Iranian Journal of Medical Microbiology

Background and Aim: Virulence factors are the ability of bacterial agents to cause various degrees of disease in organisms. Increasing attention to Gram-positive and Gram-negative isolates from different sources is important. This study aimed to describe various bacterial virulence factors.
Materials and Methods: The 80 samples were collected from various clinical sources of all genders and ages from Al-Haboubi Hospital in Nasiriyah, Iraq, from June 2022 to December 2022. The samples, including nasal, ear, eye, throat, pharynx, and urinary tract infection (UTI) swabs, were transferred to the laboratory and incubated at 37°C for 2-4 hr. Various virulence determinants, such as lipase, protease, and hemolysin, were investigated on the bacterial isolates of the study.
Results and Conclusion: Four bacterial isolates, including Klebsiella Pneumoniae, Staphylococcus aureus, Streptococcus, and Proteus mirabilis, were identified from the clinical samples. They were selected randomly to compare the production of protease enzymes between different sites of infection. The bacterial types were diagnosed using biochemical tests, and the Vitek 2 Compact system confirmed the diagnosis. Among the isolates, 31 (38.75%) were S. aureus, and other Gram-positive bacteria were 19 (23.75%) isolates for Streptococcus pyogenes. For the Gram-negative bacteria, 17 (21.25 %) isolates were K. pneumonia, and 13 (16.25%) were P. mirabilis. All isolates of this study were able to produce protease, and Gram-negative bacteria were able to produce hemolysin with the ability to produce protease and lipase. Different bacterial isolates from clinical samples showed virulence factors that could produce hemolysin, protease, and lipase.