Aislamiento, identificación y conservación de cepas bacterianas encontradas en muestras de ceviche de chochos

Abstract

The objective of the research project was to isolate, identify and conserve bacterial strains found in chochos ceviche samples that are sold outpatients in Riobamba. The analyzed samples were randomly taken from ambulatory carts following the protocol established in the INEN 1529-2: 2013 standard “MICROBIOLOGICAL CONTROL OF FOOD., TAKING, SENDING AND PREPARING SAMPLES FOR MICROBIOLOGICAL ANALYSIS". Afterwards, the isolation was carried out in selective and differential culture media by successive reseeding in order to obtain pure strains. For the identification, phenotypic and biochemical tests were carried out for each bacterial species, resulting in microorganisms of the Enterobacter, Pseudomonas, Streptocococus, Staphylococcus and Citrobacter genera; in addition, by molecular identification by Polymerase Chain Reaction (PCR) bacteria of the genus Acinetobacter. In the evaluation of the enzymatic activity, five positive strains were evidenced after being cultivated in enriched agar and formulated for each activity, resulting in Acinetobacter johnsonni and Pseudomona spp. with amylolytic activity, Staphylococcus aureus with proteolytic and lipolytic activity, and Pseudomona aeruginosa and Proteus spp. with cellulolytic activity. In total, 13 strains were identified that were preserved in 30% glycerol at -196 degrees Celsius in a cryo-freezer, this long-term preservation method guarantees biochemical and microscopic stability. The microorganisms isolated from chochos ceviche are considered a food safety problem, since most street vendors do not have good handling and hygiene practices during food preparation, therefore, training in correct hygiene practices could be timely to reduce food-borne illnesses (ETA) and generate a safer and healthier society.