Resistance to broad-spectrum antibiotics in aquatic systems: anthropogenic activities modulate the dissemination of bla(CTX-M)-like genes.

ABSTRACT: We compared the resistomes within polluted and unpolluted rivers, focusing on extended-spectrum beta-lactamase (ESBL) genes, in particular bla(CTX-M). Twelve rivers from a Portuguese hydrographic basin were sampled. Physicochemical and microbiological parameters of water quality were determined, and the results showed that 9 rivers were classified as unpolluted (UP) and that 3 were classified as polluted (P). Of the 225 cefotaxime-resistant strains isolated, 39 were identified as ESBL-producing strains, with 18 carrying a bla(CTX-M) gene (15 from P and 3 from UP rivers). Analysis of CTX-M nucleotide sequences showed that 17 isolates produced CTX-M from group 1 (CTX-M-1, -3, -15, and -32) and 1 CTX-M that belonged to group 9 (CTX-M-14). A genetic environment study revealed the presence of d

SUBMITTER: Tacao M 

PROVIDER: S-EPMC3370516 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature