Rational design of a new antibiotic class for drug-resistant infections.

The development of new antibiotics to treat infections caused by drug-resistant Gram-negative pathogens is of paramount importance as antibiotic resistance continues to increase worldwide1. Here we describe a strategy for the rational design of diazabicyclooctane inhibitors of penicillin-binding proteins from Gram-negative bacteria to overcome multiple mechanisms of resistance, including ß-lactamase enzymes, stringent response and outer membrane permeation. Diazabicyclooctane inhibitors retain activity in the presence of ß-lactamases, the primary resistance mechanism associated with ß-lactam therapy in Gram-negative bacteria2,3. Although the target spectrum of an initial lead was successfully re-engineered to gain in vivo efficacy, its ability to permeate across bacterial outer membranes was insufficient for further development. Notably, the features that enhanced target potency were found to preclude compound uptake. An improved optimization strategy leveraged porin permeation properties concomitant with biochemical potency in the lead-optimization stage. This resulted in ETX0462, which has potent in vitro and in vivo activity against Pseudomonas aeruginosa plus all other Gram-negative ESKAPE pathogens, Stenotrophomonas maltophilia and biothreat pathogens. These attributes, along with a favourable preclinical safety profile, hold promise for the successful clinical development of the first novel Gram-negative chemotype to treat life-threatening antibiotic-resistant infections in more than 25 years.

Sulbactam-durlobactam susceptibility test method development and quality control ranges for MIC and disk diffusion tests.

Sulbactam-durlobactam is a ß-lactam/ß-lactamase inhibitor combination developed to treat hospital-acquired and ventilator-associated bacterial pneumonia caused by Acinetobacter baumannii-calcoaceticus complex (ABC). Durlobactam is a diazabicyclooctane ß-lactamase inhibitor with potent activity against Ambler classes A, C, and D serine ß-lactamases and restores sulbactam activity against multidrug-resistant ABC. Studies were conducted to establish sulbactam-durlobactam antimicrobial susceptibility testing methods for both broth microdilution minimal inhibitory concentration (MIC) and disk diffusion tests as well as quality control (QC) ranges. To establish the MIC test method, combinations of sulbactam and durlobactam were evaluated using a panel of genetically characterized A. baumannii isolates which were categorized as predicted to be susceptible or resistant based on the spectrum of ß-lactamase inhibition by durlobactam. MIC testing with doubling dilutions of sulbactam with a fixed concentration of 4 µg/mL of durlobactam resulted in the greatest discrimination of the pre-defined susceptible and resistant strains. Similarly, the sulbactam/durlobactam 10/10 µg disk concentration showed the best discrimination as well as correlation with the MIC test. A. baumannii NCTC 13304 was selected for QC purposes because it assesses the activity of both sulbactam and durlobactam with clear endpoints. Multi-laboratory QC studies were conducted according to CLSI M23 Tier 2 criteria. A sulbactam-durlobactam broth MIC QC range of 0.5/4-2/4 µg/mL and a zone diameter QC range of 24-30 mm were determined for A. baumannii NCTC 13304 and have been approved by CLSI. These studies will enable clinical laboratories to perform susceptibility tests with accurate and reproducible methods.

Molecular drivers of resistance to sulbactam-durlobactam in contemporary clinical isolates of Acinetobacter baumannii.

Acinetobacter baumannii-calcoaceticus complex (ABC) causes severe infections that are difficult to treat due to pre-existing antibiotic resistance. Sulbactam-durlobactam (SUL-DUR) is a targeted ß-lactam/ß-lactamase inhibitor combination antibiotic designed to treat serious infections caused by Acinetobacter, including multidrug- and carbapenem-resistant strains. In a recent global surveillance study of 5,032 ABC clinical isolates collected from 2016 to 2021, less than 2% of ABC isolates had SUL-DUR MIC values >4 µg/mL. Molecular characterization of these isolates confirmed the primary drivers of resistance are metallo-ß-lactamases or penicillin-binding protein 3 (PBP3) mutations, as previously described. In addition, this study shows that certain common PBP3 variants, such as A515V, are insufficient to confer sulbactam resistance and that the efflux of durlobactam by AdeIJK is likely to play a role in a subset of strains.

