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Published on: September 5, 2013
Distribution of tsst-1 and mecA Genes in Staphylococcus aureus Isolated From Clinical Specimens
Roohollah Zarei Koosha1, Hamideh Mahmoodzadeh Hosseini2, Elnaz Mehdizadeh Aghdam3
1Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, IR Iran; Biology Department, Jahrom Branch, Islamic Azad University, Jahrom, IR Iran.
Background:
Staphylococcus aureus is a harmful pathogen known to express numerous virulence factors and cause severe infections. High levels of methicillin-resistant Staphylococcus aureus (MRSA) strains are one of the important healthcare problems because of the inefficient treatment of these infections.
Objectives:
The purpose of the current study is to evaluate the incidence of the toxic shock syndrome toxin (tsst-1) gene and its association with the prevalence of the mecA gene and drug resistance.
Materials And Methods:
The presence of the tsst-1 and mecA genes was investigated by polymerase chain reaction (PCR) among S. aureus isolated from 197 clinical samples. In addition, resistance tests to 12 antibiotics were carried out by the disc diffusion method.
Results:
Among the 197 isolates, 134 (68%) contained the tsst-1 genes and 172 (87.3%) contained the mecA genes. The prevalence of both genes was higher among male cases and samples purified from wounds and blood. We found no significant correlation between the presences of the two mentioned genes within isolates. The highest resistance we observed among our samples was to penicillin. None of isolates was resistant to vancomycin or linezolid. A significant correlation was observed between the presence of the mecA gene and resistance to oxacillin, gentamicin, kanamycin, erythromycin, tetracycline, cotrimoxazole, clindamycin, cephazolin and the multi-drug resistant property, which is resistance to more than three antibiotics (P < 0.05).
Conclusions:
Our outcomes showed elevated incidences of tsst-1 positive and MRSA strains with higher rates of antibiotic resistance. The conflict between our findings and other records may be due to differences in geographic regions.
Insights
This study found high rates of toxic shock syndrome toxin (tsst-1) and methicillin-resistant Staphylococcus aureus (MRSA) in clinical samples. The mecA gene correlated with resistance to multiple antibiotics, highlighting treatment challenges.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Clinical Diagnostics
Background:
- Staphylococcus aureus is a significant pathogen causing severe infections.
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a major healthcare challenge due to treatment difficulties.
Purpose of the Study:
- To determine the incidence of the toxic shock syndrome toxin (tsst-1) gene.
- To assess the association between the tsst-1 gene, the mecA gene, and antibiotic resistance patterns in Staphylococcus aureus.
Main Methods:
- Polymerase chain reaction (PCR) was used to detect tsst-1 and mecA genes in 197 S. aureus isolates.
- Antibiotic resistance was evaluated using the disc diffusion method against 12 different antibiotics.
Main Results:
- The tsst-1 gene was present in 68% and the mecA gene in 87.3% of isolates.
- The mecA gene showed a significant correlation with resistance to multiple antibiotics, including oxacillin and multi-drug resistance.
- No isolates were resistant to vancomycin or linezolid, but high resistance to penicillin was observed.
Conclusions:
- Elevated incidences of tsst-1 positive and MRSA strains were observed.
- The findings suggest a high prevalence of antibiotic resistance, potentially influenced by geographic factors.
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