Origin of Listeria monocytogenes on meat products

Listeria monocytogenes is a relevant food safety hazard in ready to eat products. Inactivation during processing, prevention of recontamination and control of multiplication are the main instruments to secure the safety of meat products. Intensive microbiological monitoring of products and the production environment are valuable tools to assess the level of control in a meat processing plant. During the course of a year all isolates found during hygiene monitoring at a meat processing plant were stored at -70 degrees Celsius. A total of 94 L. monocytogenes isolates have been analyzed by pulsed-field gel electrophoresis (PFGE) and were divided into 30 different types

Meat Juice serology underestimates prevalence of Salmonella in pig herds

Salmonella serology is used for classifying pig herds in risk categories in several national quality programs. Meat juice is used as test matrix in most of these programs. Two studies were done to compare the salmonella ELISA test results from meat juice with blood serum as a reference. Pig blood and meat samples for these studies were collected in one slaughterhouse. ELISA tests were done with a commonly applied commercial test. In the first study paired blood serum and meat juice samples from 182 pigs were collected and tested in two different laboratories. In the second study meat and blood samples were collected from 470 herds, over 20.000 samples for each matrix

Toxoplasma prevalence in Dutch slaughter pigs in the period 2012-2014

Toxoplasma gondii has frequently been named as one of the most important foodborne pathogens, in terms of its impact on human health. EFSA advised to include serological testing of pigs on T. gondii infections and audits of pig farms on risk factors for T. gondii infection (EFSA, 2011). In order to generate knowledge about the epidemiology and prevalence of T. gondii infections in pig herds we studied the long term seroprevalence on farms, persistence of infection and variation in results between and within farms. Sera which were routinely taken in Dutch pig slaughterhouses in the Netherlands for the serological monitoring of Mycobacterium avium infections in pigs (Hiller 2013) were also tested for anti T. gondii antibodies. Results of 120,666 sera, collected from January 2012 until August 2014, showed an average of 2% serological prevalence in pigs. Pigs from organic farms had a prevalence of 3,6%. Farm prevalence was much higher, ranging from approximately 30% for conventional farms to 90% for organic farms. Pigs delivered to the slaughterhouse during winter months had a higher prevalence than pigs delivered during summer months.It could be concluded that serological monitoring can be very useful in detecting farms infected with T. gondii. A test cut off of 20PP was the most appropriate

Experiences with a risk based meat inspection standard in pigs

The European Union legislation provides several possibilities to modernize meat inspection. Improvement of food safety by active contribution of food business operators in the supply chain being responsible for food safety is envisaged in these new standards

Implications of dietary lipid and carbohydrate intake on the liver and the susceptibility of hatchery-reared rainbow trout (Salmo gairdneri) to vibriosis

The hypotheses to be tested in this investigation are: 1) there is a threshold level of liver lipid and glycogen content above which the health condition of hatchery-reared fish is impaired, 2) fatty and high glycogen livers impair liver function and structure, and 3) fatty and high glycogen livers increase the susceptibility of fish to vibriosis. Under the conditions of this study, levels of hepatosomatic index, specific gravity, liver lipid and glycogen content sufficient to cause pathologic conditions in rainbow trout were not established. Blood parameters like hematocrits and mature red blood cell counts were found to be normal. The condition factors (K) were indicative of well fed fish. It was concluded that all the above parameters fell within a normal range of values representative of healthy rainbow trout. Determination of plasma alanine aminotransferase activity and histological examination of the livers did not indicate any sign of liver pathology. It was concluded that all the livers were normal and healthy, even though the liver composition varied with each dietary treatment. The disease challenge did not reveal any difference in susceptibility to vibriosis as measured by cumulative mortalities and mean day to death. The agglutinating antibody titers against Vibrio anguillarum were similar in strength and might have been protective. It was concluded that susceptibility to disease was unaffected by the different liver composition observed for each dietary treatments