N-Hydroxyformamide LpxC inhibitors, their in vivo efficacy in a mouse Escherichia coli infection model, and their safety in a rat hemodynamic assay.

UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase (LpxC), the zinc metalloenzyme catalyzing the first committed step of lipid A biosynthesis in Gram-negative bacteria, has been a target for antibacterial drug discovery for many years. All inhibitor chemotypes reaching an advanced preclinical stage and clinical phase 1 have contained terminal hydroxamic acid, and none have been successfully advanced due, in part, to safety concerns, including hemodynamic effects. We hypothesized that the safety of LpxC inhibitors could be improved by replacing the terminal hydroxamic acid with a different zinc-binding group. After choosing an N-hydroxyformamide zinc-binding group, we investigated the structure-activity relationship of each part of the inhibitor scaffold with respect to Pseudomonas aeruginosa and Escherichia coli LpxC binding affinity, in vitro antibacterial potency and pharmacological properties. We identified a novel, potency-enhancing hydrophobic binding interaction for an LpxC inhibitor. We demonstrated in vivo efficacy of one compound in a neutropenic mouse E. coli infection model. Another compound was tested in a rat hemodynamic assay and was found to have a hypotensive effect. This result demonstrated that replacing the terminal hydroxamic acid with a different zinc-binding group was insufficient to avoid this previously recognized safety issue with LpxC inhibitors.

Percutaneous CT-guided lumbar trans-facet pedicle screw fixation in lumbar microinstability syndrome: feasibility of a novel approach.

STUDY DESIGN: Prospective experimental uncontrolled trial. BACKGROUND: Lumbar microinstability (MI) is a common cause of lower back pain (LBP) and is related to intervertebral disc degeneration that leads to inability to adequately absorb applied loads. The term "microinstability" has recently been introduced to denote a specific syndrome of biomechanical dysfunction with minimal anatomical change. Trans-facet fixation (TFF) is a minimally invasive technique that involves the placement of screws across the facet joint and into the pedicle, to attain improved stability in the spine. PURPOSE: In this study, we aimed to evaluate the effectiveness, in terms of pain and disability reduction, of a stand-alone TFF in treatment of patients with chronic low back pain (LBP) due to MI. Moreover, as a secondary endpoint, the purpose was to assess the feasibility and safety of a novel percutaneous CT-guided technique. METHODS: We performed percutaneous CT-guided TFF in 84 consecutive patients presenting with chronic LBP attributable to MI at a single lumbar level without spondylolysis. Pre- and post-procedure pain and disability levels were measured using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). RESULTS: At 2 years, TFF resulted in significant reductions in both VAS and ODI scores. CT-guided procedures were tolerated well by all patients under light sedation with a mean procedural time of 45 min, and there were no reported immediate or delayed procedural complications. CONCLUSION: TFF seems to be a powerful technique for lumbar spine stabilization in patients with chronic mechanical LBP related to lumbar MI. CT-guided technique is fast, precise, and safe and can be performed in simple analgo-sedation.

Women's and girls' experiences of reproductive coercion and opportunities for intervention in family planning clinics in Nairobi, Kenya: a qualitative study.

