title: Clonal relatedness and biofilm formation of OXA-23-producing carbapenem resistant Acinetobacter baumannii isolates from hospital environment.
abstract: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a serious threat for hospitalized patients and it can survive for long periods in hospital settings, particularly on inanimate surfaces. The environment occupied by these resistant and resilient isolates may act as a reservoir for cross-colonization and outbreaks. Here, we aimed to determine the distribution of CRAB in the hospital environment and to characterize their clonal relatedness, susceptibility profile, carriage of blaOXAgenes, and biofilm formation. A total of 1080 samples were collected from various environmental surfaces and equipment of two referral hospitals in Tehran, Iran. The A. baumannii isolates were subjected to gyrB multiplex PCR, antibiotic susceptibility testing, biofilm formation assay, pulsed field gel electrophoresis (PFGE), and multiplex PCR for blaOXA-58, blaOXA-24, and blaOXA-23genes. Eighteen Acinetobacter spp. were isolated; 8 were identified as A. baumannii and 10 as A. lwoffii. Five of A. baumannii isolates were CRAB and exhibited the multidrug-resistant (MDR) phenotype as well. All CRAB isolates produced biofilm, albeit with different levels. Four of CRAB isolates harbored the blaOXA-23. The CRAB isolates were clustered into 3 distinct pulsotypes (PTs). The CRAB isolates belonging to PT1 were detected in two geographically distinct hospitals whereas those belonging to PT3 were found in two different units of same hospital. This study revealed the presence of clonally related OXA-23-producing CRAB in high risk units of referral hospitals as inter- or intra-hospital dissemination. The distribution of multiresistant A. baumannii on several surfaces and areas may increase the risk of transmission of resistant isolates to vulnerable patients.
authors: Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Amir
authors: A
authors: Aliramezani
authors: Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: mdouraghi@tums.ac.ir.
authors: Masoumeh
authors: M
authors: Douraghi
authors: Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Azade
authors: A
authors: Hajihasani
authors: Pediatrics Infectious Diseases Research Center, Department of Infectious Diseases, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Mona
authors: M
authors: Mohammadzadeh
authors: Department of Microbiology, Reference Health Laboratories, Ministry of Health, Tehran, Iran.
authors: Mohammad
authors: M
authors: Rahbar
mesh_terms: D040981:Acinetobacter baumannii / Q000145:classification* / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D018441:Biofilms / Q000254:growth & development; D016000:Cluster Analysis; D027081:DNA Gyrase / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D014644:Genetic Variation; D005838:Genotype; D006761:Hospitals; D007492:Iran / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058889:Molecular Typing; D060885:Multiplex Polymerase Chain Reaction; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000032:analysis* / Q000235:genetics
chemical_list: C466679:beta-lactamase OXA-23; D001618:beta-Lactamases; D027081:DNA Gyrase
keywords: Biofilm; Carbapenem-resistant Acinetobacter baumannii (CRAB); Healthcare environment; bla(OXA-23)