Identification of enterobacteria in the drinking water from the eastern part of the State of Mexico

The microbial load of a drinking water sample is an indicator of biological contamination that puts the health of the people who consume it at risk human health of people that consume it, for this, it is essential to guarantee this resource quality, which is important for the domestic consumption and functioning and continuity of the agricultural and industrial activities. This research was aimed at analyzing the microbial burden in drinking water of the municipalities of Ecatepec, Nezahualcóyotl, La Paz and Chalco, of the eastern part of the State of Mexico, through the identification of total and fecal coliforms. 132 samples in triplicate of drinking water from five colonies of each municipality studied, were randomly analyzed, from which it was observed that, during the warm-dry season in 16 colonies of Nezahualcóyotl and Ecatepec, there was a microbial presence of total and fecal coliforms above the maximum permissible limit of the most probable number (MPN) that is 2 MPN/100 mL, while for the cold-humid season, 14 colonies exceeded the limit. During the morphological identification and isolation through Gram staining and methylene blue, the presence of Escherichia coli, Shigella and mesophilic aerobic microorganisms was found in the four municipalities analyzed. The high biological pollution values that were recorded, could be corelated to the increased incidence of gastrointestinal diseases present in the eastern part of the State of Mexico.