Staphylococcus aureus is one of the major pathogens responsible for intramammary infections in small ruminants, causing severe economic losses in dairy farms. In addition, S. aureus can contaminate milk and dairy products and produce staphylococcal enterotoxins, being responsible for staphylococcal food poisoning. Currently, data on the population structure and the virulence gene patterns of S. aureus strains isolated from goat milk is limited. Therefore, this study aimed at defining Ribosomal Spacer PCR (RS-PCR) genotypes, clonal complexes (CC), spa types, and virulence gene profiles of S. aureus isolated from goat milk samples from Lombardy region of Italy. A total of 295 S. aureus isolates from 65 goat bulk tank milk samples were genotyped by RS-PCR. spa typing and virulence gene patterns of a subgroup of 88 isolates were determined, and MLST was performed on a further subgroup of 39 isolates, representing all the spa types identified during the analysis. This study revealed 7 major genotypic clusters (CLR, CLAA, CLZ, CLAW, CLBW, CLS, and CLI), of which S. aureus CLR (19.8%) was the most common. A total of 26 different spa types were detected, the most prevalent types were t1773 (24%), t5428 (22.7%), and t2678 (12.5%). Overall, 44.3% of all isolates harbored at least one enterotoxin gene. The most prevalent was the combination of sec-sel genes (35.2%). Based on their MLST, isolates were assigned to 14 different CC, with majority grouped as CC133 (24%), CC130 (19.6%), and CC522 (19.6%). The caprine S. aureus population was depicted with a minimum spanning tree and an evolutionary analysis based on spa typing and MLST, respectively. Then, the variability of such strains was compared to that of bovine strains isolated in the same space-time span. Our results confirmed that S. aureus isolates from goats have wide genetic variability and differ from the bovine strains, supporting the idea that S. aureus from small ruminants may constitute a distinct population.

金黄色葡萄球菌是导致小型反刍动物乳房内感染的主要病原体之一，在奶牛场造成严重的经济损失。此外，金黄色葡萄球菌会污染牛奶和乳制品并产生葡萄球菌肠毒素，导致葡萄球菌食物中毒。当前，有关种群结构和毒力基因模式的数据金黄色葡萄球菌从山羊奶分离的菌株是有限的。因此，本研究旨在确定核糖体间隔PCR（RS-PCR）基因型，克隆复合体（CC），温泉 的类型和毒力基因概况 金黄色葡萄球菌从意大利伦巴第大区的山羊奶样品中分离得到。总共295金黄色葡萄球菌 通过RS-PCR对65个山羊散装罐装牛奶样品的分离株进行基因分型。 温泉 确定了88个菌株的亚型的分型和毒力基因模式，并对39个菌株的另一个亚组进行了MLST，代表了所有 温泉分析期间确定的类型。这项研究揭示了7个主要的基因型簇（CLR，CLAA，CLZ，CLAW，CLBW，CLS和CLI），其中金黄色葡萄球菌CLR（19.8％）是最常见的。总共26个不同温泉检测到两种类型，最流行的类型是t1773（24％），t5428（22.7％）和t2678（12.5％）。总体而言，所有分离株中的44.3％具有至少一个肠毒素基因。最普遍的是秒--选基因（35.2％）。根据其MLST，将分离株分配给14个不同的CC，其中大多数分组为CC133（24％），CC130（19.6％）和CC522（19.6％）。山羊皮金黄色葡萄球菌分别用最小生成树和基于spa类型和MLST的进化分析来描述种群。然后，将此类菌株的变异性与在相同时空跨度中分离的牛菌株的变异性进行比较。我们的结果证实了金黄色葡萄球菌 来自山羊的分离株具有广泛的遗传变异性，与牛株不同，这支持了以下观点： 金黄色葡萄球菌 小反刍动物可能构成不同的种群。