A practical framework for tracing sources of Salmonella in a pig slaughter plant

Salmonella causes around 30 000 cases of human illness per year in The Netherlands, of which an estimated 25% is caused by pork. Salmonella carrying pigs and resident flora on slaughter equipment are relevant sources of carcass contamination. Although recognized, these sources from which and the routes through which Salmonella is transmitted to the pig carcasses during slaughter are not well understood in a quantitative way

Efectos de varios factores ambientales sobre las tasas de descomposición en encinares mediterráneos

Resumen de una presentación realizada en: I Simposio sobre Interacciones Planta-Suelo (ICA-CSIC, Madrid, 25-26 Febrero 2016)[ES] Los encinares son ecosistemas de gran valor que están sufriendo un proceso de decaimiento, lo que puede afectar a su capacidad para almacenar carbono. Se plantea este proyecto de tesis para estudiar el efecto del decaimiento de encinares sobre las tasas de descomposición de la hojarasca, las raíces y las herbáceas, y los factores medioambientales que la controlan. Los factores que se pretende estudiar son: la calidad de la materia en descomposición, el clima, la fotodegradación, y el efecto de diferentes conjuntos de fauna del suelo. El efecto de dichos factores sobre la descomposición se analizará a través de 4 experimentos con bolsas de descomposición. Experimento 1: Efecto del clima, de la fotodegradación y de la calidad de la hojarasca sobre las tasas de descomposición. Se ha diseñado un experimento factorial para el seguimiento de las tasas de descomposición de herbáceas y de hojas y raíces de encinas, situando bolsas en 8 encinares afectados distribuidos por el territorio peninsular español. Experimento 2: Efecto de la microfauna, la mesofauna y la macrofauna del suelo sobre los procesos de descomposición de hojarasca. Se estudiará mediante tratamientos de exclusión de fauna del suelo. Experimento 3: Efecto interactivo de la temperatura, precipitación y radiación solar sobre la descomposición de hojarasca. Se utilizarán mesocosmos para someter bolsas de hojarasca de herbáceas a dos niveles para cada uno de esos tres factores, con todas las interacciones entre ellos. Experimento 4: Contribución de diferentes procesos abióticos (fotodegradación y degradación térmica), bióticos (descomposición microbiana) así como su interacción en la descomposición de la materia orgánica. Se realizará con herbáceas bajo condiciones controladas de laboratorio. Estos experimentos permitirán describir de una manera mecanicista un proceso tan relevante para las interacciones planta-suelo como es la descomposición así como los factores medioambientales que la controlan.Peer reviewe

Case studies: Tuberculination in pig herds suspected of infection with Mycobacterium avium

Mycobacterium avium, both subspecies hominissuis (MAH) and subsp avium (MAA), are considered a significant zoonotic hazard in pigs. Therefore special attention is given to detect the presence of this hazard in pigs during post mortem meat inspection. Herds delivered at slaughter were monitored on blood antibodies against MAH. Herds with an antibody response against a MAH infection were visited. Initially a questionnaire assessing relevant risk factors for MAH was applied

Comportamiento de las comunidades microbianas del suelo frente al cambio climático en los encinares mediterráneos

