EXTRA CELLULAR BIOFILM FORMATION OF CLINICAL PATHOGEN KLEBSIELLA PNEUMONIAE AND THEIR INHIBITORY ACTIVITY WITH ANTIMICROBIAL SECONDARY METABOLITES

Abstract

Introduction: K.pneumoniae can survive in the hospital environment and colonize the bowel, respiratory and  bacterial meningitis. Humans are known to be the primary reservoir. This is a nosocomial pathogen. In recent years, the bacterium is reported to have developed new virulence genes making them resistant to a major class of antibiotics. One of the major sources for isolation and identification of therapeutics against bacterial infection are microbial secondary metabolites. Those that are obtained from Actinobacteria have antifungal, antibacterial, antioxidant, antitumor and antiviral activities. Nocardia sp is one such bacteria.

Materials and Method: The isolation of the actinomycetes was done from the marine soil.  The isolation and culture of the bacteria was done in Bennett’s culture medium and methanolic extract was prepared. The strains of Klebsiella pneumoniae were obtained from pus cells of infected patients. It was grown in Nutrient agar and MacConkey agar was used as a differential medium. 0.1% of Acridine orange dye was used to stain the biofilm of K.pneumoniae. Number of viable cells was observed at regular intervals of time under the microscope such as 24 hours, 48 hours and 72 hours.

Results: Secondary metabolite of Nocardiopsis was able to effectively inhibit the growth of the biofilm which was stained with Acridine Orange at 25µg/dL. The number of viable cells was heavily decreased after 72 hours of incubation.

Conclusion: From the results above, it can be concluded that the secondary metabolite of Nocardiopsis was able to inhibit the biofilm growth of K.pneumoniae.