We describe the epidemiology, clinical features, and molecular characterization of enterohemorrhagic Escherichia coli (EHEC) infections caused by the singular hybrid pathotype O80:H2, and we examine the influence of antibiotics on Shiga toxin production. In France, during 2005–2014, a total of 54 patients were infected with EHEC O80:H2; 91% had hemolytic uremic syndrome. Two patients had invasive infections, and 2 died. All strains carried stx2 (variants stx2a, 2c, or 2d); the rare intimin gene (eae-ξ); and at least 4 genes characteristic of pS88, a plasmid associated with extraintestinal virulence. Similar strains were found in Spain. All isolates belonged to the same clonal group. At subinhibitory concentrations, azithromycin decreased Shiga toxin production significantly, ciprofloxacin increased it substantially, and ceftriaxone had no major effect. Antibiotic combinations that included azithromycin also were tested. EHEC O80:H2, which can induce hemolytic uremic syndrome complicated by bacteremia, is emerging in France. However, azithromycin might effectively combat these infections.

Hybrid Pathotype Shiga toxin–producing E. coli O80

The objective of this study was to evaluate the evolution and risk factors of ESBL-producing Enterobacteriaceae (ESBL-E) carriage in children in the community for a long period distinguishing ST131 and non-ST131 Escherichia coli. In this prospective study, rectal samples were obtained from children aged 6–24 months by community paediatricians between 2010 and 2015. Demographic characteristics and risk factors for ESBL-E carriage were collected. Distribution of β-lactamase genes, phylogenetic groups, ST131 and virulence factors of resistant E. coli was determined. We enrolled 1886 children; 144 (7.6%) harboured ESBL-E, and this rate increased from 4.8% to 10.2% between 2010 and 2015. Risk factors for ESBL-E carriage were being cared for at home [adjusted OR (aOR) = 1.8, 95% CI = 1.1–2.9], recent antibiotic use (aOR = 1.5, 95% CI = 1.0–2.1) and travel history (aOR = 1.7, 95% CI = 1.1–2.6). Among patients carrying ESBL, E. coli (98%) and CTX-M type (90%) predominated and PapGII adhesin, characteristic of pyelonephritogenic E. coli strains, was rare (7%). In 2015, E. coli isolates frequently belonged to the phylogenetic group B2 (48%), and 37% were ST131 compared with 5% in 2010. Compared with non-ESBL-producing strains, ST131 carriage was associated with hospitalization in the last 6 months (aOR = 3.5, 95% CI = 1.4–8.8). Between 2010 and 2015, the carriage of ESBL-E in community children doubled because of the massive expansion of the E. coli ST131 clonal group. The risk for carrying ST131 was associated with previous hospitalization, but not, contrary to the counterpart, antibiotic treatment, daycare attendance or travel history.

Epidemiological surveillance of nasopharyngeal pneumococcal carriage is important for monitoring serotype distribution and antibiotic resistance, particularly before and after the implementation of pneumococcal conjugate vaccines (PCVs). With a prospective surveillance study in France, we aimed to analyze the dynamics of pneumococcal carriage, antibiotic susceptibility and serotype distribution in children aged 6 to 24 months who had acute otitis media between 2001 and 2022 with a focus on the late PCV13 period from May 2014 to July 2022. Trends were analyzed with segmented linear regression with autoregressive error. For the 17,136 children enrolled, overall pneumococcal carriage was stable during the study. During the late PCV13 period, the five most frequent serotypes were all non-PCV13 serotypes: 15B/C (14.3%), 23B (11.0%), 11A (9.6%), 15A (7.4%) and 35B (6.5%). During the same period, we observed a rebound of penicillin non-susceptibility (+0.15% per month, 95% confidence interval, +0.08 to 0.22, p < 0.001). Five serotypes accounted for 64.4% of the penicillin non-susceptible strains: 11A (17.5%), 35B (14.9%), 15A (13.9%), 15B/C (9.9%) and 19F (8.2%); non-PCV13/PCV15 accounted for <1%, and non-PCV15/PCV20 accounted for 28%. The next generation PCVs, particularly PCV20, may disrupt nasopharyngeal carriage and contribute to decreasing the rate of antibiotic resistance among pneumococci.

We developed a multiplex PCR method based on Multiple-Locus Variable-number of tandem repeats (VNTR)-Analysis (MLVA) designed for rapid typing of E. coli and Shigella isolates. The method amplifying seven VNTRs doesn9t require sequencing capillary nor fluorescent dyes. Amplification products are simply loaded on a standard agarose gel for electrophoresis and banding patterns are analyzed visually. We evaluated the method on 220 strains belonging to different collections: ECOR collection (n=72), O1:K1 isolates causing neonatal meningitis (n=38), extended-spectrum beta-lactamase-producing fecal isolates belonging to the worldwide ST131 clone (n=38), Shiga-toxin producing E. coli (STEC) of serogroups O157:H7 (n=21) and O26 (n=16, 8 belonging to an outbreak), 27 Shigella isolates (22 S. sonnei including 5 epidemic strains) and 8 reference strains. The performances were compared to MLST, the DiversiLab automated REP-PCR, PFGE and whole genome sequencing. On the ECOR collection, we found 66 different profiles. Among the clonal group O1:K1, 14 different profiles were identified. For the 37 STECs, we had 23 profiles, 1 corresponding to the 8 epidemic strains. We found 19 profiles amongst the 27 Shigella isolates, 1 corresponding to the epidemic strain. The method was able to recognize strains of the ST131 clone, to distinguish O16 and O25b serogroups and identified 15 different MLVA types among them. This method allows a simple, fast and inexpensive typing of E. coli / Shigella that can be carried out in any laboratory equipped for molecular biology with a discriminating power superior to MLST and DiversiLab REP-PCR, but slightly lower than PFGE. IMPORTANCE Fast typing methods that could easily and accurately distinguish clonal groups and unrelated isolates are of particular interest for microbiologists confronted to outbreaks or performing epidemiological studies. Highly discriminant universal methods like PFGE, optical mapping or WGS are expensive and/or time consuming. MLST is useful for phylogeny but less discriminant and requires sequencing facilities. PCR methods which are fast and easy to perform have also their drawbacks. Random PCRs and REP-PCR are universal but lack reproducibility. Other PCR methods may lack discriminatory power to differentiate isolates during outbreaks. MLVA combines the advantages of PCR methods with a high discriminatory power but in its standard form requires sequencing capillary electrophoresis. The method we have developed combines the advantages of standard PCR (simple, fast and inexpensive) with the high discriminatory power of MLVA and permits to type all E. coli (pathogenic either intestinal and extra-intestinal as well as commensal).