The bacterial genetic determinants of Escherichia coli capacity to cause bloodstream infections in humans.

Escherichia coli is both a highly prevalent commensal and a major opportunistic pathogen causing bloodstream infections (BSI). A systematic analysis characterizing the genomic determinants of extra-intestinal pathogenic vs. commensal isolates in human populations, which could inform mechanisms of pathogenesis, diagnostic, prevention and treatment is still lacking. We used a collection of 912 BSI and 370 commensal E. coli isolates collected in France over a 17-year period (2000-2017). We compared their pangenomes, genetic backgrounds (phylogroups, STs, O groups), presence of virulence-associated genes (VAGs) and antimicrobial resistance genes, finding significant differences in all comparisons between commensal and BSI isolates. A machine learning linear model trained on all the genetic variants derived from the pangenome and controlling for population structure reveals similar differences in VAGs, discovers new variants associated with pathogenicity (capacity to cause BSI), and accurately classifies BSI vs. commensal strains. Pathogenicity is a highly heritable trait, with up to 69% of the variance explained by bacterial genetic variants. Lastly, complementing our commensal collection with an older collection from 1980, we predict that pathogenicity continuously increased through 1980, 2000, to 2010. Together our findings imply that E. coli exhibit substantial genetic variation contributing to the transition between commensalism and pathogenicity and that this species evolved towards higher pathogenicity.

Genome wide association study of Escherichia coli bloodstream infection isolates identifies genetic determinants for the portal of entry but not fatal outcome.

Escherichia coli is an important cause of bloodstream infections (BSI), which is of concern given its high mortality and increasing worldwide prevalence. Finding bacterial genetic variants that might contribute to patient death is of interest to better understand infection progression and implement diagnostic methods that specifically look for those factors. E. coli samples isolated from patients with BSI are an ideal dataset to systematically search for those variants, as long as the influence of host factors such as comorbidities are taken into account. Here we performed a genome-wide association study (GWAS) using data from 912 patients with E. coli BSI from hospitals in Paris, France. We looked for associations between bacterial genetic variants and three patient outcomes (death at 28 days, septic shock and admission to intensive care unit), as well as two portals of entry (urinary and digestive tract), using various clinical variables from each patient to account for host factors. We did not find any association between genetic variants and patient outcomes, potentially confirming the strong influence of host factors in influencing the course of BSI; we however found a strong association between the papGII operon and entrance of E. coli through the urinary tract, which demonstrates the power of bacterial GWAS when applied to actual clinical data. Despite the lack of associations between E. coli genetic variants and patient outcomes, we estimate that increasing the sample size by one order of magnitude could lead to the discovery of some putative causal variants. Given the wide adoption of bacterial genome sequencing of clinical isolates, such sample sizes may be soon available.

Clinical and Bacteriological Specificities of Escherichia coli Bloodstream Infections From Biliary Portal of Entries.

BACKGROUND: Escherichia coli is frequently responsible for bloodstream infections (BSIs). Among digestive BSIs, biliary infections appear to be less severe. Respective roles of host factors, bacterial determinants (phylogroups, virulence, and antibiotic resistance), and portal of entry on outcome are unknown. METHODS: Clinical characteristics and prognosis of 770 episodes of E coli BSI were analyzed and isolates sequenced (Illumina technology) comparing phylogroups, multilocus sequence type, virulence, and resistance gene content. BSI isolates were compared with 362 commensal E coli from healthy subjects. RESULTS: Among 770 episodes, 135 were biliary, 156 nonbiliary digestive, and 479 urinary. Compared to urinary infections, BSIs of digestive origin occurred significantly more in men, comorbid, and immunocompromised patients. Digestive portal of entry was significantly associated with septic shock and death. Among digestive infections, patients with biliary infections were less likely to die (P = .032), despite comparable initial severity. Biliary E coli resembled commensals (phylogroup distribution, sequence type, and few virulence-associated genes) whereas nonbiliary digestive and urinary strains carried many virulence-associated genes. CONCLUSIONS: Escherichia coli strains responsible for biliary infections exhibit commensal characteristics and are associated with lower mortality rates, despite similar initial severity, than other digestive BSIs. Biliary drainage in addition to antibiotics in the management of biliary infections may explain improved outcome.

