健康与子宫内膜炎奶牛阴道菌群结构的比较研究

The comparison of the vaginal bacterial microbiota in healthy and metritic dairy cows

利用16SrDNA结合PCR-DGGE技术分析比较了产后45d健康奶牛和患子宫内膜炎奶牛阴道内细菌群落多样性及其差异,并通过切胶、克隆测序等步骤分析了奶牛阴道细菌种类。研究结果表明,患病奶牛DGGE图谱的条带数量、多样性指数均显著高于健康奶牛;健康奶牛阴道优势菌主要有清酒乳杆菌(Lactobacillus sakei subsp.)、魏斯杆菌(Weissella koreensis sp.)和地衣芽孢杆菌(Bacillus licheniformis),而患病组奶牛阴道内此3种优势菌含量显著降低或缺失,且也无其他明显优势菌存在;从健康和患病奶牛阴道内均分离出脆弱拟杆菌(Bacteroides fragilis)、溃疡拟杆菌(Bacteroides helcogenes)、无乳支原体(Mycoplasma agalactiae)、普氏菌(Prevotella dentalis)、产气荚膜梭菌(Clostridium perfringens str.)和肠球菌(Enterococcus hirae)等常见病原微生物,在患病奶牛阴道内分离出大肠杆菌(Escherichia coli str.K-12 substr.)、梭杆菌(Fusobacterium nucleatum subsp.)等特定致病菌。研究结果提示,子宫内膜炎奶牛阴道内菌群结构比健康奶牛更为复杂,且无优势菌,阴道菌群结构失衡可能是奶牛发生子宫内膜炎的原因。

An integrated approach based on 16S rDNA,PCR-denaturing gradient gel electrophoresis （PCR-DGGE） and clone library sequencing was used to compare the structure and diversity of bac- terial communities in vaginal samples of healthy and metritic postpartum（45 days） Holstein dairy cows. The DGGE profiles revealed that the number of bands and diversity index of metritic dairy cows were significantly higher than those of healthy cows; the vaginal flora of healthy cow was dominated by Lactobacillus sakei subP. ,Weissella koreensis sp. and Bacillus licheniformis ,which were decreased or disappeared under metritic conditions, there were no other dominant bacteria de- tected in the vaginal samples of metritic dairy cows as well. In the clone libraries from healthy and metritic dairy cows, the sequences showed high identity with Bacteroides fragilis,Bacteroides hel- cogenes ,Mycoplasma agalactiae , Prevotella dentalis , Clostridium perfringens str., Enterococcus h irae. ,however Escherichia coli str.-12 substr, and Fusobacterium nucleatum subsp, were only detected from the metritic status libraries. Our results suggest that the vaginal bacterial composi- tion in metritic dairy cows was more complex than that of healthy cows,and no dominant bacteriawas detected in the vaginal samples of metritic dairy cows as well, the ecological disorder of the va- ginal microbiota may produce the presence of cow^s endometritis.