1,720,990 research outputs found
Foodborne transmission of Toxoplasma gondii: a laboratory and literature based assessment
Full text linkToxoplasma gondii is a zoonotic parasite with a wide diffusion, a high human seroprevalence and the potential for causing severe harm when infection occurs in at-risk individuals such as pregnant women, HIV-positive individuals, recipients of organ transplants or other immunocompromised subjects. The consumption of contaminated food is estimated to account for about half of all infections worldwide, with variations across years and countries. Among food, meat is of high concern, as it is consumed in large amounts, not always well cooked, by a large part of the population.
The aim of the present project was to gain insight into the role of food as a source of human toxoplasmosis. The first step in this path was to assess the prevalence of T. gondii in livestock species commonly used as sources of meat for human consumption. To obtain relevant scientific evidence, a double-sided approach was applied. Firstly, a systematic review of all published studies dealing with the direct detection of T. gondii in meat belonging to relevant livestock species was carried out. This work allowed the estimation of the worldwide T. gondii prevalence in each species (cattle, pigs and sheep), and also the evaluation of differences due to the geographical origins and to the laboratory methods applied for diagnostic purposes. Two species were selected for a biomolecular investigation of prevalence at local level: cattle and pigs. Different reasons supported the choice to focus on these species, such as the wide consumption, the inconsistent epidemiological evidence (cattle) or the primary importance as a source of meatborne toxoplasmosis (pigs). Samples were collected from retail or ready to retail processing stages.
To support the outcomes of different activities, both from the systematic review and from experimental results, the best available epidemiological evidence about the role of different food consumption habits in human infection was systematically collected. Finally, a quantitative risk assessment model was built, thanks to all the previously collected information, to estimate the yearly probability of infection due to bovine meat and pork consumption, in Italy. The investigations carried out within the present research project allowed us to conclude that T. gondii prevalence in meat animals worldwide, as well as in Europe and Italy, is not negligible.
Sheep meat displayed the highest prevalence rate, followed by pork and beef. However, our survey confirmed that meat preparation habits make beef a relevant risk factor for T. gondii infection in humans, as confirmed by the epidemiological evidence from the literature. In addition, the model allowed us to observe that, In Italy, bovine meat contributes more to the annual toxoplasmosis incidence than does pork.Toxoplasma gondii è un parassita di interesse zoonosico con una notevole diffusione su scala mondiale, un’elevata sieroprevalenza nell’uomo ed è in grado di causare sintomatologia grave in soggetti a rischio come le donne in gravidanza e tutti i soggetti immunocompromessi. Si stima che il consumo di alimenti contaminati sia responsabile di circa la metà dei casi totali di infezione nell’uomo, con alcune differenze tra paesi. La carne, in particolare, è di notevole interesse epidemiologico in quanto viene consumata in grandi quantità dalla maggior parte della popolazione e non sempre viene cotta adeguatamente prima del consumo. L’obiettivo di questo progetto era quello di approfondire le conoscenze circa il ruolo degli alimenti come
causa di toxoplasmosi umana tenendo in considerazione l’intera filiera alimentare. Il primo passo è stato quello di stimare la prevalenza di T. gondii negli animali da reddito più comunemente utilizzati per la produzione di carne utilizzando un duplice approccio. In primis, sono stati sistematicamente raccolti gli studi pubblicati nella letteratura scientifica e riguardanti la ricerca di T. gondii nella carne di specie animali da reddito comunemente consumate. Questi studi hanno consentito di ottenere una stima di prevalenza per ogni specie selezionata (bovini, maiali e pecore) e di valutare le differenze dovute alla diversa origine geografica e al metodo diagnostico applicato. Successivamente sono state selezionate due specie (bovini, maiali) per un’indagine molecolare in grado di stimare la prevalenza su carni locali. Le specie sono state selezionate per ragioni diverse: la grande diffusione del loro consumo, evidenze epidemiologiche contrastanti (bovini), o il ruolo epidemiologico riconosciuto nella trasmissione di T. gondii (maiali). I campioni analizzati erano tutti idonei alla vendita. Per sostenere i risultati ottenuti dalle diverse attività di questo progetto, sia sul fronte della sintesi delle ricerche già pubblicate sia per quanto riguarda le attività sperimentali, una seconda systematic review è stata realizzata. In questo caso sono stati raccolti tutti gli studi epidemiologici (caso-controllo) pubblicati, indirizzati all’identificazione degli alimenti responsabili delle infezioni alimentare da T. gondii. Infine, è stato realizzato un modello di valutazione del rischio quantitativo, in grado di considerare tutti i dati e le evidenze precedentemente ottenute, con l’obiettivo di stimare la probabilità annua di contrarre toxoplasmosi a seguito del consumo di carne bovina o suina, in Italia.
