Department of Infection, King's College London and Guy's and St Thomas Hospital NHS Foundation Trust, St Thomas Hospital, London, UK.
Clin Microbiol Infect. 2009 Dec;15 Suppl 7:10-6. doi: 10.1111/j.1469-0691.2009.03092.x.
Screening patients for methicillin-resistant Staphylococcus aureus (MRSA) carriage at hospital admission is widely accepted as an essential part of MRSA control programmes. It is assumed, although not proven, that rapid reporting of screening results will improve MRSA control, provided that a clear action plan for positive cases is in place and is being followed. An effective culture screening method is direct inoculation of pooled nose, throat and perineal swabs on a well-performing MRSA-selective chromogenic agar; presumptive MRSA colonies can be confirmed rapidly by latex agglutination with antibodies directed against penicillin-binding protein 2a. This method will usually produce a positive result after 24 h of incubation in >95% of true-positive cases, and will be sufficient for most initial treatment and infection control decisions; full antimicrobial susceptibilities will be available on the next day. Inoculation of selective enrichment broth containing a colorimetric growth indicator is an alternative overnight culture method, but there may be problems with overgrowth of other organisms, such as enterococci. PCR methods are now available that can produce same-day results, provided that samples reach the laboratory in time for batch processing, but cultures are required for susceptibility testing. In comparison with culture-based methods, PCR tests are costly, and some have relatively high false-positivity rates; definitive evidence of their clinical cost-effectiveness is lacking. New point-of-care PCR tests are being introduced that are potentially even more rapid but are even more expensive; studies on the clinical cost-effectiveness of these very rapid tests are awaited.
对住院患者进行耐甲氧西林金黄色葡萄球菌（MRSA）定植筛查被广泛认为是 MRSA 控制计划的重要组成部分。尽管尚未得到证实，但人们假设，如果能快速报告筛查结果，并制定和执行明确的阳性病例行动计划，那么这将有助于控制 MRSA。一种有效的培养筛选方法是将鼻、咽和会阴拭子混合后直接接种于性能良好的 MRSA 选择性显色琼脂上；通过针对青霉素结合蛋白 2a 的抗体进行乳胶凝集，可快速确认疑似 MRSA 菌落。这种方法通常在孵育 24 小时后，在>95%的真正阳性病例中产生阳性结果，足以满足大多数初始治疗和感染控制决策的需要；第二天即可获得完整的抗生素药敏结果。接种含有比色生长指示剂的选择性增菌肉汤是另一种过夜培养方法，但其他生物体（如肠球菌）可能会过度生长。目前已有可在当天得出结果的 PCR 方法，但前提是样本及时送达实验室进行批量处理，而且还需要进行药敏试验。与基于培养的方法相比，PCR 检测费用较高，且某些方法的假阳性率相对较高；缺乏其临床成本效益的确凿证据。新的即时检测 PCR 检测正在推出，其速度更快，但费用更高；正在等待这些非常快速检测的临床成本效益研究。
