Bacteriological analysis of hospital sewage of district Hospital Ratnagiri

Hospital sewage is a waste drained out from the various clinical facilities of the hospital. The hospital sewage contains pathogens which pose severe public health threat. Most hospitals lack sewage treatment facilities and discharge the sewage untreated directly in to the public sewer. The study was aimed to analyze the hospital sewage of District hospital Ratnagiri for Coliform count by MPN and serial plate dilution method, and identification of the Bacterial isolates by conventional method from the sewage. Physico-chemical parameters like Temperature, pH, TDS, COD, BOD5, samples were determined which affect the bacterial flora of the sewage. Presumptive and Confirmatory MPN test and Serial plate dilution was performed. Coliform were isolated and identified using Gram stain, Colony characteristics and Biochemical characteristics. Temperature was 28(+1.22)°c, pH 6.52(+0.10), TDS 251(+1.41) mg/l, COD 96.9(+0.82) mg/l and BOD 69.5 (+0.58) mg/l. TDS was higher, COD and BOD values were less as compare to the permissible limits. Presumptive MPN was >1.8 x 103, Confirmatory MPN was 3.3x101 per 100 ml and coliform count by serial dilution was 6x106 CFU/ml on Blood agar and 2x106 CFU/ml on MacConkey’s agar which indicated higher counts of coliform in the sewage. Common bacteria like Escherichia coli, Pseudomonas aeruginosa, Klebsiella peumonae, Chromobacter violaceum and Bacillus subtilis were isolated. The study reveals presence of significant coliform load in the hospital sewage which poses risk of infection to the community.