The association of drug resistance of Staphylococcus species with biofilm formation

Background: Staphylococcus spp. is a gram-positive coccus that is responsible of causing different types of diseases. Biofilm production is a key factor that enhances the survival of these bacteria in vivo. Aim of the study: This study aims to evaluate the potential association between methicillin resistance and biofilm-forming ability in Staphylococcus species, and to compare this association between coagulase-positive and coagulase-negative strains. Materials and Methods: A total of 54 Staphylococcus spp. isolates were included in this study, comprising 29 coagulase-positive (13 isolates was taken from high viginal swab and 16 isolates obtained from clinical swab of patient with diabetic foot ulcer) and 25 coagulase-negative isolates from bile of patients with cholecystitis. These isolates were collected from Al-Kafeel Hospital over the period of 4 months from October 2024 to February 2025. The identification for each isolate was demonstrated by culturing it on blood, MacConkey agar and mannitol salt agar, then the diagnosis of these isolates was confirmed by using the automated VITEK® 2 system. Antimicrobial susceptibility testing was performed using the disk diffusion method, and the biofilm-forming ability of the isolates was also evaluated. Results: the study showed that 19 (65.5%) Staphylococcus aureus and 16 (64%) of Coagulase negative bacteria were resistant to cefoxitin. No significant differences in the mean of biofilm formation between Staphylococcus aureus (0.101±0.013) and Coagulase negative bacteria (0.094±0.011), however higher mean was seen for Staphylococcus aureus (0.101±0.013). Conclusion: Biofilm formation ability tends to be not affected by drug resistance of Staphylococcus species. High percentage of cefoxitin resistance were present in community and associated with different types of infections.