Impact of the phenotypic expression of temocillin resistance in Escherichia coli on temocillin efficacy in a murine peritonitis model.

BACKGROUND: Temocillin is a narrow spectrum ß-lactam active against MDR Enterobacterales. Mechanisms of acquired resistance to temocillin are poorly understood. We analysed resistance mechanisms in clinical isolates of Escherichia coli and evaluated their impact on temocillin efficacy in vitro and in a murine peritonitis model. METHODS: Two sets of isogenic clinical E. coli strains were studied: a susceptible isolate (MLTEM16S) and its resistant derivative, MLTEM16R (mutation in nmpC porin gene); and temocillin-resistant derivatives of E. coli CFT073: CFT-ΔnmpC (nmpC deletion), CFTbaeS-TP and CFTbaeS-AP (two different mutations in the baeS efflux-pump gene).Fitness cost, time-kill curves and phenotypic expression of resistance were determined. Temocillin efficacy was assessed in a murine peritonitis model. RESULTS: MICs of temocillin were 16 and 64 mg/L for MLTEM16S and MLTEM16R, respectively, and 8, 128, 256 and 256 mg/L for E. coli-CFT073, CFT-ΔnmpC, CFTbaeS-TP and CFTbaeS-AP, respectively. No fitness cost of resistance was evidenced. All resistant strains showed heteroresistant profiles, except for CFTbaeS-AP, which displayed a homogeneous pattern. In vitro, temocillin was bactericidal against MLTEM16R, CFT-ΔnmpC, CFTbaeS-TP and CFTbaeS-AP at 128, 256, 512 and 512 mg/L, respectively. In vivo, temocillin was as effective as cefotaxime against MLTEM16R, CFT-ΔnmpC and CFTbaeS-TP, but inefficient against CFTbaeS-AP (100% mortality). CONCLUSIONS: Heteroresistant NmpC porin alteration and active efflux modification do not influence temocillin efficacy despite high MIC values, unfavourable pharmacokinetic/pharmacodynamic conditions and the absence of fitness cost, whereas homogeneously expressed BaeS efflux pump alteration yielding similar MICs leads to temocillin inefficacy. MIC as sole predictor of temocillin efficacy should be used with caution.

Antimicrobial for 7 or 14 Days for Febrile Urinary Tract Infection in Men: A Multicenter Noninferiority Double-Blind, Placebo-Controlled, Randomized Clinical Trial.

BACKGROUND: The optimal duration of antimicrobial therapy for urinary tract infections (UTIs) in men remains controversial. METHODS: To compare 7 days to 14 days of total antibiotic treatment for febrile UTIs in men, this multicenter randomized, double-blind. placebo-controlled noninferiority trial enrolled 282 men from 27 centers in France. Men were eligible if they had a febrile UTI and urine culture showing a single uropathogen. Participants were treated with ofloxacin or a third-generation cephalosporin at day 1, then randomized at day 3-4 to either continue ofloxacin for 14 days total treatment, or for 7 days followed by placebo until day 14. The primary endpoint was treatment success, defined as a negative urine culture and the absence of fever and of subsequent antibiotic treatment between the end of treatment and 6 weeks after day 1. Secondary endpoints included recurrent UTI within weeks 6 and 12 after day 1, rectal carriage of antimicrobial-resistant Enterobacterales, and drug-related events. RESULTS: Two hundred forty participants were randomly assigned to receive antibiotic therapy for 7 days (115 participants) or 14 days (125 participants). In the intention-to-treat analysis, treatment success occurred in 64 participants (55.7%) in the 7-day group and in 97 participants (77.6%) in the 14-day group (risk difference, -21.9 [95% confidence interval, -33.3 to -10.1]), demonstrating inferiority. Adverse events during antibiotic therapy were reported in 4 participants in the 7-day arm and 7 in the 14-day arm. Rectal carriage of resistant Enterobacterales did not differ between both groups. CONCLUSIONS: A treatment with ofloxacin for 7 days was inferior to 14 days for febrile UTI in men and should therefore not be recommended. CLINICAL TRIALS REGISTRATION: NCT02424461; Eudra-CT: 2013-001647-32.