BACKGROUND: Reproductive coercion (RC), which includes contraceptive sabotage and pregnancy coercion, may help explain known associations between intimate partner violence (IPV) and poor reproductive health outcomes, such as unintended pregnancy. In Kenya, where 40% of ever-married women report IPV and 35% of ever-pregnant women report unintended pregnancy, these experiences are pervasive and co-occurring, yet little research exists on RC experiences among women and adolescent girls. This study seeks to qualitatively describe women's and girls' experiences of RC in Nairobi, Kenya and opportunities for clinical intervention. METHODS: Qualitative data were collected as part of the formative research for the adaptation of an evidence-based intervention to address reproductive coercion and IPV in clinical family planning counselling and provision in Nairobi, Kenya in April 2017. Focus group discussions (n = 4, 30 total participants) and in-depth interviews (n = 10) with family planning clients (ages 15-49) were conducted to identify specific forms of reproductive coercion, other partner-specific barriers to successful contraception use, and perceived opportunities for family planning providers to address RC among women and girls seeking family planning services. Additionally, data were collected via semi-structured interviews with family planning providers (n = 8) and clinic managers (n = 3) from family planning clinics. Data were coded according to structural and emergent themes, summarized, and illustrative quotes were identified to demonstrate sub-themes. Kenyan family planning providers and administrators informed interpretation. RESULTS: The results of this study identified specific forms of pregnancy coercion and contraceptive sabotage to be common, and often severe, impeding the use of contraceptives among female family planning clients. This study offers important examples of women's strategies for preventing pregnancy despite experiencing reproductive coercion, as well as opportunities for family planning providers to support clients experiencing reproductive coercion in clinical settings. CONCLUSIONS: Reproductive coercion is a critical barrier to modern contraceptive use in Kenya. Results from this study highlight opportunities for family planning providers to play a critical role in supporting women and girls in their use of contraception when reproductive coercion is present.

Protocol for a matched-pair cluster control trial of ARCHES (Addressing Reproductive Coercion in Health Settings) among women and girls seeking contraceptive services from community-based clinics in Nairobi, Kenya.

BACKGROUND: Reproductive coercion (RC) and intimate partner violence (IPV) are prevalent forms of gender-based violence (GBV) associated with reduced female control over contraceptive use and subsequent unintended pregnancy. Although the World Health Organization has recommended the identification and support of GBV survivors within health services, few clinic-based models have been shown to reduce IPV or RC, particularly in low or middle-income countries (LMICs). To date, clinic-based GBV interventions have not been shown to reduce RC or unintended pregnancy in LMIC settings. INTERVENTION: ARCHES (Addressing Reproductive Coercion in Health Settings) is a single-session, clinic-based model delivered within routine contraceptive counseling that has been demonstrated to reduce RC in the United States. ARCHES was adapted to the Kenyan context via a participatory process to reduce GBV and unintended pregnancy among women and girls seeking contraceptive services in this setting. Core elements of ARCHES include enhanced contraceptive counseling that addresses RC, opportunity for patient disclosure of RC and IPV (and subsequent warm referral to local services), and provision of a palm-sized educational booklet. METHODS: A matched-pair cluster control trial is being conducted to assess whether the ARCHES intervention (treatment condition), as compared to standard-of-care contraceptive counseling (control condition), reduces RC and IPV, and improves contraceptive outcomes for woman and girls of reproductive age (15 to 49 years) seeking contraceptive services from community-based clinics in Nairobi, Kenya. All six clinics were assigned to intervention-control pairs based on similarities in patient volume and demographics, physical structure and neighborhood context. Survey data will be collected from patients immediately prior to their clinic visit (baseline, T1), immediately after their clinic visit (exit), and at 3- and 6-months post-visit (T2 and T3, respectively). DISCUSSION: This study is the first to assess the efficacy of an adaptation of the ARCHES model to reduce GBV and improve reproductive health outside of the U.S., and one of only a small number of controlled trials to assess reductions in GBV associated with a clinic-based program in an LMIC context. Evidence from this trial will inform health system efforts to reduce GBV, and to enhance female contraceptive control and reproductive health in Kenya and globally. TRIAL REGISTRATION: Registered May 23, 2018 - ClinicalTrials.gov, NCT03534401. Unique Protocol ID: 170084.

Protocol for cluster randomized evaluation of reaching married adolescents - a gender-synchronized intervention to increase modern contraceptive use among married adolescent girls and young women and their husbands in Niger.

