Moreno Juan, Diana Leticia, Martínez Melisa, Iribarnegaray Victoria, Puentes Rodrigo
Departamento de Patobiología, Facultad de Veterinaria, Universidad de La República, Uruguay.
Heliyon. 2025 Feb 17;11(4):e42749. doi: 10.1016/j.heliyon.2025.e42749. eCollection 2025 Feb 28.
Bovine mastitis, a prevalent disease, is often attributed to staphylococci species. These microorganisms can express a diverse array of virulence genes and have the capability to form biofilms, establishing a robust defense against antimicrobials and host immune responses. In this study, we analyzed 191 spp. of which 81 % were identified as , and 19 % as non-aureus staphylococci (NAS), including species such as and . Our analysis involved determining antimicrobial susceptibility profiles, assessing biofilm-forming capacities, and identifying genes associated with virulence, biofilm formation, adhesion, and antimicrobial resistance. Notably, 17.2 % of the strains exhibited resistance to penicillin, with 97 % carrying the gene, while 9.4 % demonstrated resistance to erythromycin. All strains were sensitive to gentamicin and cefoxitin. Additionally, resistance was observed for clindamycin (8.4 %) and tetracycline (1.0 %). Concerning biofilm development, 2.6 % displayed no formation, 24.6 % were categorized as weak producers, 47.1 % as moderate, and 25.7 % as strong formers. Our investigation also unveiled the presence of virulence genes, such as superantigens like (4.7 %), (3.7 %), sec (8.4 %), (0.5 %), and (6.8 %); Panton-Valentine leukocidin () (59.7 %); haemolysins (88.5 %) and (91.1 %); genes responsible for biofilm production (87.9 %), (78.5 %), and (4.2 %); and adhesion genes (89.5 %), (20.4 %), and (89.0 %). Additionally, the strains were categorized into four groups based on their virulence attributes, revealing differences between . and NAS, with the latter showing a lower presence of the studied genes compared to strains. This research sheds light on the resistance and virulence profiles of staphylococci strains associated with bovine mastitis, providing valuable insights for potential treatment approaches.
牛乳腺炎是一种常见疾病，通常由葡萄球菌属引起。这些微生物能够表达多种毒力基因，并具有形成生物膜的能力，从而建立起对抗抗菌药物和宿主免疫反应的强大防御机制。在本研究中，我们分析了191个菌株，其中81%被鉴定为[具体菌种1]，19%为非金黄色葡萄球菌（NAS），包括[具体菌种2]和[具体菌种3]等菌种。我们的分析包括确定抗菌药物敏感性谱、评估生物膜形成能力以及鉴定与毒力、生物膜形成、黏附及抗菌药物耐药性相关的基因。值得注意的是，17.2%的菌株对青霉素耐药，其中97%携带[具体耐药基因]，而9.4%的菌株对红霉素耐药。所有菌株对庆大霉素和头孢西丁敏感。此外，还观察到对克林霉素（8.4%）和四环素（1.0%）的耐药情况。关于生物膜形成，2.6%的菌株未形成生物膜，24.6%被归类为弱生产者，47.1%为中度生产者，25.7%为强生产者。我们的研究还揭示了毒力基因的存在，如超抗原[具体超抗原1]（4.7%）、[具体超抗原2]（3.7%）、sec（8.4%）、[具体超抗原3]（0.5%）和[具体超抗原4]（6.8%）；杀白细胞素（PVL）（59.7%）；溶血素α（88.5%）和β（91.1%）；负责生物膜产生的基因icaA（87.9%）、icaD（78.5%）和bbp（4.2%）；以及黏附基因fnbA（89.5%）、ebpS（20.4%）和cna（89.0%）。此外，根据毒力属性将菌株分为四组，揭示了[具体菌种1]和NAS之间的差异，后者与[具体菌种1]菌株相比，所研究基因的存在比例较低。本研究揭示了与牛乳腺炎相关的葡萄球菌菌株的耐药性和毒力特征，为潜在的治疗方法提供了有价值的见解。
