Prevalence and characterization of virulence genes among methicillin-resistant Staphylococcus aureus isolated from Sudanese patients in Khartoum state

Staphylococcus aureus is a versatile pathogen that can cause a variety of diseases, ranging from mild to fatal infection. This study aimed to detect the virulence genes (cna, ica, hlg and sdrE) in S. aureus isolated from different types of infections in Sudanese patients admitted to different hospital in Khartoum state. This is a descriptive cross-sectional study conducted over a period of 4 months from 1 April to 30 July 2017 in Khartoum. Overall, 65 S. aureus isolates were identified using standard biochemical and microbiologic tests. Antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Nucleic acid was extracted using the guanidine hydrochloride method, and all the genes except for sdrE were detected by multiplex PCR. The ica gene was the predominant one, found in 73.85% of the isolates, with sdrE found in 38.46%, cna in 29.25% and hlg in 7.69%. The relationship between the virulence genes and resistance to antibiotics showed that the highest resistance was observed in isolates with ica and sdrE, followed by cna and hlg. There were significant relationships between methicillin resistance and the presence of sdrE and ica genes (p 0.01 for both) and between ciprofloxacin resistance and the presence of sdrE gene (p 0.03).