Combination of organic acids and low-dose gamma irradiation as antimicrobial treatment to inactivate Shiga toxin-producing Escherichia coli inoculated in beef trimmings: Lack of benefits in relation to single treatments

The aim of this study was to assess the efficacy of lactic acid (LA), caprylic acid (CA), high- (HDI) and low- (LDI) dose gamma irradiation and LDI combined with LA or CA on the inactivation of a pool of Shiga toxin-producing Escherichia coli (STEC) strains inoculated on beef trimmings. The three most efficacious treatments were selected to study their effect on meat quality parameters and sensory attributes. The inoculum included five native STEC serogroups (O26, O103, O111, O145 and O157). The treatments applied were 0.5% LA, 0.04% CA, 0.5 kGy LDI, 2 kGy HDI, LDI+LA and LDI+CA. Beef trimmings were divided into two groups; one was inoculated with high (7 log CFU/g) and the other with low (1 log CFU/g) level of inoculum. Efficacy was assessed by estimating log reduction and reduction of stx- and eae-positive samples after enrichment, respectively. Results showed that treatments with organic acids alone were not effective in reducing STEC populations. For high inoculum samples, the most effective treatment was HDI followed by LDI+LA and LDI alone or combined with CA. For low inoculum samples, the most effective treatment was HDI followed by LDI alone or combined with organic acids. Concerning meat quality parameters and sensory attributes, irradiation treatments (LDI and HDI) caused minimal changes, while LDI+LA modified them significantly compared with the control. Therefore, based on our results, no benefits were observed after combining organic acids with gamma irradiation.Fil: Cap, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Cingolani, Celeste. Comisión Nacional de Energía Atómica (CNEA). Centro Atómico Ezeiza; Argentina.Fil: Lires, Carla. Comisión Nacional de Energía Atómica (CNEA). Centro Atómico Ezeiza; Argentina.Fil: Mozgovoj, Marina Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Soteras, Trinidad. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Sucari, Adriana. Laboratorio de Alimentos Stamboulian. División Higiene y Seguridad Alimentaria y Ambiental; Argentina.Fil: Gentiluomo, Jimena. Laboratorio de Alimentos Stamboulian. División Higiene y Seguridad Alimentaria y Ambiental; Argentina.Fil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina.Fil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina. Universidad de Morón; Argentina.Fil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Horak, Celina. Comisión Nacional de Energía Atómica (CNEA). Centro Atómico Ezeiza; Argentina.Fil: Vaudagna, Sergio Ramon. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina. Universidad de Morón; Argentina.Fil: Leotta, Gerardo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias UNLP, IGEVET — (UNLP-CONICET LA PLATA). Instituto de Genética Veterinaria “Ing. Fernando N. Dulout ”; Argentina

Identification of the gamma irradiation dose applied to ground beef that reduces Shiga toxin producing Escherichia coli but has no impact on consumer acceptance

The aims of the present study were: a) to estimate the minimal dose of gamma irradiation required to reduce 5 log CFU/g of native O157 and non-O157 Shiga toxin-producing Escherichia coli population in ground beef samples inoculated with high inoculum; b) to assess its effectiveness in samples with low inoculum and 3) to evaluate consumer acceptance. Based on the results, 1 kGy was estimated as the minimal dose of gamma irradiation required to reduce 5 log CFU/g of STEC in ground beef. However, when samples with low inoculum level were subjected to 1 kGy, 3.9% of the samples were positive for stx and eae genes after an enrichment step. Consumer acceptance analysis was carried out with samples subjected to 2.5 kGy and no significant differences were found between irradiated and control samples. Therefore, 2.5 kGy was identified as the gama irradiation dose that reduces STEC but has no impact on consumer acceptance of ground beef.Instituto de Investigación de Tecnología de Alimentos (ITA)Fil: Cap, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Cap, Mariana. Instituto de Ciencia y Tecnología de Sistemas Alimentarios Sustentables (UEDD INTA CONICET); Argentina.Fil: Lires, Carla M.L. Comisión Nacional de Energía Atómica. Centro Atómico Ezeiza; Argentina.Fil: Cingolani, Celeste. Comisión Nacional de Energía Atómica. Centro Atómico Ezeiza; Argentina.Fil: Mozgovoj, Marina Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Mozgovoj, Marina Valeria. Instituto de Ciencia y Tecnología de Sistemas Alimentarios Sustentables (UEDD INTA CONICET); Argentina.Fil: Soteras, Trinidad. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Soteras, Trinidad. Instituto de Ciencia y Tecnología de Sistemas Alimentarios Sustentables (UEDD INTA CONICET); Argentina.Fil: Gentiluomo, Jimena. Laboratorio de Alimentos Stamboulian. División Higiene y Seguridad Alimentaria y Ambiental; Argentina.Fil: Príncipe, F. Cooperativa Obrera Argentina; Argentina.Fil: Sucari, Adriana. Laboratorio de Alimentos Stamboulian. División Higiene y Seguridad Alimentaria y Ambiental; Argentina.Fil: Horak, Celina I. Comisión Nacional de Energía Atómica. Centro Atómico Ezeiza; Argentina.Fil: Signorini, M. Instituto de Investigación de la Cadena Láctea (IDICAL INTA CONICET); Argentina.Fil: Vaudagna Sergio Ramon. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina.Fil: Vaudagna Sergio Ramon. Instituto de Ciencia y Tecnología de Sistemas Alimentarios Sustentables (UEDD INTA CONICET); Argentina.Fil: Leotta, Gerardo Aníbal. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria “Ing. Fernando N. Dulout” (IGEVET). (UNLP-CONICET LA PLATA); Argentina

