@article{aees20231112,
author={{Cheriyan, Letha P and R, Harish and Steffy, R.},
title={Qualitative Risk Assessment of Microbial Indicators in the Lower Reaches of Meenachil River, Kerala, India},
journal={Applied Ecology and Environmental Sciences},
volume={11},
number={1},
pages={8--14},
year={2023},
url={http://pubs.sciepub.com/aees/11/1/2},
issn={2328-3920},
abstract={Pristine natural freshwater resources being severely contaminated by microbiological pollutants is still a big issue in many parts of the world. In the present study, water samples taken from the upstream, midstream, and downstream reaches of the Meenachil River were analysed for the presence of microbial pollution indicators such as faecal coliforms (FC), faecal streptococci (FS), and <i>Eschericia coli</i>. The <i>E. coli</i> isolates were subjected to antimicrobial susceptibility tests and the multiple antibiotic resistance (MAR) indexes were calculated so as to delineate the potential risk posed by infections to humans and animals using the river for routine potable and recreational purposes. <i>E. coli</i> was consistently isolated from all the samples collected from the different zones of the river. Other faecal coliforms such as <i>Klebsiella oxytoca, Citrobacter koseri, Enterobacter, Proteus vulgaricus</i>, and <i>Shigella boydii</i> were also identified. Higher FC/FS ratios were noticed for the midstream and the downstream sites indicating the contamination from high-risk sources such as human and anthropogenic domestic wastes. The MAR index values of <i>E. coli</i> isolates ranged from 0.33 upstream, 0.416 for midstream and 0.583 for the downstream reaches. Given that <i>E. coli</i> is an ideal indicator of faecal pollution, their existence and extended survival of multiple antibiotic resistance natural freshwater pose a potential risk for the consumers. Rapid urbanization and resultant waste drainage in the downstream stretches of the river might have accelerated the deterioration of the water quality up to a certain extent. Furthermore, the riverine system as it flows downstream loses its self-purification capacity due to the loss of natural water drifts. This may be attributed to the periodic shutdown of the salinity barrier, Thanneermukkam Bund in the confluence zone of the river which results in a temporary stagnation of the running waters in the lower stretches.},
doi={10.12691/aees-11-1-2}
publisher={Science and Education Publishing}
}