Validation of a novel, low-cost, and low-power <i>Escherichia coli</i> detection kit

ABSTRACT Microbial water quality monitoring is essential for safe drinking water, but can be difficult to carry out in contexts without access to well-resourced laboratories. Numerous testing kits have been developed to operate in these contexts, but many have drawbacks in terms of precision of results, cost, and contextual fitness. To this end, Faircap has developed a new low-cost (USD 38) microbial water quality testing kit, which includes a lightweight and low-power incubator and a membrane filtration-based water quality testing device. This kit was evaluated for reliable and accurate microbial water quality testing. The incubator maintained adequate temperature conditions in all selected ambient temperatures. Escherichia coli counts were not significantly different from a reference method, and a priori risk categorization agreed 80% of the time. The membrane filtration method had high sensitivity and specificity, but E. coli counts were less than those of the reference method. The decontamination protocol applied in between tests successfully decreased E. coli concentrations to non-detectable levels, without leaving significant decontamination residual. Overall, the Faircap Portable Lab, specifically the incubator, is a promising option for microbial water quality monitoring and could result in considerable cost savings and reduction of plastic waste compared with other accepted testing methods.