The prevalence of Virulence Factors of Streptococcus Pyogenes Isolated from Pharyngitis and Septicemia in Bushehr
The prevalence of Virulence Factors of Streptococcus Pyogenes Isolated from Pharyngitis and Septicemia in Bushehr
Somayyeh Gharibi,1,*Mahnaz Gholipour shahrak,2Askar Rezai Darvishi,3Abbas Yadegar,4Saeed Tajbakhsh,5Zeinab Asen,6
1. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran 2. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran 3. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran 4. Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 5. Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran 6. Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran
Introduction: Streptococcus pyogenes, GAS, is the cause of skin, invasive and immune system
disease. Pharyngitis and septicemia are the most common and severe diseases caused by this
bacteria, respectively. Different virulence genes are involved in the onset, severity and survival
of infection, which are expressed in different strains. This study investigated the presence of
some virulence genes in samples isolated from patients with pharyngitis and septicemia.
Methods: This study was performed on 16 isolates
isolated from patients with pharyngitis and 2 isolated from the sample of septic patients. After
culturing and purifying the bacterial strain, DNA of each bacterial strain was extracted. They were confirmed by a housekeeping gene primer, Spy 1258 by PCR and then the
presence of virulence genes such as scpA, speB, speG, hasA, spd3, sla and silC was
examined.
Results: The presence of spy1258 gene was confirmed in all strains
(100%). The S. pyogenes ATCC19615 contained all of 5 genes (speB, speG, scpA,
hasA and spd3). Four samples (22.2%) carried the scpA gene and three samples contained
16.6% of the speB exotoxin gene. The speG was positive in 4 samples (22.2%) and hasA gene was
confirmed in 5 samples (27.8%). The presence of spd3 gene was positive in 4 samples (22.2%).
None of the samples carried the Sla gene and only one case (5.5%) was positive for silC
gene. Three clinical strains (16.6%) carried 6 or more of the studied factors (TS-48, TS-101 and
BC-46). None of the studied genes were found in 12 (66.7%) samples.
Conclusion: This study showed that the prevalence of virulence genes was lower in the collected
strains than the global studies. This issue highlights the need for molecular epidemiological
studies in Iran with native strains. It is suggested that additional research be conducted with a
larger sample size and sampling from a variety of invasive and non-invasive diseases.