Sheela P, Shekar Malathi, Isloor Shrikrishna, Rathnamma D, Veeregowda B M, Satyanarayana M L, Sundareshan S, Shambulingappa B E, Hegde Nagendra R
Department of Veterinary Microbiology, Veterinary College, Shivamogga, Karnataka Veterinary Animal and Fisheries Sciences University, Shivamogga, Karnataka, India.
Bioinformatics Centre, Department of Aquatic Animal Health Management, College of Fisheries, Mangaluru, Karnataka Veterinary Animal and Fisheries Sciences University, Mangaluru, Karnataka, India.
Vet World. 2021 Jan;14(1):285-291. doi: 10.14202/vetworld.2021.285-291. Epub 2021 Jan 30.
In recent times, non-aureus staphylococci (NAS) have emerged as the major organisms isolated from mastitis cases in dairy animals, with a predominance of and . As compared to , much less is known about the molecular types or the spatiotemporal epidemiology of these NAS species. In the present study, randomly amplified polymorphic DNA (RAPD) was employed to detect genetic polymorphisms, intraspecies diversity, and epidemiology of strains (n=37) isolated from bovine and bubaline mastitis cases in the state of Karnataka.
Thirty-seven isolates (14 from bovines and 23 from bubaline) isolated from subclinical mastitis cases, from organized and unorganized sectors, were subjected to RAPD typing. Further, methicillin resistance was determined by cefoxitin disk diffusion method.
The amplified DNA fragments ranged from 150 to 3000 base pairs and yielded several RAPD profiles. Further analysis using Digital Image Correlation Engine correlation coefficient and UPGMA method showed that the 37 isolates could be classified into 12 distinct RAPD types (A to L) at 62% similarity (=0.889). Four of the most predominant RAPD types, B, A, C, and E, in that order, and together, represented 65% of the isolates. High diversity was observed among the isolates both within farms and between geographic locations. Most of the isolates exhibited methicillin resistance. This is the first such report from India.
In the absence of defined multilocus sequence type protocols or sufficient sequences available in the public domain, RAPD can be employed to determine genetic diversity of isolates.
近年来，非金黄色葡萄球菌（NAS）已成为从奶牛乳腺炎病例中分离出的主要病原体，其中 菌和 菌占主导。与 菌相比，对于这些NAS菌种的分子类型或时空流行病学了解较少。在本研究中，采用随机扩增多态性DNA（RAPD）技术检测从卡纳塔克邦牛和水牛乳腺炎病例中分离出的 菌株（n = 37）的遗传多态性、种内多样性和流行病学情况。
从有组织和无组织部门的亚临床乳腺炎病例中分离出37株 菌株（14株来自牛，23株来自水牛），进行RAPD分型。此外，采用头孢西丁纸片扩散法测定耐甲氧西林情况。
扩增的DNA片段长度在150至3000个碱基对之间，产生了多个RAPD图谱。使用数字图像相关引擎相关系数和UPGMA方法进一步分析表明，37株分离株在62%相似度（= 0.889）下可分为12种不同的RAPD类型（A至L）。四种最主要的RAPD类型，依次为B、A、C和E，共占分离株的65%。在养殖场内和地理位置之间的分离株中均观察到高度多样性。大多数分离株表现出耐甲氧西林特性。这是印度的首例此类报告。
在缺乏明确的多位点序列分型方案或公共领域中可用序列不足的情况下，RAPD可用于确定 分离株的遗传多样性。