Efficacy of vancomycin lock therapy for totally implantable venous access port-related infection due to coagulase-negative staphylococci in 100 patients with cancer.

OBJECTIVES: Data on the efficacy of vancomycin catheter lock therapy (VLT) for conservative treatment of totally implantable venous access port-related infections (TIVAP-RI) due to CoNS are scarce. The aim of this study was to evaluate the effectiveness of VLT in the treatment of TIVAP-RI due to CoNS in cancer patients. METHODS: This prospective, observational, multicentre study included adults with cancer treated with VLT for a TIVAP-RI due to CoNS. The primary endpoint was the success of VLT, defined as no TIVAP removal nor TIVAP-RI recurrence within 3 months after initiation of VLT. The secondary endpoint was 3 month mortality. Risk factors for VLT failure were also analysed. RESULTS: One hundred patients were included [men 53%, median age 63 years (IQR 53-72)]. Median duration of VLT was 12 days (IQR 9-14). Systemic antibiotic therapy was administered in 87 patients. VLT was successful in 44 patients. TIVAP could be reused after VLT in 51 patients. Recurrence of infection after completion of VLT occurred in 33 patients, among which TIVAP was removed in 27. Intermittent VLT (antibiotic solution left in place in the TIVAP lumen part of the time) was identified as a risk factor for TIVAP-RI recurrence. At 3 months, 26 deaths were reported; 1 (4%) was related to TIVAP-RI. CONCLUSIONS: At 3 months, success of VLT for TIVAP-RI due to CoNS was low. However, removing TIVAP was avoided in nearly half the patients. Continuous locks should be preferred to intermittent locks. Identifying factors of success is essential to select patients who may benefit from VLT.

Incidence, risk factors and treatment of central nervous system immune reconstitution inflammatory syndrome in non-HIV patients with tuberculous meningitis: a multicentre observational study.

BACKGROUND: Immune reconstitution inflammatory syndrome (IRIS) affecting the central nervous system (CNS) is associated with poor outcomes. AIMS: To report on risk factors for CNS-IRIS following tuberculous meningitis (TBM) in HIV-negative patients. METHODS: In this retrospective multicentre study, all HIV-negative adult patients admitted between 2003 and 2021 with microbiologically proven TBM were included. The primary outcome measure was IRIS onset over follow-up. Characteristics of patients who developed IRIS were described. Factors associated with IRIS were identified using a multivariable logistic regression procedure. RESULTS: Fifty-six patients (33.0 (27.0-44.3) years, 39 (69.6%) men) with microbiologically proven TBM were studied. All patients received antituberculosis treatment and 48 (n = 48/56; 85.7%) steroids at TBM diagnosis. During a median follow-up of 18.0 (12.0-27.3) months, IRIS occurred in 28 (n = 28/56, 50.0%) patients, at a median time of 2.0 (1.0-3.0) months after antituberculosis treatment was started. IRIS involved the CNS in all but one case. Imaging revealed new (n = 23/28, 82.1%) and/or worsening (n = 21/28; 75.0%) of previously recognised lesions. Multivariable analysis showed that meningeal enhancement on brain magnetic resonance imaging (MRI) (odds ratio (OR): 15.3; 95% confidence interval (CI): (1.19-1193.5)) at TBM diagnosis and high blood albumin level (OR: 1.21; 95% CI: (1.02-1.60)) were associated with the occurrence of CNS-IRIS during follow-up. CONCLUSION: CNS-IRIS following TBM in non-HIV patients appears frequent and severe. Meningeal enhancement on brain MRI at tuberculosis diagnosis is a risk factor for CNS-IRIS.

Prior participation as a standardized patient improves OSCE scores of third-year medical students: A pilot comparative study at Université Paris Cité Medical School.

