Serratia marcescens is an opportunistic Gram negative nosocomial pathogenic bacteria. It accounts for 1%-2% of nosocomial infections confined to the respiratory tract, urinary tracts, surgical wounds in hospital settings and environments. This work was undertaken to isolate, characterize genotypically and phenotypically, S. marcescens for optimization prodigiosin production and evaluation of bioactive potentials. The test organisms were isolated from both clinical and non-clinical samples using streak and spread plate methods on peptone glycerol broth and agar. The isolate were characterized and evaluated for cephalosporin resistance using standard protocols. The pure prodigiosin was developed, optimized, extract, purify, characterized and dried using solvent-solvent extraction and other analytical methods. The prodigiosin metabolite was evaluated for phyto-constituents and antimicrobial potentials. The results showed an expressed red pigmented metabolite which appeared Gram negative bacteria and a dark, stained flagella on Scanning Electron Microscope (SEM). The biochemical tests and presence of corresponding gene from PCR via plasmid profiling confirmed the bacteria as S. mercescens. It was observed on the activity pattern, some level of resistance to first and second generation cephalosporins with average Inhibition Zone Diameter (IZD) of 5 mm but susceptible to third generation with maximum IZD of 25 mm. The optimized production yielded 0.2% bioactive principles and the metabolite subsequently, showed good antimicrobial activities with MIC and MBC between 8 and 4 mg/ml. Summarily, the activity pattern showed that the resistance could be as a result of plasmid DNA mediation and suggests the expression and production of some natural bioactive principle for diagnostics, management and treatment of some tropical diseases.
Thaddeus H. Gugu, Ibeabuchi Moses, Anthony A. Attama, Emmanuel C. Ibezim, Ganesh D. Basarkar, Sanjay B. Patil