Multidrug resistance and biofilm production among Staphylococcus aureus clinical isolates at a tertiary care hospital, Egypt.

Abstract

Staphylococcus aureus is a concerning issue due to multidrug resistance (MDR). This work aimed to detect the correlation between production of biofilm and resistance to antimicrobials among Staphylococcus aureus isolates. Methods: Out of 300 clinical specimens, 128 S. aureus were isolated, and their antibiotics susceptibility testing were analyzed by disc diffusion method. Their ability to form a biofilm was investigated by micro-titer plate (MTP) method. Finally, their biofilm production genes were determined by polymerase chain reaction. Results: 70% of isolates were multidrug resistant and 85% were methicillin resistant S. aureus (MRSA), while the least resistance was detected for linezolid, azithromycin and vancomycin (2%, 7% and 9%, respectively). Biofilm was detected phenotypically in 84.8% of isolates while biofilm genes were detected in 94.5% of isolates where ica A, ica B, ica C and ica D were detected in 91%, 92%, 70% and 90%, respectively. Multidrug resistance was more significantly determined in biofilm forming isolates than biofilm negative ones (p value<0.001). Conclusion: Biofilm producing S. aureus isolates were prevalent among patients admitted at Surgical Intensive Care Unit. They harbored biofilm genes like ica A, ica B, ica C and ica D and displayed high MDR pattern.