Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, 62511, Egypt.
Department of Hygiene, Zoonoses and Epidemiology, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, 62511, Egypt.
Curr Microbiol. 2023 May 31;80(7):229. doi: 10.1007/s00284-023-03324-x.
Using an alternative bio-product is one of the most promising ways to control bovine mastitis and avoid new intra-mammary infections. The aims of this study were to ascertain the prevalence of biofilm-forming bacteria responsible for causing clinical mastitis in dairy herds and to assess the effectiveness of bacteriocins, produced by Bacillus subtilis, in controlling the growth of these bacteria in the milk of animals. A total of 150 milk samples were collected from cows and buffalos suffering from mastitis and the etiological agents were isolated and identified by the VITEK-2-COMPACT-SYSTEM®. Additionally, the capability of the bacterial isolates to produce biofilms was determined. RT-PCR was used to detect enterotoxin-producing genes (sed and seb), resistance genes (mecA and blaZ), and biofilm-associated genes (icaA and fnbA) in the isolated bacteria. The susceptibility patterns of the bacterial isolates to bacteriocins were assessed using an agar well-diffusion assay. S. aureus was significantly more capable of producing biofilms than coagulase-negative Staphylococcus isolates. S. ubris was the strongest biofilm producer among the Streptococcus species. The sensitivity profiles of the Staphylococcus spp. (S. aureus and coagulase-negative Staphylococcus) and their biofilm producers to bacteriocins were significantly higher (100% and 90%, respectively) at the same concentration. Bacteriocins had a lethal effect on Staphylococci, Streptococci, and biofilm development at a dose of 250 µg/mL. In dairy farms, bacteriocins are a viable alternative treatment for the prevention and control of bovine clinical mastitis.
使用替代生物制品是控制奶牛乳腺炎和避免新的乳腺内感染的最有前途的方法之一。本研究的目的是确定引起奶牛临床乳腺炎的生物膜形成细菌的流行情况，并评估枯草芽孢杆菌产生的细菌素控制动物牛奶中这些细菌生长的有效性。从患有乳腺炎的奶牛和水牛中采集了 150 份牛奶样本，通过 VITEK-2-COMPACT-SYSTEM® 分离和鉴定了病原体。此外，还确定了细菌分离物产生生物膜的能力。使用 RT-PCR 检测了分离细菌中的产肠毒素基因（sed 和 seb）、耐药基因（mecA 和 blaZ）和生物膜相关基因（icaA 和 fnbA）。使用琼脂孔扩散法评估了细菌分离物对细菌素的敏感性模式。金黄色葡萄球菌比凝固酶阴性葡萄球菌分离物更能有效地产生生物膜。在链球菌属中，S. ubris 是最强的生物膜生产者。葡萄球菌属（金黄色葡萄球菌和凝固酶阴性葡萄球菌）及其生物膜生产者对细菌素的敏感性谱在相同浓度下显著更高（分别为 100%和 90%）。细菌素在 250 µg/mL 剂量下对葡萄球菌、链球菌和生物膜形成具有致死作用。在奶牛场，细菌素是预防和控制奶牛临床乳腺炎的一种可行的替代治疗方法。
