Detection of biofilm-forming genes in Staphylococcus aureus clinical isolates by PCR assay

Authors

  • Ayhan Rashid Mahmood Microbiology Department , College of Medicine, University of Kirkuk /Iraq
  • Nazik Mansour Hussein Microbiology Department ,College of Medicine , University of Kirkuk ,Iraq

Keywords:

Staphylococcus aureus, biofilm formation, ica operon genes, PCR.

Abstract

Biofilms are assemblages of bacteria encased in an extracellular matrix, as well as proteins, exopolysaccharides and macromolecules such as DNA. Bacterial biofilms are thought to play a substantial influence in over 80% of bacterial illnesses. Biofilm buildup on medical implants is responsible for about 60% of hospital-acquired infections. In this study, 150 clinical samples (wound, urine and sputum) were collected from patients admitted to surgical wards of Azadi teaching hospital/Kirkuk during the period from February to October 2018. Of these, 98 (65.3%) were females and 52 (34.7%) were males. Congo Red Agar was used to test the potential of S. aureus isolates to produce biofilms. The relationship between S. aureus biofilm producer isolates and ica ABCD operon genes was studied by using PCR. Out of all samples, S. aureus isolates were identified in 29 (19.3%) of clinical samples, and most isolates were from wound infections (n=19, 65.5%) followed by urine (n=10, 43.5%). Whereas, no S. aureus isolate was detected in sputum samples. Moreover, S. aureus biofilm producing isolates were detected in 9 (24.1%) samples and were represented as black colonies on Congo Red Agar. The results of this study indicated the icaA, icaB, icaC and icaD genes harbored in 4 (44.4%) of S. aureus biofilm forming isolates while icaA, icaC, and icaD genes were detected in 6 (66.7%) of isolates. On the other hand, all S. aureus isolates were negative for both clfB and fnbB genes.

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Published

2022-04-22