OBJECTIVE: Objective structured clinical examinations (OSCE) are one of the main modalities of skills' assessment of medical students. We aimed to evaluate the educational value of the participation of third-year medical students in OSCE as standardized patients. METHODS: We conducted a pilot OSCE session where third-year students participated in sixth-year students' OSCE as standardized patients (cases). Their scores in their own subsequent OSCE exams were compared with third-year students who had not participated (controls). Students' perceptions (stress, preparedness, ease) regarding their OSCE were compared with self-administered questionnaires. RESULTS: A total of 42 students were included (9 cases and 33 controls). Median [IQR] overall score (out of 20 points) obtained by the cases was 17 [16.3-18] versus 14.5 [12.7-16.3] for controls (p < 0.001). Students' perception of their evaluation (difficulty, stress, communication) was not significantly different between cases and controls. Most cases agreed that their participation was beneficial in reducing their stress (67%), increasing their preparedness (78%) and improving their communication skills (100%). All cases agreed that this participation should be offered more widely. CONCLUSION: Students' participation in OSCE as standardized patients led to better performance on their own OSCE and were considered beneficial. This approach could be more broadly generalized to improve student performance.

Discontinuing ß-lactam treatment after 3 days for patients with community-acquired pneumonia in non-critical care wards (PTC): a double-blind, randomised, placebo-controlled, non-inferiority trial.

BACKGROUND: Shortening the duration of antibiotic therapy for patients admitted to hospital with community-acquired pneumonia should help reduce antibiotic consumption and thus bacterial resistance, adverse events, and related costs. We aimed to assess the need for an additional 5-day course of ß-lactam therapy among patients with community-acquired pneumonia who were stable after 3 days of treatment. METHODS: We did this double-blind, randomised, placebo-controlled, non-inferiority trial (the Pneumonia Short Treatment [PTC]) in 16 centres in France. Adult patients (aged ≥18 years) admitted to hospital with moderately severe community-acquired pneumonia (defined as patients admitted to a non-critical care unit) and who met prespecified clinical stability criteria after 3 days of treatment with ß-lactam therapy were randomly assigned (1:1) to receive ß-lactam therapy (oral amoxicillin 1 g plus clavulanate 125 mg three times a day) or matched placebo for 5 extra days. Randomisation was done using a web-based system with permuted blocks with random sizes and stratified by randomisation site and Pneumonia Severity Index score. Participants, clinicians, and study staff were masked to treatment allocation. The primary outcome was cure 15 days after first antibiotic intake, defined by apyrexia (temperature ≤37·8°C), resolution or improvement of respiratory symptoms, and no additional antibiotic treatment for any cause. A non-inferiority margin of 10 percentage points was chosen. The primary outcome was assessed in all patients who were randomly assigned and received any treatment (intention-to-treat [ITT] population) and in all patients who received their assigned treatment (per-protocol population). Safety was assessed in the ITT population. This study is registered with ClinicalTrials.gov, NCT01963442, and is now complete. FINDINGS: Between Dec 19, 2013, and Feb 1, 2018, 706 patients were assessed for eligibility, and after 3 days of ß-lactam treatment, 310 eligible patients were randomly assigned to receive either placebo (n=157) or ß-lactam treatment (n=153). Seven patients withdrew consent before taking any study drug, five in the placebo group and two in the ß-lactam group. In the ITT population, median age was 73·0 years (IQR 57·0-84·0) and 123 (41%) of 303 participants were female. In the ITT analysis, cure at day 15 occurred in 117 (77%) of 152 participants in the placebo group and 102 (68%) of 151 participants in the ß-lactam group (between-group difference of 9·42%, 95% CI -0·38 to 20·04), indicating non-inferiority. In the per-protocol analysis, 113 (78%) of 145 participants in the placebo treatment group and 100 (68%) of 146 participants in the ß-lactam treatment group were cured at day 15 (difference of 9·44% [95% CI -0·15 to 20·34]), indicating non-inferiority. Incidence of adverse events was similar between the treatment groups (22 [14%] of 152 in the placebo group and 29 [19%] of 151 in the ß-lactam group). The most common adverse events were digestive disorders, reported in 17 (11%) of 152 patients in the placebo group and 28 (19%) of 151 patients in the ß-lactam group. By day 30, three (2%) patients had died in the placebo group (one due to bacteraemia due to Staphylococcus aureus, one due to cardiogenic shock after acute pulmonary oedema, and one due to heart failure associated with acute renal failure) and two (1%) in the ß-lactam group (due to pneumonia recurrence and possible acute pulmonary oedema). INTERPRETATION: Among patients admitted to hospital with community-acquired pneumonia who met clinical stability criteria, discontinuing ß-lactam treatment after 3 days was non-inferior to 8 days of treatment. These findings could allow substantial reduction of antibiotic consumption. FUNDING: French Ministry of Health.

