Vol. 3, Issue 2, Part A (2021)

The presence of pathogenic microorganisms in backwaters is of a great concern and the unsafe water is responsible for 1.2 million deaths each year. In the present study, water samples beneath the aquatic weeds, leaf and root samples of E. crassipes and P. stratiotes were collected from YMCA canal, Alappuzha, Kerala state, India, and subjected to physicochemical and microbiological analysis. The pH of the water samples were in the range of 6.6 to 6.9, salinity was nil, electrical conductivity was 5.327 mS for Eichhornia crassipes sample and 882.2 mS for Pistia stratiotes rhizosphere water sample. Total dissolved solids (TDS) were 2.777 ppm and 448 ppm for E. crassipes and P. stratiotes respectively. Heterophilic plate count of E. crassipes is 11 x 103 and 3 x 102 CFU/ml for bacteria and fungi respectively. Similarly the rhizosphere water sample of P. stratiotes showed a bacterial count of 75 × 103 CFU/ml and the fungal count was 8 x 102 CFU/ml. Human pathogens such as Klebsiella. pneumoniae, Salmonella typhi, Enterococcus faecalis, E. coli, Vibrio cholerae, Salmonella enteritidis, Enterobacter aerogenes, Vibrio vulnificus etc. were isolated from leaf, root and rhizosphere water samples. Antibiotic sensitivity studies revealed that Klebsiella pneumoniae was resistant to antibiotics like Azithromycin, Co-Trimoxazole, Cefuroxime and Cefalexin. Most of the pathogens were resistant to Cefalexin.