Complex molecular epidemiology of methicillin-resistant Staphylococcus aureus isolates from children with cystic fibrosis in the era of epidemic community-associated methicillin-resistant S aureus
Complex molecular epidemiology of methicillin-resistant Staphylococcus aureus isolates from children with cystic fibrosis in the era of epidemic community-associated methicillin-resistant S aureus
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DOI：
10.1378/chest.07-2437
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发表时间：
2008-06-01
期刊：
影响因子：
9.6
通讯作者：
Daum, Robert S.
中科院分区：
文献类型：
--
作者：
Glikman, Daniel;Siegel, Jane D.;Daum, Robert S.
背景资料：关于囊性纤维化（CF）儿童中发现的耐甲氧西林金黄色葡萄球菌（MRSA）菌株的分子类型的数据有限。我们试图从这些患者的MRSA菌株的特点，并比较他们与MRSA菌株从非CF pediatric patients.Methods：所有MRSA菌株前瞻性地收集在儿童医学中心在达拉斯，得克萨斯州，和芝加哥大学科默儿童医院在2004年至2005年。所有CF MRSA分离株进行了药敏试验，多位点序列分型，Panton-Valentine杀白细胞素基因检测（pvl+），和葡萄球菌染色体盒mec（SCCmec）typing.Results：共22 34株（64.7%）从CF患者属于克隆复合体（CC）5，并包含SCCmec II，所谓的医疗保健相关的MRSA（RA-MRSA）菌株。34株MRSA菌株中有9株（26.5%）为CC 8，并含有SCCmec IV，即所谓的社区相关MRSA（CA-MRSA）菌株。CA-MRSA菌株倾向于从新定植的CF患者中分离。相比之下，CC 8分离株在非CF患者中占主导地位（331例患者中的294例; 88.8%）。与来自非CF患者的菌株相比，来自CF儿童的MRSA菌株更可能对克林霉素（分别为65%和19%）和环丙沙星（分别为62%和17%）耐药（p < 0.001）。与肺恶化的儿童（11名儿童中的3名; p = 1.0）相比，进行监测培养的CF儿童（23名儿童中的7名）的pvl+分离株恢复率没有差异。结论：CA-MRSA（CC 8）分离株和RA-MRSA（CC 5）分离株均分布于CF儿童的呼吸道。HA-MRSA菌株占主导地位，但CA-MRSA菌株占主导地位的CF患者与新获得的MRSA菌株和非CF患者。CF儿童中CA-MRSA菌株的存在与急性加重或坏死性肺炎无关。
Background: Limited data exist about the molecular types of methicillin-resistant Staphylococcus aureus (MRSA) strains found in children with cystic fibrosis (CF). We sought to characterize MRSA strains from these patients and compare them with MRSA strains from non-CF pediatric patients.Methods: All MRSA isolates were collected prospectively at Children's Medical Center in Dallas, TX, and the University of Chicago Comer Children's Hospital in 2004 to 2005. All CF MRSA isolates underwent susceptibility testing, multilocus sequence typing, Panton-Valentine leukocidin gene detection (pvl+), and staphylococcal chromosome cassette mec (SCCmec) typing.Results: A total of 22 of 34 MRSA isolates (64.7%) from patients with CF belonged to clonal complex (CC) 5 and contained SCCmec II, so-called health-care associated MRSA (RA-MRSA) strains. Nine of 34 MRSA strains (26.5%) were CC 8, and contained SCCmec IV, so-called community-associated MRSA (CA-MRSA) strains. The CA-MRSA strains tended to be isolated from newly colonized CF patients. In contrast, CC8 isolates predominated among the non-CF patients (294 of 331 patients; 88.8%). MRSA isolates from children with CF were more likely to be resistant to clindamycin (65% vs 19%, respectively) and ciprofloxacin (62% vs 17%, respectively) compared with strains from non-CF patients (p < 0.001). There was no difference in the rate of pvl+ isolate recovery from children with CF undergoing a surveillance culture (7 of 23 children) compared with those with pulmonary exacerbation (3 of 11 children; p = 1.0).Conclusions: Both CA-MRSA (CC8) isolates and RA-MRSA (CC5) isolates populate the respiratory tracts of children with CF. HA-MRSA isolates predominated, but CA-MRSA strains predominated among CF patients with newly acquired MRSA strains and among the non-CF patients. The presence of CA-MRSA strains in children with CF was not associated with exacerbation or necrotizing pneumonia.