title: Detection of Metallo-Beta Lactamases Among Carbapenem-Resistant Pseudomonas aeruginosa.
abstract: BACKGROUND
  Carbapenems are important drugs used for the treatment of Pseudomonas aeruginosa infections, however metallo-β-lactamases (MBL) are able to efficiently hydrolyze these classes of drugs. Immediate detection of the MBL-producing P. aeruginosa is necessary in order to accurately treat infections caused by this organism.
  
  
  OBJECTIVE
  To determine the prevalence of MBL producing P. aeruginosa in burn and non-burn patients by two phenotypic tests and polymerase chain reaction (PCR) and to compare phenotypic tests with PCR.
  
  
  METHODS
  A total of 223 non-duplicate strains of P. aeruginosa were collected from three teaching hospitals of Ahvaz, Iran. Antimicrobial susceptibility and minimum inhibitory concentrations (MICs) of carbapenems (imipenem, meropenem, doripenem and ertapenem) were determined by the Kirby-Bauer and E-test methods. Combined disk (CD) test, MBL E-test and PCR were performed for carbapenem-resistant P. aeruginosa isolates.
  
  
  RESULTS
  Amongst all the P. aeruginosa isolates, 58.7% were resistant to imipenem while 31.8%, 13.5% and 74.4% were resistant to meropenem, doripenem and ertapenem, respectively. Amongst all the P. aeruginosa isolates, 44.4% were multidrug resistant and 13.45% were resistant to all of the carbapenems. The CD test with doripenem disk / 750 μg ethylene diamine tetra acetic acid (EDTA) had the highest efficiency compared to the other phenotypic tests. bla IMP and bla VIM genes were detected in 11.7% and 0.4% of isolates, respectively. bla SPM and bla NDM genes were not observed.
  
  
  CONCLUSIONS
  Epidemiological and regional evaluation of MBL-producing P. aeruginosa through simple and inexpensive methods should be considered for effective treatment of carbapenem-resistant P. aeruginosa infections.
authors.affiliation: Department of Microbiology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Farajzadeh Sheikh
authors.affiliation: Department of Microbiology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran ; Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Soodabeh
authors.initials: S
authors.lastname: Rostami
authors.affiliation: Department of Biomolecular and Biochemistry, School of Veterinary Medicine, Shahid Chamran University, Ahvaz, IR Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Jolodar
authors.affiliation: Department of Genetic, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Tabatabaiefar
authors.affiliation: Nosocomial Infections Research Centre, Isfahan University of Medical Sciences, Isfahan, IR Iran.
authors.forename: Farzin
authors.initials: F
authors.lastname: Khorvash
authors.affiliation: Department of Biostatistics and Epidemiology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Saki
authors.affiliation: Department of Microbiology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Shoja
authors.affiliation: Department of Microbiology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Raheleh
authors.initials: R
authors.lastname: Sheikhi
keywords: Carbapenemase; Metallo-beta- lactamase; Pseudomonas aeruginosa