Le analisi effettuate nel contesto di questo progetto di ricerca consentono di concludere che la prevalenza di T. gondii in specie animali comunemente consumate, nel mondo e in Europa, non è trascurabile. La carne di pecora ha la prevalenza più elevata, seguita dalla carne suina e bovina. Tuttavia l’abitudine di consumare la carne bovina cruda o poco cotta aumenta il rischio derivante da essa. Tale osservazione è confermata dagli studi epidemiologici ottenuti con la ricerca sistematica della letteratura cosi come dal modello statistico realizzato, che identifica il consumo di carne bovina come più probabile causa di toxoplasmosi nella popolazione italiana rispetto al consumo di carne suina
Weighting evidence can shape results: how to deal with 0 estimates in proportion meta-analysis
No full textIl consumo di insetti dal punto di vista della sicurezza alimentare: inquadramento normativo e valutazioned dei rischi.
No full textNanotechnology and Food: Brief Overview of the Current Scenario
No full textAbstractThe rapidly expanding sector of nanotechnologies has applications in every industrial sector. The production of food of animal origin recognizes several possibilities for technological development through the use of nanomaterials, at animal farming, food processing and product storage levels. Direct use of nanomaterials during these production stages, as well as the uptake from the environment, can lead to the presence of such materials in the final product. In this context analytical methods for the detection and characterization of nanomaterials in complex food matrices and toxicological data are strongly needed to assess the risk for consumers
EXTERNAL SCIENTIFIC REPORT: Escherichia coli and Enterobacteriaceae counts on poultry carcasses along the slaughter processing line, factors influencing the counts and relationship between visual faecal contamination of carcasses and counts: a review.
No full textVariability of Escherichia coli and Enterobacteriaceae counts on pig carcasses: A systematic review
No full textBackground: Indicator bacteria are considered an interesting target for microbiological analysis in order to obtain information about the hygiene of processes and products. Quantitative analysis targeting in- dicator bacteria offers several advantages over pathogenic bacteria since indicator bacteria prevalence and counts are higher, and their distribution is more homogeneous, than pathogens. However, although microbiological criteria addressing indicator bacteria are already in place in industrialised countries such as the EU and US, information on factors affecting their counts on carcasses at slaughter is scattered. Objectives: The aim of this review was to provide valuable information about the variability of indicator bacteria along the pig slaughterline, and to suggest suitable means for the implementation of GMP (Good Manufacturing Practices) and process hygiene in pig slaughterhouses. Conclusions: Along the slaughterline, scalding and chilling stages effectively reduce both Escherichia coli and Enterobacteriaceae counts on pig carcasses and have to be considered in the implementation of HACCP systems. Surface pasteurisation under experimental slaughter conditions was also effective; in contrast, washing did not reduce microbial contamination on pig carcasses. Evisceration was confirmed as a key contamination point, in particular regarding Enterobacteriaceae, but it has been suggested that bacterial load can be controlled by anal plugging if it is performed according to good manufacturing practices (GMP)
A systematic review of studies on Escherichia coli and Enterobacteriaceae on beef carcasses at the slaughterhouse
No full textEuropean legislation has defined as process hygiene criteria for themain livestock species (cattle, sheep, goats,
horses and pigs) themonitoring of aerobic colony count and Enterobacteriaceae. Detected values above the de- fined criteria require an improvement in slaughter hygiene and the reviewof process control. Themain source of microbiological contamination of beef carcasses along the slaughterline is of fecal origin, therefore Escherichia coli and Enterobacteriaceae seemto be themost suitable indicators to assess the hygienic status of the slaughter process. Althoughmicrobiological criteria addressing indicator bacteria have beeninplace inindustrializedcoun- tries for several years, scattered information still exists on factors affecting their counts on beef carcasses along the slaughterline. Therefore, a systematic literature review, covering the period 2000–2012, was conducted to gather information concerning: 1) counts of E. coli and Enterobacteriaceae on beef carcasses linked to different stages of the slaughterline; 2) factors influencing presence/counts of E. coli and Enterobacteriaceae on beef car- casses; and 3) the relationship between indicator bacteria (E. coli and Enterobacteriaceae) counts and visual fecal contamination of beef carcasses. According to the 41 retrieved papers the following conclusions were drawn. A decrease of the indicator bacteria counts was recorded after sequential decontamination treatments, such as pasteurization and hot water washing. Slaughterhouse characteristics influenced bacterial load of beef carcasses, although it was difficult to assess which factors (i.e., slaughterhouse throughput, design of the plant, surveillance system in place) had the greatest effect. Finally, carcasses from fecal contaminated animals had higher bacterial loads than those fromclean animals. Therefore, the development of a visual classification system of the level of dirtiness of carcasses and the application of effective treatments on the carcasses classified as dirty along the slaughterline can lead to a contamination level for these carcasses comparable to or lower than that of originally clean ones at the end of the slaughterline
EXTERNAL SCIENTIFIC REPORT: Escherichia coli and Enterobacteriaceae counts on pig and ruminant carcasses along the slaughterline, factors influencing the counts and relationship between visual faecal contamination of carcasses and counts: a review
No full textA review of the scientific literature on the control of Salmonella spp. in food-producing animals other than poultry
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