SNAP and children’s food security using the largest, most rigorous national study of food security to date. Given current proposals to reduce program size, this study underscores SNAP’s importance in affecting children’s well-being. (Read the full article)

Antibiotic overuse is common and is a major public health threat. The prevalence of antimicrobial stewardship programs in children’s hospitals is growing. Single-center studies reveal that antimicrobial stewardship programs are effective in reducing unnecessary antibiotic use. Multicenter evaluations are needed.

Antibiotic use is declining overall across a large network of freestanding children’s hospitals. Hospitals with formalized antimicrobial stewardship programs experienced greater reductions in antibiotic use than other hospitals, suggesting that these interventions are an effective strategy to address antibiotic overuse. (Read the full article)

Existing literature discusses the unique medical and psychological needs of sex trafficking victims and highlights the importance of screening patients with risk factors. However, little is known about providers’ knowledge and confidence in their ability to provide care to victims.

The study summarizes the knowledge gaps and barriers providers face when assisting pediatric sex trafficking victims. It also highlights the impact of training on providers’ confidence and ability to appropriately care for victims. (Read the full article)

Myxovirus resistance protein A (MxA) is a protein induced during viral infections. A few small-scale studies have suggested that MxA could be used as a marker of viral infection in clinical routine practice.

This study involves the largest patient population thus far and confirms the usefulness of MxA for diagnosing viral infections in children consulting the emergency department in a clinical routine setting. (Read the full article)

Insulin resistance plays a role in obesity. Recently it has been associated with increased risk of AD. Aβ42 and PSEN1 are molecules associated with increased risk of later AD. Patients affected by AD show elevated levels of plasma Aβ42.

Levels of Aβ42 and PSEN1 are significantly elevated in obese adolescents and correlated with the degree of both adiposity and systemic insulin resistance. (Read the full article)

Fifteen percent of tuberculosis cases globally are resistant to the drug isoniazid. Isoniazid resistance puts patients with tuberculosis at risk for poor treatment outcomes and threatens the effectiveness of isoniazid preventive therapy in people with latent tuberculosis infection.

We present the first global and regional estimates of the proportion of children with tuberculosis who have isoniazid-resistant disease, showing large geographic variations in risk of resistance. We estimate the number of annual incident cases of isoniazid-resistant tuberculosis in children. (Read the full article)

Treatment of idiopathic steroid-resistant nephrotic syndrome is challenging, and therapeutic options are limited. In spite of good initial response with rituximab, responders always remain prone to further relapse, necessitating either repeat course of rituximab or addition of another steroid-sparing immunosuppressant.

Mycophenolate mofetil may be an effective maintenance therapy to consider as an additive immunosuppressant after induction with rituximab in maintaining remission among children with refractory steroid-resistant nephrotic syndrome. (Read the full article)

Research demonstrates that substance use, beliefs about use, and influence from family and friends can put young adults at risk for DUI and RWDD. Much of this research is cross-sectional and focuses on risk factors identified in young adults.

This longitudinal study emphasizes the importance of prevention efforts in early adolescence at multiple levels to reduce high school DUI/RWDD, because marijuana beliefs and marijuana use by peers and family members during middle school were associated with high school DUI/RWDD. (Read the full article)

A student-centered approach to teaching mathematics enables students to develop conceptual understanding and to grow as confident mathematicians.

The unexpected transition to online classes due to the COVID-19 pandemic has prompted many changes for undergraduate students and their instructors. To understand the magnitude of these impacts and potentially improve digital learning, researchers in the Penn State School of Engineering Design and Professional Programs have received a $196,136 grant from the National Science Foundation.

Source: www.businessinsider.com - Saturday, May 09, 2020
Dating apps like Tinder, Bumble, and Hinge have reported increased use amid the coronavirus pandemic, while touting virtual dating alternatives for users instead of meeting up in person. Swaths of users are still encouraging matches to break quarantine to have sex and go on dates, despite social distancing guidelines and fines to comply with them. An illustrator on Instagram has been collecting screenshots of these situations, and told Business Insider that users will brand themselves as "badasses," dispute the effectiveness of isolating, and lash out in anger and hurl abusive language when they're rejected. Spokespeople for Grindr, Tinder and Bumble told Business Insider they've informed users to adhere to social-distancing guidelines, but did not respond to inquiries about actions they're taking against users in places where violating lockdown orders can be against the law. Visit Business Insider's homepage for more stories . As millions remain confined to their homes to prevent the spread of coronavirus, the desire for human contact and connection has risen dramatically and led some to search for ways to break those social distancing rules. Popular dating apps — including Tinder , Bumble , and Hinge — have reported significant increases during the outbreak of swiping activity, matches between users, and messages exchanged. It's also led to the introduction of a breed of users who are interested in shirking lockdown orders, an

It took rickshaw driver Mohammad Rasheed a year to save 300 rupees to buy his daughter a bike, so when he found three billion rupees ($22.5 million) had passed through an unused bank account in his name, he was stunned ... and scared.

