Background: Wildlife zoos provide the opportunity for children and adults to interact with animals, However, it's unknown that the risk of contact with animals, which carried zoonotic pathogens and antimicrobial resistant bacteria.Objectives: This study aimed to investigate the prevalence and antimicrobial susceptibility of extended-spectrum β-lactamases Escherichia coli (ESBLs-EC) from a wildlife zoo in China.Methods: A total of 93 wildlife faecal samples were collected from a wildlife zoo.Agar dilution method was used to determine the resistant phenotype. Whole genomes sequencing and bioinformatic analysis were employed to evaluate the molecular typing and genetic relationships of ESBLs-EC.Results: A total of 23 CTX-M-positive ESBLs-EC were isolated from swan (n = 14), squirrel monkey (n = 5), black hat hanging monkey (n = 2), gibbon monkey (n = 1) and phoenicopteridae (n = 1) respectively. All ESBLs-EC strains were resistant to cefotaxime, tetracycline, ciprofloxacin and trimethoprim-sulfamethoxazole, but susceptible to colistin, tigecycline, meropenem and amikacin. By screening whole genome sequences, ESBLs-EC strains main carried bla CTX-M-55 (34.8%, 8/23) and bla CTX-M-14 (26.0%, 6/23), following by bla CTX-M-27 (21.7%, 5/23), bla CTX-M-15 (13.0%, 3/23) and bla CTX-M-121 (4.3%, 1/23). ESBLs-EC strains mainly belonged to phylogroup A (60.9%, 14/23), and ST48, ST746 and ST616 (3 strains respectively, 13.0%) were major ST types. Core genome-based single nucleotide polymorphism (SNP) analysis suggested that strains from the swan, over the phylogenetic tree, have a closer genetic relationship with strains from other animals (black hat hanging monkey, gibbon monkey, phoenicopteridae and squirrel monkey).Conclusions: CTX-M type ESBLs-EC can transmit between animals in wildlife zoos, which may be a risk of spread to animal keepers, veterinarians and visitors whenThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Background: Tigecycline is regarded as a last-resort antimicrobial agent against multidrug resistance (MDR). However, resistance-nodulation-division efflux pump resistance genes, such as tmexCD3-toprJ3, that confer resistance to tigecycline have emerged.Objectives: This study aimed to characterise the tmexCD3-toprJ3 gene cluster in Pseudomonas juntendi and Proteus terrae isolated from a pig farm.Methods: Samples were obtained from a Chinese piggery and included 92 pig faecal samples, 56 wastewater samples, 23 drinking water samples, 28 sow vagina samples and nine sow uterus swabs. The presence of tmexCD3-toprJ3 was detected using a polymerase chain reaction assay, and the antimicrobial susceptibility profile of the tmexCD3-toprJ3-positive isolates was determined using the broth dilution method. Genomic locations were identified using whole-genome sequencing and bioinformatics. Results:We identified two tmexCD3-toprJ3-positive isolates, and both isolates were highly resistant to antibiotics such as tigecycline. In addition, we identified several mobile elements (ISPa7, ISCfr1, ISVsa3) and insertion sequences (TnAs2, TnAs3) in tmexCD3-toprJ3-positive isolates that could increase the potential for the spread of MDR. Conclusions:To the best of our knowledge, this study is the first to report the detection of tmexCD3-toprJ3 in P. juntendi and P. terrae isolated from a pig farm.