Quantification of Pathogenic Microorganisms in River and Groundwater Samples at Riverbank Filtration (RBF) Site

Abstract

There are numerous methods for counting the number of bacterial cells in the study of microbiology. The techniques include direct microscopic counts, turbidimetric measurement, and standard plate counts (Viable Counts). The standard approach was chosen for this bacterial enumeration because it is simple to use and significantly more sensitive than turbidimetric testing. A plate count is typically performed by dilution of the original sample, 1 ml transfer onto an agar plate, and even distribution across the plate's surface. Colonies emerged when the agar plates were incubated at 37 °C for 24 hours. Colony-forming unit (CFU) can then be computed as the total number of viable cells. To ascertain the presence of Salmonella, Shigella, and Escherichia coli bacteria, samples of river water and groundwater were subjected to water analysis. Eosin Methylene Blue (EMB) agar, Salmonella-Shigella (SS) agar, McConkey II Sorbitol agar, and Xylose Lysine Deoxycholate (XLD) agar were the four different types of agar used in the spread plate method. All plates underwent a 24 hour incubation period at 37 °C, after which the colony forming unit (CFU) per milliliter was determined.