La fièvre des élections s’empare de l’Afrique centrale. Pour la seconde fois depuis la fin des guerres qui ont dévasté la région, les scrutins s’enchaînent au Burundi, au Rwanda, en République centrafricaine et au Congo.

Election fever has spread across Central Africa. For the second time since the end of the disastrous civil wars in the region, electoral processes have been launched in Burundi, Rwanda, Central African Republic and the Congo.

Insufficient political will has thwarted regional efforts to stop the murderous Lord’s Resistance Army (LRA) but vigorous diplomacy led by the African Union (AU), an immediate military push and complementary civilian initiatives could end the misery of thousands.

The Framework Agreement signed by the UN, African organisations and eleven countries and the deployment of an intervention brigade in North Kivu are positive steps, but conflicts in the Kivu region of the Democratic Republic of the Congo also require a bottom-up approach aimed at improving intercommunal relations and restoring peace at the local level.

What should be included in a measure of school quality? If not by standardized test scores, how should we measure student achievement? Julian Vasquez Heilig and I each have some thoughts.

Background: This study summarizes drug resistance analyses in 4 recent phase 2b trials of the respiratory syncytial virus (RSV) fusion inhibitor presatovir in naturally infected adults.

Methods: Adult hematopoietic cell transplant (HCT) recipients, lung transplant recipients, or hospitalized patients with naturally acquired, laboratory-confirmed RSV infection were enrolled in 4 randomized, double-blind, placebo-controlled studies with study-specific presatovir dosing. Full-length RSV F sequences amplified from nasal swabs obtained at baseline and postbaseline were analyzed by population sequencing. Substitutions at RSV fusion inhibitor resistance-associated positions are reported.

Results: Genotypic analyses were performed on 233 presatovir-treated and 149 placebo-treated subjects. RSV F variant V127A was present in 8 subjects at baseline. Population sequencing detected treatment-emergent substitutions in 10/89 (11.2%) HCT recipients with upper and 6/29 (20.7%) with lower respiratory tract infection, 1/35 (2.9%) lung transplant recipients, and 1/80 (1.3%) hospitalized patients treated with presatovir; placebo-treated subjects had no emergent resistance-associated substitutions. Subjects with substitutions at resistance-associated positions had smaller decreases in viral load during treatment relative to those without, but similar clinical outcomes.

Conclusions: Subject population type and dosing regimen may have influenced RSV resistance development during presatovir treatment. Subjects with vs without genotypic resistance development had decreased virologic responses but comparable clinical outcomes.

QPX7728 is a new ultra-broad-spectrum inhibitor of serine and metallo beta-lactamases from a class of cyclic boronates that gave rise to vaborbactam. The spectrum and mechanism of beta-lactamase inhibition by QPX7728 were assessed using purified enzymes from all molecular classes. QPX7728 inhibits class A ESBLs (IC₅₀ range 1-3 nM) and carbapenemases such as KPC (IC₅₀ 2.9±0.4 nM) as well as class C P99 (IC₅₀ of 22±8 nM) with a potency that is comparable or higher than recently FDA approved BLIs avibactam, relebactam and vaborbactam. Unlike those other BLIs, QPX7728 is also a potent inhibitor of class D carbapenemases such as OXA-48 from Enterobacteriaceae and OXA enzymes from A. baumannii (OXA-23/24/58, IC₅₀ range 1-2 nM) as well as MBLs such as NDM-1 (IC₅₀ 55±25 nM), VIM-1 (IC₅₀ 14±4 nM) and IMP-1 (IC₅₀ 610±70 nM). Inhibition of serine enzymes by QPX7728 is associated with progressive inactivation with a high efficiency k₂/K ranging from of 6.3 x 10⁴ (for P99) to 9.9 x 10⁵ M^-1 s^-1 (for OXA-23). This inhibition is reversible with variable stability of the QPX7728-beta-lactamase complexes with target residence time ranging from minutes to several hours: 5-20 minutes for OXA carbapenemases from A. baumanii, ~50 minutes for OXA-48 and 2-3 hours for KPC and CTX-M-15. QPX7728 inhibited all tested serine enzymes at 1:1 molar ratio. Metallo-beta-lactamases NDM, VIM, and IMP were inhibited by a competitive mechanism with fast-on-fast-off kinetics, with K_is of 7.5±2.1 nM, 32±14 nM and 240±30 nM for VIM-1, NDM-1 and IMP-1, respectively. QPX7728 ultra-broad-spectrum of BLI inhibition combined with its high potency enables combinations with multiple different beta-lactam antibiotics.

