title: Frequency of Aminoglycoside-Resistance Genes in Methicillin-ResistantStaphylococcus aureus(MRSA) Isolates from Hospitalized Patients.
abstract: BACKGROUND
  Staphylococcus aureusis one of the most important causative agents in community- and hospital-acquired infections. Aminoglycosides are powerful bactericidal drugs that are often used in combination with beta-lactams or glycopeptides to treat staphylococcal infections.
  
  
  OBJECTIVE
  The main objective of the present study was to determine the prevalence of aminoglycoside resistance among methicillin-resistantStaphylococcus aureus(MRSA) isolates in hospitalized patients in Sari and Tehran, Iran.
  
  
  METHODS
  In this study, 174 MRSA strains isolated from different clinical samples, such as blood, sputum, tracheal exudates, bronchus, pleura, urine, wounds, and catheters, were collected from hospitalized patients in Tehran and Sari during 2014. Antibiotic susceptibility testing was performed against nine antibiotics with the Kirby-Bauer disk diffusion method according to CLSI guidelines. The MRSA strains were examined with oxacillin and cefoxitin disks. MRSA was then validated by detection of themecAgene. PCR was used to evaluate the prevalence of the aminoglycoside-resistance genesaac (6')-Ie/aph (2"),aph (3')-IIIa, andant (4')among the MRSA isolates.
  
  
  RESULTS
  The results of drug susceptibility testing showed that the highest rate of resistance was against erythromycin in Tehran (84.4%) and gentamicin (71.7%) in Sari. All isolates were sensitive to vancomycin, and all strains harbored themecAgene. Theaac (6')-Ie/aph (2"),aph (3')-IIIa, andant (4')-Iagenes were detected among 134 (77%), 119 (68.4%), and 122 (70.1%) of the isolates, respectively.
  
  
  CONCLUSIONS
  The present study showed a high prevalence of aminoglycoside-resistance genes among MRSA isolates in two cities in Iran.
authors: Department of Microbiology, School of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors: Seyed Mohsen
authors: SM
authors: Mahdiyoun
authors: Department of Medical Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, IR Iran.
authors: Hossein
authors: H
authors: Kazemian
authors: Department of Microbiology, Molecular and Cellular Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran.
authors: Mohammad
authors: M
authors: Ahanjan
authors: Department of Medical Microbiology School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors: Hamidreza
authors: H
authors: Houri
authors: Department of Medical Microbiology School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors: Mehdi
authors: M
authors: Goudarzi
keywords: Aminoglycosides; Drug Resistance; Methicillin-Resistant Staphylococcus aureus