Minimum Biofilm Eradication Concentration (MBEC) Assay of Silver and Selenium Nanoparticles against Biofilm forming Staphylococcus aureus

Staphylococcus aureus is a most important bacterium that causes nosocomial infections and the etiologic agent of a wide range of diseases related with major mortality and morbidity. Total 36 positive clinical samples viz. urine, blood and pus collected from different patients were found to harbor Staphylococcus aureus with a maximum isolation from pus samples i.e. 30 (83.33%) and minimum isolation from urine samples i.e. 2 (5.56%). The degree of capacity to biofilm forming Staphylococcus aureus isolates to different phenotypic analysis of biofilm formation by Congo red agar (CRA) Nil, Tube method (TM) 5 (13.89%), and Tissue culture plate method (TCP) 12 (33.33%). The application of silver and Selenium nanoparticles as antimicrobials are gaining relevance in the medical field. Silver nanoparticles, due to their unique properties, use in day-by-day many applications in human life. The major uses of silver nanoparticles in the clinical and medical fields consist of investigative applications and curative applications. Selenium metal is an essential micronutrient for human beings and animals. Selenium nanoparticles showed the highest bactericidal and antimicrobial properties. Minimal biofilm eradication concentrations (MBEC) were determined by 96-well microtitre plate. The antibacterial effects of silver and selenium nanoparticles were evaluated with respect to growth, biofilm formation of Staphylococcus aureus strains. Among the three biofilm forming Staphylococcus aureus strains showed OD 450 i.e. 0.019, 0.039, 0.075 value 0.080 for AgNPs whereas SeNPs couldn't showed any 0.080 value against biofilm forming S. aureus strains. In case of MBEC test, AgNPs showed more affective against biofilm forming Staphylococcus aureus strains compared of SeNPs. Finally we suggested that AgNPs showing best antimicrobial activity against SeNPs.