Molecular characterization of extended spectrum β -lactamases enterobacteriaceae causing lower urinary tract infection among pediatric population.

The β-lactam antibiotics have traditionally been the main treatment of Enterobacteriaceae infections, nonetheless, the emergence of species producing β- Lactamases has rendered this class of antibiotics largely ineffective. There are no published data on etiology of urinary tract infections (UTI) and antimicrobial resistance profile of uropathogens among children in Qatar. The aim of this study is to determine the phenotypic and genotypic profiles of antimicrobial resistant Enterobacteriaceae among children with UTI in Qatar. Bacteria were isolated from 727 urine positive cultures, collected from children with UTI between February and June 2017 at the Pediatric Emergency Center, Doha, Qatar. Isolated bacteria were tested for antibiotic susceptibility against sixteen clinically relevant antibiotics using phoenix and Double Disc Synergy Test (DDST) for confirmation of extended-spectrum beta-lactamase (ESBL) production. Existence of genes encoding ESBL production were identified using polymerase chain reaction (PCR). Statistical analysis was done using non-parametric Kappa statistics, Pearson chi-square test and Jacquard's coefficient. 201 (31.7%) of samples were confirmed as Extended Spectrum β -Lactamases (ESBL) Producing Enterobacteriaceae. The most dominant pathogen was 166 (83%) followed by 22 (11%). Resistance was mostly encoded by CTX-M (59%) genes, primarily CTX-MG1 (89.2%) followed by CTX-MG9 (7.7%). 37% of isolated bacteria were harboring multiple genes (2 genes or more). isolates were categorized into 11 clusters, while were grouped into five clonal clusters according to the presence and absence of seven genes namely TEM, SHV, CTX-MG1, CTX-MG2, CTX-MG8 CTX-MG9 CTX-MG25. Our data indicates an escalated problem of ESBL in pediatrics with UTI, which mandates implementation of regulatory programs to reduce the spread of ESBL producing Enterobacteriaceae in the community. The use of cephalosporins, aminoglycosides (gentamicin) and trimethoprim/sulfamethoxazole is compromised in Qatar among pediatric population with UTI, leaving carbapenems and amikacin as the therapeutic option for severe infections caused by ESBL producers

Investigation of Kingella kingae Invasive Infection Outbreaks in Day Care Facilities: Assessment of a Rapid Genotyping Tool Targeting the DNA Uptake Sequence.

Outbreaks of Kingella kingae invasive infections have recently been reported in day care centers. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) revealed that although the invasive strains had widespread dissemination in the day care population, less virulent strains were also circulating in the facilities. However, these typing tools are costly, time-consuming, and labor-intensive and provide delayed results. A study was conducted to assess the performance of a rapid and cost-effective genotyping tool targeting the DNA uptake sequence (DUS) in the investigation of outbreaks of K. kingae disease. DUS typing (DUST) patterns of each strain from 7 different clusters were compared to distinguish genotypically linked strains from others. PFGE and, when available, MLST results were used as gold standards. DUST was assessed on 80 K. kingae isolates from Nir-Itzhak (n = 14), Tel-Nof (n = 14), Palmahim (n = 5), Umm-al-Fahm (n = 7), Eilat (n = 8), Nevatim (n = 15) in Israel and Paris, France (n = 17). A unique DUST pattern was involved in the Nir-Itzhak, Palmahim, Umm-al-Fahm, and Paris episodes. Two DUST patterns were found in Eilat, whereas at least 3 were identified in the Tel-Nof and Nevatim episodes. In total, 11 (13.8%) children carried a K. kingae isolate that differed from the outbreak strain. These results were concordant with those obtained with the traditional PFGE and MLST methods. DUST appears to be sensitive and specific in distinguishing the invasive outbreak strain from others in asymptomatic carriers and could be useful to limit unnecessary exposure of the entire day care population to selective antibiotic pressure

MiniBioReactor Array (MBRA) <i>in vitro</i> gut model: a reliable system to study microbiota-dependent response to antibiotic treatment

Abstract Background Antimicrobial drugs are mostly studied for their impact on emergence of bacterial antibiotic resistance, but their impact on the gut microbiota is also of tremendous interest. In vitro gut models are important tools to study such complex drug–microbiota interactions in humans. Methods The MiniBioReactor Array (MBRA) in vitro microbiota system; a single-stage continuous flow culture model, hosted in an anaerobic chamber; was used to evaluate the impact of three concentrations of a third-generation cephalosporin (ceftriaxone) on faecal microbiota from two healthy donors (treatment versus control: three replicates per condition). We conducted 16S microbiome profiling and analysed microbial richness, diversity and taxonomic changes. β-Lactamase activities were evaluated and correlated with the effects observed in the MBRA in vitro system. Results The MBRA preserved each donor’s specificities, and differences between the donors were maintained through time. Before treatment, all faecal cultures belonging to the same donor were comparable in composition, richness, and diversity. Treatment with ceftriaxone was associated with a decrease in α-diversity, and an increase in β-diversity index, in a concentration-dependent manner. The maximum effect on diversity was observed after 72 h of treatment. Importantly, one donor had a stronger microbiota β-lactamase activity that was associated with a reduced impact of ceftriaxone on microbiota composition. Conclusions MBRA can reliably mimic the intestinal microbiota and its modifications under antibiotic selective pressure. The impact of the treatment was donor- and concentration-dependent. We hypothesize these results could be explained, at least in part, by the differences in β-lactamase activity of the microbiota itself. Our results support the relevance and promise of the MBRA system to study drug–microbiota interactions. </jats:sec

Independent Host Factors and Bacterial Genetic Determinants of the Emergence and Dominance of Escherichia coli Sequence Type 131 CTX-M-27 in a Community Pediatric Cohort Study

The recent emergence and diffusion in the community of Escherichia coli isolates belonging to the multidrug-resistant and CTX-M-27-producing sequence type 131 (ST131) C1-M27 cluster makes this cluster potentially as epidemic as the worldwide E. coli ST131 subclade C2 composed of multidrug-resistant isolates producing CTX-M-15. Thirty-five extended-spectrum beta-lactamase (ESBL)-producing ST131 isolates were identified in a cohort of 1,885 French children over a 5-year period. </jats:p

Inoculum effect of Enterobacterales co-expressing OXA-48 and CTX-M on the susceptibility to ceftazidime/avibactam and meropenem

International audienceThe treatment of infections caused by OXA-48/CTX-M-coproducing Enterobacterales may be based on new beta-lactam/beta-lactamase inhibitors, such as ceftazidime/avibactam (CZA), or on high dose of meropenem (MER). However, bacterial density at the infection site may vary widely, and the inoculum effect of such antimicrobial strategies has never been specifically investigated. To determine if CZA or MER susceptibilities are impacted by high inocula of Enterobacterales co-expressing both enzymes: OXA-48 like and CTX-M