Survival of Foodborne Pathogens in Low and Nonalcoholic Craft Beer.

Breweries and beverage companies have recently been interested in creating innovative beer varieties that deviate from traditional beer styles, with either low-alcohol content <2.5% alcohol by volume (ABV) or the absence of alcohol altogether (<0.5% ABV). Traditional beers (up to 10% ABV) contain numerous intrinsic and extrinsic factors preventing pathogens from proliferation or propagation. Physiochemical properties such as a low pH, presence of ethanol and hop acids, limited oxygen, and specific processing techniques, including wort boiling, pasteurization, filtration, cold storage, and handling, all contribute to microbial stability and safety. The potential change or absence in one or more of these antimicrobial hurdles can render the final product susceptible to pathogen survival and growth. In this study, the effect of pH, storage temperature, and ethanol concentration on the growth or die-off of foodborne pathogens in low and nonalcoholic beers was evaluated. pH and ethanol concentrations were adjusted from their initial values of 3.65 and <0.50% ABV to pHs 4.20, 4.60, and 4.80; and 3.20 ABV, respectively. The samples were inoculated with individual five-strain cocktails of E. coli O157:H7, S. enterica, and L. monocytogenes, then stored at two different temperatures (4 and 14°C) for 63 days. Microbial enumeration was performed using selective agar with incubation at 35°C. Results showed that nonalcoholic beers allowed for pathogen growth and survival, as opposed to the low-alcoholic ones. E. coli O157:H7 and S. enterica grew approximately 2.00 log  at 14°C, but no growth was observed at 4°C. L. monocytogenes was more susceptible and fell at, or below, the detection limit rapidly in all the conditions tested. The results show that storage temperature is critical in preventing the growth of pathogens. pH did not appear to have a significant effect on the survival of pathogens (p < 0.05). This challenge study demonstrates the need for beverage manufacturers to prioritize and maintain food safety plans along with practices specific to low- and nonalcoholic beer manufacturers.

Purification and characterization of antifungal lipopeptide produced by Bacillus velezensis isolated from raw honey.

Raw honey contains a diverse microbiota originating from honeybees, plants, and soil. Some gram-positive bacteria isolated from raw honey are known for their ability to produce secondary metabolites that have the potential to be exploited as antimicrobial agents. Currently, there is a high demand for natural, broad-spectrum, and eco-friendly bio-fungicides in the food industry. Naturally occurring antifungal products from food-isolated bacteria are ideal candidates for agricultural applications. To obtain novel antifungals from natural sources, we isolated bacteria from raw clover and orange blossom honey to evaluate their antifungal-producing potential. Two Bacillus velezensis isolates showed strong antifungal activity against food-isolated fungal strains. Antifungal compound production was optimized by adjusting the growth conditions of these bacterial isolates. Extracellular proteinaceous compounds were purified via ammonium sulfate precipitation, solid phase extraction, and RP-HPLC. Antifungal activity of purified products was confirmed by deferred overlay inhibition assay. Mass spectrometry (MS) was performed to determine the molecular weight of the isolated compounds. Whole genome sequencing (WGS) was conducted to predict secondary metabolite gene clusters encoded by the two antifungal-producing strains. Using MS and WGS data, we determined that the main antifungal compound produced by these two Bacillus velezensis isolates was iturin A, a lipopeptide exhibiting broad spectrum antifungal activity.

Significance of hepatitis B surface antigen, IgM/IgG core antibody and hepatitis B virus DNA in blood donors.

INTRODUCTION: Identification of hepatitis B virus carriers in blood donors is imperative in order to avoid transmission of the disease via blood transfusion. OBJECTIVE: To determine if blood donors with positive results for serological markers HBsAg and anti-HBc were hepatitis B virus DNA carriers. METHODS: 12,745 samples were collected from six Ecuadorian blood banks and analyzed for HBsAg, anti-HBc and anti-HBs infectious markers by automated ELISA. All samples that tested positive for one, two or all three markers were analyzed with molecular techniques to determine the presence of viral DNA. RESULTS: 27.5 % of the samples that were reactive for anti-HBc alone and 100 % of those with positive results for HbsAg and IgM/IgG anti-HBc were identified to contain hepatitis B virus DNA (p = 0.001). CONCLUSIONS: The selection of infection markers, as well as the detection methods define the results. Performing two serological and one molecular test is important in order to identify hepatitis B virus carriers and prevent its transmission.

INTRODUCCIÓN: La identificación de portadores del virus de la hepatitis B en donantes de sangre es imperativo para evitar la transmisión de la enfermedad a través de transfusiones sanguíneas. OBJETIVO: Determinar si los donantes de sangre con resultados positivos en los marcadores serológicos HbsAg y anti-HBc eran portadores del ADN del virus de la hepatitis B. MÉTODOS: Se recolectaron 12 745 muestras de seis bancos de sangre ecuatorianos, las cuales fueron analizadas con pruebas serológicas para identificar marcadores infecciosos de HBsAg, anti-HBc, anti-HBs mediante ELISA automatizada. Todas las muestras positivas para uno, dos o los tres marcadores fueron analizadas con técnica molecular para determinar la presencia del ADN viral. RESULTADOS: Se identificó que 27.5 % de las muestras reactivas solo a anti-HBc y 100 % de las muestras con resultados positivos de HBsAg/anti-HBc-IgM/IgG presentaron ADN del virus de la hepatitis B (p = 0.001). CONCLUSIONES: La elección de los marcadores de infección y los métodos de detección definen los resultados. Es importante la realización de dos pruebas serológicas y una molecular para identificar a los portadores del virus de la hepatitis B y evitar su transmisión.