BACKGROUND: Early marriage and early childbearing are highly prevalent in Niger with 75% of girls married before age 18 years and 42% of girls giving birth between ages 15 and 18 years. In 2012, only 7% of all 15-19-year-old married adolescents (male and female) reported use of a modern contraceptive method with barriers including misinformation, and social norms unsupportive of contraception. To meet the needs of married adolescents and their husbands in Niger, the Reaching Married Adolescents (RMA) program was developed with the goal of improving modern contraceptive method uptake in the Dosso region of Niger. METHODS: Using a four-arm cluster randomized control design, the RMA study seeks to assess whether household visits only (Arm 1), small group discussions only (Arm 2), or a combination of both (Arm 3), as compared to controls (no intervention - Arm 4), improve modern contraceptive method use among married adolescent girls and young women (AGYW), age 13-19 years-old, in three districts of the Dosso region. Intervention conditions were randomly assigned across the three districts, Dosso, Doutchi, and Loga. Within each district, eligible villages were assigned to either that intervention condition or to the control condition (12 intervention and 4 control per district). Across the three intervention conditions, community dialogues regarding modern contraceptive use were also implemented. Data for the study was collected at baseline (April - June 2016), at 24 months post-intervention (April - June 2018), and a final round of data collection will occur at 40 months post-intervention (October - December 2019). DISCUSSION: The RMA intervention is a gender-synchronized and community-based program implemented among married adolescent girls and their husbands in the context of rural Niger. The intervention is designed to provide education about modern contraception and to promote gender equity in order to increase uptake of modern contraceptive methods. Results from this cluster randomized control study will contribute to the knowledge base regarding the utility of male engagement as a strategy within community-level approaches to promote modern contraceptive method use in the high need context of West Africa. TRIAL REGISTRATION: Registered October 2017 - ClinicalTrials.gov NCT03226730.

What is the role of vertebral augmentation for osteoporotic fractures? A review of the recent literature.

PURPOSE: Vertebral augmentation procedures such as vertebroplasty and kyphoplasty are utilized in the treatment of vertebral compression fractures (VCFs). However, their capacity for providing analgesia, reducing disability, and improving quality of life in patients with osteoporotic VCFs remains a topic of debate. The objective of this narrative review is to summarize the latest evidence for the safety and efficacy of vertebral augmentation for osteoporotic vertebral compression fractures (VCFs). METHODS: A systematic literature search was conducted using the PubMed and Cochrane electronic databases for systematic reviews, review articles, meta-analyses, and randomized clinical trials prior to May 2017. The keywords were "vertebroplasty," "kyphoplasty," and "vertebral augmentation." RESULTS: Thirty-three papers (7 systematic reviews, 6 cohort studies, 15 randomized clinical trials, and 5 international guidelines) were included in this narrative review. CONCLUSION: Vertebral augmentation is a safe procedure, with low rates of serious complications and no increase in subsequent post-treatment fracture risk.

IL-5 promotes induction of antigen-specific CD4+CD25+ T regulatory cells that suppress autoimmunity.

Immune responses to foreign and self-Ags can be controlled by regulatory T cells (Tregs) expressing CD4 and IL-2Rα chain (CD25). Defects in Tregs lead to autoimmunity, whereas induction of Ag-specific CD4+CD25+ Tregs restores tolerance. Ag-specific CD4+CD25+ FOXP3+Tregs activated by the T helper type 2 (Th2) cytokine, IL-4, and specific alloantigen promote allograft tolerance. These Tregs expressed the specific IL-5Rα and in the presence of IL-5 proliferate to specific but not third-party Ag. These findings suggest that recombinant IL-5 (rIL-5) therapy may promote Ag-specific Tregs to mediate tolerance. This study showed normal CD4+CD25+ Tregs cultured with IL-4 and an autoantigen expressed Il-5rα. Treatment of experimental autoimmune neuritis with rIL-5 markedly reduced clinical paralysis, weight loss, demyelination, and infiltration of CD4+ (Th1 and Th17) CD8+ T cells and macrophages in nerves. Clinical improvement was associated with expansion of CD4+CD25+FOXP3+ Tregs that expressed Il-5rα and proliferated only to specific autoantigen that was enhanced by rIL-5. Depletion of CD25+ Tregs or blocking of IL-4 abolished the benefits of rIL-5. Thus, rIL-5 promoted Ag-specific Tregs, activated by autoantigen and IL-4, to control autoimmunity. These findings may explain how Th2 responses, especially to parasitic infestation, induce immune tolerance. rIL-5 therapy may be able to induce Ag-specific tolerance in autoimmunity.