Malaria parasites invade and replicate within red blood cells (RBCs), extensively modifying their structure and gaining access to the extracellular environment by placing the plasmodial surface anion channel (PSAC) into the RBC membrane. Expression of members of the cytoadherence linked antigen gene 3 (clag3) family is required for PSAC activity, a process that is regulated epigenetically. PSAC is a well-established route of uptake for large, hydrophilic antimalarial compounds and parasites can acquire resistance by silencing clag3 gene expression, thereby reducing drug uptake. We found that exposure to sub-IC50 concentrations of the histone methyltransferase inhibitor chaetocin caused substantial changes in both clag3 gene expression and RBC permeability, reversing acquired resistance to the antimalarial compound blasticidin S that is transported through PSAC. Chaetocin treatment also altered progression of parasites through their replicative cycle, presumably by changing their ability to modify chromatin appropriately to enable DNA replication. These results indicate that targeting histone modifiers could represent a novel tool for reversing epigenetically acquired drug resistance in P. falciparum.

Continuous spread of antimalarial drug resistance is a threat to current chemotherapy efficacy. Therefore, characterizing the genetic diversity of drug resistance markers is needed to follow treatment effectiveness and further update control strategies. Here, we genotyped Plasmodium falciparum resistance gene markers associated with sulfadoxine-pyrimethamine (SP) and artemisinin-based combination therapy (ACT) in isolates from pregnant women in Ghana. The prevalence of the septuple IRNI-A/FGKGS/T pfdhfr/pfdhps haplotypes including the pfdhps A581G and A613S/T mutations was high at delivery among post-SP treatment isolates (18.2%) compared to those of first-antenatal care (before initiation of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP); 6.1%; p = 0.03). Regarding the pfk13 marker gene, two non-synonymous mutations (N458D and A481C) were detected at positions previously related to artemisinin resistance in isolates from Southeast-Asia. These mutations were predicted in silico to alter the stability of the pfk13 propeller-encoding domain. Overall, these findings highlight the need for intensified monitoring and surveillance on additional mutations associated with increased SP resistance as well as emergence of resistance against artemesinin derivatives.

Since 2012, single low dose of primaquine (SLDPQ, 0.25mg/kg) has been recommended with artemisinin-based combination therapies, as first-line treatment of acute uncomplicated Plasmodium falciparum malaria, to interrupt its transmission, especially in low transmission settings of multidrug, including artemisinin, resistance. Policy makers in Cambodia have been reluctant to implement this recommendation due to primaquine safety concerns and lack of data on its efficacy.

In this randomized controlled trial, 109 Cambodians with acute uncomplicated P. falciparum malaria received dihydroartemisinin-piperaquine (DP) alone or combined with SLDPQ on the first treatment day. Transmission-blocking efficacy of SLDPQ was evaluated on Days 0, 1, 2, 3, 7, 14, 21, 28 and recrudescence by reverse transcriptase polymerase chain reaction (RT-PCR) (gametocyte prevalence) and membrane-feeding assays with Anopheles minimus mosquitoes (gametocyte infectivity). Without the influence of recrudescent infections, DP+SLDPQ reduced gametocyte carriage 3 fold compared to DP. Of 48 patients tested on Day 0, only three patients were infectious to mosquitoes (~6%). Post-treatment, three patients were infectious: on D14 (3.5%, 1/29), and on the first and seventh day of recrudescence (8.3%, 1/12 for each); this overall low infectivity precluded our ability to assess its transmission blocking efficacy.

Our study confirms effective gametocyte clearance of SLDPQ when combined with DP in multidrug resistant P. falciparum and the negative impact of recrudescent infections due to poor DP efficacy. Artesunate-mefloquine (ASMQ) has replaced DP and ASMQ-SLDPQ has been deployed to treat all P. falciparum symptomatic patients to further support the elimination of multidrug resistant P. falciparum in Cambodia.

Objectives: Antibiotic combination therapy is used for severe infections caused by multidrug-resistant (MDR) Gram-negative bacteria. Yet, data of which combinations are most effective is lacking. This study aimed to evaluate the in vitro efficacy of polymyxin B in combination with 13 other antibiotics against four clinical strains of MDR Pseudomonas aeruginosa.

