Moroni P, Pisoni G, Antonini M, Ruffo G, Carli S, Varisco G, Boettcher P
Department of Animal Pathology, Hygiene, and Veterinary Public Health, University of Milan, Milan 20133, Italy.
J Dairy Sci. 2005 May;88(5):1694-704. doi: 10.3168/jds.S0022-0302(05)72841-1.
A total of 156 goats from 2 commercial dairy goat farms were monitored for intramammary infections during an entire lactation. Most of the infections (80.7%) observed were due to coagulase-negative staphylococci (CNS) species. In herd 1, nearly all of the infections (96%) were due to CNS species, with Staphylococcus caprae (SCAP) being the most common specific pathogen observed, accounting for about 43% of the infections. In herd 2, the proportion of the infections due to CNS was 67% and Staphylococcus epidermidis (SEPI) was the most common pathogen (48% of infections) and SCAP was not present. Linear somatic cell scores (SCS) were greater in milk from infected udder halves, with an average difference of 0.78 SCS. The SCS for infected udder halves was greater than noninfected for all CNS species, although differences among species were observed. The ranking across CNS species was SCAP > other CNS > SEPI > no infection. However, infections by SEPI tended to be more persistent. Increased SCS was associated with a statistically significant decrease in milk yield, but no effect was observed for intramammary infections (IMI). Ninety-seven isolates of CNS (53 SCAP and 44 SEPI) were investigated for in vitro susceptibility to several antimicrobial agents. Benzylpenicillin was the most effective antimicrobial agent against SCAP and SEPI. A concentration of 0.05 microg/mL was sufficient to inhibit growth of 90% of SCAP colonies, and 0.10 microg/mL yielded a similar effectiveness for SEPI. Amoxicillin and the combination of amoxicillin and clavulanic acid were only slightly less effective. Tetracycline (62.5 microg/mL) and tilmicosin (500 microg/mL) were the least effective treatments for SEPI and SCAP, respectively.
在整个泌乳期对来自2个商业奶山羊场的156只山羊进行了乳房内感染监测。观察到的大多数感染（80.7%）是由凝固酶阴性葡萄球菌（CNS）引起的。在第1个畜群中，几乎所有感染（96%）都是由CNS引起的，其中山羊葡萄球菌（SCAP）是观察到的最常见的特定病原体，约占感染的43%。在第2个畜群中，CNS引起的感染比例为67%，表皮葡萄球菌（SEPI）是最常见的病原体（占感染的48%），未发现SCAP。感染的乳房半侧所产牛奶的线性体细胞评分（SCS）更高，平均差异为0.78 SCS。对于所有CNS菌种，感染的乳房半侧的SCS均高于未感染的，尽管各菌种之间存在差异。CNS菌种的排名为SCAP>其他CNS>SEPI>未感染。然而，SEPI引起的感染往往更持久。SCS升高与产奶量在统计学上显著下降相关，但未观察到对乳房内感染（IMI）有影响。对97株CNS（53株SCAP和44株SEPI）进行了几种抗菌药物的体外敏感性研究。苄青霉素是对SCAP和SEPI最有效的抗菌药物。0.05微克/毫升的浓度足以抑制90%的SCAP菌落生长，0.10微克/毫升对SEPI产生类似的效果。阿莫西林以及阿莫西林与克拉维酸的组合效果稍差。四环素（62.5微克/毫升）和替米考星（500微克/毫升）分别是对SEPI和SCAP效果最差的治疗药物。
