Assessing Microbial Quality of Mumbai's Coastal Waters for Potential Public Health Risks.

This study focuses on the statistical estimation of coliform count and isolation of the faecal indicator coliform Escherichia coli (E. coli) in water samples collected from 7 beaches along the Mumbai coastline: Aksa, Dana Pani, Versova, Juhu, Bandra, Dadar Chowpatty, and Girgaon Chowpatty. The salinity of seawater was calculated using a pycnometer. The extent of faecal contamination was detected by determining the Most Probable Number in the fresh sample on day 0, and with 7 days intervals up to 21 days for the stored sample. This was done to monitor the coliform count over time. The MPN determination was carried out using MacConkey broth with inverted Durham tubes. Following enumeration by the MPN technique, the representative positive tubes were used to isolate the faecal indicator coliform Escherichia coli using MacConkey agar and Eosin-Methylene Blue agar. The typical pink colonies of Escherichia coli isolated on MacConkey agar were subjected to biochemical tests such as Indole production, Methyl Red test, Voges-Proskauer test, Citrate utilization Urea hydrolysis, Lactose utilization and the Triple Sugar Iron test. The presence of Escherichia coli was further confirmed using Modified MUG EC broth.