McAdams Ryan M, Ellis Michael W, Trevino Sherry, Rajnik Michael
Department of Neonatology, US Naval Hospital Okinawa and 18th Medical Group, Kadena Air Base, Japan.
Pediatr Int. 2008 Dec;50(6):810-5. doi: 10.1111/j.1442-200X.2008.02646.x.
Reports of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in neonatal intensive care units (NICU) and in otherwise healthy patients without obvious risk factors have been increasing in frequency. Described herein is a cluster of cases of CA-MRSA USA300 strains in an NICU affecting infants, health-care workers and the health-care workers' families.
Infants and health-care workers with infection and colonization due to MRSA between 1 January 2004 and 30 June 2005 in a tertiary care center NICU in San Antonio, TX were studied. Antimicrobial susceptibility testing and polymerase chain reaction detection of the mecA gene characterized the MRSA isolates. All MRSA cases were reviewed for clinical severity of infection and outcome.
During the 18 months studied, a total of four (0.6%) of 676 infants had CA-MRSA bacteremia or colonization. One infant with necrotizing pneumonia died and three health-care workers who directly cared for the infected infants developed soft-tissue infections caused by CA-MRSA. Four family members of two health-care workers subsequently developed soft-tissue infections. All of the analyzed isolates (eight of nine) belonged to pulsed-field type USA300 and possessed Panton-Valentine leukocidin genes, which have been associated with severe skin and soft-tissue infections, and necrotizing pneumonia.
It is likely that the CA-MRSA USA300 strain can be transmitted between NICU patients to health-care workers and their family members. The CA-MRSA cases reported here reinforce the virulence of CA-MRSA USA300 strains and emphasize the need to embrace infection control practices designed to protect hospitalized patients, health-care workers and their family members.
新生儿重症监护病房（NICU）以及无明显危险因素的健康患者中，社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）的报告频率不断增加。本文描述了在一家NICU中发生的一组CA-MRSA USA300菌株感染病例，涉及婴儿、医护人员及其家庭成员。
对2004年1月1日至2005年6月30日期间在德克萨斯州圣安东尼奥市一家三级医疗中心NICU中因耐甲氧西林金黄色葡萄球菌（MRSA）感染和定植的婴儿及医护人员进行了研究。通过抗菌药敏试验和聚合酶链反应检测mecA基因对MRSA分离株进行了鉴定。对所有MRSA病例的感染临床严重程度和结局进行了回顾。
在研究的18个月期间，676名婴儿中有4名（0.6%）发生了CA-MRSA菌血症或定植。一名患有坏死性肺炎的婴儿死亡，三名直接护理感染婴儿的医护人员发生了由CA-MRSA引起的软组织感染。两名医护人员的四名家庭成员随后也发生了软组织感染。所有分析的分离株（9株中的8株）属于脉冲场类型USA300，并具有与严重皮肤和软组织感染以及坏死性肺炎相关的杀白细胞素基因。
CA-MRSA USA300菌株很可能在NICU患者与医护人员及其家庭成员之间传播。本文报告的CA-MRSA病例强化了CA-MRSA USA300菌株的毒力，并强调需要采用旨在保护住院患者、医护人员及其家庭成员的感染控制措施。
