Virulence genes distributed among Staphylococcus aureus causing wound infections and their correlation to antibiotic resistance.

BACKGROUND: Staphylococcus aureus causes many human infections, including wound infections, and its pathogenicity is mainly influenced by several virulence factors. AIM: This study aimed to detect virulence genes (hla, sea, icaA, and fnbA) in S. aureus isolated from different wound infections among Egyptian patients admitted to Minia University Hospital. This study also aimed to investigate the prevalence of these genes in methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA), and vancomycin-resistant S. aureus isolates and the resistance and sensitivity to different antibiotic classes. METHODS: A cross-sectional study was carried out from November 2019 to September 2021. Standard biochemical and microbiological tests revealed 59 S. aureus isolates. The Kirby-Bauer disc diffusion method was used to determine antibiotic susceptibility. DNA was extracted using a DNA extraction kit, and polymerase chain reaction was used to amplify all genes. RESULTS: A total of 59 S. aureus isolates were detected from 51 wound samples. MRSA isolates accounted for 91.5%, whereas MSSA isolates accounted for 8.5%. The multidrug resistance (MDR) percentage in S. aureus isolates was 54.2%. S. aureus showed high sensitivity pattern against vancomycin, linezolid, and chloramphenicol. However, a high resistance pattern was observed against oxacillin and piperacillin. sea was the most predominant gene (72.9%), followed by icaA (49.2%), hla (37.3%), and fnbA (13.6%). sea was the commonest virulence gene among MRSA isolates (72.2%), and a significant difference in the distribution of icaA was found. However, sea and icaA were the commonest genes among MSSA isolates (79.9%). The highest distribution of sea was found among ciprofloxacin-resistant isolates (95.2%). CONCLUSION: The incidence of infections caused by MDR S. aureus significantly increased with MRSA prevalence. sea is the most predominant virulence factor among antibiotic-resistant strains with a significant correlation to piperacillin, gentamicin, and levofloxacin.

Prevalence and resistance profile of bacteria isolated from wound infections among a group of patients in upper Egypt: a descriptive cross-sectional study.

AIM: This cross-sectional survey aimed to identify aerobic bacteria, antimicrobial resistance, and multi-drug resistance profiles of bacteria isolated from different wound infections among a group of Egyptian patients. RESULTS: Of 120 positive samples, 170 isolates were identified. Polymicrobial infections were determined in 55% of samples. The dominant Gram-positive isolated strains were Staphylococcus aureus, especially from wound infections because of accidents (71.8%). Piperacillin, methicillin, ampicillin/sulbactam, and amoxicillin/clavulanic acid were all highly resistant to S. aureus and Coagulase-negative Staphylococci. The prevalence of methicillin-resistant S. aureus in wound infections was 89.9%. S. aureus showed superior sensitivity to vancomycin (85.3%) and linezolid (81.3%). The highest prevalence of Gram-negative isolates was for Pseudomonas aeruginosa (40%), which was highly sensitive to ciprofloxacin (79.2%) and highly resistant to levofloxacin (83.3%). Several isolates revealed a multi-drug resistance profile (52.4%). The overall MDR rate of Gram-positive and Gram-negative isolates were 50% and 54.9%, respectively. CONCLUSION: The prevalence of MRSA isolated from various wound infections and MDR is a warning issue in Upper Egypt. It should implement a health education strategy and hygiene measures to prevent the spread of wound infection-causing organisms in the community.