Molecular epidemiology and characterization of genotypic analysis of Acinetobacter baumannii strains isolates from south China

抄録

This study aimed to analyze the molecular epidemiologic characteristics of Acinetobacter baumannii. A total of 398 isolates were collected from seven parts of south China from January to June, 2012. Drug susceptibility was tested against 15 commonly used antibiotics and 146 multi-drug resistant strains (resistant to more than 7 drugs) were identified, representing 36.7% of the total. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used for molecular typing. Based on PFGE results with a cut off of 70% similarity on the DNA electrophoresis bands, 146 strains were divided into 15 clusters with cluster A as the largest cluster (33.6%, distributed in all districts except Jiaxing). Cluster B was also very popular and included 14.4% of total strains. In addition, MLST results revealed 11 sequences types (ST) with ST208 as the most popular one followed by ST191 and ST729. Furthermore, in this study, 4 new alleles and 6 new STs were discovered. Our results showed that multi-drug resistant Acinetobacter baumannii in south China shared the same origin with other popular strains in other countries. The nosocomial infection caused by Acinetobacter baumannii has been extremely severe in south China. Continuous monitoring and judicious antibiotic usage are required.