Specificities of acute cholangitis in patients with cancer: a retrospective comparative study of 130 episodes.

Pancreatic and biliary duct cancers are increasing causes of acute cholangitis (AC). We retrospectively characterize 81 cancer-associated cholangitis (CAC) compared to 49 non-cancer-associated cholangitis (NCAC). Clinical and biological presentations were similar. However, in CAC, antibiotic resistance and inadequate empirical antibiotic therapy were more frequent; more patients required ≥ 2 biliary drainages; and mortality at day 28 was higher than in NCAC. Death was associated with initial severity and CAC in a multivariate analysis. Cholangitis associated with pancreatic or biliary duct cancers requires specific empirical antimicrobial therapy; early use of biliary drainage may improve outcomes.

Clinical and microbiological characteristics of reflux cholangitis following bilio-enteric anastomosis.

Twenty-five patients with reflux cholangitis (RC) defined as acute cholangitis (AC) with normal abdominal imaging occurring > 3 months after bilioenteric anastomosis were described and compared to 116 AC patients with biliary obstruction (tumoral, lithiasis). RC episodes occurred a median 4.5 months after surgery; 18 (72%) had recurrent RC (n ≥ 3). RC episodes were less severe than obstructive AC; the outcome was favorable with short antibiotic courses and no selection of antibiotic-resistance. However, multiple recurrent RC occurred in 20 patients (80%). Prophylactic or pre-emptive antibiotics were successful in 3 and 11 patients. Revision surgery for jejunal loop lengthening was successful in 2/4 patients.

Activity of the combination of colistin and fosfomycin against NDM-1-producing Escherichia coli with variable levels of susceptibility to colistin and fosfomycin in a murine model of peritonitis.

BACKGROUND: Alternative treatments are needed against NDM-1-producing Escherichia coli. Colistin (COL) and fosfomycin (FOS) often remain active in vitro but selection of resistant mutants is frequent if used separately. We determined whether the combination of colistin and fosfomycin may be useful to treat infections with NDM-1-producing E. coli with varying levels of resistance. METHODS: Isogenic derivatives of E. coli CFT073 with blaNDM-1 and variable levels of resistance to colistin and fosfomycin (CFT073-NDM1, CFT073-NDM1-COL and CFT073-NDM1-FOS, respectively) were used. The combination (colistin + fosfomycin) was tested in vitro and in a fatal peritonitis murine model. Mortality and bacterial loads were determined and resistant mutants detected. RESULTS: Colistin MICs were 0.5, 16 and 0.5 mg/L and fosfomycin MICs were 1, 1 and 32 mg/L against CFT073-NDM1, CFT073-NDM1-COL and CFT073-NDM1-FOS, respectively. In time-kill curves, combining colistin with fosfomycin was synergistic and bactericidal against CFT073-NDM1 and CFT073-NDM1-FOS, with concentrations of 4× MIC (for both drugs), but not against CFT073-NDM1-COL (concentrations of colistin = 0.5× MIC), due to regrowth with fosfomycin-resistant mutants. Mice died less and bacterial counts were lower in spleen with the combination compared with monotherapy against all strains; the combination prevented selection of resistant mutants except for CFT073-NDM1-COL where fosfomycin-resistant mutants were found in all mice. CONCLUSIONS: Combining colistin and fosfomycin was beneficial in vitro and in vivo against NDM-1-producing E. coli, even with strains less susceptible to colistin and fosfomycin. However, the combination failed to prevent the emergence of fosfomycin-resistant mutants against colistin-resistant strains. Combining colistin and fosfomycin constitutes an alternative for treatment of NDM-1 E. coli, except against colistin-resistant strains.

