Investigation of acquired resistant genes and mobile genetic elements indrug-resistant Acinetobacter baumannii isolated from Pujiang, Zhejiang province

OBJECTIVE To investigate the distribution of acquired resistant genes and mobile genetic elements,and phylogenetic analysis among agroup of drug-resistant Acinetobacter baumannii,so as to understand the drug-resistant mechanism and epidemiological situation.METHODS A total of 20 strains of A.baumannii were collected from the Pujiang People′s Hospital,Zhejiang Province in 2015.Then,resistance genes were analyzed by PCR,including 32 kinds of acquired beta-lactamase genes,15 kinds of acquired resistant genes to aminoglycosides,and 10 kinds of genetic markers of mobile genetic elements.In addition,sample cluster analysis was performed（UPGMA）.RESULTS Totally 4kinds of acquired beta-lactamase genes（blaTEM,blaADC,blaOXA-23 group,and blaOXA-66）,3kinds of acquired resistant genes to aminoglycosides（aac（3）-Ⅰ,aac（6′）-Ⅰb,and ant（3″）-Ⅰ）,5kinds of genetic markers of mobile genetic elements（intⅠ1,tnpU,tnp513,ISaba1,and IS26）were positive in20 strains of A.Baumannii,and positive rates were high,and were divided into 6kinds of positive models.Sample cluster analysis showed that strains were divided into cluster A and B,and clones existed in 2clusters:strain No.1-2-4-5-7-9-17-19 and strain No.3-10 in cluster A,and strain No.16-18,strain No.6-14-20,strain No.8-11-12-13 in cluster B.CONCLUSION Acquired resistant genes to beta-lactams and aminoglycosides in this group of A.baumannii played a key role in resistance to beta-lactams and aminoglycosides,and these genes were mediated by mobile genetic elements.It is important to monitor and control noscomial infection intime depending on phylogenetic analysis among strains.