Demonstration of Virulence Markers and Methicillin Susceptibility of Staphylococci in Various Clinical Isolates at SKMC&H, Muzaffarpur, Bihar, India

Abstract

Introduction: The staphylococci are a diverse group of bacteria that cause diseases ranging from minor skin infections to life-threatening bacteremia. The organism can produce an array of potential virulence factors such as alpha-, beta-, gamma- and delta-toxins, coagulase and slime formation. Hence, the current study was done to demonstrate some virulence factors in coagulase positive (COPS) and coagulase negative staphylococcal (CONS) isolates from various clinical samples and their further correlation with methicillin susceptibility. Methodology: This current study was an observational study conducted by Department of Microbiology of Shri Krishna Medical College & Hospital, Muzaffarpur, Bihar during a study period of 6 months from July 2020 to December 2020. A total of 100 staphylococcal isolates from various clinical specimens were included in the study. The isolates subjected to the following tests to demonstrate the virulence markers: Coagulase, Phosphatase, DNase (Deoxyribonucleic), Hemolysis, Slime Formation. Methicillin susceptibility was done by cefoxitin disc diffusion method as per CLSI guidelines. Descriptive statistics was applied to calculate different variables in the table and arrange them in order. Results were statistically analyzed by using SPSS for Windows (version16.0).Results: Of the 100 Staphylococcal isolates, 92 were coagulase positive and 8 coagulase negative. Phosphatase was expressed by all. DNAse was observed in 59, hemolysis in 60 and slime formation in 34 isolates. Statistical correlation was carried out between methicillin resistance and various virulence markers. Statistical significance was not observed in Coagulase and DNAse markers. Statistically significant correlation was observed between virulence markers haemolysin and slime formationin both coagulase positive and negative Staphylococci with methicillin resistance. Conclusion: Given the number and severity of S. aureus infections it is important to understand the nature and pathogenesis of infections and the current strategies available for therapy and prevention.