Department of Veterinary Microbiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Korea.
Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
BMC Vet Res. 2024 Nov 1;20(1):503. doi: 10.1186/s12917-024-04360-w.
Livestock-associated Staphylococcus aureus (LA-SA) has gained global attention because of its ability to colonize farm animals and transmit to the environment and humans, leading to symptomatic infections and the spread of antimicrobial resistance (AMR). In the last decade, numerous studies have reported a high prevalence of S. aureus clonal complex (CC) 398 in pig farms.
In this study, 163 S. aureus isolates were collected from healthy pigs (n = 110), farm environments (n = 42), and farm workers (n = 11), and their AMR profiles and epidemiological characteristics were analyzed. We identified 51 (31.3%) methicillin-resistant S. aureus (MRSA) and 112 (68.7%) methicillin-susceptible S. aureus (MSSA), with 161 (98.8%) isolates belonging to the CC398 lineage. The highest prevalence of spa type t571 was observed among the CC398 isolates. All 47 sequence type (ST) 398 MRSA isolates carried staphylococcal cassette chromosome mec (SCCmec) V, while four ST541 isolates carried SCCmec IV. High levels of resistance to commonly used antibiotics, including phenicols, quinolones, lincosamides, macrolides, aminoglycosides, and tetracyclines, have been observed on Korean pig farms. Notably, 21 cfr-positive CC398 isolates (four ST541-SCCmec IV MRSA and 17 ST398 MSSA) displaying increased resistance to linezolid were identified in healthy pigs.
In summary, these findings suggest that the multidrug-resistant CC398 S. aureus lineage predominantly colonizes healthy pigs and farm environments in Korea. The emergence of cfr-positive S. aureus at human-animal interfaces presents a significant threat to food safety and public health.
由于能够在农场动物中定植并传播到环境和人类中，导致有症状感染和抗微生物药物耐药性（AMR）的传播，与牲畜相关的金黄色葡萄球菌（LA-SA）引起了全球关注。在过去的十年中，许多研究报告了猪场内金黄色葡萄球菌克隆复合体（CC）398 的高流行率。
在这项研究中，从健康猪（n=110）、农场环境（n=42）和农场工人（n=11）中收集了 163 株金黄色葡萄球菌分离株，并分析了它们的 AMR 谱和流行病学特征。我们鉴定出 51 株（31.3%）耐甲氧西林金黄色葡萄球菌（MRSA）和 112 株（68.7%）甲氧西林敏感金黄色葡萄球菌（MSSA），其中 161 株（98.8%）分离株属于 CC398 谱系。CC398 分离株中 spa 型 t571 的流行率最高。所有 47 株 ST398-MRSA 分离株均携带葡萄球菌盒染色体 mec（SCCmec）V，而 4 株 ST541 分离株携带 SCCmec IV。在韩国的猪场中，观察到对常用抗生素（包括苯氧青霉素类、喹诺酮类、林可酰胺类、大环内酯类、氨基糖苷类和四环素类）的高水平耐药性。值得注意的是，在健康猪中发现了 21 株 cfr 阳性 CC398 分离株（4 株 ST541-SCCmec IV-MRSA 和 17 株 ST398-MSSA），它们对利奈唑胺的耐药性增加。
总之，这些发现表明，多药耐药性 CC398 金黄色葡萄球菌谱系主要定植于韩国的健康猪和农场环境中。在人畜界面出现 cfr 阳性金黄色葡萄球菌对食品安全和公共卫生构成了重大威胁。
