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Updated: Feb 23, 2026
Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
Published on: September 5, 2013
Prevalence and molecular typing of methicillin-resistant Staphylococcus aureus carrying Panton-Valentine leukocidin
Maryam Rahimpour Hesari1, Ali Salehzadeh1, Reza Kazemi Darsanaki2
11 Department of Biology, Rasht Branch, Islamic Azad University , Rasht, Iran.
Abstract:
Panton-Valentine leukocidin (pvl) toxin is an important virulence factor of Staphylococcus aureus. The main genes are coa and spa for distinguishing and typing of S. aureus isolates. The aim of this study was to investigate antibiotic resistance, presence of mecA and pvl genes, as well as epidemiological typing of these isolates according to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in clinical sample isolated from Rasht city, Iran. A total of 250 clinical samples have been isolated from different hospitals. First, isolates of S. aureus were identified through microbiological methods and their antibiotic sensitivity was determined by disk diffusion agar based on a standard method of Clinical and Laboratory Standards Institute. DNA was extracted by boiling and presence of pvl and mecA genes was investigated by PCR using specific primers. To type these isolates, amplification of fragments of coa and spa genes was done and restriction enzyme digestion pattern was determined by PCR-RFLP method. Among the 250 samples, 50 isolates belonged to S. aureus and results of antibiotic sensitivity showed that 68% (34 samples) of isolates were methicillin resistant. Frequency of mecA and pvl genes among S. aureus isolates were 60% (30 samples) and 20% (10 samples). The PCR of coa gene showed three patterns whereas that of spa gene showed two patterns for enzyme digestion. Result of PCR-RFLP using HaeIII enzymes for coa gene and Bsp1431 for spa gene showed three patterns for enzyme digestion. Recent studies indicated increase in the resistance of S. aureus to different antibiotics, which is a serious problem in the treatment of infections resulting from S. aureus in this region. The result of PCR of pvl showed high frequency of this gene in this region, and coa and spa typing by PCR-RFLP was a useful tool for typing of S. aureus isolates.
Insights
This study found high rates of antibiotic resistance and the presence of Panton-Valentine leukocidin (PVL) toxin genes in Staphylococcus aureus clinical isolates from Rasht, Iran. Epidemiological typing using PCR-RFLP identified distinct patterns for coa and spa genes.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Epidemiology
Background:
- Staphylococcus aureus is a significant pathogen, with Panton-Valentine leukocidin (PVL) as a key virulence factor.
- Antibiotic resistance in S. aureus poses a growing global health challenge.
- Typing methods are crucial for understanding the epidemiology of S. aureus infections.
Purpose of the Study:
- To investigate antibiotic resistance patterns, prevalence of mecA and pvl genes, and perform epidemiological typing of S. aureus clinical isolates.
- To assess the utility of PCR-RFLP for S. aureus isolate characterization.
- To analyze clinical samples from Rasht city, Iran.
Main Methods:
- Microbiological identification of S. aureus from 250 clinical samples.
- Antibiotic sensitivity testing using disk diffusion.
- DNA extraction followed by PCR for mecA and pvl genes.
- PCR-RFLP of coa and spa genes using specific restriction enzymes (HaeIII and Bsp1431).
Main Results:
- 50 S. aureus isolates were identified; 68% were methicillin-resistant (MRSA).
- mecA gene was detected in 60% and pvl gene in 20% of isolates.
- PCR-RFLP revealed three distinct patterns for coa gene and two for spa gene.
Conclusions:
- High prevalence of antibiotic resistance and PVL genes in S. aureus from Rasht.
- PCR-RFLP is an effective tool for epidemiological typing of S. aureus.
- Findings highlight the need for surveillance and control of S. aureus infections in the region.
