مجله دانشکده پزشکی اصفهان (Feb 2015)
Frequency of Metallo-β-Lactamase and Antimicrobial Resistance Patterns of Acinetobacter Baumannii in Carbapenem-Resistant Isolates from Intensive Care Units of the Hospitals in Isfahan City, Iran
Abstract
Background: Acinetobacter baumannii is a gram-negative non-fermenting cocobacill or cocci, which is mostly found in soil, different water sources, and many healthcare environments. It is intrinsically resistance to many antibiotics. Nowadays, carbapenem is the last drug to be used for the treatment of infection of multidrug-resistant (MDR) Acinetobacter baumannii. Carbapenem-resistance in Acinetobacter baumannii strains is also expanding and in turn. The present study aimed to assess the frequency of metallo-β-lactamase (MBL) and antimicrobial resistance patterns of Acinetobacter baumannii in carbapenem-resistant isolates from intensive care units (ICUs). Methods: In a cross-sectional study during 2012-2013, Acinetobacter baumannii isolates from clinical specimens of patients hospitalized in the intensive care units (ICU) in hospitals of Isfahan city, Iran, were identified using genetic and biochemical methods. The susceptibility of isolates was determined via standard disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI). Metallo-β-lactamase-producing isolates were identified using Double Disc Synergy Test (DDST). Findings: 100 isolates were determined as Acinetobacter baumannii. The antimicrobial patterns of isolates showed that 62% of isolates were resistant to amikacin, 88% to tetracycline, 92% to ceftazidime, 96% to imipenem and meropenem, 93% to ampicillin-sulbactam, and 98% to ciprofloxacin, trimethoprim-sulfamethoxazole and cefepime. From 96 non-susceptible Acinetobacter baumannii strains imipenem, 95 (97.9%) were found to produce metallo-β-lactamase. Conclusion: To prevent spreading of the nosocomial infections caused by Acinetobacter baumannii in intensive care units, the rapid and accurate report of metallo-β-lactamase seems to be necessary in order to better monitor and more accurate tracking of multidrug-resistant strains.
