title: Behavior of Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Shigella flexneri and Shigella sonnei during production of pulque, a traditional Mexican beverage.
abstract: Pulque is a typical fermented alcoholic beverage of central Mexico, produced from the nectar of maguey agave plants. Production systems are largely artisanal, with inadequate hygiene conditions and exposure to multiple contamination sources. No data exist on pulque microbiological safety and the behavior of pathogenic microorganisms in agave nectar and pulque. An initial trial was done of the behavior of Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Shigella flexneri and Shigella sonnei during fermentation of nectar from a single producer, nectar mixture from different producers, and seed pulque. A second trial simulating artisanal pulque production was done by contaminating fresh nectar with each of the five strains, storing at 22°C for 14 h, adding seed pulque, and fermenting until pulque was formed. During incubation at 16 or 22°C in the first trial, all the pathogenic strains multiplied in both the single producer nectar and the nectar mixture, reaching maximum concentrations at 12 h. Strains concentration then decreased slowly. In the seed pulque, the strains did not multiply and tended to die. In the second trial, all strains increased concentration from 0.7 to 1.6 log at 22°C, and from 0.5 to 1.1 at 16°C in the first 14 h. After addition of seed pulque, they were quickly deactivated until none was detected in the final product. The results suggest that the potential risk to consumers of contracting any of the five tested pathogenic bacterial strains from pulque is low.
authors.affiliation: Centro de Investigaciones Químicas, Instituto de Ciencias Básicas e Ingeniería, Universidad Autónoma del Estado de Hidalgo, Centro Universitario, Carretera Pachuca-Tulancingo Km. 4.5, 42183 Mineral de la Reforma, Hidalgo, Mexico.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Gómez-Aldapa
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Díaz-Cruz
authors.forename: Angélica
authors.initials: A
authors.lastname: Villarruel-López
authors.forename: M del Refugio
authors.initials: Mdel R
authors.lastname: Torres-Vitela
authors.forename: Javier
authors.initials: J
authors.lastname: Añorve-Morga
authors.forename: Esmeralda
authors.initials: E
authors.lastname: Rangel-Vargas
authors.forename: Jorge F
authors.initials: JF
authors.lastname: Cerna-Cortes
authors.forename: J Gabriel
authors.initials: JG
authors.lastname: Vigueras-Ramírez
authors.forename: Javier
authors.initials: J
authors.lastname: Castro-Rosas
mesh_terms: D027882:Agave / Q000382:microbiology*; D000434:Alcoholic Beverages / Q000382:microbiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D017753:Ecosystem; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000502:physiology; D008800:Mexico; D012486:Salmonella typhimurium / Q000502:physiology; D012763:Shigella flexneri / Q000502:physiology; D012764:Shigella sonnei / Q000502:physiology; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000502:physiology