Bacteriophage Based Pathogen Reduction in Sewage Sludge

Biological hazard in water resources in the form of pathogenic organisms are responsible for major outbreak in most of the developing countries. The goal which gains momentum is removal of pathogens. Every effort leading to reduction in sewage pollution and pathogenic microbes has to be promoted and implemented. This necessitates to search for novel approaches that does not harm the environment. One such novel approach is exploring the possibilities of bacteriophages for pathogen removal. Sewage sludge samples were collected from different locations of Tamil Nadu and analysed. The pH of the sludge samples varied from 6.26 to 8.23 and alkaline pH was observed in Coovum sample. Highest EC was recorded by Vellore sample (4.62 dSm^-1). The total heterotroph population ranged from 11 × 10⁶ to 24 × 10¹⁴/kg of dewatered sludge. Higher frequency of antibiotic resistant E. coli, Pseudomonas sp., Streptococcus sp. and Bacillus spp. were observed in all the places, which clearly indicated the extent of pollution. E. coli and Salmonella typhi showed resistance to almost all the antibiotics and intermediate resistance to 3 antibiotics. None of the sewage sludge samples had phages against MTCC culture. Phage treatment resulted in 100 % removal of S. typhi from sewage sludge.