Community fecal carriage of broad-spectrum cephalosporin-resistant Escherichia coli in Tunisian children

The spread of extended spectrum β-lactamases (ESBL) and plasmid mediated AmpC β-lactamases (pAmpC) was evaluated in Escherichia coli strains collected from the intestinal microbiota of healthy children in Tunisia. The carriage rate of CTXRE. coli was 6.6% (7 of 105 samples) and one strain/sample was further characterized (7 isolates). These isolates harbored blaCTX-M-1 (n = 4), blaCTX-M-15 (n = 2), and blaCMY-2 gene (n = 1), which were usually located on FIB replicon type and carried class 1 integrons. The acc(6′)-Ib-cr variant was identified in one isolate that harbored blaCTX-M-15. CTXRE. coli isolates were genetically unrelated and belonged to B1 (n = 3/ST155/ST398/ST58), D (n = 2/ST117/ST493), B2 (n = 1/ST127), and A (n = 1/ST746) phylogroups. Strain virulence scores varied from 3 to 12, and frequently harbored the pathogenicity island PAI IV536.The intestinal tract of healthy children constitute an important reservoir of ESBL producing E. coli. Thus, improvement of hygiene measures mainly in the school environment and rational use of antibiotics would be of great help in preventing selection and diffusion of resistant strains from intestinal microbiota.