Effect of spdC gene expression on virulence and antibiotic resistance in clinical Staphylococcus aureus isolates

Abstract

Surface protein display C (SpdC) protein was described as a novel virulence factor of Staphylococcus aureus that affects biofilm formation and pathogenesis and favors resistance to antimicrobials targeting cell wall. We evaluated the possible correlation between spdC gene expression level and virulence as well as antibiotic resistance phenotypes in S. aureus clinical isolates. The antimicrobial susceptibility of S. aureus clinical isolates (n = 100) was determined by the disk diffusion method. Vancomycin susceptibility was determined by the broth microdilution method. The level of the extracellular proteases and delta-hemolysin was evaluated by measuring the proteolysis and hemolysis zone diameters in skim milk and blood agar plates, respectively. Biofilm formation was assayed using the 96-well microtiter plate method. Most of the isolates (81%) were multidrug-resistant and about half of the isolates (49%) were methicillin-resistant S. aureus. Hemolysin, protease, and biofilm production were detectable in 79%, 71%, and 96% of the isolates. No significant correlation was detectable between the level of spdC gene expression and the activity of tested virulence factors or the antimicrobial resistance phenotype. Therefore, the role of SpdC protein as a virulence regulator in S. aureus needs further evaluation together with the determination of the predominant regulators for each virulence factor.

Effect of povidone-iodine and propanol-based mecetronium ethyl sulphate on antimicrobial resistance and virulence in Staphylococcus aureus

“…Their resistance pattern is similar to that reported in other countries, where most of the tested S. aureus clinical isolates (84.5%) were MRSA. Similar rates of MRSA (79.6%) were reported in Egypt [ 47 , 48 ] and other countries such as Italy, Portugal, and France [ 49 , 50 ]. The predominance of MDR was recorded elsewhere [ 47 , 51 , 52 ].…”

Determination of the antibacterial effect of bee venom against rainbow trout pathogens and antibiotic resistance gene expression

“…A fl uorescence reading was performed at the end of each amplifi cation. Relative quantifi cation in which the relevant gene expression was normalized to a housekeeping gene using the 2 ʌCT method was fi rst used, and then the results were evaluated for differences in gene expression with 2 ʌʌCT and Fold Change analyses, and the graphical values were obtained [35].…”