广州小学生鼻腔多重耐药金黄色葡萄球菌耐药谱和基因特征

Antibiotic resistance spectrum and genetic characteristics of MDRSA nasal isolate among primary school students

目的探究小学生鼻腔多重耐药金黄色葡萄球菌(multidrug-resistant staphylococcus aureus,MDRSA)的耐药谱和基因携带特征,为预防和控制儿童鼻腔MDRSA耐药产生及临床用药的选择提供科学依据。方法采用多阶段分层整群抽样方法,抽取广州市8所小学1705名小学生,对儿童鼻腔分离鉴定出的金黄色葡萄球菌(SA)进行药物敏感实验,分析MDRSA的耐药谱,用多重聚合酶链式反应(PCR)技术测定耐药、毒素和免疫逃避(immune evasion cluster,IEC)基因。结果MDRSA携带率为20.76%(354/1705),MDRSA占SA的比例为96.20%(354/368)。MDRSA对青霉素(99.72%)、红霉素(96.33%)、克林霉素(90.96%)和替考拉宁(90.11%)的耐药率高,同时对6类及以上抗生素耐药率为67.80%(240/354)。主要携带耐药基因Bla Z(92.66%)、Tet(M)(49.72%),毒素基因Tst(25.42%),IEC基因Sak(92.09%)和Hlb(61.58%)。结论健康儿童鼻腔MDRSA携带率较高,MDRSA对多种抗生素有高耐药率,且耐药类别≥6的比例高。

Objective To investigate the antibiotic resistance spectrum and genetic characteristics of multidrug-resistant Staphylococcus aureus( MDRSA) nasal isolate among primary school students,and to provide a scientific basis for the prevention and control of masal MDRSA resistance and the selection of clincal drugs in children. Methods Antibiotic susceptibility experiments were performed on all SA isolates of 1 705 primary school students from 8 primary schools in Guangzhou selected by using multistage cluster stratified sampling method. MDRSA antibiotic susceptibility spectrum was analyzed,and the resistant,virulence and immune evasion cluster( IEC) genes detected by polymerase chain reaction( PCR). Results The prevalence of MDRSA nasal carriage was 20.76%( 354/1 705),and the proportion of multidrug resistance among SA isolates was 96.20%( 354/368). The predominant resistant antibiotics of MDRSA isolates were penicillin( 99.72%),erythromycin( 96.33%),clindamycin( 90.96%) and teicoplanin( 90.11%). Notably,240( 67.80%,240/354) MDRSA isolates were resistant to more than six antimicrobial categories.And the predominant detection rates of resistant genes were Bla Z( 92.66%),Tet( M)( 49.72%),virulence genes Tst( 25.42%)and IEC genes Sak( 92.09%),Hlb( 61.58%). Conclusion We found high prevalence of nasal colonization MDRSA from healthy children. Moreover,MDRSA isolates has a high resistant rate to multiple antibiotics,and the proportion of resistant to ≥6 antimicrobial categories is high.