Occurrence and Diversity of CTX-M-Producing Escherichia coli From the Seine River

Abstract

CTX-M-producing Escherichia coli are spreading since 1999 both in clinical and in community settings. Environmental samples such as rivers have also been pointed out as being vectors for ESBL producers. In this report, we have investigated the presence and the diversity of CTX-M-producing E. coli isolates in two samplings of the Seine River (next to Notre Dame), Paris France, performed in June 2016 and 2017. The total number of bacteria growing on the selective ChromID ESBL agar was 3.1 × 105 cfu/L (23.8% of all growing bacteria) in 2016, whereas it was 100-fold lower in 2017 (3 × 103 cfu/L; 8.3% of all growing bacteria). However, among them, the prevalence of ESBL-producing E. coli increased from <0.1 to 1.1% in one-year. ESBLs were exclusively of the CTX-M-type: CTX-M-1 (n = 5), CTX-M-15 (n = 7), CTX-M-14 (n = 1), and CTX-M-27 (n = 2). The isolates belonged to several multi locus sequence types, and a wide diversity of incompatibility groups of plasmids were identified in those E. coli isolates. The occurrence and diversity of E. coli isolates belonging to many clones and producing many CTX-M-variants have been identified in our study. The presence of these bacteria in rivers that are open again for recreational usage (swimming) is worrying as it may contribute to further dissemination of ESBL producers in the community.

Trueperella pyogenes Isolates from Livestock and European Bison (Bison bonasus) as a Reservoir of Tetracycline Resistance Determinants

“…It is well-known that the overuse of antimicrobials in agriculture may lead to an increased selection of resistant strains [ 60 ]. However, it seems that one of the essential reasons for a high prevalence of antimicrobial resistance genes in the environment may be the horizontal transfer of these genes from fecal microbiota of livestock to environmental bacteria [ 61 , 62 ]. The tetW gene, the most widespread tetracycline resistance determinant in bacteria of different origins, may be a good example of disseminating resistance genes among clinical and environmental strains.…”

Chromosomal integration of blaCTX-M genes in diverse Escherichia coli isolates recovered from river water in Japan

“…Previous studies have reported the predominance of CTX-M ESBLs among environmental E. coli . For example, CTX-M-14(-like) was prevalent among ESBLEC in surface waters in China, Japan, and Korea, and CTX-M-15 was prevalent among ESBLEC in surface waters in France, Germany, and Switzerland ( Falgenhauer et al., 2021 ; Girlich et al., 2020 ; Jang et al., 2013 ; Liu et al., 2018 ; Miyagi and Hirai, 2019 ; Zurfluh et al., 2013 ).…”

Chromosomal integration of blaCTX-M genes in diverse Escherichia coli isolates recovered from river water in Japan

“…However, some previous studies also detected ESBL genes on chromosomes and suggested that integration of ESBL genes into chromosomes could contribute to the maintenance of ESBL genes in the absence of antibiotic selection pressure (5)(6)(7). Although previous studies have reported the occurrence of ESBLEC in environmental waters, limited information exists regarding the locations (chromosome or plasmid) and genetic contexts of ESBL genes in environmental ESBLEC (8)(9)(10)(11).…”