Molecular Identification of Extended-Spectrum-β-Lactamase Genes from Enterobacteriaceae Isolated from Healthy Human Carriers in Switzerland

Abstract

In this study, fecal samples from 586 healthy humans were investigated to determine the occurrence of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae in Swiss people. A total of 5.8% of the human fecal samples yielded ESBL producers, and all of the 34 isolated strains were Escherichia coli. PCR analysis revealed that 14 strains produced CTX-M-15, 10 produced CTX-M-1, 7 strains produced CTX-M-14, and 2 strains produced CTX-M-2 ESBLs. One strain produced SHV-12 ESBL. Of the 34 isolates, 15 produced additional TEM-1 broad-spectrum β-lactamases. By serotyping, a high degree of diversity among the strains was found.