Methods: We evaluated the interactions of polymyxin B in combination with amikacin, aztreonam, cefepime, chloramphenicol, ciprofloxacin, fosfomycin, meropenem, minocycline, rifampicin, temocillin, thiamphenicol or trimethoprim by automated time-lapse microscopy using predefined cut-off values indicating inhibition of growth (≤10⁶ CFU/mL) at 24 h. Promising combinations were subsequently evaluated in static time-kill experiments.

Results: All strains were intermediate or resistant to polymyxin B, anti-pseudomonal β-lactams, ciprofloxacin and amikacin. Genes encoding β-lactamases (e.g., bla_PAO and bla_OXA-50) and mutations associated with permeability and efflux were detected in all strains. In the time-lapse microscopy experiments, positive interactions were found with 39 of 52 antibiotic combination/bacterial strain setups. Enhanced activity was found against all four strains with polymyxin B used in combination with aztreonam, cefepime, fosfomycin, minocycline, thiamphenicol and trimethoprim. Time kill experiments showed additive or synergistic activity with 27 of the 39 tested polymyxin B combinations, most frequently with aztreonam, cefepime, and meropenem.

Conclusion: Positive interactions were frequently found with the tested combinations, also against strains that harboured several resistance mechanisms to the single drugs and with antibiotics that are normally not active against P. aeruginosa. Further study is needed to explore the clinical utility of these combinations.

β-lactam resistance in Staphylococcus aureus limits treatment options. Stp1 and Stk1, a serine-threonine phosphatase and kinase respectively, mediate serine-threonine kinase (STK) signaling. Loss of function point mutations in stp1 were detected among laboratory passaged, β-lactam resistant S. aureus strains lacking mecA and blaZ, the major determinants of β-lactam resistance in the bacteria. Loss of Stp1 function facilitates β-lactam resistance of the bacteria.

Carbapenem-resistant Gram-negative pathogens are a critical public health threat and there is an urgent need for new treatments. Carbapenemases (β-lactamases able to inactivate carbapenems) have been identified in both serine β-lactamase (SBL) and metallo β-lactamase (MBL) families. The recent introduction of SBL carbapenemase-inhibitors has provided alternative therapeutic options. Unfortunately, there are no approved inhibitors of MBL-mediated carbapenem-resistance and treatment options for infections caused by MBL-producing Gram-negatives are limited. Here, we present ZN148, a zinc-chelating MBL-inhibitor capable of restoring the bactericidal effect of meropenem and in vitro clinical susceptibility to carbapenems in >98% of a large international collection of MBL-producing clinical Enterobacterales strains (n=234). Moreover, ZN148 was able to potentiate the effect of meropenem against NDM-1-producing Klebsiella pneumoniae in a murine neutropenic peritonitis model. ZN148 showed no inhibition of the human zinc-containing enzyme glyoxylase II at 500 μM and no acute toxicity was observed in an in vivo mouse model with cumulative dosages up to 128 mg/kg. Biochemical analysis showed a time-dependent inhibition of MBLs by ZN148 and removal of zinc ions from the active site. Addition of exogenous zinc after ZN148 exposure only restored MBL activity by ~30%, suggesting an irreversible mechanism of inhibition. Mass-spectrometry and molecular modelling indicated potential oxidation of the active site Cys221 residue. Overall, these results demonstrate the therapeutic potential of a ZN148-carbapenem combination against MBL-producing Gram-negative pathogens and that ZN148 is a highly promising MBL inhibitor, capable of operating in a functional space not presently filled by any clinically approved compound.

Antimicrobial peptides and proteins play critical roles in the host defense against invading pathogens. We recently discovered that recombinantly expressed human and mouse serum amyloid A1 (rhSAA1 and rmSAA1) proteins have potent antifungal activities against the major human fungal pathogen Candida albicans. At high concentrations, rhSAA1 disrupts C. albicans membrane integrity and induces rapid fungal cell death. In the current study, we find that rhSAA1 promotes cell aggregation and targets the C. albicans cell wall adhesin Als3. Inactivation of ALS3 in C. albicans leads to a striking decrease in cell aggregation and cell death upon rhSAA1 treatment, suggesting that Als3 plays a critical role in SAA1 sensing. We further demonstrate that deletion of the transcriptional regulators controlling the expression of ALS3, such as AHR1, BCR1, and EFG1 in C. albicans results in similar effects to that of the als3/als3 mutant upon rhSAA1 treatment. Global gene expression profiling indicates that rhSAA1 has a discernible impact on the expression of cell wall- and metabolism-related genes, suggesting that rhSAA1 treatment could lead to a nutrient starvation effect on C. albicans cells.