In vitro antibacterial activity of sulbactam-durlobactam in combination with other antimicrobial agents against Acinetobacter baumannii-calcoaceticus complex.

Combinations of the ß-lactam/ß-lactamase inhibitor sulbactam-durlobactam and seventeen antimicrobial agents were tested against strains of Acinetobacter baumannii in checkerboard assays. Most combinations resulted in indifference with no instances of antagonism. These results suggest sulbactam-durlobactam antibacterial activity against A. baumannii is unlikely to be affected if co-dosed with other antimicrobial agents.

Perinatal Injectable Opioid Agonist Therapy (iOAT) Administration: A Case Series.

OBJECTIVES: Untreated opioid use disorder (OUD) in pregnancy may lead to adverse outcomes for the individual and fetus. Injectable opioid agonist therapy (iOAT) is the highest intensity treatment for severe refractory OUD currently available; however, research on perinatal administration is limited. We present the first known case series of 13 pregnant or postpartum participants who received intravenous hydromorphone while admitted to the Families in Recovery (FIR) unit, an in-patient perinatal stabilization unit in Canada. METHODS: Patients who received iOAT at FIR between 2019 and 2022 were invited to participate. Prospectively enrolled participants completed a self-report sociodemographics and exposures survey. Medical/social backgrounds of participants at admission, iOAT and other opioid agonist therapy administration, and health/social outcomes of mother and infant at discharge were collected on all participants via retrospective maternal and infant medical chart review. RESULTS: Participants initiated iOAT while pregnant (n = 5) or postpartum (n = 8) and received iOAT for 23 days on average. At discharge, 8 participants underwent planned transition to community with infant in their care and a discharge plan including outpatient prescriptions, housing arrangements, follow-up appointments, and supportive programming. All infants received oral morphine after delivery and were discharged in good health. CONCLUSIONS: This is the first known case series of iOAT administration in the peripartum. The cases illustrate iOAT as an option that can achieve OUD stabilization in perinatal individuals to support patient engagement and retention in care.

Breastfeeding on Injectable Opioid Agonist Therapy: A Case Report.

BACKGROUND: Injectable opioid agonist therapy (iOAT) is the highest-intensity treatment currently available in Canada for individuals with severe opioid use disorder. However, there is limited data on iOAT administration in the perinatal period, with no research, practice guidelines, or known reports of breastfeeding on iOAT. This article presents the first known case of an individual breastfeeding on iOAT. CASE SUMMARY: We present a case of a pregnant 32-year-old woman from Canada with severe opioid use disorder, who stabilized with iOAT and chose to breastfeed her infant. She presented to hospital at 38 + 6 gestation in labor, unstable in her substance use disorder despite multiple interventions and was initiated on iOAT (intravenous hydromorphone) shortly after delivery. Before initiation of breastfeeding the infant was admitted to the neonatal intensive care unit for monitoring. On day 9 of life the infant received breastmilk for the first time, and was discharged from neonatal intensive care unit on day 12 of life with no clinical evidence of sedation or respiratory depression. The infant maintained mixed feeding and at 58 days of life was discharged in the mother and father's care, a healthy infant with stable vitals. DISCUSSION: This case suggests positive infant and maternal health and social outcomes for breastfeeding on iOAT. Further research on perinatal iOAT use and the pharmacokinetics of high-dose hydromorphone in breastmilk is required to inform clinical practice guidelines to safely support individuals and their infants who are impacted by substance use.

CARD11 signaling in regulatory T cell development and function.

Regulatory T cells (Tregs) are a critical subset of CD4 T cells that modulate the immune response to prevent autoimmunity and chronic inflammation. CARD11, a signaling hub and scaffold protein that links antigen receptor engagement to activation of NF-κB and other downstream signaling pathways, is essential for the development and function of thymic Tregs. Mouse models with deficiencies in CARD11 and CARD11-associated signaling components generally have Treg defects, but some mouse models develop overt autoimmunity and inflammatory disease whereas others do not. Inhibition of CARD11 signaling in Tregs within the tumor microenvironment can potentially promote anti-tumor immunity. In this review, we summarize evidence for the involvement of CARD11 signaling in Treg development and function and discuss key unanswered questions and future research opportunities.

