Antibiotic Susceptibility and Resistance Patterns of Staphylococcus aureus Isolated from Pus Samples in Tobruk Medical Center at Tobruk, Libya

• Fatalla Merjan Daboos

  Faculty of Medical Technology, Tobruk University, Tobruk, Libya.

  Author

• Eisa S Omar

  Department of Microbiology, Faculty of Medicine, University of Tobruk, Tobruk, Libya.

  Author

• Osama Muftah Ahmed

  Faculty of Medical Technology, Tobruk University, Tobruk, Libya

  Author

Staphylococcus aureus is a leading cause of purulent infections worldwide, with rising concerns about antibiotic resistance, particularly methicillin-resistant S. aureus (MRSA). This study aimed to determine the prevalence and antimicrobial susceptibility patterns of S. aureus isolated from pus samples at Tobruk Medical Center, Libya. Methods: A total of 127 pus samples were collected from patients with suspected S. aureus infections between April and December 2023. Specimens were cultured on Blood and Mannitol Salt agars. S. aureus isolates were identified using standard microbiological techniques (Gram stain, catalase, and coagulase tests). Antimicrobial susceptibility testing was performed against nine antibiotics (Levofloxacin, Clindamycin, Gentamicin, Doxycycline, Erythromycin, Penicillin, Ciprofloxacin, Cefoxitin, and Tetracycline) using the Kirby-Bauer disk diffusion method, following CLSI guidelines. Results: Out of 127 samples, 60 (47.2%) were culture-positive for S. aureus. The isolates exhibited high resistance rates to Penicillin (62.82%) and Erythromycin (58.97%). Cefoxitin disc testing identified a high prevalence of MRSA at 53.84%. In contrast, the highest susceptibility was observed to Gentamicin (57.69%), Ciprofloxacin (57.69%), and Doxycycline (51.28%). Levofloxacin also showed good activity with a susceptibility rate of 48.71%. Conclusion: This study reveals an alarmingly high prevalence of MRSA and multidrug-resistant S. aureus in pus isolates from our setting. Penicillin and Erythromycin are ineffective as empirical treatments. Gentamicin, Ciprofloxacin, and Doxycycline retained higher efficacy. These findings underscore the critical need for continuous antimicrobial resistance surveillance and stringent antibiotic stewardship policies to guide effective treatment and control the spread of resistant strains in Tobruk, Libya

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