title: Biofilm Formation and Virulence Factors Among Pseudomonas aeruginosa Isolated From Burn Patients.
abstract: BACKGROUND
  Pseudomonas aeruginosa possesses a variety of virulence factors and infections caused by multidrug-resistant P. aeruginosa (MDRPA) in burn patients are a public health problem.
  
  
  OBJECTIVE
  The aim of this study was to determine the antibiotic resistance pattern, the biofilm formation, the prevalence of MDRPA and two virulence genes (nan1 and exoA) among P. aeruginosa isolated from burn patients.
  
  
  METHODS
  A total of 144 isolates of P. aeruginosa were collected from burn patient at the Burn Centre of Tehran, Iran, between March 2013 and July 2013. Antibiotic susceptibility test was performed via agar disk diffusion method. The ability of producing biofilm was examined by crystal violet microtiter plate assay and the prevalence of the exoA and nan1 genes among the isolates was determined by polymerase chain reaction (PCR).
  
  
  RESULTS
  A high rate of resistance was seen against ciprofloxacin (93.7%), aztreonam (86.8%), piperacillin (85.4%), ceftazidime (82.6%), amikacin (82%) and imipenem (79.2%). In total, 93.1% of the isolates were characterized as MDRPA. Biofilm formation was seen in 92.4% of the isolates. The prevalence of the exoA and nan1 genes were 75% and 11.8% among the isolates, respectively.
  
  
  CONCLUSIONS
  The high rate of MDRPA and its ability to produce biofilm is an alarm for public health. The statistical analysis showed that biofilm production in the MDRPA isolates was significantly higher than that in the non-MDRPA isolates (P < 0.001).
authors.affiliation: Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, IR Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Ghanbarzadeh Corehtash
authors.affiliation: Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, IR Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Khorshidi
authors.affiliation: Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, IR Iran.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Firoozeh
authors.affiliation: Biostatistics Department, Truma Research center, Kashan University of Medical Sciences, Kashan, IR Iran.
authors.forename: Hosein
authors.initials: H
authors.lastname: Akbari
authors.affiliation: Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran.
authors.forename: Azam
authors.initials: A
authors.lastname: Mahmoudi Aznaveh
keywords: Biofilms; Burns; Pseudomonas aeruginosa; Virulence factors