Status of carbapenem-resistant Acinetobacter baumannii harboring carbapenemase: First systematic review and meta-analysis from Iran

Carbapenem-resistant Acinetobacter baumannii (CRAB) has been considered as an important pathogen causing hospital-acquired infections thought the world. Class A carbapenemases, class B (metallo-beta-lactamases; MBLs) and class D (oxacillinases) are the most important enzymes that are able to hydrolyze carbapenems. There are various reports on the CRAB harboring carbapenemase genes in Iran; but, a comprehensive analysis on the prevalence of CRAB and carbapenemases has not yet been performed. We systematically searched different electronic databases including: Medline (via PubMed), Embase, Web of Science, and the Iranian Database from January 2000 to December 2018. Meta-analysis was performed using the Comprehensive Meta-Analysis (Biostat V2.2) software. Our analysis indicated that the pooled prevalence of resistance to imipenem and meropenem was 81.1% (95% CI 76.6-84.9) and 83.6% (95% CI 78.7-87.5), respectively. Among genes encoding class D carbapenemases OXA-23, OXA-24, and OXA-58 were found with the prevalence 73.7% (95% CI 66.5-79.8), 21.9% (95% CI 15.2-30.4), and 6.2% (95% CI 3.1-11.9), respectively. Among genes encoding class B carbapenemases, IMP, VIM and NDM genes were found with the prevalence 16.7% (95% CI 5-43.2) and 12.3% (95% CI 5.3-25.8) and 2.7% (95% CI 1.3-5.5), respectively. Genes encoding class A carbapenemases were not observed. The results of this study indicated that imipenem and meropenem resistance rates are high in Iran and these drugs are not recommended for A. baumannii infections. Thereby, antimicrobial stewardship and improvements in infection control practices are recommended strategies for prevention and spread of these strains.