石河子地区规模化奶牛场隐性乳房炎中链球菌的分离鉴定及耐药性检测

Isolation,identification and drug resistance test of Streptococcus from subclinical mastitis at the large-scale dairy farms in Shihezi area

为了解石河子地区奶牛隐性乳房源炎致病菌——链球菌的流行情况,试验采用CMT法检测石河子周边地区奶牛场奶牛隐性乳房炎的感染率,并分离鉴定链球菌,采用纸片扩散法对分离菌株的耐药性进行检测。结果表明:试验区奶牛隐性乳房炎的总阳性率为44.56%(869/1 950),共分离菌株208株,其中链球菌的分离率为47.11%(98/208);分离出的链球菌主要对氟苯尼考、庆大霉素等药物高度敏感,对红霉素、阿莫西林、链霉素具有耐药性。说明链球菌为奶牛隐性乳房炎的主要致病菌之一,对很多药物产生耐药性,建议临床使用一些新药,同时加强奶牛饲养管理及卫生管理。

To understand the prevalence state of Streptococcus as one of the pathogenic bacteria causing subclinical mastitis in dairy cows in Shi- hezi area, the California mastitis test （CMT） was used to detect the infection rate of subclinieal mastitis in dairy cows at the large - scale dairy farms in the surrounding area of Shihezi city, and the Streptococcus was isolated and identified. The disc diffusion method （ K - B method） was used to test the drug resistance of the isolated strains. The results showed that the total positive rate of subclinical mastitis in dairy cows from the experimental area was 44.56% （869/1 950） ; a total number of 203 strains were isolated, of which the isolation rate of StreptOcoccus was 47. 11% （98/208）. Drug susceptibility test showed that isolated Streptococcus was highly sensitive to florfenicol, gentamicin, and other drugs, and was resistant to erythromycin, amoxicillin, streptomycin. The results indicate that Streptococcus is one of the major pathogenic bacteria of sub- clinical mastitis in dairy cows, and is resistant to many drugs. Thus, it is recommended to use some new drugs in clinical practice; meanwhile, feeding management and sanitary control in dairy cows should be strengthened.