Determination of Pseudomonas Aeruginos Producing Metallo-Beta-Lactamases Isolated from Clinical Specimens by Imipenem-EDTA Combined Disk Method in Ahwaz, Iran

Pseudomonas aeruginosa is a causative agent of nosocomial infections. Metallo-beta-lactamases (MBLs) are considered among the most crucial resistant agents of Pseudomonas aeruginosa to carbapenem. Because of the important role of carbapenemes in the treatment of Pseudomonas infections، in this study، the Pseudomonas aeruginosa producing metallo-beta-lactamases were investigated. A total of 236 Pseudomonas aeruginosa were examined. These isolates were collected from hospitalized patients’ clinical specimens in Imam Khomeini and Golestan hospitals of Ahvaz، Iran. After identification of the isolates by standard biochemical tests، their antimicrobial resistant patterns to 10 common antibiotics were determined based on CLSI protocol by disk diffusion agar method. Finally، the metallo-beta-lactamase production by Pseudomonas aeruginosa isolates was identified by Imipenem-EDTA combined disk method. Of 236 Pseudomonas aeruginosa isolates، 122 isolates (51. 4%) were resistent to imipenem. Based on the results of Imipenem-EDTA combined disk method، production of metallo-beta-lactamases was known in 110/122 (90%) Pseudomonas aeruginosa isolates. Since MBLs producing Pseudomonas aeruginosa are resistant to all other beta-lactam antibiotics، it is vital to screen imipenem non-susceptible isolates of Pseudomonas aeruginosa for MBLs production. This will be effective in the selection of suitable antibiotic and recovery pace of the patients.