Zavari Ali, Badouei Mahdi Askari, Hashemi Tabar Gholamreza
Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
Microb Pathog. 2025 Feb;199:107222. doi: 10.1016/j.micpath.2024.107222. Epub 2024 Dec 10.
Non-typhoidal Salmonella (NTS) is a significant foodborne pathogen that poses a threat to human health by causing infections and potentially acquiring antibiotic resistance. We evaluated thirty-five Salmonella serovars previously isolated from cattle, sheep, goats, and their retail meat in Razavi Khorasan Province, Iran. The isolates were confirmed with Salmonella polyvalent antiserum. Furthermore, PCR was used to identify the Salmonella Enteritidis, Salmonella Typhimurium, and the host-adapted serovars Salmonella Dublin and Salmonella Abortusovis. Additionally, the antimicrobial susceptibility of the serovars was evaluated using the disk diffusion method. Subsequently, the occurrence of antimicrobial resistance genes and virulence factors was evaluated using the PCR technique. Molecular typing revealed that 20 % of the isolates were S. Typhimurium, 11.4 % were S. Dublin, 8.6 % were S. Enteritidis, 5.7 % were S. Abortusovis, and 54.3 % (19 isolates) were classified as non-typed serovars. Salmonella isolates showed high susceptibility to ciprofloxacin (91.4 %), colistin (88.6 %), gentamicin (88.6 %), and cefotaxime (85.7 %) while exhibiting high resistance to others such as ampicillin (88.6 %), streptomycin (74.3 %), and tetracycline (51.4 %). The most prevalent resistance genes in non-typhoidal Salmonella (NTS) are bla (91.4 %), sul1 (65.7 %), and aadA (54.3 %). Additionally, twenty-five isolates (71.4 %) showed multi-drug resistance profiles. The most frequent virulence genes are stn (100 %), iroN (100 %), and pefA (42.9 %). The current study has revealed that Salmonella serovars isolated from sheep and goats, like those from cattle, exhibit multi-drug resistance and harbor antimicrobial resistance genes. Additionally, they possess diverse virulence factors that can threaten human health by spreading diseases and developing drug resistance, leading to antibiotic treatment failure.
非伤寒沙门氏菌（NTS）是一种重要的食源性病原体，通过引起感染并可能获得抗生素耐药性，对人类健康构成威胁。我们评估了先前从伊朗拉扎维霍拉桑省的牛、羊、山羊及其零售肉类中分离出的35种沙门氏菌血清型。这些分离株用沙门氏菌多价抗血清进行了确认。此外，采用聚合酶链反应（PCR）来鉴定肠炎沙门氏菌、鼠伤寒沙门氏菌以及宿主适应性血清型都柏林沙门氏菌和流产绵羊沙门氏菌。另外，使用纸片扩散法评估了这些血清型的抗菌药敏性。随后，采用PCR技术评估了抗菌耐药基因和毒力因子的存在情况。分子分型显示，20%的分离株为鼠伤寒沙门氏菌，11.4%为都柏林沙门氏菌，8.6%为肠炎沙门氏菌，5.7%为流产绵羊沙门氏菌，54.3%（19株）被归类为未分型血清型。沙门氏菌分离株对环丙沙星（91.4%）、黏菌素（88.6%）、庆大霉素（88.6%）和头孢噻肟（85.7%）表现出高度敏感性，而对其他药物如氨苄西林（88.6%）、链霉素（74.3%）和四环素（51.4%）表现出高度耐药性。非伤寒沙门氏菌（NTS）中最普遍的耐药基因是bla（91.4%）、sul1（65.7%）和aadA（54.3%）。此外，25株分离株（71.4%）表现出多重耐药谱。最常见的毒力基因是stn（100%）、iroN（100%）和pefA（42.9%）。当前研究表明，从绵羊和山羊中分离出的沙门氏菌血清型与从牛中分离出的一样，表现出多重耐药性并携带抗菌耐药基因。此外，它们拥有多种毒力因子，可通过传播疾病和产生耐药性威胁人类健康，导致抗生素治疗失败。