Temocillin as an alternative treatment for acute bacterial cholangitis: a retrospective microbiology susceptibility-based study of 140 episodes.

With rising antibiotic resistance, alternatives to carbapenems are needed for acute cholangitis (AC). Temocillin reaches high biliary concentrations with limited impact on microbiota. We retrospectively included 140 AC episodes and assessed the efficacy of temocillin using microbiology susceptibility testing from blood cultures. Considering all bacteria collected by episode, resistance to temocillin, PIP/TAZ and 3GC occurred in 27/140 (26%), 32 (22.8%) and 31 (22%) episodes, respectively (p = 0.7). After documentation, temocillin could have spared PIP/TAZ or carbapenems in 14/26 and 4/11 episodes. Temocillin may constitute an alternative treatment after microbiological documentation by sparing carbapenems and/or PIP/TAZ, but not as an empirical therapeutic option.

Analysis of Paradoxical Efficacy of Carbapenems against Carbapenemase-Producing Escherichia coli in a Murine Model of Lethal Peritonitis.

The clinical benefit of carbapenems against carbapenemase-producing Enterobacteriaceae (CPE) remains in question. MICs of imipenem (IMP) and ertapenem (ERT) against isogenic derivatives of the wild-type strain Escherichia coli CFT073 producing KPC-3, OXA-48, or NDM-1 were 0.25, 2, 16, and 64 mg/liter for IMP and 0.008, 0.5, 8, and 64 mg/liter for ERT, respectively. Swiss ICR-strain mice with peritonitis were treated for 24 h with IMP or ERT. Despite a limited duration of time during which free antibiotic concentrations were above the MIC (down to 0% for the NDM-1-producing strain), IMP and ERT significantly reduced bacterial counts in spleen and peritoneal fluid at 24 h (P < 0.005) and prevented mortality. Several possible explanations were investigated. Addition of 4% albumin or 50% normal human serum did not modify IMP activity. Bacterial fitness of resistant strains was not altered and virulence did not decrease with resistance. In the presence of subinhibitory concentrations of ERT, growth rates of OXA-48, KPC-3, and NDM-1 strains were significantly decreased and filamentation of the NDM-1 strain was observed. The expression of blaNDM-1 was not decreased in vivo compared to in vitro No zinc depletion was observed in infected mice compared with Mueller-Hinton broth. In conclusion, a paradoxical in vivo efficacy of IMP and ERT against highly resistant carbapenemase-producing E. coli was confirmed. Alternative mechanisms of antibacterial effects of subinhibitory concentrations of carbapenems may be involved to explain in vivo activity. These results are in agreement with a potential clinical benefit of carbapenems to treat CPE infections, despite high carbapenem MICs.

Pyogenic liver abscess in liver transplant recipient: A warning signal for the risk of recurrence and retransplantation.

