Prevalence of aac(۶') - Ie / aph (۲") and aph (۳') - IIIa genes among clinical isolates of Staphylococcus aureus isolated from patients of selected hospitals in Mashhad

Background and Aim : Staphylococcus aureus is considered as one of the most important pathogenic bacteria and the most common type of nosocomial infections. Enzymatic inactivation of aminoglycosides by aminoglycoside-modifying enzymes (AMES) is the main mechanism of resistance to these antibiotics in S. aureus. The aim of this study was to investigate the prevalence of aac (۶ ') - Ie / aph (۲") and aph (۳') - IIIa resistance gene among clinical isolates of S. aureus.Methods : Clinical staphylococcus aureus isolates were isolated during September ۲۰۱۹- March ۲۰۲۰ from selected hospitals in Mashhad. The pattern of antibiotic susceptibility to gentamicin, tobramycin, and amikacin were determined by disc diffusion method. DNA was extracted and prevalence of aac (۶ ') -Ie / aph (۲") and aph (۳') - IIIa resistance genes were detected by PCR and electrophoresisResults : The results of this study showed that among ۱۰۰ isolates of S. aureus ۱۹, ۲۷, and ۴۵ percent of these isolates were resistant to gentamicin, tobramycin and amikacin respectively. Also, ۶۲ and ۴۴ of S. aureus isolates had the aac (۶ ') - Ie / aph (۲ ") and aph (۳') - IIIa genes.Conclusion : Due to the high percentage of genes encoding aminoglycoside resistance in S. aureus isolates which were isolated from hospital sources, continuous monitoring of nosocomial infection control processes is necessary to prevent the spread of resistant bacteria in the environment and its transmission to patients

Keywords:

Aminoglycoside resistance , Polymerase chain reaction , S. aureus