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

Abstract The spread of extended spectrum β-lactamases (ESBL) and plasmid mediated AmpC β-lactamases (pAmpC) was evaluated in E. coli strains collected from the intestinal microbiota of healthy children in Tunisia. The carriage rate of CTXR E. coli was 6.6% (7 of 105 samples) and one strain/sample was further characterized (7 isolaes). 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 . CTXR E. 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.