A study was designed to investigate the enteric bacterial population associated with farmed freshwater fish and its environment, limnological quality of carp farm and the existing association between these parameters. Enteric indicator bacterial counts were determined following the United States Food and Drug Administration (USFDA) methods and the physico-chemical parameters according to the standard methods of American Public Health Association (APHA). Fish samples yielded mean microbiological counts in the range of 4.19 to 4.85 log CFU g-1, sediment in the range of 5.18±0.01 to 6.34±0.01 log CFU g-1, pond water in the range of 3.64±0.03 to 6.10±0.04 log CFU mL-1. Fish and feeder canal water showed higher count for all indicator bacterial count. Sediment showed 2 log cycle higher count of sulphite reducing clostridia. Emerging pathogen E. coli O157:H7 were absent in all the samples analyzed. Aeromonas (26.2%) followed by Enterobacter (24.6%) were the dominant flora recovered. Escherichia, Klebsiella, Serratia, Hafnia, Plesiomonas, Shigella, Salmonella, Morganella and Yersinia were the other opportunistic enteric bacterial pathogens detected from this system. The rearing practices such as natural fertilization and feeding could have influenced the enteric flora. Study on the various physico-chemical parameters of pond water revealed that they were within the suitable range for the freshwater fish culture throughout farming phase. Correlation analysis revealed a significant positive correlation between physico-chemical parameters such as total organic carbon (TOC), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) with that of Total Plate Count (TPC), Total Enterobacteriaceae Count (TEC), Total Coliforms (TC), Faecal Coliforms (FC) and E. coli (EC). Presence of bacteria of public health significance in the aquaculture ponds envisages a strict hygienic handling and processing of fish from the culture systems for ensuring public health safety.
A. Surendraraj, K.H. Sabeena Farvin, R. Yathavamoorthi and N. Thampuran, 2009. Enteric Bacteria Associated with Farmed Freshwater Fish and its Culture Environment in Kerala, India. Research Journal of Microbiology, 4: 334-344.