Extended-spectrum beta-lactamase producing Escherichia coli in hospital wastewaters and sewage treatment plants in Queensland, Australia


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Guendogdu A. , JENNISON A. V. , SMITH H. V. , STRATTON H., KATOULI M.

CANADIAN JOURNAL OF MICROBIOLOGY, vol.59, no.11, pp.737-745, 2013 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 59 Issue: 11
  • Publication Date: 2013
  • Doi Number: 10.1139/cjm-2013-0515
  • Title of Journal : CANADIAN JOURNAL OF MICROBIOLOGY
  • Page Numbers: pp.737-745

Abstract

We investigated the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in untreated hospital wastewaters and 2 sewage treatment plants (STPs). A collection of 252 ESBL-producing E. coli isolates from hospital wastewater and STPs were typed and tested for resistance to 17 antimicrobial agents and for the presence of integron-associated integrases (intI gene) and ESBL genes. Eighty-nine percent (n = 176) of the ESBL-producing E. coli strains from hospital wastewater were found in more than 1 sample (common types), with 1 common type accounting for 35% of isolates, found in all samples. These strains were also resistant to up to 9 non-beta-lactam antibiotics and showed the same pattern of resistance in all samples. More than 73% of the hospital wastewater isolates possessed SHV-type ESBL as opposed to isolates from STPs that carried only CTX-M-type ESBL genes. The prevalence of the intI gene did not differ between the sources of the isolates. Certain ESBL-producing E. coli were dominant in hospital wastewaters. These strains possessed beta-lactamase genes that were different from isolates found in STPs. From a public health point of view, the presence of such a high level of ESBL-producing E. coli strains in hospital wastewaters is of great importance.