Evaluation of genetic diversity of carbapenem-resistant Acinetobacter baumannii isolates using ERIC-PCR

Abstract Acinetobacter baumannii (A. baumannii) is one of the major opportunistic human pathogens related to several nosocomial infections. The infections due to this germ can be transmitted rapidly between patients. Typing methods are necessary to control the spread of such strains. From 81 clinical A. baumannii isolates, 23 carbapenem-resistant A. baumannii strains (CRAB) were selected for their similar profiles (antibiograms and expression of carbapenemases), to determine their diversity. Genetic relatedness among CRAB strains was evaluated using ERIC-PCR method. ERIC-PCR analysis showed high genetic diversity among the investigated strains. All CRAB isolates were classified into 15 ERIC types; ten of them represent a single ERIC-type. The greatest heterogeneity was related to the intensive care unit ward. According to our results, 13 (56.5%) strains were categorized into five main genotypes. These genotypes include multi-drug resistant isolates (MDR)harboring at least one class of carbapenemases, with particular attention to clonal transmission of high-risk A. baumannii in Moroccan hospital. The current study showed that the investigate isolates were genetically unrelated. Based on the great capacity of CRAB strains to colonize in hospital, the establishment, at the intra-hospital level, of an infection control policy would appear to be effective in reducing the spread of such high-risk isolates.