A longitudinal Study of CA-MRSA Nasal Colonization in College Sports Participants

描述（由申请人提供）：金黄色葡萄球菌在近三分之一的人的鼻腔前定植，是儿童和成人皮肤和软组织感染的主要原因。由于社区相关耐甲氧西林金黄色葡萄球菌（CA-MRSA）生物的出现，葡萄球菌感染的治疗变得更具挑战性。除了CA-MRSA引起的感染增加外，无症状鼻腔携带CA-MRSA的病例也有所增加。某些特定人群出现CA-MRSA感染的风险增加，如青少年、年轻人和运动队参与者。由于CA-MRSA的高发病率和偶尔的死亡率，我们需要更好地了解是什么因素导致了CA-MRSA的定植和疾病。根据我们的初步数据表明，CA-MRSA感染菌株代表了定植CA-MRSA菌株的一个子集，我们假设CA-MRSA鼻腔定植增加了CA-MRSA感染的风险，但只有当定植菌株表达一种或多种促进临床疾病发展的毒力因子时。本提案的总体目标是精确定义金黄色葡萄球菌鼻腔携带的流行病学和随后的金黄色葡萄球菌感染的风险。我们选择了一群大学生运动员，他们被认为比一般人群有更高的皮肤和软组织感染风险。提出了三个综合的具体目标：1)前瞻性地确定两个赛季健康运动队参与者中金黄色葡萄球菌和CA-MRSA鼻腔携带的频率；2)确定团队成员CA-MRSA和甲氧西林敏感金黄色葡萄球菌（MSSA）临床葡萄球菌感染的频率；3)确定与鼻腔定植和感染相关的微生物因素。该建议是我们早期研究儿科人群CA-MRSA鼻腔定植工作的自然延伸。它将由一个经验丰富的导师团队指导，并将补充我在儿科传染病、实验室研究和流行病学方面的培训。此外，该提案支持我努力成为一名独立研究者，定义葡萄球菌携带和疾病的临床和分子流行病学。

DESCRIPTION (provided by applicant): Staphylococcus aureus colonizes the anterior nares of nearly one-third of people and is the leading cause of skin and soft tissue infections in children and adults. Treatment of staphylococcal infections has become more challenging due to the emergence of community-associated methicillin-resistant S. aureus (CA-MRSA) organisms. In addition to the rise in infections due to CA-MRSA, asymptomatic nasal carriage with CA-MRSA also has increased. Specific groups appear to be at increased risk for CA-MRSA infections, such as adolescents, young adults, and sports team participants. As a result of the high morbidity and occasional mortality seen with CA-MRSA, we need to better understand what factors contribute to colonization and disease with this organism. Based on our preliminary data suggesting that infecting strains of CA-MRSA represent a subset of colonizing CA-MRSA strains, we hypothesize that CA-MRSA nasal colonization increases the risk for CA-MRSA infections, but only when the colonization strain expresses one or more virulence factors that promote the development of clinical disease. The overall goal of this proposal is to precisely define the epidemiology of S. aureus nasal carriage and subsequent risk for S. aureus infections. We have selected a population of college student-athletes, considered to be at higher risk for skin and soft tissue infections than the general population. Three integrated specific aims are proposed: 1) To prospectively determine the frequency of nasal carriage of S. aureus and CA-MRSA in a cohort of healthy sports team participants during the course of two seasons; 2) to define the frequency of clinical staphylococcal infections with CA-MRSA and methicillin-susceptible S. aureus (MSSA) in the team members; and 3) to identify the microbial factors associated with nasal colonization and infection. This proposal is a natural extension of our earlier work studying nasal colonization with CA-MRSA in the pediatric population. It will be guided by an experienced mentorship team and will complement my training in pediatric infectious diseases, laboratory research, and epidemiology. Furthermore, the proposal supports my efforts to become an independent investigator defining the clinical and molecular epidemiology of staphylococcal carriage and disease.