Bradley A J, Leach K A, Breen J E, Green L E, Green M J
School of Clinical Veterinary Science, University of Bristol, Langford.
Vet Rec. 2007 Feb 24;160(8):253-7. doi: 10.1136/vr.160.8.253.
A survey of clinical and subclinical mastitis was carried out on 97 dairy farms in England and Wales, selected at random from members of a national milk recording scheme. The farmers were asked to collect aseptic milk samples from five consecutive cases of clinical mastitis and from five quarters with high somatic cell counts using a defined protocol, and they completed a questionnaire that included information on the cows sampled, the herd and the history of mastitis in the herd. The samples were collected throughout the year. The mean incidence of clinical mastitis was 47 cases per 100 cows per year (estimated from historic farm records) and 71 cases per 100 cows per year (estimated from the samples collected). Streptococcus uberis and Escherichia coli were isolated in pure culture from 23.5 per cent and 19.8 per cent, respectively, of the clinical samples; 26.5 per cent of the clinical samples produced no growth. The most common isolates from the samples with high cell counts were coagulase-negative staphylococci (15 per cent), S uberis (14 per cent) and Corynebacterium species (10 per cent). Staphylococcus aureus and coagulase-positive staphylococci together accounted for 10 per cent of the samples with high somatic cell counts; 39 per cent produced no bacterial growth.
对来自英国全国牛奶记录计划成员的97个奶牛场进行了临床和亚临床乳腺炎调查。这些奶牛场是随机挑选的。要求养殖户按照既定方案，从连续5例临床乳腺炎病例以及5个体细胞计数高的乳腺中采集无菌牛奶样本，并填写一份问卷，内容包括所采样奶牛、牛群以及牛群乳腺炎病史等信息。样本全年采集。临床乳腺炎的平均发病率为每年每100头奶牛47例（根据农场历史记录估算）以及每年每100头奶牛71例（根据所采集样本估算）。乳房链球菌和大肠杆菌分别从23.5%和19.8%的临床样本中纯培养分离得到；26.5%的临床样本未培养出细菌。体细胞计数高的样本中最常见的分离菌为凝固酶阴性葡萄球菌（15%）、乳房链球菌（14%）和棒状杆菌属（10%）。金黄色葡萄球菌和凝固酶阳性葡萄球菌在体细胞计数高的样本中占10%；39%未培养出细菌。
