儿科Panton-Valentine杀白细胞素基因阳性耐甲氧西林金黄色葡萄球菌分子特征及Panton-Valentine杀白细胞素基因多态性和耐药特征  

Molecular Characteristics,Variations in Panton-Valentine Leukocidin Gene Sequences,and Resistance Cha-racteristics of Panton-Valentine Leukocidin Gene-Positive Methicilin-Resistant Staphylococcus Aureus Isolated from Pediatric Patients

作　　者：孙静[1] 李向梅[1] 孙明姣[1] 王丽娟[1] 刘颖超[1] 王传清[2] 邓秋莲[3] 刘岚[4] 杨永弘[1] 沈叙庄[1] 

机构地区：[1]首都医科大学附属北京儿童医院,北京市儿科研究所,儿科学国家重点学科,教育部儿科重大疾病研究重点实验室,北京100045 [2]复旦大学附属儿科医院新生儿科,上海201102 [3]广州市儿童医院检验科,广州510120 [4]重庆医科大学附属儿童医院检验科,重庆400014

出　　处：《实用儿科临床杂志》2012年第22期1707-1711,共5页Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金国际(地区)合作与交流项目(81061160509);国家自然科学基金(81171648)

摘　　要：目的研究儿童感染Panton-Valentine杀白细胞素(PVL)基因阳性耐甲氧西林金黄色葡萄球菌(MRSA)分离株分子特征、PVL基因序列变异情况及耐药特征。方法对PVL阳性MRSA感染患儿临床资料进行回顾性调查,分析病例临床特征;采用PCR联合测序对MRSA临床分离株进行多位点序列分型(MLST);并应用分段PCR扩增PVL基因,拼接序列与日本ST30 CA-MRSA菌株NN1的PVL序列进行比对,分析序列变异与STs分型之间的关系,构建系统树对PVL基因的系统发生多样性进行分析;采用琼脂稀释法进行16种抗生素的体外药物敏感试验。结果在73例PVL阳性MRSA感染病例中:皮肤软组织感染35例(47.9%),肺炎27例(37.0%),其他严重感染及健康儿童分离株中也检测到PVL基因;社区感染55例(75.3%)。感染菌株MLST分型共有9种,最常见的3种为ST59、ST910、ST338,分别占53.4%、17.8%、9.6%。PVL序列检测及比对结果:共发现9个核苷酸位点变异,其中3个为非同义突变(16 C→A,62 C→T,527 A→G),其余均为同义突变;有9种不同的单体型序列,各STs分型在9种序列中呈散在分布;所研究的MRSA 71株为H型,仅2株R型。PVL阳性MRSA菌株对红霉素、克林霉素、头孢呋辛耐药率高达94.5%、86.3%和82.2%。结论 PVL阳性MRSA分离株来源广泛,以皮肤软组织感染和肺炎为主;分子分型以ST59型最为常见;lukSF-PV序列高度保守,序列变异主要为H型,R型罕见。Objective To investigate the molecular characteristics,the variations in the Panton -Valentine leukocidin （PVL） gene se- quences, and the resistance characteristics of PVL gene -positive methicillin- resistant Staphylococcus aureus （MRSA） isolated from pediat- ric patients. Methods Disease distribution was retrospectively investigated and clinical characteristics of PVL - positive MRSA infections were analyzed. Muhilocus sequence typing （MLST） was analyzed via polymerase chain reaction （PCR） in combination with sequence. Seg- mented PCR was then used to amplify the PVL gene, and the spliced sequences were compared with the PVL gene sequence of the Japanese ST30 CA - MRSA strain NN1. The relationship between sequence variations and STs was analyzed. Phylogenetic tree was constructed to study the phylogenetic diversity of the PVL gene. Susceptibility to 16 antimicrobials was determined by using the agar dilution method. Results PVL - positive MRSA was mostly isolated from skin infection and pneumonia, which accounted for 47.9% and 37.0% of all cases, respective- ly. However,the PVL gene was also detected in isolates from healthy children and those with severe infections. Up to 75.3% of the isolates were community- associated. Nine sequence types （STs） were obtained, with ST59 （53.4%） as the most frequent ST, followed by ST 910 （ 17.8% ） ,and ST 338 （9.6%）. Single nucleotide polymorphisms were identified in nine locations in the PVL genes,among which three （ 16 C→A ,62 C→T, and 527 A→G） were non -synonymous, while others were synonymous. Nine unique haplotypes were identified, and the STs were scattered among them. Most of the MRSA infections were H haplotypes, and only two isolates were R haplotypes. In vitro antibiotic sus- ceptibility testing suggested that the resistance rates of the isolates to erythromycin, clindamycin, and cefuroxime were 94.5%, 86.3%, and 82.2% ,respectively. Conclusions PVL - positive MRSA isolates are widespread and skin infection and pneumonia are

关 键 词：金黄色葡萄球菌 甲氧西林耐药 Panton—Valentine杀白细胞素 等位基因变异 

分 类 号：R440[医药卫生—诊断学]