BACKGROUND: Pyogenic liver abscesses in liver transplant recipients (PLA-LTR) are a rare disease whose specificities compared with PLA in non-transplanted patients (PLA-C) are unknown. METHODS: A retrospective case-control study was conducted in a French academic hospital from January 1, 2010, to December 31, 2014. RESULTS: Among 176 patients diagnosed with PLA, 14 were LTR; each case was matched with 3 PLA-C controls by date of PLA diagnosis and pathophysiological mechanism of PLA. Median time from liver transplantation to PLA diagnosis was 34.5 months. Among 14 PLA-LTR, 8/14 (57.1%) had bacteremia and 10/14 (71.4%) had positive PLA cultures. Most commonly isolated bacteria were Enterobacteriaceae (9/14; 64.3%), Enterococcus spp. (4/14; 28.6%), and anaerobic bacteria (3/14; 21.4%). Clinical, radiological, and microbiological characteristics did not significantly differ between PLA-LTR and PLA-C but there was a tendency toward more diabetic patients and a less acute presentation. All but one PLA-LTR were associated with ischemic cholangitis, whereas this was a rare cause among PLA-C (13/14 vs 3/42, respectively, P < .001) among patients with PLA-LTR. In contrast, hepatobiliary neoplasia was rare in PLA-LTR but frequent in PLA-C (1/14 vs 24/42, P = .001). No significant difference was found between PLA-LTR and PLA-C in terms of duration of antibiotic therapy (6.5 and 6 weeks, respectively), PLA drainage rates (10/14 and 26/42, respectively), or mortality at 12 months after PLA diagnosis (2/14 and 5/42, respectively). Recurrence rates within the first year were observed in 6/14 patients (42.9%), and retransplantation was needed in 5/14 (35.7%). CONCLUSIONS: Occurrence of PLA in LTR is a severe event leading to high risk of recurrence and retransplantation.

Implementation of a large-scale simulation-based cardiovascular clinical examination course for undergraduate medical students - a pilot study.

BACKGROUND: We report the implementation of a large-scale simulation-based cardiovascular diagnostics course for undergraduate medical students. METHODS: A simulation-based course was integrated into the curriculum of second-year medical students (> 400 students/year). The first session aimed at teaching cardiac auscultation skills on mannequins and the second at teaching blood pressure measurement, peripheral arterial examination, and the clinical examination of heart failure in a technical skill-based manner and in a scenario. RESULTS: A total of 414 (99.8%) and 402 (98.5%) students, as well as 102 and 104 educators, participated during the 2016-2017 and 2017-2018 academic years across both types of sessions. The number of positive appreciations by students was high and improved from the first to the second year (session 1: 77% vs. 98%, session 2: 89% vs. 98%; p < 0.0001). Similar results were observed for educators (session 1: 84% vs. 98%, p = 0.007; session 2: 82% vs. 98%, p = 0.01). Feedbacks by students were positive regarding the usefulness of the course, fulfillment of pedagogical objectives, quality of the teaching method, time management, and educator-student interactivity. In contrast, 95% of students criticized the quality of the mannequins during the first year leading to the replacement of the simulation material the following year. Students most appreciated the auscultation workshop (25%), the practical aspect of the course (22%), and the availability of educators (21%). CONCLUSIONS: Despite the need to commit significant human and material resources, the implementation of this large-scale program involving > 400 students/year was feasible, and students and educators reacted favorably.

Hypervirulent Klebsiella pneumoniae in Cryptogenic Liver Abscesses, Paris, France.

Liver abscesses containing hypervirulent Klebsiella pneumoniae have emerged during the past 2 decades, originally in Southeast Asia and then worldwide. We hypothesized that hypervirulent K. pneumoniae might also be emerging in France. In a retrospective, monocentric, cohort study, we analyzed characteristics and outcomes for 199 consecutive patients in Paris, France, with liver abscesses during 2010-2015. We focused on 31 patients with abscesses containing K. pneumoniae. This bacterium was present in most (14/27, 52%) cryptogenic liver abscesses. Cryptogenic K. pneumoniae abscesses were more frequently community-acquired (p<0.00001) and monomicrobial (p = 0.008), less likely to involve cancer patients (p<0.01), and relapsed less often (p<0.01) than did noncryptogenic K. pneumoniae liver abscesses. K. pneumoniae isolates from cryptogenic abscesses belonged to either the K1 or K2 serotypes and had more virulence factors than noncryptogenic K. pneumoniae isolates. Hypervirulent K. pneumoniae are emerging as the main pathogen isolated from cryptogenic liver abscesses in the study area.

Single-dose oral ciprofloxacin prophylaxis as a response to a meningococcal meningitis epidemic in the African meningitis belt: A 3-arm, open-label, cluster-randomized trial.

