Methods for detection and enumeration of coliforms in drinking water: a review

Ensuring the microbiological safety of drinking water is of paramount importance to protect public health. Coliform bacteria, including Escherichia coli, serve as key indicators of water contamination and the potential presence of harmful pathogens. Accurate and reliable detection and enumeration of coliforms in drinking water are essential for monitoring water quality and implementing appropriate interventions. This review article provides an overview of various traditional culture-based methods and rapid molecular methods employed for the analysis of coliforms in drinking water, highlighting their strengths, limitations, and advancements. Culture-based methods such as multiple-tube fermentation (most probable number) and membrane filtration techniques have long been used as standard methods for coliform detection. The emerging molecular-based approaches, including polymerase chain reaction (PCR), quantitative PCR, and nucleic acid sequencing offer improved sensitivity, specificity, and turnaround time. This comprehensive review provides a valuable resource for researchers, water quality professionals, and policymakers engaged in the detection and enumeration of coliform bacteria in drinking water. It offers an up-to-date understanding of different methods, their advancements, and the potential integration of novel technologies. By critically evaluating these approaches, this review aims to contribute to the ongoing efforts toward ensuring safe drinking water for all. HIGHLIGHTS The need for microbiological water quality assessment has been highlighted.; Concept of indicator microorganisms for estimating the water quality.; Classical and modern methods for the detection of coliforms in drinking water.; Advantages and limitations of molecular methods for enumeration of coliforms.; Evaluation of the need for alternative methods for the detection of indicator microorganisms.;