Examining the Prevalence and Antibiotic Susceptibility of S. aureus Strains in Hospitals: An Analysis of the pvl Gene and Its Co-Occurrence with Other Virulence Factors

Abstract

S. aureus is a pathogenic bacterium that causesinfections. Its virulence is due to surface components, proteins, virulence genes, SCCmec, pvl, agr, and SEs, which are low molecular weight superantigens. SEs are usually encoded by mobile genetic elements, and horizontal gene transfer accounts for their widespread presence in S. aureus. This study analyzed the prevalence of MRSA and MSSA strains of S. aureus in two hospitals in Greece between 2020-2022 and their susceptibility to antibiotics. Specimens collected were tested using the VITEK 2 system and the PCR technique to detect SCCmec types, agr types, pvl genes, and sem and seg genes. Antibiotics from various classes were also tested. This study examined the prevalence and resistance of S. aureus strains in hospitals. It found a high prevalence of MRSA and that the MRSA strains were more resistant to antibiotics. The study also identified the genotypes of the S. aureus isolates and the associated antibiotic resistances. This highlights the need for continued surveillance and effective strategies to combat the spread of MRSA in hospitals. This study examined the prevalence of the pvl gene and its co-occurrence with other genes in S. aureus strains, as well as their antibiotic susceptibility. The results showed that 19.15% of the isolates were pvl-positive and 80.85% were pvl-negative. The pvl gene co-existed with other genes, such as the agr and enterotoxin genes. The results could inform treatment strategies for S. aureus infections.

Keywords: PVL gene; Staphylococcus aureus; agr genes; enterotoxin genes; pcr method.

Figure 1

Eighteen (12.76%) S. aureus strains were pvl-positiveMRSA, nine (6.39%) were pvl-positive MSSA, confirmed through phenotypic testing and by PCR method.

Figure 2

The co-occurrence of agr, sem, and seg genesinMRSA pvl+ strains.