Resende C A, Figueiredo A M
Universidade Federal do Rio de Janeiro, Instituto de Microbiologia, Brazil.
J Med Microbiol. 1997 Feb;46(2):145-9. doi: 10.1099/00222615-46-2-145.
Methicillin-resistant Staphylococcus aureus (MRSA) are important nosocomial pathogens Diseases caused by these resistant bacteria frequently are serious and there is a need to control the spread of epidemic MRSA clones in hospitals. However, detection is complicated by the fact that expression of the resistance is variable and, commonly, heterogeneous within strains. The reliability of several tests recommended to discriminate heterogeneous MRSA isolates from borderline-resistant and susceptible strains was evaluated. Screening for growth on agar with methicillin 25 mg/L was the only method that detected all MRSA strains tested, but screening on agar with methicillin 10 mg/L or oxacillin 6 mg/L detected all but one of 10 heterogeneously resistant strains tested. None of the borderline-resistant nor any truly susceptible staphylococci tested grew on any of these screening plates.
耐甲氧西林金黄色葡萄球菌（MRSA）是重要的医院病原体。这些耐药菌引起的疾病通常很严重，因此有必要控制医院中流行的MRSA克隆的传播。然而，耐药性的表达是可变的，而且通常在菌株内是异质性的，这使得检测变得复杂。我们评估了几种用于区分异质性MRSA分离株与临界耐药和敏感菌株的检测方法的可靠性。在含25mg/L甲氧西林的琼脂上筛选生长是唯一能检测到所有测试MRSA菌株的方法，但在含10mg/L甲氧西林或6mg/L苯唑西林的琼脂上筛选能检测到10株异质性耐药菌株中的9株。测试的临界耐药葡萄球菌和任何真正敏感的葡萄球菌在这些筛选平板上均未生长。
