Bombyk R A M, Bykowski A L, Draper C E, Savelkoul E J, Sullivan L R, Wyckoff T J O
Division of Science and Mathematics, University of Minnesota, Morris, MN 56267, USA.
J Appl Microbiol. 2008 Jun;104(6):1726-31. doi: 10.1111/j.1365-2672.2007.03681.x. Epub 2007 Dec 20.
To assess whether conventional and organic dairy management practices are associated with differences in the susceptibility of Staphylococcus to antimicrobial agents.
Staphylococcus was isolated from milk samples collected from conventional and organic dairies in west-central Minnesota. Isolates were categorized as (1) coagulase-positive, (2) novobiocin-sensitive coagulase-negative or (3) novobiocin-resistant coagulase-negative. Novobiocin-resistant coagulase-negative Staphylococcus (CNS) was more common on conventional farms and novobiocin-sensitive CNS predominated the isolates from organic farms. Overall, a larger proportion of isolates from organic rather than conventional farms were susceptible to erythromycin, pirlimycin and tetracycline. However, for pirlimycin and tetracycline, different patterns of susceptibility were observed among Staphylococcus categories.
In this study, organic dairy management was associated with more overall antimicrobial susceptibility among Staphylococcus than was conventional management. However, different patterns of susceptibility among Staphylococcus categories suggest that multiple management practices, including some unrelated to antimicrobial use, may contribute to the observed differences in susceptibility.
This study adds to our understanding of the implications of dairy management choices.
评估传统和有机奶牛养殖管理方式是否与葡萄球菌对抗菌药物的敏感性差异相关。
从明尼苏达州中西部传统和有机奶牛场采集的牛奶样本中分离出葡萄球菌。分离株分为三类：（1）凝固酶阳性；（2）对新生霉素敏感的凝固酶阴性；（3）对新生霉素耐药的凝固酶阴性。对新生霉素耐药的凝固酶阴性葡萄球菌（CNS）在传统农场更为常见，而对新生霉素敏感的CNS在有机农场的分离株中占主导地位。总体而言，来自有机农场而非传统农场的分离株中，对红霉素、吡利霉素和四环素敏感的比例更高。然而，对于吡利霉素和四环素，不同类别葡萄球菌的药敏模式有所不同。
在本研究中，与传统养殖管理相比，有机奶牛养殖管理使葡萄球菌总体上对抗菌药物更敏感。然而，不同类别葡萄球菌的药敏模式表明，多种管理方式，包括一些与抗菌药物使用无关的方式，可能导致了观察到的药敏差异。
本研究增进了我们对奶牛养殖管理选择影响的理解。