INVESTIGATING ASSOCIATIONS AMONG RELATEDNESS, GENETIC DIVERSITY, AND CAUSES OF MORTALITY IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS).

Southern sea otter (Enhydra lutris nereis) population recovery is influenced by a variety of factors, including predation, biotoxin exposure, infectious disease, oil spills, habitat degradation, and resource limitation. This population has also experienced a significant genetic bottleneck, resulting in low genetic diversity. We investigated how two metrics, familial relatedness and genetic diversity, are correlated with common causes of mortality in southern sea otters, including cardiomyopathy, acanthocephalan (Profilicollis spp.) peritonitis, systemic protozoal infection (Toxoplasma gondii and Sarcocystis neurona), domoic acid intoxication, end-lactation syndrome, and shark bite. Microsatellite genetic markers were used to examine this association in 356 southern sea otters necropsied from 1998 to 2012. Significant associations with genetic diversity or familial relatedness (P<0.05) were observed for cardiomyopathy, acanthocephalan peritonitis, and sarcocystosis, and these associations varied by sex. Adult male cardiomyopathy cases (n=86) were more related than the null expectation (P<0.049). Conversely, female acanthocephalan peritonitis controls (n=110) were more related than the null expectation (P<0.004). Including genetic diversity as a predictor for fatal acanthocephalan peritonitis in the multivariate logistic model significantly improved model fit; lower genetic diversity was associated with reduced odds of sea otter death due to acanthocephalan peritonitis. Finally, male sarcocystosis controls (n=158) were more related than the null expectation (P<0.011). Including genetic diversity in the multivariate logistic model for fatal S. neurona infection improved model fit; lower genetic diversity was associated with increased odds of sea otter death due to S. neurona. Our study suggests that genetic diversity and familial relatedness, in conjunction with other factors such as age and sex, may influence outcome (survival or death) in relation to several common southern sea otter diseases. Our findings can inform policy for conservation management, such as potential reintroduction efforts, as part of species recovery.

Calcineurin inhibitors target Lck activation in graft-versus-host disease.

Calcineurin inhibitors (CNIs) such as cyclosporin A and FK506 are widely administered immunosuppressive drugs. Calcineurin relieves inhibitory phosphorylation from nuclear factor of activated T cells (NFAT) transcription factors downstream of T cell receptor engagement, resulting in their nuclear translocation and the production of cytokines, including IL-2, IFN-γ, and TNF-α. It was previously believed that CNIs downregulate immunity by reducing NFAT activation. However, work from Otsuka et al. in this issue of the JCI revealed a second mechanism by which CNIs suppress T cell function. The authors previously reported that calcineurin removes an inhibitory phosphate from the tyrosine kinase Lck at Ser59 (Lck-S59) and that this dephosphorylation positively regulates T cell activation. In the present work, the authors showed that inhibition of Lck-S59 dephosphorylation was essential for the CNI-mediated suppression of acute graft-versus-host disease (aGVHD). These findings have important implications for future approaches to the management of aGVHD, organ transplant rejection, and autoimmune disease.

Vertebral augmentation.

Vertebral augmentation, including vertebroplasty and kyphoplasty, is a minimally invasive, image-guided procedure in which cement (typically polymethylmethacrylate (PMMA)) is injected into a vertebral body to treat painful fractures. The majority of vertebroplasty and kyphoplasty procedures are performed to treat symptomatic osteoporotic compression fractures refractory to conservative medical therapy; however, there is also evidence to suggest the benefits of augmentation in patients with refractory pain in the acute compression setting. The primary goal of augmentation is decreasing pain and improving a patient's functional status. The secondary goal of augmentation is vertebral body stabilization. This chapter outlines the indications, contraindications, techniques, and literature behind vertebral augmentation.

Ceftazidime-Avibactam Resistance Mutations V240G, D179Y, and D179Y/T243M in KPC-3 ß-Lactamase Do Not Alter Cefpodoxime-ETX1317 Susceptibility.

