Immunology and Parasitology Fellowship Program Universidade Federal de Uberlândia Av. Pará n 1720 Bloco C - Campus.
Braz J Infect Dis. 2010 Jan-Feb;14(1):71-6. doi: 10.1590/s1413-86702010000100014.
Methicillin-resistant Staphylococcus aureus is an established nosocomial pathogen (HA-MRSA, hospital acquired MRSA), but has recently begun to appear in the community (CA-MRSA, community acquired MRSA). The cause of resistance to methicillin and all other beta-lactam antibiotics is the mecA gene, which is situated on a mobile genetic element, the Staphylococcal Cassette Chromosome mec (SCCmec). Seven major variants of SCCmec, type I to VII are distinguished. HA-MRSA disseminated worldwide and causes the majority of S. aureus nosocomial infections with a limited number of clones disseminated including the Brazilian Epidemic Clone (BEC, ST239-MRSA-III). CA-MRSA isolates are susceptible to non-beta-lactam antibiotics, usually isolated from healthy individuals which do not possess any unknown risk factors for MRSA infection and are associated with a larger clonal diversity compared with HA-MRSA. However, during recent years distinction between HA-MRSA and CA-MRSA is beginning to fade. Actually, knowledge about MRSA disseminating clones is required to implement any strategies to control the transmission of MRSA either within hospitals or in community. For this reason, rapid identification of strains is an important issue. The rate of HA-MRSA can be reduced substantially through the implementation of interventions strategies, even in settings where MRSA is endemic as in most Brazilian hospitals. However, these policies could be quite complicated in the light of an increasing CA-MRSA prevalence in healthcare facilities, considering that distinction between HA-MRSA and CA-MRSA has started to disappear.
耐甲氧西林金黄色葡萄球菌是一种已确立的医院病原体（HA-MRSA，医院获得性耐甲氧西林金黄色葡萄球菌），但最近已开始在社区出现（CA-MRSA，社区获得性耐甲氧西林金黄色葡萄球菌）。对甲氧西林和所有其他β-内酰胺类抗生素产生耐药性的原因是 mecA 基因，该基因位于移动遗传元件，葡萄球菌盒染色体 mec（SCCmec）上。区分出 SCCmec 的七个主要变体，I 型至 VII 型。HA-MRSA 已在全球传播，并导致大多数金黄色葡萄球菌医院感染，传播的克隆数量有限，包括巴西流行克隆（BEC，ST239-MRSA-III）。CA-MRSA 分离株对非β-内酰胺类抗生素敏感，通常从无任何未知耐甲氧西林金黄色葡萄球菌感染危险因素的健康个体中分离出来，与 HA-MRSA 相比，其克隆多样性更大。然而，近年来，HA-MRSA 和 CA-MRSA 之间的区别开始消失。实际上，为了实施任何控制 MRSA 在医院内或社区内传播的策略，都需要了解 MRSA 传播的克隆。因此，快速鉴定菌株是一个重要问题。即使在 MRSA 流行的环境（如大多数巴西医院）中，通过实施干预策略，也可以大大降低 HA-MRSA 的发生率。然而，鉴于医疗保健设施中 CA-MRSA 的患病率不断增加，这些政策可能会变得相当复杂，因为 HA-MRSA 和 CA-MRSA 之间的区别已经开始消失。
