M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
Res Vet Sci. 2013 Oct;95(2):347-51. doi: 10.1016/j.rvsc.2013.05.015. Epub 2013 Jul 1.
This study aimed at testing the applicability of mannitol salt agar (MSA), a medium generally used in human medicine for differentiating Staphylococcus aureus from coagulase-negative staphylococci (CNS), for culturing bovine-associated CNS species. All test isolates from a comprehensive collection of well-identified CNS species, including both reference strains and field isolates, were able to grow. Subsequently, bulk milk samples and teat apex swabs were used to examine the capability of MSA for yielding CNS under field conditions. Sixty-nine and 47 phenotypically different colonies were retrieved from bulk milk and teat apices, respectively. The majority of isolates from teat apices were staphylococci, whereas in bulk milk, staphylococci formed a minority. After 24h of growth, recovery of separate colonies of CNS was much more convenient on MSA compared to a non-selective blood agar. The results of this study indicate that MSA is a suitable medium for both growth and recovery of bovine-associated CNS.
本研究旨在测试甘露醇盐琼脂（MSA）的适用性，MSA 是一种常用于人类医学中区分金黄色葡萄球菌和凝固酶阴性葡萄球菌（CNS）的培养基，用于培养牛相关 CNS 物种。从全面收集的经过充分鉴定的 CNS 物种的测试分离物，包括参考菌株和田间分离物，均能够生长。随后，使用批量牛奶样品和乳头尖端拭子检查 MSA 在田间条件下产生 CNS 的能力。从批量牛奶和乳头尖端分别回收了 69 和 47 个表型不同的菌落。乳头尖端的大多数分离物是葡萄球菌，而在批量牛奶中，葡萄球菌则占少数。在 24 小时的生长后，与非选择性血琼脂相比，MSA 更方便地回收单独的 CNS 菌落。本研究结果表明，MSA 是一种适合生长和回收牛相关 CNS 的培养基。
