Serotyping and Antimicrobial Resistance Profiling of Multidrug-Resistant Non-Typhoidal <i>Salmonella</i> from Farm Animals in Hunan, China

• Main Authors: Zhuohui Zhang (Author), Jiyun Li (Author), Rushun Zhou (Author), Qianqian Xu (Author), Shiyin Qu (Author), Hongguang Lin (Author), Yan Wang (Author), Pishun Li (Author), Xiaofeng Zheng (Author)
• Format: Book
• Published: MDPI AG, 2023-07-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics12071178; 2079-6382
• Keywords: chicken farm; foodborne pathogen; horizontal transmission; multidrug resistance; pig farm; <i>Salmonella typhimurium</i> monophasic variant; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 12, Iss 7, p 1178 (2023)

Non-typhoidal <i>Salmonella</i> (NTS) is a foodborne pathogen and a prevalent causative agent for disease outbreaks globally. The <i>Salmonella</i> enterica serovar 4,[5],12:i:- (S.4,[5],12:i:-) belongs to the monophasic variant of <i>Salmonella typhimurium</i>, which is of current global concern. In this study, the epidemiology and genomic characterization of S. 4,[5],12:i:- isolates from 17 livestock farms in Hunan Province between 2019 and 2020, as well as their susceptibility to 14 antimicrobial agents, were profiled. Twelve <i>Salmonella</i> serotypes were identified using the White-Kauffmann-Le Minor scheme, and whole-genome sequencing analyses were conducted based on these isolates. Overall, 107 <i>Salmonella</i> strains were isolated, of which 73% (78/107) were multidrug resistant. Resistance to tetracycline (85.05%) was found to be the most prevalent, followed by the <i>oqxAB</i> and <i>aac(6')-Ib-cr</i> genes. <i>S. typhimurium</i> (monophasic) 4,[5],12:i:- was the most common serotype, followed by <i>S. typhimurium</i> and <i>S. derby.</i> Most antimicrobial-resistant strains were isolated from pigs, indicating that they could be important reservoirs of resistant non-typhoidal <i>Salmonella</i> strains. The presence of similar genetic environments in S. 4,[5],12:i:- indicates both vertical and horizontal transmission of resistance plasmids, which may promote the spread of drug resistance genes. Appropriate measures should be taken to curb the prevalence of S. 4,[5],12:i:-.