Prevalence and Genomic Investigation of Multidrug-Resistant Salmonella Isolates from Companion Animals in Hangzhou, China

Lin Teng; Sihao Liao; Xin Zhou; Chenghao Jia; Mengyao Feng; Hang Pan; Zhengxin Ma; Min Yue

doi:10.3390/antibiotics11050625

Prevalence and Genomic Investigation of Multidrug-Resistant Salmonella Isolates from Companion Animals in Hangzhou, China

Antibiotics (Basel). 2022 May 5;11(5):625. doi: 10.3390/antibiotics11050625.

Authors

Lin Teng¹, Sihao Liao¹, Xin Zhou¹, Chenghao Jia¹, Mengyao Feng¹, Hang Pan¹, Zhengxin Ma², Min Yue^{1

3}

Affiliations

¹ Department of Veterinary Medicine, Institute of Preventive Veterinary Sciences, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
² Mount Desert Island Biological Laboratory, Bar Harbor, ME 04609, USA.
³ Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou 310058, China.

Abstract

Salmonella is a group of bacteria that constitutes the leading cause of diarrheal diseases, posing a great disease burden worldwide. There are numerous pathways for zoonotic Salmonella transmission to humans; however, the role of companion animals in spreading these bacteria is largely underestimated in China. We aimed to investigate the prevalence of Salmonella in pet dogs and cats in Hangzhou, China, and characterize the antimicrobial resistance profile and genetic features of these pet-derived pathogens. In total, 137 fecal samples of pets were collected from an animal hospital in Hangzhou in 2018. The prevalence of Salmonella was 5.8% (8/137) in pets, with 9.3% (5/54) of cats and 3.6% (3/83) of dogs being Salmonella positive. By whole-genome sequencing (WGS), in silico serotyping, and multilocus sequence typing (MLST), 26 pet-derived Salmonella isolates were identified as Salmonella Dublin (ST10, n = 22) and Salmonella Typhimurium (ST19, n = 4). All of the isolates were identified as being multidrug-resistant (MDR), by conducting antimicrobial susceptibility testing under both aerobic and anaerobic conditions. The antibiotics of the most prevalent resistance were streptomycin (100%), cotrimoxazole (100%), tetracycline (96.20%), and ceftriaxone (92.30%). Versatile antimicrobial-resistant genes were identified, including floR (phenicol-resistant gene), blaCTX-M-15, and blaCTX-M-55 (extended-spectrum beta-lactamase genes). A total of 11 incompatible (Inc) plasmids were identified, with IncA/C2, IncFII(S), and IncX1 being the most predominant among Salmonella Dublin, and IncFIB(S), IncFII(S), IncI1, and IncQ1 being the most prevailing among Salmonella Typhimurium. Our study applied WGS to characterize pet-derived Salmonella in China, showing the presence of MDR Salmonella in pet dogs and cats with a high diversity of ARGs and plasmids. These data indicate a necessity for the regular surveillance of pet-derived pathogens to mitigate zoonotic diseases.

Keywords: Salmonella; antimicrobial resistance; pets; prevalence; whole genome sequencing.

Grants and funding

This study was supported by the National Program on the Key Research Project of China (2019YFE0103900 and 2017YFC1600103), as well as the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 861917–SAFFI, National Natural Science Foundation of China (31872837&32150410374), Zhejiang Provincial Natural Science Foundation of China (LR19C180001), and Zhejiang Provincial Key R&D Program of China (2021C02008 and 2020C02032).