AUTHOR=Girlich Delphine , Bonnin Rémy A. , Naas Thierry 

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

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.603578

DOI=10.3389/fmicb.2020.603578

ISSN=1664-302X

ABSTRACT=<p>CTX-M-producing <italic>Escherichia coli</italic> 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 <italic>E. coli</italic> 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 × 10<sup>5</sup> cfu/L (23.8% of all growing bacteria) in 2016, whereas it was 100-fold lower in 2017 (3 × 10<sup>3</sup> cfu/L; 8.3% of all growing bacteria). However, among them, the prevalence of ESBL-producing <italic>E. coli</italic> increased from &lt;0.1 to 1.1% in one-year. ESBLs were exclusively of the CTX-M-type: CTX-M-1 (<italic>n</italic> = 5), CTX-M-15 (<italic>n</italic> = 7), CTX-M-14 (<italic>n</italic> = 1), and CTX-M-27 (<italic>n</italic> = 2). The isolates belonged to several multi locus sequence types, and a wide diversity of incompatibility groups of plasmids were identified in those <italic>E. coli</italic> isolates. The occurrence and diversity of <italic>E. coli</italic> 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.</p>