Enteric Bacteria and Water Quality of Freshwater Prawn Macrobrachium rosenbergii (De Man) in Culture Environment from Kerala, India

摘要

Enteric bacterial population associated with farmed freshwater prawn and its environment, water quality of prawn farm and the existing association between these parameters were studied. Microbiological parameters were determined following the United States Food and Drug Administration (USFDA) methods and the physico-chemical parameters as per the standard methods of American Public Health Association (APHA). Prawn samples yielded a mean Total Plant Count (TPC) in the range of 4.57 to 6.66 log cfu g~(-1) and was the highest among all other samples. Prawns followed by water samples had the higher level of enteric indicator organisms. Sediment showed higher count of sulphite reducing clostridia. Emerging pathogen E. coli O157:H7 were absent in all thesamples analyzed. Enterobacter (31.5%) followed by Citrobacter (13.2%) and non enteric bacteria Aeromonas (11%) were the dominant flora recovered. Escherichia, Klebsiella, Hafnia, Serratia, Salmonella and Shigella were the other opportunistic enteric bacterial pathogens detected from this system. The rearing practices such as use of cow dung as fertilizer and microbiologically contaminated feed could have influenced the enteric flora. Study on various physico-chemical parameters of pond water revealed that they were within the suitable range for the freshwater prawn culture. Correlation'analysis revealed a significant positive correlation between pollution indicator parameters such as Total Organic Carbon (TOC), Biological Oxygen Demand (BOD), ChemicalOxygen Demand (COD) with that of Total Plate Count (TPC) and Total Enterobacteriaceae Count (TEC) of the pond water and prawn samples. Presence of bacteria of public health significance in the aquaculture pond envisages strict hygienic handling, processing of prawn from this system and cooking prior to consumption to ensure public health safety.