Resumen de una presentación realizada en: I Simposio sobre Interacciones Planta-Suelo (ICA-CSIC, Madrid, 25-26 Febrero 2016)En las últimas décadas hemos comprobado como el cambio climático ha causado un aumento de las sequías a nivel peninsular, provocando que especies tan adaptadas a las condiciones de sequía estacional Mediterráneas como la encina (Quercus ilex) se estén viendo afectadas por fenómenos de decaimiento a lo largo de toda la Península Ibérica. Esta pérdida de salud de los encinares se relaciona íntimamente con la ecología de las comunidades microbianas de los suelos que juegan una labor esencial en el funcionamiento ecosistémico. En esta tesis vamos a estudiar el papel de las comunidades microbianas de suelos frente al fenómeno de decaimiento del encinar y su relación con cambios en las dinámicas de carbono (C) y nutrientes. Para ello, proponemos un diseño experimental multidisciplinar en el que se estudiarán cambios potenciales en la estructura (diversidad y composición taxonómica) y el funcionamiento de las comunidades microbianas (bacterias y hongos) a lo largo de gradientes de decaimiento (suelos de encinas sanas, defoliadas, muertas y suelos sin cobertura de la encina) y climático (cubriendo el área de distribución de Q. ilex subsp ballota), así como su asociación con cambios en los ciclos biogeoquímicos del suelo (mineralización de C y N). Para esto, se seleccionaron 18 parcelas a lo largo de la Península Ibérica abarcando gran parte de su área de distribución. En estas parcelas se realizó un muestreo extensivo en el que se recogieron por una lado datos del hábitat de la encina, desde el grado de defoliación hasta la cobertura que la rodeaba; y por otro, muestras para el estudio de las características físicoquímicas del suelo así como la estructura y funcionamiento de las comunidades microbianas que lo habitan. De este modo, tendremos un mejor conocimiento del funcionamiento de sistema planta-suelo, y su relación con las dinámicas de C y nutrientes integrando escalas micro (comunidades microbianas) hasta macro (área de distribución de la encina) en ambientes con defoliación.Peer reviewe

Cascading effects associated with climate-change-induced conifer mortality in mountain temperate forests result in hot-spots of soil CO 2 emissions

Climate change-induced tree mortality is occurring worldwide, at increasingly larger scales and with increasing frequency. How climate change-induced tree mortality could affect the ecology and carbon (C) sink capacity of soils remains unknown. This study investigated regional-scale drought-induced tree mortality, based on events that occurred after a very dry year (2012) in the Carpathians mountain range (Romania), which caused mortality in three common conifer species: Scots pine, Black pine, and Silver fir. This resulted in hot-spots of biogenic soil CO 2 emissions (soil respiration; Rs). Four to five years after the main mortality event, Rs-related soil CO 2 emissions under dead trees were, on average, 21% (ranging from 18 to 35%) higher than CO 2 emissions under living trees. Total (Rs) and heterotrophic (R H )-related soil CO 2 emissions were strongly related to alterations in the soil environment following tree mortality (e.g. changes in quantity and quality of soil organic matter, microclimate, pH or fine root demography). Moreover, the massive mortality event of 2012 resulted in greater presence of successional vegetation (broadleaf seedlings, shrubland and grasses), which may control the environmental factors that either directly or indirectly affected biotic soil fluxes (Rs and R H ). Besides the well-known direct effects of climate change on soil CO 2 emissions, the cascading effects triggered by climate change-induced tree mortality could also exert a strong indirect impact on soil CO 2 emissions. Overall, climate change-induced tree mortality alters the magnitude of environmental controls on Rs and hence determines how the ecosystem C budget responds to climate change. © 2019 Elsevier LtdThis work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) with the projects VERONICA ( CGL2013-42271-P ) and the project IBERYCA ( CGL2017-84723-P ), and by the Romanian Ministry of Education and Scientific Research through UEFISCDI with the projects TREEMORIS ( PN-II-RU-TE-2014-4-0791 ), NATIvE ( PN-III-P1-1.1-PD-2016-0583 ), and BIOCARB ( PN-III-P1-1.1-TE-2016-1508 ). This research was also supported by the Basque Government through the BERC 2018-2021 program, and by the Spanish Ministry of Economy and Competitiveness (MINECO) through the BC3 María de Maeztu excellence accreditation ( MDM-2017-0714 ). I.C. Petritan was partially funded by the H2020/ERA-NET/ERA-GAS (Project 82/2017, Mobilizing and monitoring climate positive efforts in forests and forestry, FORCLIMIT ). Many thanks to Cosmin Zgremtia, Ionela Medrea, Andrei Apafaian, Raluca Enescu and Marta Ramos for their valuable help during field campaigns and laboratory work