title: Biofilm formation and antimicrobial resistance in methicillin-resistant Staphylococcus aureus isolated from burn patients, Iran.
abstract: BACKGROUND
  Burns are the most serious forms of trauma and a major cause of mortality worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common pathogens of burn wound infections; treatment has faced serious problems due to antibiotic resistance in these strains. Biofilm formation, which increases antibiotic resistance capabilities and is considered to be a virulence factor, also causes treatment failure and recurrent staphylococcal infections in burn patients.
  
  
  METHODS
  A total of 135 pus/wound swabs were collected; S. aureus was identified by confirmatory tests. The icaA/D and mecA genes were detected in DNA extracts by polymerase chain reaction assay separately. To determine the prevalence of biofilm formation, a modified Congo red agar and the microtiter plate method were used. Investigation of antibiotic resistance was performed using the disk diffusion method.
  
  
  RESULTS
  S. aureus (48.87%) was identified in 65 (48.87%) samples, of which 40 (61.53%) were confirmed to be MRSA. Among MRSA and methicillin-sensitive S. aureus (MSSA) isolates, 97.5% and 60% produced biofilm, respectively. Resistance of MRSA isolates to amikacin, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, mupirocin, rifampin, tetracycline, and tobramycin was 64.1%, 76.92%, 51.28%, 87.18%, 71.8%, 10.26%, 5.13%, 89.74%, and 61.54%, respectively. All MRSA and MSSA isolates were susceptible to fusidic acid, linezolid, teicoplanin, tigecycline, and vancomycin.
  
  
  CONCLUSIONS
  The high prevalence of biofilm-producing, drug-resistant S. aureus isolates in our study suggests that epidemiological studies on the characteristics of common strains found in burn centers and a definition of their antibiotic resistance pattern would be helpful for therapeutic decisions.
authors.affiliation: School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. s-ohadian@razi.tums.ac.ir.
authors.forename: Solmaz
authors.initials: S
authors.lastname: Ohadian Moghadam
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Pourmand
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Aminharati
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D002056:Burns / Q000150:complications*; D024881:Drug Resistance, Bacterial; D006801:Humans; D007492:Iran; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D046915:Penicillin-Binding Proteins; D013203:Staphylococcal Infections / Q000382:microbiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; D037521:Virulence Factors; C487789:mecA protein, Staphylococcus aureus