Hospital-Acquired Mupirocin-Resistant MRSA in Post-Partum Women and Newborns

摘要： 耐甲氧西林金黄色葡萄球菌（MRSA）是导致住院患者和 社区居民。最初被描述为医院和医疗保健相关的病原体，新 社区相关MRSA（CA-MRSA）菌株已成为人群感染的重要原因， 居住在社区的个人。最近，CA-MRSA，如脉冲场凝胶电泳所定义， 这种“DNA指纹”形式的病毒已成为越来越多的医疗保健获得性感染的原因。一场大规模的 在一个大型城市教学中发生了由CA-MRSA（USA 300 -0114）的高致病性菌株引起的感染 产后妇女和出院后不久新生儿住院。莫匹罗星耐药， 大部分的分离株在爆发期间，这是一个不寻常的和意想不到的发现。 医院相关MRSA菌株（HA-MRSA）定植和感染的风险因素相当好 建立，但在这一高风险人群中CA-MRSA定植和感染的风险因素仍然存在 定义不好。通过使用新的，先进的统计模型，目前的研究旨在描述风险 CA-MRSA的莫匹罗星耐药和莫匹罗星敏感菌株定植和感染的因素 USA 300 -0114在这次疫情中。鉴于新生儿托儿所的动态性质， 如果怀疑发生了传播，将确定传播动力学和传播率 使用一个开放的易感-感染-感染模型。最后，实验室研究，以确定遗传 将平行进行定植和感染MRSA分离株的组成和其他特征 临床流行病学调查，目的是确定耐药性的机制， 局部抗菌剂的传播和病原体毒力和耐药性之间可能存在联系。 拟议的研究将检查这一人群中定植和感染的风险因素，然而， 这些发现将可能推广到CA-MRSA在其他人群中的传播， 非爆发设置。此外，关于耐药性发展的重要信息， 将获得对非殖民化中常用的局部药剂的抗性机制。这些信息 最终将对这些药物在常规感染控制和去殖民化中的使用产生影响。

Abstract: Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of significant morbidity among hospitalized and community-dwelling persons. Initially described as a hospital- and healthcare-associated pathogen, new strains of community-associated MRSA (CA-MRSA) have emerged as an important cause of infection among of community-dwelling individuals. More recently CA-MRSA, as defined by pulsed-field gel electrophoresis, a form of "DNA fingerprinting", has become a growing cause of healthcare-acquired infection. A large outbreak of infection caused by a highly pathogenic strain of CA-MRSA (USA300-0114) occurred at a large urban teaching hospital among post-partum women and newborns soon after discharge. Resistance to mupirocin was noted in a large proportion of isolates during the outbreak, which was an unusual and unexpected finding. Risk factors for colonization and infection with hospital-associated strains of MRSA (HA-MRSA) are fairly well established, but the risk factors for CA-MRSA colonization and infection in this high risk population remain poorly defined. By the use of novel, advanced statistical modeling, the current study aims to delineate the risk factors for colonization and infection with mupirocin-resistant and mupirocin-susceptible strains of CA-MRSA USA300-0114 during this outbreak. Given the dynamic nature of the newborn nursery, the setting in which transmission is suspected to have occurred, transmission dynamics and transmission rates will be determined using an open Susceptible-Infected-Recovered model. Finally, laboratory studies to determine the genetic makeup and other characteristics of the colonizing and infecting MRSA isolates will be performed in parallel with the clinical epidemiological investigations with the aim of determining mechanisms by which resistance to topical antimicrobial agents is spread and possible linkage between pathogen virulence and resistance. The proposed study will examine risk factors for colonization and infection in this population, however, some of the findings will likely be generalizable to CA-MRSA transmission in other populations both in the outbreak and non-outbreak setting. Furthermore, important information regarding development of resistance and mechanisms of resistance to topical agents commonly used in decolonization will be obtained. This information will ultimately have implications for the use of these agents in routine infection control and decolonization.