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Updated: Jul 2, 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
Multiplex PCR detection of the antibiotic resistance genes in Staphylococcus aureus strains isolated from auricular
T Zmantar1, K Chaieb, F Ben Abdallah
1Laboratoire d'Analyse, Traitement et Valorisation des Polluants de l'Environnement et des Produits, Faculté de Pharmacie, Monastir, Tunisia. zmantar_t@yahoo.fr
Abstract:
Thirty-five Staphylococcus aureus strains from auricular infections were isolated. The identification of strains was confirmed by Api ID 32 Staph strips, the antibiotic susceptibility test was performed using ATB Staph kit. PCR assay was used to detect the oxacillin resistance gene (mecA) and the erythromycin genes (ermA, ermB, ermC, msrA and mef). The susceptibility profile of all strains revealed a low resistance level to oxacillin and erythromycin. The PCR results show that 60 % of the strains are mecA positive. The frequency of erythromycin genes was: ermA (+) 22.8 %, ermB (+) 45.7, ermC (+) 17.1, msrA (+) 28.6. The mef gene was not detected in any strain. No correlations between genotypic and phenotypic methods for the determination of oxacillin and erythromycin resistance was found. However, multiplex PCR technique was shown to be a fast, practical and economic technique for the detection of methicillin-and erythromycin-resistant staphylococci.
Insights
This study investigated Staphylococcus aureus from ear infections, finding low resistance to oxacillin and erythromycin. Multiplex PCR efficiently detected resistance genes, highlighting its practical application for identifying resistant staphylococci.
Area of Science:
- Microbiology
- Molecular Biology
- Clinical Science
Background:
- Staphylococcus aureus is a common cause of auricular infections.
- Antibiotic resistance in S. aureus is a growing public health concern.
- Understanding resistance mechanisms is crucial for effective treatment.
Purpose of the Study:
- To identify and characterize Staphylococcus aureus strains isolated from auricular infections.
- To determine the prevalence of oxacillin and erythromycin resistance genes using PCR.
- To evaluate the correlation between genotypic and phenotypic resistance detection methods.
Main Methods:
- Isolation and identification of 35 Staphylococcus aureus strains from ear infections.
- Antibiotic susceptibility testing using ATB Staph kit.
- Polymerase Chain Reaction (PCR) assay for detecting mecA, ermA, ermB, ermC, msrA, and mef genes.
Main Results:
- Low levels of resistance to oxacillin and erythromycin were observed phenotypically.
- 60% of strains were mecA positive, indicating methicillin resistance potential.
- Prevalence of erythromycin resistance genes: ermA (22.8%), ermB (45.7%), ermC (17.1%), msrA (28.6%).
- The mef gene was not detected in any strain.
- No significant correlation was found between genotypic and phenotypic resistance determination.
Conclusions:
- Multiplex PCR is a rapid, practical, and cost-effective method for detecting methicillin- and erythromycin-resistant Staphylococcus.
- Further research is needed to understand the discrepancy between genotypic and phenotypic resistance findings.
- Effective surveillance of antibiotic resistance in S. aureus from clinical isolates is essential.
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