Characterization of Staphylococcus epidermidis isolates from hospitalized patients in Isfahan and Tehran teaching hospitals

Research paper by Amirmorteza Ebrahimzadeh Namvar, Seyed Asghar Havaei, Sharareh Moghim, Abdolaziz Rastegar Lari

Indexed on: 01 Feb '15Published on: 01 Feb '15Published in: Molecular Genetics, Microbiology and Virology


Coagulase-negative Staphylococci especially Staphylococcus epidermidis is considered as an important reason of medical implant devices and nosocomial infections. Different virulence factors such as biofilm formation, delta toxin and autolysin increase the pathogenicity of this microorganism. However the ability of biofilm production is one of the main causes of microorganism attachment to various surfaces and may lead to chronic infections. On the other hand resistance to antimicrobial agents containing penicillinase resistant penicillins (i.e. oxacillin, methicillin) has been predominantly emerged in the past several years. PBP2a is encoded by mecA gene that conferred as meticillin resistant main reason. The mentioned gene is carried by the Staphylococcal chromosomal cassette mec (SCCmec) as a mobile genetic element. The aim of this study was evaluating the S. epidermidis isolates biofilm production and determining the various types of SCCmec elements in hospitalized patients. A total 115 Staphylococcus epidermidis strains were studied for the ability of biofilm formation, the frequency of both ica and mecA gene and also the existence of various SCCmec types in hospitalized patients. In CRA (70.4%) of isolates formed black colonies while in the molecular PCR method the prevalence of ica gene among isolates was (82.6%) and 96 were mecA positive. By multiplex PCR method five different types of SCCmec have been identified. Determination of biofilm formation in nosocomial infections, and also evaluation of SCCmec elements may be lead to a significant solution to prevent the infection prevalence in health care units.