Massive Increase, Spread, and Exchange of Extended Spectrum {beta}-Lactamase-Encoding Genes Among Intestinal Enterobacteriaceae in Hospitalized Children With Severe Acute Malnutrition in Niger.

Background. From the time of CTX-M emergence, extended-spectrum β-lactamase-producing enterobacteria (ESBL-E) have spread worldwide in community settings as well as in hospitals, particularly in developing countries. Although their dissemination appears linked to Escherichia coli intestinal carriage, precise paths of this dynamic are largely unknown. Methods. Children from a pediatric renutrition center were prospectively enrolled in a fecal carriage study. Antibiotic exposure was recorded. ESBL-E strains were isolated using selective media from fecal samples obtained at admission and, when negative, also at discharge. ESBL-encoding genes were identified, their environments and plasmids were characterized, and clonality was assessed with polymerase chain reaction-based methods and pulsed-field gel electrophoresis for E. coli and Klebsiella pneumoniae. E. coli strains were subjected to multilocus sequence typing. Results. The ESBL-E carriage rate was 31% at admission in the 55 children enrolled. All children enrolled received antibiotics during hospitalization. Among the ESBL-E-negative children, 16 were resampled at discharge, and the acquisition rate was 94%. The bla(CTX-M-15) gene was found in >90% of the carriers. Genetic environments and plasmid characterization evidenced the roles of a worldwide, previously described, multidrug-resistant region and of IncF plasmids in CTX-M-15 E. coli dissemination. Diversity of CTX-M-15-carrying genetic structures and clonality of acquired ESBL E. coli suggested horizontal genetic transfer and underlined the potential of some ST types for nosocomial cross-transmission. Conclusions. Cross-transmission and high selective pressure lead to very high acquisition of ESBL-E carriage, contributing to dissemination in the community. Strict hygiene measures as well as careful balancing of benefit-risk ratio of current antibiotic policies need to be reevaluated

Revisiting susceptibility testing in MDR-TB by a standardized quantitative phenotypic assessment in a European multicentre study

Objectives Treatment outcome of MDR-TB is critically dependent on the proper use of second-line drugs as per the result of in vitro drug susceptibility testing (DST). We aimed to establish a standardized DST procedure based on quantitative determination of drug resistance and compared the results with those of genotypes associated with drug resistance. Methods The protocol, based on MGIT 960 and the TB eXiST software, was evaluated in nine European reference laboratories. Resistance detection at a screening drug concentration was followed by determination of resistance levels and estimation of the resistance proportion. Mutations in 14 gene regions were investigated using established techniques. Results A total of 139 Mycobacterium tuberculosis isolates from patients with MDR-TB and resistance beyond MDR-TB were tested for 13 antituberculous drugs: isoniazid, rifampicin, rifabutin, ethambutol, pyrazinamide, streptomycin, para-aminosalicylic acid, ethionamide, amikacin, capreomycin, ofloxacin, moxifloxacin and linezolid. Concordance between phenotypic and genotypic resistance was >80%, except for ethambutol. Time to results was short (median 10 days). High-level resistance, which precludes the therapeutic use of an antituberculous drug, was observed in 49% of the isolates. The finding of a low or intermediate resistance level in 16% and 35% of the isolates, respectively, may help in designing an efficient personalized regimen for the treatment of MDR-TB patients. Conclusions The automated DST procedure permits accurate and rapid quantitative resistance profiling of first- and second-line antituberculous drugs. Prospective validation is warranted to determine the impact on patient car

Implementation of an antibiotic resistance surveillance tool in Madagascar, the TSARA project: a prospective, observational, multicentre, hospital-based study protocol.

