Producción Científica Profesorado

Acid and alcohol tolerance of Escherichia coli O157:H7 in pulque, a typical Mexican beverage.



Castro Rosas, Javier

2012

Carlos A. Gómez-Aldapa, Claudio A. Díaz-Cruz, Angelica Villarruel-López, M. del Refugio Torres-Vitela, Esmeralda Rangel-Vargas and Javier Castro-Rosas. 2012. Acid and alcohol tolerance of Escherichia coli O157:H7 in pulque, a typical Mexican beverage. International Journal of Food Microbiology.154(1-2):79-84


Abstract


Pulque is a traditional Mexican fermented alcoholic beverage produced from the nectar of maguey agave plants. No data exist on the behavior of Escherichia coli O157:H7 in agave nectar and pulque. An initial trial was done of the behavior of E. coli O157:H7 during fermentation of nectar from a single producer, a nectar mixture from different producers and seed pulque. A second trial simulating artisanal pulque production was done by contaminating fresh nectar with a cocktail of three E. coli O157:H7 strains, storing at 16 and 22 C for 14 h, adding seed pulque and fermenting until pulque was formed. A third trial used pulque from the second trial stored at 22 C as seed to ferment fresh nectar at 22 C for 48 h (fermentation cycle). This procedure was repeated for an additional two fermentation cycles. During incubation at 16 or 22 C in the first trial, the E. coli O157:H7 strains multiplied in both the single producer nectar and nectar mixture, reaching maximum concentration at 12 h. E. coli O157:H7 cell concentration then decreased slowly, although it survived at least 72 h in both fermented nectars. E. coli O157:H7 did not multiply in the seed pulque but did survive at least 72 h. In the second trial, the numbers of E. coli O157:H7 increased approximately 1.5 log CFU/ml at 22 C and 1.2 log CFU/ml at 16 C after 14 h. After seed pulque was added, E. coli O157:H7 concentration decreased to approximately 2 log CFU/ml, and then remained constant until pulque was produced. In the third trial, the E. coli O157:H7 cells multiplied and survived during at least three nectar fermentation cycles. The results suggest that E. coli O157:H7 can develop acid and alcohol tolerance in pulque, and constitutes a public health risk for pulque consumers.






Artículos relacionados

An in situ method to study the reaction catalyzed by alkaline phosphatase on DNP

The role of foods in Salmonella infections. In: Salmonella - A Dangerous Foodborne Pathogen

Condiciones microbiológicas en el proceso de sacrificio en un rastro municipal del estado de Hidalgo

Behavior of Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Shigella flex...

APLICACIÓN DE SALES DE ACIDOS ORGÁNICOS EN LA CONSERVACIÓN DE CARNE DE CONEJO.

Optimization of thermal protein precipitation from acid whey

SIMULACIÓN MATEMÁTICA DE UN DIGESTOR ANAEROBIO TIPO TANQUE AGITADO PARA EL TRATAMIENTO DE VERTIDOS R...

Survival of Brucella abortus in milk fermented with a yoghurt starter culture

COLORANT EXTRACTION FROM RED PRICKLY PEAR (OPUNTIA LASIACANTHA) FOR FOOD APPLICATION

Degradación anaerobia de dos tipos de lactosuero en reactores UASB