Davies S, Zadik P M
Public Health Laboratory, Sheffield.
J Clin Pathol. 1997 Mar;50(3):257-8. doi: 10.1136/jcp.50.3.257.
The control of methicillin resistant Staphylococcus aureus (MRSA) relies on the rapid and sensitive detection of carriage. The roles of an enrichment broth, duration of incubation, and Baird-Parker medium containing ciprofloxacin (BPC) were evaluated in comparison with standard media in a centre where the prevalence of ciprofloxacin resistance among MRSA is over 98%. Screening swabs from 402 sites were plated onto BPC, mannitol salt agar (MSA), and MSA with methicillin (MMSA). The swabs were enriched in Tryptone-T broth with 6% salt for 24 hours and the broths subcultured onto BPC, MSA, and MMSA. MRSA was isolated from 134 swabs. Significantly more isolates were obtained by incubating culture plates for 42 hours rather than 18 hours, by the use of broth enrichment, and by addition of methicillin or ciprofloxacin to media. BPC was the most sensitive medium (107 isolates (80%) by direct culture at 42 hours), grew the fewest contaminants, and allowed provisional reporting of 73% of isolates at 18 hours by colonial appearance and use of Staphaurex Plus rapid latex reagent. This may allow the introduction of infection control measures a day earlier than when other established methods are used.
耐甲氧西林金黄色葡萄球菌（MRSA）的控制依赖于对其携带情况的快速灵敏检测。在一个MRSA对环丙沙星耐药率超过98%的中心，将一种增菌肉汤、培养时间以及含环丙沙星的贝尔德-帕克培养基（BPC）与标准培养基相比较，评估了它们的作用。从402个部位采集的筛查拭子分别接种于BPC、甘露醇盐琼脂（MSA）以及含甲氧西林的MSA（MMSA）上。拭子在含6%盐的胰蛋白胨肉汤中增菌24小时，然后将肉汤转种到BPC、MSA和MMSA上。从134个拭子中分离出了MRSA。通过将培养平板孵育42小时而非18小时、使用肉汤增菌以及在培养基中添加甲氧西林或环丙沙星，获得的分离株显著增多。BPC是最灵敏的培养基（42小时直接培养时有107株分离株（80%）），生长的污染物最少，并且通过菌落外观和使用Staphaurex Plus快速乳胶试剂，18小时时可对73%的分离株进行初步报告。这可能比使用其他既定方法提前一天采取感染控制措施。
