Abstract
Species belonging to Enterobacter cloacae complex have been isolated in numerous environments and samples of various origins. They are also involved in opportunistic infections in plants, animals, and humans. Previous prospection in Guadeloupe (French West Indies) indicated a high frequency of E. cloacae complex strains resistant to third-generation cephalosporins (3GCs) in a local lizard population (Anolis marmoratus), but knowledge of the distribution and resistance of these strains in humans and the environment is limited. The aim of this study was to compare the distribution and antibiotic susceptibility pattern of E. cloacae complex members from different sources in a “one health” approach and to find possible explanations for the high level of resistance in non-human samples. E. cloacae complex strains were collected between January 2017 and the end of 2018 from anoles, farm animals, local fresh produce, water, and clinical human samples. Isolates were characterized by the heat-shock protein 60 gene-fragment typing method, and whole-genome sequencing was conducted on the most frequent clusters (i.e., C-VI and C-VIII). The prevalence of resistance to 3GCs was relatively high (56/346, 16.2%) in non-human samples. The associated resistance mechanism was related to an AmpC overproduction; however, in human samples, most of the resistant strains (40/62) produced an extended-spectrum beta-lactamase. No relation was found between resistance in isolates from wild anoles (35/168) and human activities. Specific core-genome phylogenetic analysis highlighted an important diversity in this bacterial population and no wide circulation among the different compartments. In our setting, the mutations responsible for resistance to 3GCs, especially in ampD, were diverse and not compartment specific. In conclusion, high levels of resistance in non-human E. cloacae complex isolates are probably due to environmental factors that favor the selection of these resistant strains, and this will be explored further.
Highlights
Bacteria in the Enterobacter cloacae complex (ECC) are widely distributed in numerous terrestrial and aquatic environments, and in air and space equipment (Singh et al, 2018; DavinRegli et al, 2019; Uchida et al, 2020)
In non-human isolates, ECC strains (WT and third-generation cephalosporin (3GC)-R) were isolated from 57.9% (44/76) of fresh produce and 42.9% (72/168) of anole samples; half of the raw water samples (20/40) were positive, while ECC strains were isolated from only 29.0% of livestock samples (18/62)
Resistance to 3GCs was found in 16.2% of nonhuman samples (56/346) and was due only to cephalosporinase overproduction (CoP)
Summary
Bacteria in the Enterobacter cloacae complex (ECC) are widely distributed in numerous terrestrial and aquatic environments, and in air and space equipment (Singh et al, 2018; DavinRegli et al, 2019; Uchida et al, 2020). ECC are found in the gut microbiota of animals, including reptiles, mammals, and humans, and some studies have reported that the complex is endophytic (Liu et al, 2012; Singh et al, 2013; Davin-Regli et al, 2019). This bacterial complex includes phytopathogenic clones (Humann et al, 2011), infection-causing strains in wild fauna and domestic animals (Haenni et al, 2016; Goldberg et al, 2019), and opportunistic pathogens that are involved in a wide variety of human infections, especially those associated with health care (Garinet et al, 2018). Some phylogenetic clades are associated with previous hsp clusters, and a novel cluster was reported (Beyrouthy et al, 2018)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
