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. 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.

Remarkable geographical variations between India and Europe in carriage of the staphylococcal surface protein-encoding sasX/sesI and in the population structure of methicillin-resistant Staphylococcus aureus belonging to clonal complex 8

“…Of note, sesI-carrying S. aureus strains were even more abundant biofilm formers than sasX-carrying strains. This might be because sesI is a known colonization factor in S. epidermidis, whereas sasX is considered to be a virulence factor promoting lung disease, abscess formation and mechanisms of immune evasion [3,5,12,29]. Recent data also show that SasX is an effector rather than a regulatory protein, as biofilm formation by sasX knockout strains was significantly impaired compared with the wild-type strains and again restored in sasX-complemented strains [5].…”