International Journal of Scientific World, 3 (2) (2015) 239-243 www.sciencepubco.com/index.php/IJSW ©Science Publishing Corporation doi: 10.14419/ijsw.v3i2.5168 Research Paper Investigating prevalence of pathogenic genes (ETA and TSST-1) in Staphylococcus aureus isolated from different wards of the hospitals by PCR method Rashid Ramazanzadeh 1 , Hadi Mohammadi Talvar 2 *,Mahdi Mirzaii 3 ,Seyed Sajjad Hasheminasab 4 ,Hanar Narenji 5 1 Cellular & Molecular Research Center and Microbiology Department, Faculty of Medicine, Kurdistan University of Medical Sciences, Sanandaj- Iran 2 Islamic Azad University, Science and Research Campus, Kurdistan branch, Sanandaj, Iran 3 Faculty of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran 4 Faculty of Veterinary Medicine, Department of Parasitology, University of Tehran, Tehran-Iran 5 Department of Microbiology, School of Medicine Science, Sanandaj, Iran *Corresponding author E-mail: Hadimohammadi202@gmail.com Copyright © 2015 Rashid Ramazanzadeh et al This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Staphylococcus aureus is the most common pathogenic organisms in the hospitals and communities' infections. It is responsible for more than 80 percent of infectious diseases. The purpose of the present paper is to determine the incidence of Staphylococcus pathogenic genes isolated from different wards of hospitals by PCR method. This study included 61 Staphylococcus aureusisolates collected from different wards hospital, between 2011 and 2012 in University of Kurdistan (Toohhid and Besat hospitals). All isolates were previously identified as Staphylococcus aureusby a standard microbiological procedure. It isolates were incubated at 37Ċ for 24h on blood agar; single colonies were tested with tube and slide coagulase, catalase tests and growth on Manito salt agar. Following genomic DNA extraction, the presence of ETA, TSST-1 genes was analyzed by PCR.61 strains of Staphylococcus aureushave been isolated from different wards of the hospital. Frequency of tst gene was 81% and eta gene was 47%. Moreover, frequency of strains with both eta and tst genes was 40%. Results of the present paper indicate that the prevalence of Staphylococcusaureus results on prevalence of eta and tst genes, and this is a matter of concern. Keywords: TSST-1; ETA; Staphylococcus aureus; PCR Method; Penicillin. 1. Introduction In 1950, the emergence of antibiotic-resistant strains provided a better understanding of epidemiology of Staphylococcus aureus disease. At first, emergence of penicillin was very helpful for treating Staphylococcus aureus infections. However, a considerable number of penicillin-resistant strains were obtained from Staphylococcus aureus infections in 1946[1]. Pathogenesis of Staphylococcus aureus could be because of its producing pyrogenic toxins. In fact, secretion of this toxin significantly stimulates T-lymphocytes, which are called superantigens (SAgs) [2], [3].So So far, far, 15 types of super antigens in Staphylococcus aureus have been recognized and Staphylococcal enterotoxin A- M, exfoliative toxin A, B, and toxic shock syndrome toxin (TSST-1) are some samples of it. TSST-1 is a protein with molecule weight approximately equal to 24kDa and isoelectric point 6.8-7.2, which are coded by tst gene of Staphylococcus aureus. Release of TSST-1 in blood flow results in acute clinical conditions such as toxic shock syndrome (TSS), syndrome of sudden death of infants, and Kawasaki syndrome’s gene is presented in more than 70 percent of Staphylococcus aureus strains isolated from patients with TSS. TSS is characterized by skin rashes, high fever, severe fall in blood pressure, and muscle pains. If TSS is not treated up to one hour after the emergence of symptoms, it could result in a fatal shock. Two third of TSS is related to using tampons; however, some cases are related to localizing infections, surgery wounds and insects bites [4-6]. TSST-1 is one of the important factors related to