The purpose of this study was to determine the antimicrobial resistance-related genes in Staphylococcus aureus isolated from patients referred to 14 teaching hospitals, Tehran, Iran.
A total of 225 S. aureus were obtained from clinical samples in a period of 12 months. Antimicrobial resistance, minimum inhibitory concentration minimal inhibitory concentration and Inducible resistance phenotypes were determined based on the Clinical laboratory standard institute (CLSI) guidelines. PCR was performed for amplification of mecA/B/C, iles-2, ermA/B/C and ereA/B genes.
39.5 and 40.8% of isolates were resistant to oxacillin and cefoxitin (FOX), respectively. The frequency of constitutive macrolide-lincosamide-streptograminB, inducible macrolide-lincosamide-streptograminB and MS phenotypes were 55.3, 28.6 and 16.1%, respectively. 40.8, 4, 7.5, 6.2, 16 and 3.1% of strains harbored the mecA, ileS-2, ermA, ermB, ermC and ereA genes, respectively.
The frequency of methicillin-resistant S. aureus isolates in our hospitals was high and disk diffusion testing using FOX or oxacillin and/or FOX minimal inhibitory concentration E test as an alternative to PCR for identification of methicillin-resistant S. aureus is suggested. This study highlights the hypothesis that rapid testing plays an important role in antibiotic stewardship by getting patients on targeted therapy faster.
aDepartment of Microbiology, School of Medicine
bMicrobial Biotechnology Research Center
cDepartment of Pediatrics, Iran University of Medical Sciences, Tehran
dDepartment of Microbiology, School of Medicine, Babol University of Medical Sciences, Babol
eDepartment of Microbiology, Faculty of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Correspondence to Gholamreza Irajian, Department of Microbiology, School of Medicine, Iran University of Medical Science, Tehran, Iran. Tel: +98 21 8805 8649; fax: +98 21 8805 8649; e-mail: Irajian@gmail.com; Shabnam Razavi, Microbial Biotechnology Research Center, Iran University of Medical Sciences, Tehran, Iran. E-mail: email@example.com
Received 21 September, 2018
Revised 5 January, 2019
Accepted 13 January, 2019