Impact of genetic diversity and antibiotic-resistance of Salmonella isolated from feral cats: One Health approach

Abstract

Free-living cats usually live in colonies in urban areas, especially close to parks and neighbourhoods where people feed them without any sanitary control. This can pose a human, animal and environmental health concern due to the close contact between uncontrolled colonies, the population and other domestic and/or wild animals. Thus, this study aimed to assess the genetic diversity and antimicrobial resistance (AMR) among Salmonella enterica subsp. enterica strains isolated from feral cats in a previous epidemiological study in the Gran Canaria island (Spain). A total of nineteen Salmonella isolates were obtained from November 2018 to January 2019 in a Salmonella epidemiological study in feral cats. All isolates obtained were genotyped by pulsed-field gel electrophoresis (PGFE) and were tested for antimicrobial susceptibility, in accordance with Decision 2013/652/EU. PFGE analysis revealed isolates clustering by serovar, with identical clones for serovars Bredeney and Grancanaria, while differing pulsotypes were observed for serovars Florida (88.89 % similarity) and Nima (83.23 % similarity). All but two isolates were resistant to at least one antimicrobial. The results obtained demonstrate that feral cats in the region investigated are a reservoir of Salmonella strains resistant to gentamicin (94.1 %) and of the critically important antimicrobial tigecycline (23.5 %). Hence, they could excrete AMR strains through their faeces and contaminate the environment, favoring the spread of such bacteria to cohabiting pets. Moreover, this widespread presence of AMR Salmonella clones across various serovars highlights the urgent need to implement efficient antimicrobial stewardship and control programs by the local governments due to the ongoing need to protect human and animal health under a One Health concept.