Multi-drug resistance among Gram-negative bacteria is a major global public health threat. Metallo-β-lactamases (MBLs) target the most widely-used antibiotic class, the β-lactams, including the most recent-generation carbapenems. Interspecies spread renders these enzymes a serious clinical threat and there are no clinically-available inhibitors. We present crystal structures of IMP-13, a structurally-uncharacterized MBL from Gram-negative Pseudomonas aerugionasa found in clinical outbreaks globally, and characterize the binding using solution NMR-spectroscopy and molecular-dynamics simulations. Crystal structures of apo IMP-13 and bound to four clinically-relevant carbapenem antibiotics (doripenem, ertapenem, imipenem and meropenem) are presented. Active site plasticity and the active-site loop, where a tryptophan residue stabilizes the antibiotic core scaffold, are essential to the substrate-binding mechanism. The conserved carbapenem scaffold plays the most significant role in IMP-13 binding, explaining the broad substrate specificity. The observed plasticity and substrate-locking mechanism provide opportunities for rational drug design of novel metallo-β-lactamase inhibitors, essential in the fight against antibiotic resistance.

Resistance to amoxicillin-clavulanate, a widely used beta-lactam/beta-lactamase inhibitor combination antibiotic, is rising globally, yet susceptibility testing remains challenging. To test whether whole-genome sequencing (WGS) could provide a more reliable assessment of susceptibility than traditional methods, we predicted resistance from WGS for 976 E. coli bloodstream infection isolates from Oxfordshire, UK, comparing against phenotypes from the BD Phoenix (calibrated against EUCAST guidelines). 339/976 (35%) isolates were amoxicillin-clavulanate resistant. Predictions based solely on beta-lactamase presence/absence performed poorly (sensitivity 23% (78/339)) but improved when genetic features associated with penicillinase hyper-production (e.g. promoter mutations, copy number estimates) were considered (sensitivity 82% (277/339); p<0.0001). Most discrepancies occurred in isolates with peri-breakpoint MICs. We investigated two potential causes; the phenotypic reference and the binary resistant/susceptible classification. We performed reference standard, replicated phenotyping in a random stratified subsample of 261/976 (27%) isolates using agar dilution, following both EUCAST and CLSI guidelines, which use different clavulanate concentrations. As well as disagreeing with each other, neither agar dilution phenotype aligned perfectly with genetic features. A random-effects model investigating associations between genetic features and MICs showed that some genetic features had small, variable and additive effects, resulting in variable resistance classification. Using model fixed-effects to predict MICs for the non-agar dilution isolates, predicted MICs were in essential agreement (±1 doubling dilution) with observed (BD Phoenix) MICs for 691/715 (97%) isolates. This suggests amoxicillin-clavulanate resistance in E. coli is quantitative, rather than qualitative, explaining the poorly reproducible binary (resistant/susceptible) phenotypes and suboptimal concordance between different phenotypic methods and with WGS-based predictions.

Objectives: Carbapenemase-producing Enterobacterales and specifically KPC-producing Klebsiella pneumoniae (KPC-Kp) are rapidly spreading worldwide. The prognosis of ventilator-associated pneumonia (VAP) caused by KPC-producing Klebsiella pneumoniae (KPC-Kp) is not well known. Our study tries to assess whether ventilator-associated pneumonia caused by a KPC-Kp strain is associated with higher all-cause mortality than if caused by carbapenem-susceptible isolates.

Study design and methods: This is a retrospective cohort study of patients with VAP due to K. pneumoniae from a 35-bed polyvalent Intensive Care Unit in a university hospital (> 40,000 annual admissions) between January 2012 and December 2016. Adjusted multivariate analysis was used to study the association of KPC-Kp with 30-day all-cause mortality (Cox regression).

Results. We analyze 69 cases of K. pneumoniae VAP of which 39 were produced by a KPC-Kp strain with high-level resistance to meropenem (MIC > 16 mg/mL). All-cause mortality at 30 days was 41% in the KPC-Kp group (16/39) and 33.3% in the carbapenem-susceptible cases (10/30). KPC-Kp etiology was not associated with higher mortality when controlled for confounders (adjusted hazard ratio [lsqb]HR[rsqb] 1.25; 95% CI: 0.46–3.41). Adequate targeted therapy (HR 0.03; 95% CI: <0.01–0.23) was associated with all-cause mortality.

Conclussion. Assuming the limitations due to the available sample size, the prognosis of VAP caused by KPC-Kp is similar to VAPs caused by carbapenem-susceptible K. pneumoniae when appropriate treatment is used.