Evaluation of aminoglycoside modifying enzymes, SCCmec, coagulase gene and PCR-RFLP coagulase gene typing of Staphylococcus aureus isolates from hospitals in Shiraz, southwest of Iran

Javad Fathi; Zahra Hashemizadeh; Reza Solymani Dehkordi; Abdollah Bazargani; Kasra Javadi; Hossein Hosseini-Nave; Mahtab Hadadi

doi:10.1016/j.heliyon.2022.e10230

Evaluation of aminoglycoside modifying enzymes, SCCmec, coagulase gene and PCR-RFLP coagulase gene typing of Staphylococcus aureus isolates from hospitals in Shiraz, southwest of Iran

Heliyon. 2022 Aug 13;8(8):e10230. doi: 10.1016/j.heliyon.2022.e10230. eCollection 2022 Aug.

Authors

Javad Fathi^{1

2}, Zahra Hashemizadeh^{1

3}, Reza Solymani Dehkordi⁴, Abdollah Bazargani¹, Kasra Javadi¹, Hossein Hosseini-Nave⁵, Mahtab Hadadi¹

Affiliations

¹ Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
² Student Research Committee, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
³ Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
⁴ Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
⁵ Department of Microbiology and Virology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.

Abstract

Staphylococcus aureus is an important human pathogen that causes various infections. Aminoglycosides are broad-spectrum antibiotics used to treat methicillinresistant S. aureus (MRSA) infections. Typing of S. aureus isolates by coagulase gene typing and PCR-RFLP coa gene is a fast and suitable method for epidemiological studies. Aim of the present study was to evaluate the resistance to aminoglycosides, staphylococcal chromosomal cassette mec (SCCmec) types, coagulation typing and PCR-RFLP coa gene in clinical isolates of S. aureus. 192 S. aureus isolates were collected from Namazi and Shahid Faghihi hospitals. Antibiotic resistance was measured by disk diffusion method and MIC was determined for gentamicin. The presence of genes encoding aminoglycoside modifying enzymes (AME) and mecA gene were assessed by PCR. Also the coagulase typing, PCR-RFLP coa gene, and SCCmec typing were performed. Out of 192 isolated S. aureus isolates, 83 (43.2%) MRSA isolates were identified. In this study, a high resistance to streptomycin and gentamicin (98.7%) were observed. Among the AME genes, the aac (6')-Ie-aph (2″) gene was the most common. Based on the SCCmec typing, it was determined that the prevalence of SCCmec type III (45.8%) was highest. From the amplification of the coa gene, 5 different types were obtained. Also, in digestion of coa gene products by HaeIII enzyme, 10 different RFLP patterns were observed. According to this study, aminoglycoside resistance is increasing among MRSA isolates. As a result, monitoring and control of aminoglycoside resistance can be effective in the treatment of MRSA isolates. Also, typing of S. aureus isolates based on coagulase gene polymorphism is a suitable method for epidemiological studies.

Keywords: AMEs gene; Coagulase typing; RFLP coa; SCCmec typing; Staphylococcus aureus.