Potential Exposure Risk Associated with the High Prevalence and Survival of Indicator and Pathogenic Bacteria in the Sediment of Vembanadu Lake, India

Abstract

Prevalence of faecal coliform bacteria and the survival of Escherichia coli, Vibrio parahaemolyticus and Salmonella paratyphi were studied in the water and sediment from Vembanadu Lake in the presence and absence of protozoan predators. The density of faecal coliform bacteria ranged between mean MPN value 5080-9000/100 ml in water and 110,000-988,000/1 g in sediment (p < 0.01), which was 110 times greater than in overlying water. The laboratory microcosm studies revealed that E. coli, V. parahaemolyticus and S. paratyphi showed significantly higher survival (p < 0.05) potential in sediment than in overlying water both in the presence and absence of protozoan predators. The results indicate that Vembanadu Lake sediment constitutes a reservoir of pathogenic bacteria and exhibits potential health hazard from possible resuspension and subsequent ingestion during recreational activities. Therefore, assessment of bacterial concentration in freshwater lake sediments used for contact and non-contact recreation is of considerable significance for the proper assessment of micro- bial pollution of the overlying water and the management and protection of related health risk at specific recreational sites. In addition, assessment of the bacterial concentration in sediments can be used as a relatively stable indicator of long-term mean bacterial concentration in the water column above.

Genetic relatedness of faecal coliforms and enterococci bacteria isolated from water and sediments of the Apies River, Gauteng, South Africa

“…Many families in southern Africa including South Africa and especially those residing in non-metropolitan areas still rely on river water for drinking and other domestic purposes (Donovan et al 2008; Abhirosh et al 2010). Microbiological contamination of drinking water is one of the main causes in the spread of waterborne diseases (Franz 2005).…”

Spatio-Temporal Variations in Pathogenic Bacteria in the Surface Sediments of the Zuari Estuary, Goa, India

“…19). As sediment acts as reservoir of pathogenic bacteria, monitoring the bacterial load in the sediment can provide stable indicator of their long-term abundance in the water column 20 . Zuari estuary is located along the central west coast of India (1527.5N, 7348E) and is influenced by the south west (SW) monsoon 21 , hereafter referred to as the monsoon.…”