The resistance of multi-drug resistant Acinetobacter baumannii to tigecycline

Abstract

Objective To investigate the resistance of Acinetobacter baumannii to clinical common antibiotics and new drug tigecycline. Methods Six hundred and two Acinetobacter baumannii isolates were collected from 2008 to 2009 in four teaching hospitals in Zhejiang province. Agar dilution method was used to detect the resistance of 13 clinical commom antibiotics, polymyxin B and tigecycline. Homology analysis of 24 multi-drug resistant Acinetobacter baumannii strains was used to investigate the relationship of each strain with the method of pulsed field gel electrophoresis. Results From 2008 to 2009, the Acinetobacter baumannii isolates of four teaching hospitals in Zhejiang province were mainly isolated from respiratory specimens with the number of 277 (86.0%) strains in 2009, the number of blood samples decreased from 15 (5.4%) strains in 2008 to 5 ( 1.5% ) strains in 2009, and there were no obvious change in other specimens. Acinetobacter baumannii strains were resistant to 13 clinical common antibiotics at different degree, fluctuated from 35.0% to 85.0%. Compared with the resistance in 2008, levofloxacin and tobramyxin decreased 0. 9% and 9.0% in 2009, respectively. However, the resistance of other antibiotics increased at different degree, the resistance of ceftriaxone and cefepime increased about 10.0%, and the resistance of imipenem and meropenem increased to 74.2% (239/602) and 70.8% (228/602) in 2009,respectively. Acinetobacter baumannii showed high resistance to tigecycline with the percent of 78.9% (475/602), while it was only 3.7% (22/602) for polymyxin B. There were six cloning types among the 24 Acinetobacter baumannii isolates, and the most common type was type A with the percent of 50%.Conclusions The resistance of tigecycline makes the situation of nosocomial infectious more serious. It is necessary to control the transmission of multi-drug resistant Acinetobacter baumannii immediately. Key words: Acinetobacter baumannii; Minocycline; Drug resistance, multiple, bacterial; Electrophoresis, gel, pulsed-field