Kudinha T, Simango C
Department of Veterinary Services, Causeway, Harare, Zimbabwe.
J S Afr Vet Assoc. 2002 Jun;73(2):62-5. doi: 10.4102/jsava.v73i2.557.
This study was carried out to determine the prevalence of coagulase-negative staphylococci in clinical and subclinical mastitis in commercial and small-scale farms in Zimbabwe. Thirty five quarter milk samples from clinical mastitis cases and 371 quarter milk samples from cows with subclinical mastitis were cultured for bacterial pathogens. The most frequent pathogens isolated in clinical mastitis were the enteric bacteria (31.4%), followed by coagulase negative staphylococci (22.9%) and then Staphylococcus aureus (17.1%), whereas in subclinical mastitis S. aureus (34.2%) and coagulase-negative staphylococci were (33.2%) the most common. Bacillus species were only isolated in milk samples from subclinical mastitis. Coagulase-negative staphylococci were observed in mixed infections with other bacteria in only 2.2 of the 406 milk samples from clinical and subclinical mastitis where they were isolated together with Bacillus species in 6 of the 9 mixed infection cases. About 95% of the milk samples from which 131 coagulase-negative staphylococci were isolated had correspondingly high somatic cell counts. The coagulase-negative staphylococci isolated most frequently were S. chromogenes (7.9%), S. epidermidis (7.4%) and S. hominis (5.9%). They were all associated with high somatic cell counts. All the coagulase-negative staphylococci isolates were susceptible to cloxacillin and erythromycin, and more than 90% of the isolates were susceptible to neomycin, penicillin and streptomycin. The highest resistance was to tetracycline (17.6%), followed by lincomycin (13.7%). About 8% of the isolates were resistant to both penicillin and streptomycin.
本研究旨在确定津巴布韦商业农场和小规模农场临床型和亚临床型乳腺炎中凝固酶阴性葡萄球菌的流行情况。对来自临床型乳腺炎病例的35份乳区乳样和来自亚临床型乳腺炎奶牛的371份乳区乳样进行细菌病原体培养。临床型乳腺炎中分离出的最常见病原体是肠道细菌（31.4%），其次是凝固酶阴性葡萄球菌（22.9%），然后是金黄色葡萄球菌（17.1%），而在亚临床型乳腺炎中，金黄色葡萄球菌（34.2%）和凝固酶阴性葡萄球菌（33.2%）最为常见。芽孢杆菌属仅在亚临床型乳腺炎的乳样中分离到。在临床型和亚临床型乳腺炎的406份乳样中，仅2.2份乳样中观察到凝固酶阴性葡萄球菌与其他细菌混合感染，其中9例混合感染病例中有6例是与芽孢杆菌属一起分离到的。从分离出131株凝固酶阴性葡萄球菌的乳样中，约95%的乳样相应地有高体细胞计数。最常分离到的凝固酶阴性葡萄球菌是产色葡萄球菌（7.9%）、表皮葡萄球菌（7.4%）和人葡萄球菌（5.9%）。它们都与高体细胞计数有关。所有分离出的凝固酶阴性葡萄球菌对氯唑西林和红霉素敏感，超过90%的分离株对新霉素、青霉素和链霉素敏感。耐药性最高的是四环素（17.6%），其次是林可霉素（13.7%）。约8%的分离株对青霉素和链霉素都耐药。