Mutations in KPC-2 and KPC-3 ß-lactamase can confer resistance to the ß-lactam/ß-lactamase inhibitor antibacterial intravenous drug combination ceftazidime-avibactam, introduced in 2015. Avibactam was the first of the diazabicyclooctane class of non-ß-lactam ß-lactamase inhibitors to be approved for clinical use. The orally bioavailable prodrug ETX0282 of the diazabicyclooctane ß-lactamase inhibitor ETX1317 is in clinical development in combination with the oral ß-lactam prodrug cefpodoxime proxetil for use against complicated urinary tract infections. We investigated the effects of 3 ceftazidime-avibactam resistance mutations in KPC-3 (V240G, D179Y, and D179Y/T243M) on the ability of ETX1317 to overcome KPC-3-induced cefpodoxime resistance. Isogenic Escherichia coli strains, each expressing the wild-type or a mutant KPC-3 at similar levels, retained susceptibility to cefpodoxime-ETX1317 (1:2) with essentially identical minimal inhibitory concentrations of 0.125-0.25 µg/mL cefpodoxime. The KPC-3 mutations had little or no effect on the kinact/Ki values for inhibition by each of 3 diazabicyclooctanes: avibactam, durlobactam (ETX2514), and ETX1317. The KM values for hydrolysis of cefpodoxime were similar for all 4 variants, but the kcat values of the D179Y and D179Y/T243M variants were much lower than those of the wild-type and V240G mutant enzymes. All 4 KPC-3 variants formed stable, reversibly covalent complexes with ETX1317, but dissociation of ETX1317 was much slower from the D179Y and D179Y/T243M mutants than from the wild-type and V240G mutant enzymes. Thus, the KPC-3 variants examined here that cause resistance to ceftazidime-avibactam do not cause resistance to cefpodoxime-ETX1317.

Social network and social normative characteristics of married female adolescents in Dosso, Niger: Associations with modern contraceptive use.

In this study we analysed the social networks of a sample of married adolescent girls (ages 13-19 years) residing in Dosso, Niger (N = 322); data were collected for evaluation of a family planning (FP) intervention. Participants were asked to name individuals important in their lives (alters) using three name generating questions as part of a larger survey on reproductive health, social norms, and FP. One alter per girl was then recruited to be separately interviewed (N = 250). This provided us with two separate datasets: one with data from each respondent regarding each person that they nominated, and one with the interviewed alters matched with the respondent who nominated them. We found that married adolescent girls who were nulliparous were more likely to have no alters and that those in the intervention had the most alters. Alters of treatment participants were more likely to have used FP. Respondents were more likely to have used FP when their sisters or in-laws had, but there was no correlation with use by friends. Our results provide evidence of diffusion of the FP program to those close to intervention participants. Future research should study these dynamics, crucial to understanding intervention costing, impact, and normative change.

Results from a mobile drug checking pilot program using three technologies in Chicago, IL, USA.

BACKGROUND: Opioid overdose deaths in the United States continue to rise, with the majority of deaths involving fentanyl. Drug checking has been used in Europe and Canada to assess adulteration of the illegal drug supply, but faces legal barriers in the United States. We are presenting information from a pilot mobile program offering drug checking services to participants of a harm reduction program in Chicago, Illinois, USA. METHODS: Drug checking services were provided at five mobile outreach and one fixed-point drop-in location in Chicago, IL, between March 2019 and August 2020. Three technologies were used: a Fourier transform infrared spectroscopy (FTIR) spectrometer, a handheld high-pressure mass spectrometer (HPMS), and immunoassay fentanyl test strips (FTS). We report on results generated by this combination of technology during the study period. RESULTS: During the study period, 422 total samples were tested, the majority of which were sold as dope/heroin (66.7 %). Of the 282 samples sold as dope/heroin, 12.8 % matched to fentanyl on the FTIR, 47.5 % had fentanyl identified on the HPMS, and 57.8 % produced a positive FTS. CONCLUSIONS: This pilot program demonstrated the feasibility of using three technologies to assess for the presence of fentanyl in user-submitted samples, revealed discordant results from the technologies, and provided information on the local drug market.