Contribution of Contaminated Environmental Surfaces to the Transmission of Multidrug-resistant Acinetobacter baumannii in Special Care Units of a Hospital in Tehran, Iran

Introduction: Acinetobacter baumannii is one of the major causes of nosocomial infections. We investigated the presence of A. baumannii among patients and the environment in special care units of a hospital in Tehran, Iran. Methods: Sixty-nine non-duplicate clinical and environmental samples were collected from ICU, Post-ICU, and CCU in EbneSina Hospital (Tehran, Iran) from June 2015 to April 2016. The isolates were identified using standard biochemical tests, and their identity was confirmed by detection of blaoxa51 gene. Susceptibility to 14 antibiotics was determined by the disc diffusion method, and genetic fingerprinting of the isolates was performed by random amplified polymorphic DNA (RAPD-PCR). Results: We recovered 66 A. baumannii isolates, 41 from patients, and 25 from the environment. All isolates from patients were resistant to all tested antibiotics except colistin. Environmental isolates were resistant to piperacillin (100%), tetracycline, piperacillin/tazobactam, beta-lactams and quinolones (86%), and amikacin (81%) but sensitive to colistin. The RAPD-PCR results revealed 35 clusters with 80% similarity. Despite the heterogeneity among the RAPD-PCR profiles, similar patterns were observed among 11 clusters comprising both clinical and environmental isolates. Conclusion: The results of this research suggest that the presence of A. baumannii on hospital surfaces could have played an essential role in causing infection in the hospitalized patients. J Med Microbiol Infec Dis, 2018, 6 (2-3): 37-42.