Molecular Detection of Macrolide and Lincosamide-Resistance Genes in Clinical Methicillin-Resistant Staphylococcus aureus Isolates from Kerman, Iran

Background: Staphylococcus aureus is a common pathogen in hospitals and communities. Antibiotic resistance is a major public health problem. Objectives: The aim of this study was the determination of antimicrobial susceptibility patterns and to perform molecular detection of macrolide and lincosamide-resistance genes in clinical S. aureus isolates from Kerman, Iran. Methods: From February 2014 to December 2015, a total of 170 clinical S. aureus isolates were obtained. Resistance to different antibiotics was determined by the disk diffusion method. Methicillin-resistant S. aureus (MRSA) and inducible clindamycin resistance were confirmed by phenotypic methods, and polymerase chain reaction (PCR) was used to detect the nuc, mecA, ermA, ermB, ermC, and mrsA/B genes. Results: All isolates were sensitive to linezolid and vancomycin. In total, more than 50% of the isolates were multidrug resistant (MDR) and 52.5% were MRSA. Inducible clindamycin resistance was observed in 12.5% of the isolates. The prevalences of the mecA, ermA, ermB, ermC, and mrsA/B genes in the isolates were 39.5% (69/170), 11% (19/170), 3.5% (6/170), 20.5% (35/170), and 10.5% (18/170), respectively. Conclusions: A high prevalence of macrolide and lincosamide-resistant genes were found in S. aureus isolates from nosocomial and community-acquired infections in Kerman, Iran. The investigation of antibiotic resistance may provide crucial information about the control of such infections, and it is necessary to accurately identify antibiotic resistance on routine susceptibility tests.