中国大陆 59 型耐甲氧西林金黄色葡萄球菌克隆复合体感染的分子和临床特征。
Molecular and clinical characteristics of clonal complex 59 methicillin-resistant Staphylococcus aureus infections in Mainland China.
机构信息
Key Laboratory of Major Diseases in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
出版信息
PLoS One. 2013 Aug 7;8(8):e70602. doi: 10.1371/journal.pone.0070602. eCollection 2013.
Detailed molecular analyses of Clonal Complex 59 (CC59) methicillin-resistant Staphylococcus aureus (MRSA) isolates from children in seven major cities across Mainland China were examined. A total of 110 CC59 isolates from invasive and non-invasive diseases were analyzed by multilocus sequence typing (MLST), Staphylococcus cassette chromosome mec (SCCmec) typing, staphylococcal protein A (spa) typing and pulsed-field gel electrophoresis (PFGE). Antibiotics susceptibilities, carriage of plasmids and 42 virulence genes and the expression of virulence factors were examined. ST59 (101/110, 91.8%) was the predominant sequence type (ST), while single locus variants (SLVs) belonging to ST338 (8/110, 7.3%) and ST375 (1/110, 0.9%) were obtained. Three SCCmec types were found, namely type III (2.7%), type IV (74.5%) and type V (22.7%). Seven spa types including t437, which accounted for 87.3%, were determined. Thirteen PFGE types were obtained. PFGE types A and B were the major types totally accounting for 81.8%. The dominant clone was ST59-t437-IVa (65.5%), followed by ST59-t437-V (14.5%). The positive rate of luks-PV and lukF-PV PVL encoding (pvl) gene was 55.5%. Plasmids were detected in 83.6% (92/110) of the strains. The plasmid size ranging from 23.4 kb to 50 kb was most prevalent which accounted for 83.7% (77/92). A significantly lower expression of hla was found in ST59-t437-IVa compared with ST59-t437-V. Among the 110 cases, 61.8% of the patients were less than 1 year old. A total of 90 cases (81.8%) were community-associated (CA) infections whereas 20 cases (18.2%) were hospital-associated (HA) infections. Out of the 110 patients, 36.4% (40/110) were diagnosed with invasive infectious diseases in which ST59-t437-IVa accounted for 67.5% (27/40). In brief, ST59-t437-IVa was proved as the dominant clone in CC59 MRSA strains. The carriage rate of pvl gene was high. CC59 MRSA could result in CA and HA infections. The majortiy of MRSA infection children were in young age.
对中国大陆 7 个主要城市儿童中分离的克隆群 59（CC59）耐甲氧西林金黄色葡萄球菌（MRSA）的 110 株临床分离株进行了详细的分子分析。采用多位点序列分型（MLST）、葡萄球菌盒式染色体 mec（SCCmec）分型、葡萄球菌蛋白 A（spa）分型和脉冲场凝胶电泳（PFGE）对 110 株侵袭性和非侵袭性疾病的 CC59 分离株进行了分析。检测了抗生素敏感性、质粒携带情况和 42 种毒力基因以及毒力因子的表达。ST59（101/110，91.8%）是主要的序列型（ST），而属于 ST338（8/110，7.3%）和 ST375（1/110，0.9%）的单核苷酸变异（SLV）也被发现。发现了三种 SCCmec 类型，分别是 III 型（2.7%）、IV 型（74.5%）和 V 型（22.7%）。确定了 7 种 spa 型，包括占 87.3%的 t437。获得了 13 种 PFGE 型。A 型和 B 型 PFGE 是主要类型，共占 81.8%。优势克隆是 ST59-t437-IVa（65.5%），其次是 ST59-t437-V（14.5%）。luks-PV 和 lukF-PV PVL 编码（pvl）基因的阳性率为 55.5%。83.6%（92/110）的菌株检测到质粒。最常见的质粒大小为 23.4 kb 至 50 kb，占 83.7%（77/92）。与 ST59-t437-V 相比，ST59-t437-IVa 中 hla 的表达明显降低。在 110 例患者中，61.8%的患者年龄小于 1 岁。共有 90 例（81.8%）为社区获得性（CA）感染，20 例（18.2%）为医院获得性（HA）感染。在 110 例患者中，36.4%（40/110）被诊断为侵袭性传染病，其中 ST59-t437-IVa 占 67.5%（27/40）。简而言之，ST59-t437-IVa 被证明是 CC59-MRSA 菌株中的主要克隆。pvl 基因的携带率很高。CC59-MRSA 可导致 CA 和 HA 感染。大多数 MRSA 感染患儿年龄较小。
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