Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences, Anand, Gujarat, India.
J Appl Microbiol. 2012 Apr;112(4):639-50. doi: 10.1111/j.1365-2672.2012.05244.x. Epub 2012 Feb 20.
Metagenomic analysis of milk samples collected from Kankrej, Gir (Bos indicus) and crossbred (Bos taurus × B. indicus) cattle harbouring subclinical mastitis was carried out by next-generation sequencing 454 GS-FLX technology to elucidate the microbial community structure of cattle milk.
Milk samples from Kankrej, Gir and crossbred cattle were subjected to metagenomic profiling by pyrosequencing. The Metagenomic analysis produced 63·07, 11·09 and 7·87 million base pairs (Mb) of sequence data, assembled in 264 798, 56 114 and 36 762 sequences with an average read length of 238, 197 and 214 nucleotides in Kankrej, Gir and crossbred cattle, respectively. Phylogenetic and metabolic profiles by the web-based tool MG-RAST revealed that the members of Enterobacteriales were predominant in mastitic milk followed by Pseudomonadales, Bacillales and Lactobacillales. Around 56 different species with varying abundance were detected in the subclinically infected milk. Escherichia coli was found to be the most predominant species in Kankrej and Gir cattle followed by Pseudomonas aeruginosa, Pseudomonas mendocina, Shigella flexneri and Bacillus cereus. In crossbred cattle, Staphylococcus aureus followed by Klebsiella pneumoniae, Staphylococcus epidermidis and E. coli were detected in descending order. Metabolic profiling indicated fluoroquinolones, methicillin, copper, cobalt-zinc-cadmium as the groups of antibiotics and toxic compounds to which the organisms showed resistance. Sequences indicating potential of organisms exhibiting multidrug resistance against antibiotics and resistance to toxic compounds were also present. Interestingly, presence of bacteriophages against Staph. aureus, E. coli, Enterobacter and Yersinia species was also observed.
The analysis identified potential infectious organisms in mastitis, resistance of organisms to antibiotics and chemical compounds and the natural resistance potential of dairy cows.
The findings of this study may help in formulating strategies for the prevention and treatment of mastitis in dairy animals and consequently in reducing economic losses incurred because of it.
采用下一代测序 454 GS-FLX 技术对患有隐性乳腺炎的卡克伦牛（Bos indicus）、吉拉牛（Gir）和杂交牛（Bos taurus × B. indicus）的牛奶样本进行宏基因组分析，以阐明奶牛乳微生物群落结构。
通过焦磷酸测序对卡克伦牛、吉拉牛和杂交牛的牛奶样本进行宏基因组分析。宏基因组分析产生了 63.07、11.09 和 7.87 百万碱基对（Mb）的序列数据，分别在 264798、56114 和 36762 个序列中组装，平均读长分别为 238、197 和 214 个核苷酸。基于网络工具 MG-RAST 的系统发育和代谢分析表明，肠杆菌目成员在乳腺炎乳中占优势，其次是假单胞菌目、芽孢杆菌目和乳杆菌目。在亚临床感染乳中检测到约 56 种不同丰度的物种。在卡克伦牛和吉拉牛中，大肠杆菌是最主要的物种，其次是铜绿假单胞菌、门多萨假单胞菌、福氏志贺菌和蜡样芽孢杆菌。在杂交牛中，金黄色葡萄球菌次之，随后是肺炎克雷伯菌、表皮葡萄球菌和大肠杆菌。代谢分析表明，氟喹诺酮类、甲氧西林、铜、钴-锌-镉是微生物表现出抗药性的抗生素和有毒化合物的组。也存在表明微生物对多种抗生素和有毒化合物具有耐药性的序列。有趣的是，还观察到针对金黄色葡萄球菌、大肠杆菌、肠杆菌和耶尔森氏菌的噬菌体的存在。
该分析确定了乳腺炎中的潜在感染生物、生物对抗生素和化学化合物的耐药性以及奶牛的天然耐药潜力。
本研究的结果可能有助于制定预防和治疗奶牛乳腺炎的策略，从而减少由此造成的经济损失。
