Genotype Diversity and Evaluation of Biofilm Formation in sasX Positive Methicillin-Resistant Staphylococcus aureus

Abstract

Objectives: Staphylococcus aureus surface protein X (sasX) is a newly described protein that has different roles in virulence, such as biofilm formatin, as a bacterial approach for pathogenesis. SasX gene was initially found in eastern Asian countries, yet, studiese have shown spreading of this gene to other strains. Because there is no report on this gene in Iran, the current study aimed at determining the prevalence, genotype diversity, and evaluation of biofilm formation in sasX positive methicillin-resistant Staphylococcus aureus (MRSA). Methods: This experimental study was conducted on strains isolated from inpatients during 2014 to 2015. Cultivation, identification, and confirmation of MRSA isolates were performed. The evaluation of biofilm production, sasX gene detection, and Random amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR) were done. Data collection and comparison were performed by SPSS and gelcompare softwares. Results: Overall, 140 isolates (77.8%) formed a biofilm and 23 (12.6%) isolates were sasX positive. Amongst 23 sasX+ strains, 21 (91.3%) isolates created a biofilm. The RAPD-PCR analysis of 23 sasX positive isolates showed 19 RAPD types with 4 common types (CT) and 15 single types (ST). Conclusions: Frequency of sasX gene was somewhat similar to another study in eastern countries and the ability of biofilm formation in sasX+ strains compared to all of MRSA isolates were not significant (P value > 0.05) and a correlation was not found between RAPD type and biofilm grade.