In Mexico, gastrointestinal diseases are the leading cause of medical consultation and death, and are therefore considered a public health problem. The most common bacterial strain associated with diarrhea includes E. coli. We are currently suffering from bacterial resistance spread throughout the world. Due to the increase in therapeutic failures in infections caused by microorganisms such as enterobacteria, studies have been directed at investigating the mechanisms of resistance of these germs and the presence of bacteria producing enzymes that inactivate beta-lactam antibiotics (beta-lactamases) has been proven. Within the group of beta-lactamase-producing bacteria are the beta-lactamase-producing bacteria (BLEE). The objective of this study is to determine the prevalence of BLEE-producing Escherichia coli strains in diarrheal samples from a hospital in the comarca lagunera.