Prevalence of day-care centre children (France) with faecal CTX-M-producing Escherichia coli comprising O25b:H4 and O16:H5 ST131 strains

Determining the prevalence of children in day-care centres (DCCs) carrying faecal extended-spectrum -lactamase (ESBL)-producing Enterobacteriaceae and molecularly characterizing those belonging to the Escherichia coli species. Stools were collected from childrens diapers (JanuaryApril 2012) in randomly chosen DCCs and plated onto ChromID ESBL. Colonies growing on this medium were identified by the Vitek 2 system and tested for antibiotic susceptibility and for ESBL production by the double-disc synergy test. ESBL genotypes were determined as well as phylogenetic groups, ERIC-2 (enterobacterial repetitive intergenic consensus) PCR profiles and sequence types (STs) for the E. coli isolates. Serotypes, virotypes, fimH alleles, ESBL-carrying plasmids and PFGE patterns were determined for the ST131 E. coli isolates. Among 419 children from 25 participating DCCs, 1 was colonized by CTX-M-15-producing Klebsiella pneumoniae and 27 (6.4) by E. coli, which all produced CTX-M enzymes [CTX-M-15 (37), CTX-M-1 (26), CTX-M-14 (22), CTX-M-27 (11) and CTX-M-22 (4)]. The 27 E. coli isolates, 55.5 belonging to group B2, displayed 20 ERIC-2 PCR profiles and 16 STs. The ST131 E. coli isolates were dominant (44), displayed serotypes O25b:H4 and O16:H5, fimH alleles 30 and 41 and virotypes A and C. According to the PFGE patterns, one strain of E. coli ST131 producing a CTX-M-15 enzyme carried by an IncF F2:A1:B plasmid had spread within one DCC. This study shows a notable prevalence (6.4) of DCC children with faecal CTX-M-producing E. coli isolates comprising a high proportion of E. coli ST131 isolates, suggesting that these children might be a reservoir of this clone.