Distribution of potentially pathogenic enteric bacteria in coastal sea waters along the Southern Kerala coast, India.

ABSTRACT

This study evaluated the relationship between the traditional indicators of faecal pollution, total coliforms (TC), faecal coliforms (FC) and Faecal streptococci (FS), and the presence of few potentially pathogenic enteric bacteria, Vibrio cholerae (VC), Vibrio parahaemolyticus (VP), Shigella spp. (SH) and Salmonella spp. (SL) in coastal sea water. The distributional statuses of these bacteria were also studied along the Southern Kerala coast. Cluster analyses were done to identify similar groups of indicator as well as enteric pathogenic bacteria. Kochi was found to be highly polluted with enteric pathogens and indicator bacteria (TC of 4700, VC of 820, FC of 920 and FS of 410 CFU ml-1). Percentage incidence of VC (97.42%) was comparatively higher than the traditional indicator bacteria (TC 95.04%, FC of 63.64% and FS of 47.64%). VC found to be rather stable and showed significant relationship with all the traditional indicator bacteria (R² > 0.370), suggests that both quantitatively and qualitatively the abundance of Vibrio cholerae can determine faecal pollution, could be used as a faecal pollution indicator bacterium, especially in the marine environment where traditional indicator bacteria failed to survive. It would be advisable to always perform the detection of SH and VP beside the traditional indicators as no significant relationship (R²<0.076, p>0.05) exists among them.