Microbiological Quality of High-Demand Food from Three Major Cities in Ecuador.
Salazar-Llorente, E., Morales, M., Sornoza, I., Mariduena-Zavala, M. G., Gu, G., Nou, X., Ortiz, J., Maldonado-Alvarado, P. and Cevallos-Cevallos, J. M.
Escuela Superior Politecnica del Litoral (ESPOL), Centro de Investigaciones Biotecnologicas del Ecuador.
ESPOL, Facultad de Ingenieria Mecanica y Ciencias de la Produccion, U.S. Department of Agriculture Agricultural Research Service, Beltsville, Maryland, USA.
Environmental Microbiology and Food Safety Laboratory, U.S. Department of Agriculture Agricultural Research Service, Beltsville, Maryland, USA.
Department of Biosciences, Food Nutrition and Health Research Unit, Faculty of Chemical Sciences, Cuenca University, Cuenca, Ecuador.
Escuela Politecnica Nacional, Departamento de Alimentos y Biotecnologia, P.O. Box 17-01-2759, Quito, Ecuador.
(ORCID: https://orcid.org/0000-0003-4609-7998 [J.M.C.C.]).
ESPOL, Facultad de Ciencias de la Vida, Campus Gustavo Galindo, Km. 30
ABSTRACT: Bacterial foodborne diseases are among the most important public health issues worldwide, but in Ecuador, reports on the microbiological quality of food are scarce. In this cross-sectional study, 450 samples of high-demand Ecuadorian food, including bolon, encebollado, sauces, ceviche, fruit, fruit juice, fruit salad, cheese, raw chicken, and ground beef, were collected from popular street markets in the cities of Guayaquil, Quito, and Cuenca. Populations of total aerobic mesophilic bacteria, total coliforms, fecal coliforms, Escherichia coli, Salmonella enterica, and Listeria monocytogenes were examined on composited samples by plate count following the local regulations (Norma Tecnica Ecuatoriana, Instituto Ecuatoriano de Normalizacion) for each kind of food. The individual and interaction effects of the city and food type on the levels of each bacterial group were assessed by two-way analysis of variance. Selected colonies from each culture were identified using Biolog OmniLog ID and sequencing of the V3 to V4 region on the 16S rRNA gene. Average total aerobic mesophilic bacteria, total coliform, fecal coliform, and E. coli levels were 5.10 +/- 0.12, 2.50 +/- 0.16, 1.09 +/- 0.12, and 0.83 +/- 0.12 log CFU/g or mL, respectively, with significant variations among the cities. The prevalence of Salmonella in chicken and sauces and L. monocytogenes in cheese and fruit salad was greater than 20%. Opportunistic pathogens including Klebsiella pneumoniae, Staphylococcus sciuri, and Enterococcus spp. were frequently identified in the samples from all three cities. High prevalence of spoilage microorganisms such as Bacillus amyloliquefaciens and biocontrol bacteria such as Lactococcus lactis was also observed. This is the first report on the microbiological quality of food from Ecuador. HIGHLIGHTS:
Journal of Food Protection 84(1): 128-138 (2021)