BACKGROUND: Antibiotic prophylaxis for contacts of meningitis cases is not recommended during outbreaks in the African meningitis belt. We assessed the effectiveness of single-dose oral ciprofloxacin administered to household contacts and in village-wide distributions on the overall attack rate (AR) in an outbreak of meningococcal meningitis. METHODS AND FINDINGS: In this 3-arm, open-label, cluster-randomized trial during a meningococcal meningitis outbreak in Madarounfa District, Niger, villages notifying a suspected case were randomly assigned (1:1:1) to standard care (the control arm), single-dose oral ciprofloxacin for household contacts within 24 hours of case notification, or village-wide distribution of ciprofloxacin within 72 hours of first case notification. The primary outcome was the overall AR of suspected meningitis after inclusion. A random sample of 20 participating villages was enrolled to document any changes in fecal carriage prevalence of ciprofloxacin-resistant and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae before and after the intervention. Between April 22 and May 18, 2017, 49 villages were included: 17 to the control arm, 17 to household prophylaxis, and 15 to village-wide prophylaxis. A total of 248 cases were notified in the study after the index cases. The AR was 451 per 100,000 persons in the control arm, 386 per 100,000 persons in the household prophylaxis arm (t test versus control p = 0.68), and 190 per 100,000 persons in the village-wide prophylaxis arm (t test versus control p = 0.032). The adjusted AR ratio between the household prophylaxis arm and the control arm was 0.94 (95% CI 0.52-1.73, p = 0.85), and the adjusted AR ratio between the village-wide prophylaxis arm and the control arm was 0.40 (95% CI 0.19‒0.87, p = 0.022). No adverse events were notified. Baseline carriage prevalence of ciprofloxacin-resistant Enterobacteriaceae was 95% and of ESBL-producing Enterobacteriaceae was >90%, and did not change post-intervention. One limitation of the study was the small number of cerebrospinal fluid samples sent for confirmatory testing. CONCLUSIONS: Village-wide distribution of single-dose oral ciprofloxacin within 72 hours of case notification reduced overall meningitis AR. Distributions of ciprofloxacin could be an effective tool in future meningitis outbreak responses, but further studies investigating length of protection, effectiveness in urban settings, and potential impact on antimicrobial resistance patterns should be carried out. TRIAL REGISTRATION: ClinicalTrials.gov NCT02724046.

Ceftriaxone promotes the emergence of AmpC-overproducing Enterobacteriaceae in gut microbiota from hospitalized patients.

Epidemiological data suggest that ceftriaxone may promote the emergence of commensal AmpC-overproducing Enterobacteriaceae because of a high biliary excretion. We tested this hypothesis in hospitalized patients either treated by ceftriaxone alone or receiving no antibiotics. Hospitalized patients with no previous antibiotics or hospitalization in the last 3 months, treated only with ceftriaxone, were prospectively included. For each ceftriaxone-treated patient, a control patient receiving no antibiotics was included. Clinical data and stools were collected at T0 (before antibiotics) and T1 (at the end of ceftriaxone treatment or at discharge) and T2 (3-6 months after T1) for the ceftriaxone-treated patients and at T0 and T1 for control patients. Third-generation cephalosporin-resistant Enterobacteriaceae were detected, identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), and characterized genetically. Clonal relatedness was evaluated by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Fifteen ceftriaxone and 22 control patients were included. Patients' characteristics did not differ. At T0, 2/15 ceftriaxone-treated versus 1/22 control patients carried third-generation cephalosporin-resistant Enterobacteriaceae (p = 0.6). At T1, 4/15 (27%) ceftriaxone-treated patients carried AmpC producers versus 0/22 control patients (p = 0.02). Additionally, two and three subjects carried extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in the ceftriaxone and control groups, respectively (p = 1). At T2, three ceftriaxone-treated patients still carried AmpC-producing Enterobacteriaceae with the same RAPD profile as at T1. In hospitalized subjects with no other selective pressure, treatment by ceftriaxone alone promotes the gut colonization by AmpC-overproducing Enterobacteriaceae in over a quarter of patients, with a persistent carriage after the end of antibiotic exposure. The ecological impact of ceftriaxone should not be underestimated.