Comparison of six commercial systems for the detection of non-O157 STEC in meat and vegetables

Shiga toxin-producing Escherichia coli (STEC) are important pathogens transmitted by food that may cause severe illness in human beings. Thus, systems for STEC detection in food should have increasingly higher sensitivity and specificity. Here we compared six commercial systems for non-O157 STEC detection in meat and vegetables and determined their sensitivity, specificity and repeatability. A total of 46 samples (meat n = 23; chard n = 23) were experimentally contaminated with strains O26:H11, O45:H-, O103:H2, O111:NM, O121:H19 and O145:NM isolated in Argentina. Strain detection was confirmed by isolation according to ISO 13136:2012. Detection of the stx and eae genes in meat samples was highly satisfactory with all commercial kits, but only five had 100% sensitivity and specificity in chard. Of four kits evaluated for serogroup detection, three had 100% sensitivity and specificity, and one had 93.7% sensitivity and 100% specificity. All kits were adequate to analyze meat but not vegetable samples, and were not therefore validated for the latter matrix. The challenge for microbiology laboratories is to identify the advantages and disadvantages of the available kits for STEC detection in food based on a clear knowledge of the particular needs of each laboratory.EEA RafaelaFil: Costa, Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Sucari, Adriana. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Epszteyn, Sergio. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Oteiza, Juan Martín. Centro de Investigación y Asistencia Técnica a la Industria. Laboratorio de Microbiología de los Alimentos (Neuquén); ArgentinaFil: Gentiluomo, Jimena. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Melamed, Celia. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Figueroa, Yamila. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Mingorance, Santiago Emmanuel. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Grisaro, Agustina. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Spioussas, Silvia. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Buffoni Almeida, Mariana. Centro Estudios Infectológicos “Dr. Daniel Stamboulian”. División Higiene y Seguridad Alimentaria y Ambiental; ArgentinaFil: Caruso, Mailen. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Pontoni, Andrés. Buenos Aires. Dirección General de Higiene y Seguridad Alimentaria. Laboratorio de Investigación y Monitoreo; ArgentinaFil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin

Comprehensive evaluation and implementation of improvement actions in bovine abattoirs to reduce pathogens exposure

The slaughter process plays an important role in animal welfare, meat quality, safety and public health through the meat production chain. In this study, we performed a three-stage evaluation: I) comprehensive evaluation, II) implementation of improvement actions and III) verification of the success of the actions implemented in three abattoirs from Argentina during 2016-2018. Risk was estimated using two checklists, quantified on a 1–100 scale and classified as high (1–40), moderate (41–70) and low (71–100). In stages I and III, Salmonella spp., E. coli O157:H7 and non-O157 STEC were detected and isolated in samples from carcasses (n = 252), the environment (n = 252); head meat (n = 21) and viscera washing and chilling water (n = 105). Carcass samples were analyzed for mesophilic aerobic organisms, coliforms and E. coli enumeration. Of 201 water samples taken, 42.0–75.6 % were non-potable quality. After the implementation of improvement actions in stage II (building, processes, systems for water purification and training), the estimation of risk of contamination was reduced from high to moderate in all three abattoirs, the count of indicator microorganisms decreased in two abattoirs, and the presence of pathogens significantly decreased. Salmonella spp. was not isolated from any of the samples collected in two abattoirs. Isolation of E. coli O157:H7 decreased in carcass and was not isolated from viscera washing and chilling water. Isolation of non-O157 STEC decreased in carcass but not in environmental samples. Finally, 75.0–95.0 % of water samples were of potable quality. Although this was only the first step in the process of change and improvement of abattoirs, the assessment of the situation and the proposal of solutions to correct deviations in a joint effort with the health authorities helped to implement a work model for enhancing food safety before meat reaches consumers.Fil: Costa, Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Pracca, Gabriela. No especifíca;Fil: Sucari, Adriana. No especifíca;Fil: Galli, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Ibargoyen, José. No especifíca;Fil: Gentiluomo, Jimena. No especifíca;Fil: Brusa, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Martinez Zugazua, Matías. No especifíca;Fil: Figueroa, Yamila. No especifíca;Fil: Londero, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Roge, Ariel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Silva, Hernán. No especifíca;Fil: Van Der Ploeg, Claudia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Signorini, Marcelo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Oteiza, Juan Martín. Centro de Investigación y Asistencia Técnica a la Industria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentin