Characteristic, antibiotic resistance and molecular typing of Staphylococcus aureus isolated from intensive care unit and burn patients based on coagulase gene analysis

Abstract

Staphylococcus aureus as an opportunistic pathogen of humans poses many risks to global health. This study examines antimicrobial susceptibility pattern, virulence determinants and genetic diversity of S. aureus strains isolated from ICU and burn patients based on coa gene polymorphism. Between March 2019 and February 2020, we investigated 75 S. aureus isolates collected from clinical specimens. Phenotypic resistance was assessed by Kirby–Bauer disk diffusion method. PCR was applied for the detection of virulence encoding genes. Strains were characterized based on coa gene polymorphism by Multiplex-PCR assay. In the present study, out of 75 isolates, 15 strains (20%) harbored pvl encoding gene. Also, the prevalence of tsst encoding gene in the current study was found to be 17.3%. Out of 75 S. aureus strains, coa types III, X, VIII, I, VII, VI and II were identified in 33.4%, 21.3%, 13.3%, 10.7%, 9.3%, 6.7% and 5.3% of strains, respectively. coa types III (58.2%), I (18.6%), VI (11.6%), II (9.3%), and VII (2.3%) belonged to ICU patients and coa types X (50%), VIII (31.3%), and VII (18.7%) belonged to strains obtained from burn patients. All HLMUPR strains isolated from ICU patients belonged to coa type III while HLMUPR strains isolated from burn patients belonged to coa type X. Seven different coa types in the present study suggesting infection in hospitalized patients is caused by S. aureus strains harboring different variant of the coa gene which emphasized the special attention for monitoring and antimicrobial stewardship programs for S. aureus infections within hospitals.