Characterization of antimicrobial resistance profiles in Escherichia coli isolated from captive mammals in Ecuador.

BACKGROUND: This study focuses on the AMR profiles in E. coli isolated from captive mammals at EcoZoo San Martín, Baños de Agua Santa, Ecuador, highlighting the role of wildlife as reservoirs of resistant bacteria. AIMS: The aim of this research is to investigate the antimicrobial resistance profiles of E. coli strains isolated from various species of captive mammals, emphasizing the potential zoonotic risks and the necessity for integrated AMR management strategies. MATERIALS & METHODS: A total of 189 fecal samples were collected from 70 mammals across 27 species. These samples were screened for E. coli, resulting in 90 identified strains. The resistance profiles of these strains to 16 antibiotics, including 10 ß-lactams and 6 non-ß-lactams, were determined using the disk diffusion method. Additionally, the presence of Extended-Spectrum Beta-Lactamase (ESBL) genes and other resistance genes was analyzed using PCR. RESULTS: Significant resistance was observed, with 52.22% of isolates resistant to ampicillin, 42.22% to ceftriaxone and cefuroxime, and 27.78% identified as ESBL-producing E. coli. Multiresistance (resistance to more than three antibiotic groups) was found in 35.56% of isolates. Carnivorous and omnivorous animals, particularly those with prior antibiotic treatments, were more likely to harbor resistant strains. DISCUSSION: These findings underscore the role of captive mammals as indicators of environmental AMR. The high prevalence of resistant E. coli in these animals suggests that zoos could be significant reservoirs for the spread of antibiotic-resistant bacteria. The results align with other studies showing that diet and antibiotic treatment history influence resistance profiles. CONCLUSION: The study highlights the need for an integrated approach involving veterinary care, habitat management, and public awareness to prevent captive wildlife from becoming reservoirs of antibiotic-resistant bacteria. Improved waste management practices and responsible antibiotic use are crucial to mitigate the risks of AMR in zoo environments and reduce zoonotic threats.

Genomic insights of mcr-1 harboring Escherichia coli by geographical region and a One-Health perspective.

The importance of the One Health concept in attempting to deal with the increasing levels of multidrug-resistant bacteria in both human and animal health is a challenge for the scientific community, policymakers, and the industry. The discovery of the plasmid-borne mobile colistin resistance (mcr) in 2015 poses a significant threat because of the ability of these plasmids to move between different bacterial species through horizontal gene transfer. In light of these findings, the World Health Organization (WHO) recommends that countries implement surveillance strategies to detect the presence of plasmid-mediated colistin-resistant microorganisms and take suitable measures to control and prevent their dissemination. Seven years later, ten different variants of the mcr gene (mcr-1 to mcr-10) have been detected worldwide in bacteria isolated from humans, animals, foods, the environment, and farms. However, the possible transmission mechanisms of the mcr gene among isolates from different geographical origins and sources are largely unknown. This article presents an analysis of whole-genome sequences of Escherichia coli that harbor mcr-1 gene from different origins (human, animal, food, or environment) and geographical location, to identify specific patterns related to virulence genes, plasmid content and antibiotic resistance genes, as well as their phylogeny and their distribution with their origin. In general, E. coli isolates that harbor mcr-1 showed a wide plethora of ARGs. Regarding the plasmid content, the highest concentration of plasmids was found in animal samples. In turn, Asia was the continent that led with the largest diversity and occurrence of these plasmids. Finally, about virulence genes, terC, gad, and traT represent the most frequent virulence genes detected. These findings highlight the relevance of analyzing the environmental settings as an integrative part of the surveillance programs to understand the origins and dissemination of antimicrobial resistance.