Chung Hee-Jung, Jeon Hong-Seon, Sung Heungsup, Kim Mi-Na, Hong Soo-Jong
Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736, Republic of Korea.
J Clin Microbiol. 2008 Mar;46(3):991-5. doi: 10.1128/JCM.00698-07. Epub 2008 Jan 3.
In this study, we investigated the rate of colonization of skin of children with atopic dermatitis (AD) by methicillin-resistant Staphylococcus aureus (MRSA) and characterized the isolates. Active skin lesions in pediatric AD patients were cultured with Rodac Staph (Komed, Korea). S. aureus isolates were examined for drug susceptibilities, analyzed for the eta, etb, tst, and pvl genes, and typed using agr polymorphism, pulsed-field gel electrophoresis of SmaI-restricted chromosomal DNA, and staphylococcal cassette chromosome mec (SCCmec) typing. Eighty-seven (75.4%) of 115 patients had cultivable S. aureus isolates, 16 of which (18.3%) were MRSA. All MRSA isolates were susceptible to chloramphenicol, rifampin, cotrimoxazole, and ciprofloxacin. While methicillin-susceptible S. aureus (MSSA) isolates were composed of 23 isolates of singular types and nine clusters comprising 48 isolates, MRSA isolates were typed into three clones: eight isolates of pulsotype A-agr-1-SCCmec IV, five isolates of pulsotype B-agr-3-SCCmec IIb-etb positive, and three isolates of pulsotype C-agr-3-SCCmec IV. Three SCCmec IVA MRSA isolates were tst positive, but none were positive for the pvl or eta gene. Among 71 MSSA isolates, 7 isolates were tst positive, 6 of which were pulsotype F-agr-3, and 9 of 10 agr-4 isolates were eta positive. The average ages of patients carrying MSSA, SCCmec IVA MRSA, and SCCmec IIb MRSA were 7.7 +/- 4.6, 3.1 +/- 1.5, and 8.2 +/- 3.1 years, respectively. Among the patients carrying MRSA, two patients had been treated with oral antimicrobials, and one had been admitted to the hospital 18 months previously. In conclusion, community-acquired MRSA isolates of a few clones colonized the skin of patients with AD without risk factors for the acquisition of hospital-acquired MRSA, which suggested that the skin of children with AD may represent a significant reservoir of MRSA colonization in the community.
在本研究中，我们调查了患有特应性皮炎（AD）的儿童皮肤被耐甲氧西林金黄色葡萄球菌（MRSA）定植的比率，并对分离株进行了特征分析。采用Rodac Staph（韩国Komed公司）对儿科AD患者的活动性皮肤损害进行培养。对金黄色葡萄球菌分离株进行药敏试验，分析eta、etb、tst和pvl基因，并采用agr多态性、SmaI酶切染色体DNA的脉冲场凝胶电泳以及葡萄球菌盒式染色体mec（SCCmec）分型进行分型。115例患者中有87例（75.4%）培养出可培养的金黄色葡萄球菌分离株，其中16例（18.3%）为MRSA。所有MRSA分离株对氯霉素、利福平、复方新诺明和环丙沙星敏感。甲氧西林敏感金黄色葡萄球菌（MSSA）分离株由23株单一类型和9个包含48株的簇组成，而MRSA分离株分为三个克隆型：8株脉冲型A-agr-1-SCCmec IV、5株脉冲型B-agr-3-SCCmec IIb-etb阳性和3株脉冲型C-agr-3-SCCmec IV。3株SCCmec IVA MRSA分离株tst阳性，但pvl或eta基因均为阴性。在71株MSSA分离株中，有7株tst阳性，其中6株为脉冲型F-agr-3，10株agr-4分离株中有9株eta阳性。携带MSSA、SCCmec IVA MRSA和SCCmec IIb MRSA患者的平均年龄分别为7.7±4.6岁、3.1±1.5岁和8.2±3.1岁。在携带MRSA的患者中，有2例曾接受口服抗菌药物治疗，1例在18个月前曾住院。总之，少数克隆型的社区获得性MRSA分离株定植于无医院获得性MRSA危险因素的AD患者皮肤，这表明AD患儿的皮肤可能是社区中MRSA定植的重要储存库。