Significación de los marcadores infecciosos para identificar portadores de hepatitis B en donantes de sangre / Significance of hepatitis B surface antigen, IgM/IgG core antibody and hepatitis B virus DNA in blood donors

Resumen Introducción: La identificación de portadores del virus de la hepatitis B en donantes de sangre es imperativo para evitar la transmisión de la enfermedad a través de transfusiones sanguíneas. Objetivo: Determinar si los donantes de sangre con resultados positivos de los marcadores serológicos HbsAg y anti-HBc eran portadores de ADN del virus de la hepatitis B. Métodos: Se recolectaron 12 745 muestras de seis bancos de sangre ecuatorianos, las cuales fueron analizadas con pruebas serológicas para identificar los marcadores infecciosos HBsAg, anti-HBc, anti-HBs mediante prueba ELISA automatizada. Todas las muestras positivas para uno, dos o los tres marcadores fueron analizadas con técnica molecular para determinar la presencia de ADN viral. Resultados: Se identificó que 27.5 % de las muestras reactivas solo a anti-HBc y 100 % de las muestras con resultados positivos de HBsAg/anti-HBc-IgM/IgG presentaron ADN del virus de la hepatitis B (p = 0.001). Conclusiones: La elección de los marcadores de infección y los métodos de detección definen los resultados. Es importante la realización de dos pruebas serológicas y una molecular para identificar a los portadores del virus de la hepatitis B y evitar su transmisión.

Abstract Introduction: Identification of hepatitis B virus carriers in blood donors is imperative in order to avoid transmission of the disease via blood transfusion. Objective: To determine if blood donors with positive results for serological markers HBsAg and anti-HBc were hepatitis B virus DNA carriers. Methods: 12,745 samples were collected from six Ecuadorian blood banks and analyzed for HBsAg, anti-HBc and anti-HBs infectious markers by automated ELISA. All samples that tested positive for one, two or all three markers were analyzed with molecular techniques to determine the presence of viral DNA. Results: 27.5 % of the samples that were reactive for anti-HBc alone and 100 % of those with positive results for HbsAg and IgM/IgG anti-HBc were identified to contain hepatitis B virus DNA (p = 0.001). Conclusions: The selection of infection markers, as well as the detection methods define the results. Performing two serological and one molecular test is important in order to identify hepatitis B virus carriers and prevent its transmission.

Evaluation of Foodborne Pathogen Die-off in Back-Sweetened Wine and Apple Cider Models.

ABSTRACT: Wine and alcoholic apple cider are commonly back-sweetened with unpasteurized juice to produce fresh, natural, and palatable sweetened alcoholic beverages. Foodborne pathogens may be introduced from unpasteurized juice into alcoholic beverages through this back-sweetening process. Although foodborne pathogens generally do not survive under low pH conditions or a high alcohol environment, the die-off of these pathogens has not been established to ensure the microbiological safety of the products. To establish the holding conditions that would provide the required 5-log pathogen reduction requirements for these back-sweetened beverages, we evaluated the survival of three common foodborne pathogens, E. coli O157:H7, Salmonella enterica, and Listeria monocytogenes, in modified white grape juice and apple juice models. White grape juice and apple juice were modified with hydrochloric acid and sodium hydroxide and with ethanol to achieve conditions that are similar to back-sweetened white wine and alcoholic apple cider in regard to pH and ethanol content. Foodborne pathogen cocktails were inoculated separately into modified juice models, and their survival in the juice models was recorded over a 96-h period. Our results show that a combination of low pH and high ethanol content resulted in faster pathogen die-off compared with higher pH and lower ethanol conditions. The holding times required for different combinations of pH and ethanol concentration for each juice model to achieve a 5-log reduction were reported. This research provides data to validate pathogen die-off to comply with juice hazard analysis and critical control point 5-log pathogen inactivation requirements for back-sweetened wine and alcoholic apple cider.

Implementation of ATP and Microbial Indicator Testing for Hygiene Monitoring in a Tofu Production Facility Improves Product Quality and Hygienic Conditions of Food Contact Surfaces: A Case Study.

Rapid ATP testing and microbiological enumeration are two common methods to monitor the effectiveness of cleaning and sanitation in the food industry. In this study, ATP testing and microbiological enumeration were implemented at a tofu production facility with the goal of improving cleaning practices and overall plant hygiene. Results from ATP monitoring were used to target areas of the production environment needing additional cleaning; ATP results were verified by microbiological enumeration of aerobic microorganisms, lactic acid bacteria, and yeasts and molds. Products from the production line were enumerated for the same microorganisms to determine if there was an impact on product quality. After the implementation of ATP monitoring and targeted cleaning, there was a statistically lower proportion of swabs that failed to meet established sanitary requirements for ATP, aerobic microorganisms, and lactic acid bacteria (p < 0.05), but not for yeasts and molds. ATP swabs and microbiological enumeration agreed on site hygiene 75.1% (72.3-77.7%, 95% CI) of the time. Product data indicated that unpasteurized finished products contained a statistically lower microbial load of the three groups of organisms following implementation of the practices (p < 0.05).ImportanceCleaning and sanitation are critical to maintaining safe and high-quality food production. Monitoring these activities is important to ensure proper execution of procedure and to assure compliance with regulatory guidelines. The results from monitoring activities can direct targeted cleaning of areas with higher risk of contamination from foodstuffs and microorganisms. The results of this study show that ATP monitoring and microbiological enumeration are useful tools to verify and improve the efficacy of cleaning and sanitation practices, which can have a positive impact on both plant hygiene and product quality. However, testing regimes and critical parameters will vary based on the product and facility.