Characterization of Virulence Factors and Prophage Profiles of Methicillin-Resistant Staphylococcus aureus Strains Isolated from a Referral Hospital in Tehran, Iran

摘要

Background: Methicillin-resistant Staphylococcus aureus (MRSA) has been considered as an important pathogen with a variety of virulence factors in communities and hospitals worldwide. Objectives: In this study, we focused on the detection of different virulence factors and enterotoxin genes of MRSA strains isolated from a referral hospital in Tehran, Iran. Moreover, the presence of different prophage types was studied. Methods: A total of 491 MRSA strains were isolated during three years from a referral hospital in Tehran. The staphylococcal enterotoxin ( sea - seq ) and pvl , hlb , sak , eta and tst genes were detected. A multiplex-polymerase chain reaction (PCR) assay was used for prophage typing of MRSA isolates. Results: Totally, 11 enterotoxin and 5 virulence factor genes were detected in MRSA strains. The sea , sek , seq , and hlb genes were present in all the MRSA and other enterotoxin genes. sel , seg , sem , sei , sen , seo , sec and sep were detected in 32.8%, 20.3%, 12.6%, 8.3%, 4.1%, 2.6%, 1.6% and 0.4% of the strains, respectively. A total of 93%, 81%, 15.9% and 5.7% of the strains harbored the sak , eta , tst and pvl genes, respectively. SGF, SGFa and SGFb proghage type genes were detected in 100% of the MRSA strains, and four different prophage patterns were identified among the strains. Conclusions: The presence of different prophage-encoded virulence factors among MRSA strains enable MRSA to produce a broad range of diseases, indicating MRSA strains as a potential threat to patients’ health.