Investigation On Molecular Epidemiology Of Multidrug-Resistant Acinetobacter Baumannii

Objective:To investigate the drug resistance and homology of multidrug-resistant Acinetobacter baumannii(MDRAB),and analyze the prevalent cases,so as to provide reference for the prevention of the nosocomial infection and the clinical reasonable application of antibiotics.Methods:A total of 31 MDRAB isolates between June 2012 and December 2012 from the First Affiliated Hospital of Nanjing Medical University were collected,the bacteria were identified by automatic microbial identification system of BioMerieux Vitek-2 Compact,the susceptibility test of 12 kinds of antimicrobial agents was determined by K-B method,the homology analysis of the strains was determined by pulsed-field gel electrophoresis(PFGE).Retrospective investigation was performed on the clinical characteristics and therapeutic efficacy turnover of the patients with MDRAB infection.Results:The antimicrobial susceptibility showed that resistance rate of 31 MDRAB isolates to 9 antibiotics was 100%,including 4 kinds of antibacterial drugs.The results of PFGE demonstrated that 31 isolates were classified into 5 distinct genotypes,named type A,B,C,D,E and accounting for 12.90%,64.52%,9.68%,6.45%,6.45%respectively,among those 20 isolates belonged to clone B were the predominant epidemic strain.The patients with MDRAB infection were distributed among 9 wards,10(32.26%)isolates were from cardiothoracic surgery,9(29.03%)isolates were from intensive care unit,4(12.90%)isolates were from geriatric intensive care unit.The time of detected of 31 MDRAB isolates were mainly centralized in the fourth quarter,48.39%in November,19.35%in December,16.13%in October,9.68%in September,3.23%in July,3.23%in June.There were 15 patients complicated with infection in 31 MDRAB.The average age of the patients was 64,and 97%of them were undergone invasive procedures.Conclusions:The MDRAB was seriously resistant to almost all clinically-used antibiotics.It may be closely related to a variety of factors,such as the clonal spread,age of patients,long hospitalization time,invasive treatment and patients with multiple underlying medical conditions.It is necessary to strengthen the monitoring of drug resistant for effectively control the nosocomial infection.