MOLECULAR CHARACTERIZATION AND PHYLOGENETIC ANALYSIS OF A NOVEL STAPHYLOCOCCUS AUREUS STRAIN ISOLATED FROM BURN INFECTIONS IN IRAQ

Abstract

Background: Staphylococcus aureus is a major opportunistic pathogen associated with burn infections due to its ability to produce virulence factors and form biofilms that enhance infection persistence. The increasing prevalence of antibiotic-resistant strains, particularly methicillin-resistant Staphylococcus aureus (MRSA), has created a growing challenge for effective treatment. Consequently, attention has shifted toward alternative antimicrobial agents, including medicinal plant extracts and nanomaterials. Taraxacum officinale has been reported to possess antibacterial properties, while zinc oxide nanoparticles (ZnO NPs) have demonstrated promising activity against various pathogenic bacteria. Therefore, this study aimed to isolate and identify Staphylococcus aureus from burn infections and evaluate the antibacterial activity of Taraxacum officinale extract and ZnO nanoparticles against the isolates.

Methodology: Clinical isolates (n=112) were collected from burn patients in Baghdad and identified using Mannitol Salt Agar and biochemical tests. Antimicrobial resistance and virulence profiles were determined via Kirby-Bauer disk diffusion (CLSI standards) and PCR for mecA, icaD, and crtN genes. Simultaneously, Taraxacum officinale extract and Zinc Oxide Nanoparticles (ZnO NPs) were prepared. Their antibacterial efficacy was evaluated using the agar well diffusion method. The chemical composition of the plant extract was further characterized via High-Performance Liquid Chromatography (HPLC).

Results: The results showed that several isolates of Staphylococcus aureus were successfully identified from burn infections. Molecular analysis confirmed the presence of the mecA, icaD, and crtN genes in some isolates. The tested isolates exhibited varying patterns of antibiotic resistance. Both Taraxacum officinale extract and zinc oxide nanoparticles (ZnO NPs) demonstrated notable antibacterial activity against the bacterial isolates.

Conclusion: These findings suggest that Taraxacum officinale extract and ZnO nanoparticles may serve as promising alternative or complementary agents for controlling antibiotic-resistant Staphylococcus aureus.