Perdomo Angela, Solano-Gutierrez Juan Sebastian, Thompson Jonathan, Calle Alexandra
School of Veterinary Medicine, Texas Tech University, Amarillo, TX 79106, USA.
School of Veterinary Medicine, Texas Tech University, Amarillo, TX 79106, USA.
Res Vet Sci. 2025 Sep;193:105728. doi: 10.1016/j.rvsc.2025.105728. Epub 2025 May 29.
Staphylococcus aureus is a highly adaptable microorganism that harbors virulence factors driving its pathogenicity, affecting animals and humans. Forty S. aureus isolates were collected from a dairy farm operation and were subjected to several phenomics, genomics, and proteomics tests, including antimicrobial susceptibility, biofilm evaluation, strain typing for isolate-relatedness determination, and enterotoxin production. Further characterization involved whole genome sequencing (WGS) and protein detection using mass spectrometry on a subset of isolates (enterotoxin-positive and enterotoxin-negative). All isolates were susceptible to the tested antibiotics except for Gatifloxacin (GAT), for which 100 % displayed intermediate resistance. All isolates produced biofilms, with a noticeable surge at 48 h compared to 24 h (p < 0.001). Additionally, 10 % of the isolates (n = 4) produced enterotoxins associated with human infections. Strain typing via infrared biotyping (IRBT) categorized the 40 isolates into six distinctive groups, indicating close relationships among S. aureus recovered from different samples, demonstrating a movement of the organism within the farm. Genomic characterization of enterotoxin-positive and enterotoxin-negative isolates identified two sequencing types, ST151 and ST351, accompanied by spa types t529 and t9001. Genomics and proteomics analyses revealed various virulence factors, encompassing cytolytic toxins, immune evasion mechanisms, extracellular matrix (ECM)-binding proteins, proteases, enterotoxins, and chromosomal point mutations. In addition to virulence factors, this study shows how this bacterium moves around the farm, potentially becoming an environmental pathogen, increasing the risk of transmission and infection for humans and animals.
金黄色葡萄球菌是一种适应性很强的微生物，它携带多种毒力因子，可导致致病性，对动物和人类均有影响。从一个奶牛场运营中收集了40株金黄色葡萄球菌分离株，并对其进行了多项表型组学、基因组学和蛋白质组学测试，包括抗菌药敏试验、生物膜评估、用于确定分离株相关性的菌株分型以及肠毒素产生情况检测。进一步的表征涉及对一部分分离株（产肠毒素和不产肠毒素的）进行全基因组测序（WGS）和使用质谱法进行蛋白质检测。除加替沙星（GAT）外，所有分离株对所测试的抗生素均敏感，100%的分离株对加替沙星表现出中介耐药性。所有分离株均能产生生物膜，与24小时相比，48小时时生物膜形成明显增加（p < 0.001）。此外，10%的分离株（n = 4）产生了与人类感染相关的肠毒素。通过红外生物分型（IRBT）进行的菌株分型将40株分离株分为六个不同的组，表明从不同样本中分离出的金黄色葡萄球菌之间关系密切，证明了该微生物在农场内的移动情况。产肠毒素和不产肠毒素分离株的基因组表征确定了两种测序类型，即ST151和ST351，同时伴有spa型t529和t9001。基因组学和蛋白质组学分析揭示了多种毒力因子，包括溶细胞毒素、免疫逃避机制、细胞外基质（ECM）结合蛋白、蛋白酶、肠毒素和染色体点突变。除毒力因子外，本研究还展示了这种细菌在农场内的传播方式，它有可能成为一种环境病原体，增加人类和动物传播及感染的风险。
