iarjimphIARJIMPHIARJIMPH2709-331Xhttps://doi.org/10.47310/iarjimph.2025.v06i01.016Antibiotic Resistance and Virulence Profiles of Staphylococcus aureus in Respiratory Samples from Children in KirkukSarahMaher Yaqoob Al AzzawiB.Sc. Medical Lab Tech., Kirkuk Health Directorate, IraqBackground: Staphylococcus aureus is a leading pathogen implicated in pediatric respiratory infections, often exhibiting resistance to multiple antibiotics and producing various virulence factors. Its ability to colonize the nasopharynx and form biofilms complicates treatment and increases the risk of chronic and recurrent infections. Objective: This study aimed to isolate and identify S. aureus strains from pediatric respiratory samples in Kirkuk, Iraq and to evaluate their antibiotic susceptibility profiles, virulence characteristics and biofilm-forming capabilities. Methods: A total of 90 nasopharyngeal swabs were collected from children under 12 years with symptoms of respiratory infection. Samples were cultured and identified using standard biochemical methods. Virulence factors such as coagulase, DNase, gelatinase, hemolysin and enzyme production were phenotypically detected. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Biofilm production was assessed using three methods: Tissue Culture Plate (TCP), Tube Method and Congo Red Agar (CRA). Statistical analysis was conducted using SPSS version 26.0. Results: Of the 90 samples, 85 (94.44%) were culture-positive, yielding 128 bacterial isolates, of which S. aureus accounted for 60 (46.88%). Among these, 85% were methicillin-resistant, 75% vancomycin-resistant and 70% produced beta-lactamase. Levofloxacin showed the highest sensitivity (85%), followed by azithromycin, ceftazidime and imipenem (75% each), while all isolates were resistant to amoxicillin. All S. aureus isolates produced coagulase, DNase, gelatinase and urease, with 45% being strong biofilm producers by TCP method. A statistically significant association was observed between biofilm formation and detection method (χ² = 7.71, p = 0.034). Conclusion: The study reveals a high prevalence of multidrug-resistant and virulent S. aureus strains in pediatric respiratory infections in Kirkuk. These findings underscore the need for regular surveillance, targeted antimicrobial therapy and incorporation of biofilm assessment in clinical microbiology diagnostics.