STUDY PREVALENCE OF AGR IN STAPHYLOCOCCUS AUREUS

Background and Aim:This bacterium is one of the main causes of hospital and community-acquired infections worldwide, leading to diseases including skin and soft tissue infections, necrotic pneumonia, endocarditis, septicemia , osteomyelitis, and food poisoning (due to production of enterotoxin). Infections caused by S. aureus are due to various factors like toxins and the creation of biofilms with quorum sensing (QS). The accessory gene regulator (agr) gene, as the regulator of biofilm production and isolation, is an effective factor for pathogen and bacteria resistance. The present study was carried out with the aim to determine the agr gene content among S. aureus isolates. This research is the first special study of coagulase gene polymorphism among isolates of S. aureus isolated from patients in IranMethods:In this study, 90 isolates of S. aureus were identified and confirmed by phenotypic method and their DNA was extracted using lysostaphin enzyme. Then, the agr gene was analyzed by multiplex polymerase chain reaction (Multiplex PCR) methodResults:The results of PCR and electrophoresis of S. aureus isolates indicated the agr I, agr II, agr III, and agr IV gene levels as 43.33%, 92.03%, 43.33%, and 16.08%, respectivelyConclusion:In many human diseases caused by S. aureus, the agr system is responsible for controlling and coordinating the production of virulence factors, exotoxin secretion, and hemolysins. Taking into account the significance of agr gene in regulating expression of cell surface proteins, exotoxin secretion, hemolysins, and virulence factors, examining its rate in each area is inevitable in order to prevent and treat this bacterium

Keywords:

S. aureus , Biofilm , Multiplex PCR , agr , Electrophoresis