Lactic Acid Bacteria as Inhibitory Agents of Escherichia coli ATCC 25922

In the search to generate new natural alternatives that are less harmful to the body, the use of Lactic Acid Bacteria (LAB) has been chosen due to its ability to grow in different conditions and generate antagonism against other pathogenic microorganisms. Escherichia coli has been the cause of emerging food outbreaks, especially in children and the elderly who have weak immune systems, being a risk to public health. In addition, this pathogen has been demonstrating decreased sensitivity to antibiotics. The present study sought to evaluate the antimicrobial power of 4 LAB strains isolated from food from the Huila-Colombia region against Escherichia coli ATCC 25922 through disc-diffusion and well-diffusion. The strains that inhibited in the presence of cells were L, D (strains isolated from coffee fermentation mass), and 12 (Huila cheese isolate), obtaining inhibition percentages of 37.27±4.15, 32.65±0.97 and 23.47±0.34 for strains L, D and 12, respectively. In the absence of cells, the organic acids of strains L and D obtained from the coffee fermentation process stood out, with inhibition percentages of 27.28±0.27 and 23.63±1.00 respectively. The findings demonstrate the effectiveness of strains native to the region, exalting those obtained from the coffee chain. We performed a multifactorial analysis between LAB and inhibition methods, finding statistically significant differences between methods with p<0.05. In order to know the viability of LAB under in vitro and in vivo conditions, it is important to study other parameters and evaluate the feasibility of using them as a biotherapeutic treatment.