Microbiological quality of drinking water used in public schools from the city of Tepatitlan, Jalisco

Abstract

This study aimed to evaluate the microbiological quality of drinking water in public schools from the city of Tepatitlan de Morelos, Jalisco, Mexico (3 kindergartens, 15 elementary and 4 high schools) through quantification of free chlorine content, total coliform bacteria (OCT), and fecal bacteria (OCF); in addition to the qualitative search for Enterobacteriaceae. In general, 9% of the schools tested met the criteria established by the Official Mexican Standard for free chlorine content (0.2 to 1.5 mg/L), while 59% of the samples exceeded the recommended limits, and 32% was not detected. Regarding OCT and OCF content, these bacteria were detected in water samples from schools (K1 and S3) that did not contain chlorine when arriving from the municipal network, but also in specimens (P7, P8, and P15) that contained excessive residual chlorine; from this, concluding that the contamination of water may be from the origin and/or due to dirty storage tanks. It is important to note that Escherichia coli bacteria were identified in 13.6% of the samples; in addition, strains such as Citrobacter freundii, Klebsiella spp, and Pseudomona spp. were isolated. The presence of pathogenic bacteria in drinking water in educational institutions indicates that it can be a potential vector of gastrointestinal diseases, so it is recommended that preventive cleaning maintenance be carried out in cisterns and tanks and frequent monitoring of the microbiological quality of the water.