CTX-M-15-producing Escherichia coli clone B2-O25b-ST131 and Klebsiella spp. isolates in municipal wastewater treatment plant effluents
Monika Dolejska , Petra Frolkova , Magdalena Florek , Ivana Jamborova , Michaela Purgertova , Iva Kutilova , Alois Cizek , Sebastian Guenther , Ivan Literak
AbstractObjectives: The global occurrence of antibiotic resistance genes in bacteria in water environments is an increasing concern. Treated wastewater was sampled daily over a 45 day period from the outflow of a municipal wastewater treatment plant in Brno, Czech Republic, and examined for extended-spectrum β-lactamase (ESBL)-producing bacteria. Methods: Water samples were cultivated on MacConkey agar with cefotaxime (2 mg/L) and individual colonies were examined for ESBL production. Phenotypic ESBL-positive bacteria identified as Escherichia coli or Klebsiella spp. were tested for the presence of antibiotic resistance genes, the virulence gene afa/dra and the blaCTX-M upstream region. Genetic relatedness was analysed by PFGE, multilocus sequence typing and plasmid analysis. Results: A total of 68 ESBL-producing Enterobacteriaceae isolates were detected in 34 out of 45 wastewater samples. ESBL-producing isolates included 26 E. coli isolates, 4 Klebsiella pneumoniae isolates and 1 Klebsiella oxytoca isolate. The pandemic and multiresistant B2-O25b-ST131 clone was predominant, being detected among 19 E. coli isolates, and 17 of the B2-O25b-ST131 isolates were positive for the FIA replicon and the afa/dra operon and had an IS26 element flanking blaCTX-M-15. Seventeen of the B2-O25b-ST131 isolates showed closely related PFGE profiles (defined by 84% band similarity) and belonged to identical clonal groups. Conclusions: The results highlight the inadequacy of the treatment process in removing multiresistant bacteria from municipal wastewater and point to a risk of transmission of clinically important multiresistant strains, such as the pandemic ST131 clone, to the environment. This is the first study demonstrating the pandemic ST131 clone in wastewater.
|Journal series||Journal of Antimicrobial Chemotherapy, ISSN 0305-7453, e-ISSN 1460-2091, (A 40 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Antibiotic resistance; MLST; Plasmids|
|ASJC Classification||; ;|
|Publication indicators||= 68; = 64; : 2011 = 1.77; : 2011 = 5.068 (2) - 2011=4.792 (5)|
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