INTRODUCTION: Antimicrobial resistance (AMR) has become a significant public health threat. Without any interventions, it has been modelled that AMR will account for an estimated 10 million deaths annually by 2050, this mainly affects low/middle-income countries. AMR has a systemic negative perspective affecting the overall healthcare system down to the patient's personal outcome. In response to this issue, the WHO urged countries to provide antimicrobial stewardship programmes (ASPs). ASPs in hospitals are a vital component of national action plans for AMR, and have been shown to significantly reduce AMR, in particular in low-income countries such as Madagascar.As part of an ASP, AMR surveillance provides essential information needed to guide medical practice. We developed an AMR surveillance tool-Technique de Surveillance Actualisée de la Résistance aux Antimicrobiens (TSARA)-with the support of the Mérieux Foundation. TSARA combines bacteriological and clinical information to provide a better understanding of the scope and the effects of AMR in Madagascar, where no such surveillance tool exists. METHODS AND ANALYSIS: A prospective, observational, hospital-based study was carried out for data collection using a standardised data collection tool, called TSARA deployed in 2023 in 10 hospitals in Madagascar participating in the national Malagasy laboratory network (Réseau des Laboratoires à Madagascar (RESAMAD)). Any hospitalised patient where the clinician decided to take a bacterial sample is included. As a prospective study, individual isolate-level data and antimicrobial susceptibility information on pathogens were collected routinely from the bacteriology laboratory and compiled with clinical information retrieved from face-to-face interviews with the patient and completed using medical records where necessary. Analysis of the local ecology, resistance rates and antibiotic prescription patterns were collected. ETHICS AND DISSEMINATION: This protocol obtained ethical approval from the Malagasy Ethical Committee n°07-MSANP/SG/AGMED/CNPV/CERBM on 24 January 2023. Findings generated were shared with national health stakeholders, microbiologists, members of the RESAMAD network and the Malagasy academic society of infectious diseases

Entérobactéries productrices de bêta-lactamases à spectre élargi : épidémiologie, facteurs de risque et mesures de prévention

International audienc

Genotypic characterization of five subspecies of Mycobacterium kansasii.

Different molecular typing methods including restriction fragment length polymorphism (RFLP) analysis with the major polymorphic tandem repeat (MPTR) probe and the IS1652 probe, pulsed-field gel electrophoresis (PFGE), amplified fragment length polymorphism (AFLP) analysis, and PCR restriction analysis of the hsp-65 gene (PRA) were applied to clinical and water isolates of Mycobacterium kansasii. RFLP with the MPTR probe, PRA, PFGE, and AFLP analysis revealed five homogeneous clusters which appeared to be subspecies. RFLP with the MPTR probe and PRA gave patterns specific for each cluster, whereas PFGE and AFLP analysis gave polymorphic patterns. IS1652 was present in two of the five clusters and provided polymorphic patterns for one cluster only. The two IS1652-positive clusters were Accuprobe negative (Accuprobe test; Gen-Probe Inc.), and only two other clusters were Accuprobe positive. A PCR test based on the detection of a species-specific fragment (M. Yang, B.C. Ross, and B. Dwyer, J. Clin. Microbiol. 31:2769-2772, 1993) was positive for all M. kansasii strains. This PCR test is an accurate, rapid, and specific M. kansasii identification test. No subspecies was particularly more virulent, because all clusters contained clinical strains, from AIDS patients and non-AIDS patients, and environmental strains

Installing biosafety level 3 containment laboratories in low- and middle-income countries: challenges and prospects from Mali's experience

In Mali, the incidence of tuberculosis (TB) is estimated at 56 cases per 100 000 people, with a prevalence of multidrug-resistant TB in new cases of 1.7% (range, 0.3–3.1%) and in retreatment cases of 17% (range, 4.4–30%). Appropriate biosafety conditions for performing routine TB culture and antimicrobial susceptibility testing have been lacking. In 2015, a biosafety level 3 (BSL3) laboratory set up in a shipping container was donated to the Malian Ministry of Health and Public Hygiene to provide capacity for TB testing. This laboratory is now managed by Malian laboratory staff and is processing samples at the national level. We explain the necessary steps for establishing and running a BSL3 laboratory. Despite the acute need for functioning and sustainable BSL3 laboratories, low- and middle-income countries are faced with a complex process and must overcome many challenges. Keywords: biosafety, BSL3, capacity-building, culture, DST, LMICs, Mali, Tuberculosi

Predictive factors for extended-spectrum beta-lactamase producing Enterobacteriaceae causing infection among intensive care unit patients with prior colonization

International audienc

Selection during Cefepime Treatment of a New Cephalosporinase Variant with Extended-Spectrum Resistance to Cefepime in an Enterobacter aerogenes Clinical Isolate

Enterobacter aerogenes resistant to cefepime (MIC, 32 μg/ml) was isolated from a patient treated with cefepime for an infection caused by a strain of E. aerogenes overproducing its AmpC β-lactamase (MIC of cefepime, 0.5 μg/ml). The AmpC β-lactamase of the resistant strain had an L-293-P amino acid substitution and a high k(cat)/K(m) ratio for cefepime. Both of these modifications were necessary for resistance to cefepime