Owens W E, Ray C H, Watts J L, Yancey R J
Mastitis Research Laboratory, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Homer 71040, USA.
J Dairy Sci. 1997 Feb;80(2):313-7. doi: 10.3168/jds.S0022-0302(97)75940-X.
Antimicrobial susceptibility testing was conducted on a variety of mastitis pathogens. The infected quarters were subsequently treated during lactation with a commercially available product containing penicillin and novobiocin that was designed for lactating cows. Cows were treated as per the recommendations of the product manufacturer, and cures were determined by the absence of bacteria in both sets of duplicate quarter milk samples that were collected at 28 d posttreatment. Comparisons were made between the susceptibility of the bacteria and the therapeutic success or failure. All isolates tested were considered to be susceptible to the penicillin and novobiocin combination. Bacteriologic cure rates for newly acquired Staphylococcus aureus intramammary infection (IMI) (< 2 wk in duration) at 28 d posttreatment were 70%. Cure rates for chronic Staph. aureus IMI (> 4 wk duration) were much lower (35%), reaffirming previous reports of the intractable nature of chronic Staph. aureus IMI. Cure rates for subclinical IMI caused by other organisms were 90% for Streptococcus agalactiae, 91% for Streptococcus uberis, 90% for Streptococcus dysgalactiae, 77% for other Streptococcus spp., and 71% for Staphylococcus spp. other than Staph. aureus. In vitro testing was considered to be a predictor of therapy outcome for IMI caused by Staphylococcus spp., newly acquired Staph. aureus, Strep. uberis, Strep. dysgalactiae, and Strep. agalactiae, but was not considered to be a useful predictor of efficacy for chronic IMI caused by Staph. aureus.
对多种乳腺炎病原体进行了药敏试验。随后在泌乳期用一种市售的含青霉素和新生霉素的产品对感染的乳腺进行治疗，该产品专为泌乳奶牛设计。奶牛按照产品制造商的建议进行治疗，治疗后28天采集的两组重复乳腺牛奶样本中均无细菌则判定为治愈。对细菌的药敏性与治疗成功或失败进行了比较。所有测试的分离株均被认为对青霉素和新生霉素联合敏感。治疗后28天，新感染的金黄色葡萄球菌乳房内感染（IMI，病程<2周）的细菌学治愈率为70%。慢性金黄色葡萄球菌IMI（病程>4周）的治愈率要低得多（35%），再次证实了先前关于慢性金黄色葡萄球菌IMI难治性的报道。由其他病原体引起的亚临床IMI的治愈率，无乳链球菌为90%，乳房链球菌为91%，停乳链球菌为90%，其他链球菌属为77%，除金黄色葡萄球菌外的葡萄球菌属为71%。体外试验被认为是由葡萄球菌属、新感染的金黄色葡萄球菌、乳房链球菌、停乳链球菌和无乳链球菌引起的IMI治疗结果的预测指标，但不是由金黄色葡萄球菌引起的慢性IMI疗效的有用预测指标。
