Departments of Microbiology and Preclinical Sciences, Milas Faculty of Veterinary Medicine, Mugla Sitki Kocman University, Mugla 48000, Türkiye.
Department of Medical Laboratory Techniques, Vocational School of Health, Istanbul Gelisim University, Istanbul 34310, Türkiye.
J Vet Sci. 2024 Sep;25(5):e72. doi: 10.4142/jvs.24032.
Identifying bovine mastitis agents using molecular methods to reveal their phylogenetic relationships and antimicrobial resistance profiles is essential for developing up-to-date databases in mastitis cases that cause severe economic losses.
This study examined bacterial mastitis agents in cows with clinical and subclinical mastitis observed in various dairy cattle farms to reveal their phylogenetic relationships and antibiotic resistance properties.
Sixty-two clinical and subclinical bovine mastitis milk samples were collected from 15 dairy farms. The polymerase chain reaction (PCR) was used to amplify the 16S rRNA gene regions of the bacteria. The 16S rRNA gene sequences obtained from sequencing include the V4-V6 regions. The strains were compared using a similarity analysis method that produced phylogenetic trees using the Molecular Evolutionary Genetics Analysis 11 program. Antibiotic susceptibilities were determined using the Kirby-Bauer disk diffusion method.
Sixty-three bacteria were isolated and identified in this study. The most isolated bacteria from all mastitis cases were spp. (30.2%), (25.4%), spp. (14.3%), and spp. (7.9%), respectively. The phylogenetic trees were drawn from the 16S rRNA sequences. Some of these bacteria showed resistance to different types of antibiotics at varying rates.
The bacteria isolated in this study originated from environmental sources. Regular cleaning of barns and proper hygiene practices are essential. Regular screenings for mastitis should be conducted in herds instead of the random or empirical use of antibiotics.
使用分子方法鉴定牛乳腺炎病原体，揭示其系统发育关系和抗生素耐药谱，对于建立导致严重经济损失的乳腺炎病例的最新数据库至关重要。
本研究检测了在不同奶牛场观察到的临床和亚临床乳腺炎奶牛中的细菌性乳腺炎病原体，以揭示其系统发育关系和抗生素耐药特性。
从 15 个奶牛场采集了 62 份临床和亚临床牛乳腺炎牛奶样本。使用聚合酶链反应（PCR）扩增细菌的 16S rRNA 基因区域。从测序中获得的 16S rRNA 基因序列包括 V4-V6 区域。使用分子进化遗传学分析 11 程序产生的相似性分析方法对菌株进行比较。使用 Kirby-Bauer 圆盘扩散法测定抗生素敏感性。
本研究共分离鉴定出 63 株细菌。所有乳腺炎病例中分离最多的细菌分别为 spp.（30.2%）、 （25.4%）、 spp.（14.3%）和 spp.（7.9%）。从 16S rRNA 序列绘制了系统发育树。这些细菌中的一些对不同类型的抗生素表现出不同程度的耐药性。
本研究中分离的细菌来源于环境来源。定期清洁畜舍和采取适当的卫生措施至关重要。应定期对畜群进行乳腺炎筛查，而不是随机或凭经验使用抗生素。
