Prevalence and antimicrobial susceptibility patterns of Pseudomonas aeruginosa and Staphylococcus aureus isolates from diverse wound infections: A single-center cross-sectional study

Background: Wound infection is a prevalent kind of nosocomial infection that can lead to serious health complications. Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), are major causes of hospital-acquired wound infections. This work aimed to evaluate the prevalence and antimicrobial susceptibility patterns of P. aeruginosa and S. aureus isolates among various wound infections from November 2023 to October 2024. Methods: This observational cross-sectional study included 100 patients with acute or chronic wound infections who were admitted to Tanta University Hospitals. Wound swabs were collected aseptically and underwent the routine microbiological identification for the detection of P. aeruginosa and S. aureus then antibiotic sensitivity testing of isolates using disc diffusion method. Results: P. aeruginosa and S. aureus represented 32% and 22% of total wound infections, respectively. The dominance of P. aeruginosa over S. aureus isolates was found among infected burn wounds, bed sores and diabetic foot ulcers (68.75%/12.5%), (36.36% /18.18%), (22.2% /16.6%), respectively. Meanwhile, the predominance of S. aureus over P. aeruginosa isolates was found in surgical site infections (SSIs) (33.3% /13.3%). Moreover, 90.6% of P. aeruginosa isolates were multidrug resistant and 86.3% of S. aureus isolates were methicillin resistant S.aureus (MRSA). Aztreonam was effective against 53.1% of P. aeruginosa isolates and 72.7% of S. aureus isolates were sensitive to linezolid. Conclusion: P. aeruginosa and S. aureus isolates, particularly resistant phenotypes, represented a significant proportion of wound infections. Additionally, P. aeruginosa prevails in burns and bed sores, while S. aureus in SSIs. Linezolid is still an important option against MRSA and aztreonam against P. aeruginosa.