老年住院患者感染鲍曼不动杆菌克隆相关性及耐药表型分析研究

Clonal Relatedness and Antimicrobial Susceptibility Profiling of Acinetobacter Baumannii Isolates from Senile Patients

目的对分离自老年住院患者的鲍曼不动杆菌药物敏感性和基因型进行横向和纵向分析,以获得其耐药表型及克隆相关性。方法横向分析对象是2013~2014年间分离自170例老年住院患者的170株鲍曼不动杆菌,纵向分析对象是随机选择8例长期感染鲍曼不动杆菌的老年患者,共收集77株反复分离出的菌株。结果 170株非重复菌株中75.3%对碳青霉烯类药物不敏感,表现为泛耐药或多重耐药,分布在老年病房的各个科室;通过脉冲电场凝胶电泳(PFGE)把170株菌分为36个型,其中Ⅰ型(共119株菌)为主要流行株,表现为泛耐药。纵向研究中,77株菌都为泛耐药表型,PFGE分型显示其中76株菌都属于Ⅰ型。结论泛耐药鲍曼不动杆菌在该院老年病房肆虐流行,克隆播散是其最主要的传播方式。相关人员需要加强管控措施阻断人与人之间的水平传播,阻止泛耐药菌的继续播散。

Objective To investigate the clonal relatedness of A. baumannii isolates from senile patients by conducting cross- sectional and longitudinal studies on antimicrobial susceptibility profiling and genomic diversity. Methods Cross-sectional study was done among the 170 non-repetitive A. baumannii isolates which were collected from senile patients during two years. Longitudinal study was conducted among 77 A. baumannii collected from 8 senile patients within longtime hospitalization. Results 75.3% of the 170 isolates were non-susceptible to carbapenems,and the phenotype were XDR or MDR which spread evenly all over the senile wards. The isolates belonged to 36 pulsotypes determined by PFGE. Groups I （containll9 isolates） were major epidemic strains, which were CRAB with XDR phenotype. In longitudinal study, comparison of pulsotypes was performed for each patient and all isolates were clustered into group I except one isolate. All the 77 isolates were XDR. Conclusion Extensive drug-resistance of A. baumannii was a serious problem in the gerontal wards. Clone dissemination was the most important style of XDR strains spread. Horizontal infection control measures to interrupt person-to-person transmission should be reinforced to reduce the further spread of XDR A. baumannii.