Characteristics of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Enterobacteriaceae Isolates from Rivers and Lakes in Switzerland

Abstract

One of the currently most relevant resistance mechanisms in Enterobacteriaceae is the production of enzymes that lead to modern expanded-spectrum cephalosporin and even carbapenem resistance, mainly extended-spectrum ␤-lactamases (ESBLs) and carbapenemases. A worrisome aspect is the spread of ESBL and carbapenemase producers into the environment. The aim of the present study was to assess the occurrence of ESBL-and carbapenemase-producing Enterobacteriaceae and to further characterize ESBL-and carbapenemase-producing Enterobacteriaceae in rivers and lakes in Switzerland. ESBL-producing Enterobacteriaceae were detected in 21 (36.2%) of the 58 bodies of water sampled. One river sample tested positive for a carbapenemase-producing Klebsiella pneumoniae subsp. pneumoniae strain. Seventy-four individual strains expressing an ESBL phenotype were isolated. Species identification revealed 60 Escherichia coli strains, seven Klebsiella pneumoniae subsp. pneumoniae strains, five Raoultella planticola strains, one Enterobacter cloacae strain, and one Enterobacter amnigenus strain. Three strains were identified as SHV-12 ESBL producers, and 71 strains carried genes encoding CTX-M ESBLs. Of the 71 strains with CTX-M ESBL genes, 8 isolates expressed CTX-M-1, three produced CTX-M-3, 46 produced CTX-M-15, three produced CTX-M-55, one produced CTX-M-79, six produced CTX-M-14, and four produced CTX-M-27. Three of the four CTX-M-27 producers belonged to the multiresistant pandemic sequence type E. coli B2:ST131 that is strongly associated with potentially severe infections in humans and animals.

Prevalence of CTX-M beta-Lactamases in Escherichia coli from community-acquired urinary tract infections and associated risk factors among women in Cameroon

“…Water certainly promotes the circulation of Enterobacteriaceae strains (be they resistant or not). [18][19][20][21][22][23][24][25] Moreover, access to drinking water is not properly insured in many parts of the city. As such, Enterobacteriaceae from stools can easily affect many people through contaminated water.…”

Wastewater as a point source of antibiotic-resistance genes in the sediment of a freshwater lake

“…Consequently, bacterial pathogens are assumed to acquire resistance traits from the environment via horizontal gene transfer (Aminov, 2009;Martinez, 2009a). Moreover, various studies have demonstrated that wastewater and animal waste contain large numbers of resistant bacteria, which can pass through the wastewater treatment plant (WWTP) and reach the receiving water bodies (Teuber, 2001;Kü mmerer, 2004;Jury et al, 2011;Rizzo et al, 2013;Zurfluh et al, 2013). There is growing concern that continuous discharge of these contaminants may, at least locally, lead to an increase in the natural resistance background levels and thus enhance the likelihood of antibiotic-resistance genes (ARGs) being transferred back to human and animal commensals or even pathogens (Kim and Aga, 2007;Martinez, 2009b;Cantas et al, 2013).…”

Antimicrobial resistance and integrons of ESBL-producing thermotolerant coliforms from a water reservoir in Tai'an, China

“…The filters were incubated for 24 hours at 44.5 ℃ in 10 mL of Enterobacteria Enrichment Broth (Haibo, Qingdao, China). One loopful of each of the enrichment cultures was inoculated onto chromogenic Brilliance ESBL agar (Oxoid, Hampshire, UK) to select for ESBL-producers [5,19,20]. All suspected ESBLproducing bacteria were re-selected by MacConkey agar containing cefotaxime 64 mg/mL (Haibo, Qingdao, China) [11].…”

“…It is believed that drug resistant bacteria from humans and animals, discharged into water bodies, could result in the spread of resistance genes within the bacterial community [3][4][5][6][7]. Therefore, the persistence of antibiotic-resistant intestinal bacteria in water environments, particularly extended-spectrum β-lactamase (ESBL)-producing bacteria, could elicit an important public health risk [8,9].…”