Detection of Metallo-β-lactamase-producing Imipenem-resistant Pseudomonas Aeruginosa and their Antibiotic-resistance

Objective To investigate metallo-β-lactamase-producing imipenem-resistant Pseudomonas aeruginosa and antibiotic-resistance,and give some suggestions for clinical antibiotic selection.Methods Bacterium identification and antimicrobial susceptibility were tested by WalkAway-40 full automated microbial analytic instrument and the producing of metallo-β-lactamases(MBLs)was detected by double-disk synergy test(DDST).Results From 1999 to 2005,the resistance rates of Pseudomonas aeruginosa to imipenem grew from 13.0% to 39.1%.The resistance rates of imipenem-resistant Pseudomonas aeruginosa to amikacin,ceftazidime,piperacillin/tazobactam and cefepime ranged from 60% to 63%,and to tobramycin,aztreonam,gentamicin,ciprofloxacin,piperacillin,the rates were 66.5%,68.0%,70.7%,71.0% and 72.2% respectively.The incidence of MBLs was 15.7%.Conclusion Imipenem-resistant Pseudomonas aeruginosa increased year by year and their antimicrobial resistance were serious.Producing MBLs is one of the important mechanisms of Pseudomonas aeruginosa which resistant to imipenem.The clinical laboratories should reinforce the detection of MBLs.