title: Beta-Lactamase Encoded Genes blaTEM and blaCTX Among Acinetobacter baumannii Species Isolated From Medical Devices of Intensive Care Units in Tehran Hospitals.
abstract: BACKGROUND
  Excessive consumption of antimicrobial materials in hospitals is considered as the main encoder leading to the emergence, development and acquisition of new bacterial resistance to beta-lactamase.
  
  
  OBJECTIVE
  Owing to the lack of proper information regarding the mechanism of the bacterial resistance to antibiotics and responsible genes in the country, the current study aimed to consider the resistance or sensitivity of the Acinetobacter baumannii multi drug resistant (MDR) isolates facing 2% glutaraldehyde. The study was conducted in the selected intensive care units in Tehran hospitals, Iran, in 2013.
  
  
  METHODS
  In this study conducted over a period of 10 months, A. baumannii species were isolated by bacterial culture following biochemical tests from intensive care units (ICUs) of some hospitals in Tehran, Iran (Fayazbaksh, Taleghani, Imam Khomeini, Valiasr, Labafinejad). The resistance and sensitivity of the isolates to antibiotics were considered according to the clinical and laboratory standard institute CLSI (2012) guidelines. By multiplex PCR method, blaCTX and blaTEM genes were detected and finally, MDR strains were treated with 2% glutaraldehyde. PCR was used for each strain of MDR using specific primers.
  
  
  RESULTS
  In the current study, 131 A. baumannii isolates (22.3%) out of 588 were studied. The level of resistance to various antibiotics was in the range of 69.4% to 100%. The frequencies of blaTEM and blaCTX genes were 3.2% and 19.4%, respectively. MIC50% and MIC90% of imipenem and meropenem antibiotics were 32 ± 1 µg/mL and 64 ± 1 µg/mL, respectively (P < 0.9). However no resistance to glutaraldehyde was observed. Different bands of MDR strains were observed in the PCR product by electrophoresis.
  
  
  CONCLUSIONS
  It seems that besides the variety and prevalence of blaTEM and blaCTX, enormous mechanisms such as porin and leaking systems (efflux pumps) are responsible for the information of the A. baumannii resistance to disinfectants. The study on an accurate consideration of the resistance in strains and other microorganisms is advised.
authors.affiliation: Department of Microbiology, Guilan Science and Research Branch, Islamic Azad University, Rasht, IR Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Khalilzadegan
authors.affiliation: International Branch, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Sade
authors.affiliation: Microbiology Group, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Hussein
authors.initials: H
authors.lastname: Godarzi
authors.affiliation: Microbiology Group, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Gita
authors.initials: G
authors.lastname: Eslami
authors.affiliation: Microbiology Group, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Hallajzade
authors.affiliation: Microbiology Group, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Fallah
authors.affiliation: Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Davood
authors.initials: D
authors.lastname: Yadegarnia
keywords: Acinetobacter baumannii; Antimicrobial Resistance; Disinfectants; Lactamase Genes