Carlo D'Ascenzi

Seroprevalence, Detection of DNA in Blood and Milk, and Genotyping of Toxoplasma gondii in a Goat Population in Italy

Toxoplasma gondii is the causative agent of a major zoonosis with cosmopolitan distribution and is known to be transmitted mainly by the ingestion of undercooked or raw animal products. Drinking unpasteurized goats milk is a risk factor associated with human toxoplasmosis. However, very little is known about the excretion of DNA in goat milk. Aim of the present study was to determine the seroprevalence of T. gondii infection using a modified agglutination test (MAT), to detect T. gondii DNA by nested-PCR (n-PCR) in samples of blood and milk from seropositive goats, and to genotype DNA isolates using 11 molecular markers in 127 adult lactating goats from 6 farms in Italy. Positive MAT results were found in 60.6% of goats while 13% of blood and milk samples from seropositive goats were positive to n-PCR. A kappa coefficient of 1 indicated a perfect agreement between blood and milk n-PCR. Genetic characterization of isolates revealed the occurrence of genotype III (n = 7), genotype I (n = 1), and atypical genotypes with hints for genotype I (n = 2). Our results suggest that the risk of excretion of Toxoplasma tachyzoites might frequently occur in milk of seropositive goats testing positive to n-PCR on blood.

Occurrence of Vancomycin-Resistant Enterococci in Foods of Animal Origin Purchased in Tuscany

Enterococci are ubiquitous microorganisms, commonly found in plants, insects and wild animals, and are normal residents of the gastrointestinal tract of both animals and humans. They frequently occur in large numbers in certain foods, especially those of animal origin. Over the last 10 years, enterococci have emerged as major nosocomial pathogens, thus representing an increasingly important problem for public health, in relation to their ability to acquire resistance to some antimicrobial agents of relevance to human therapy, such as glycopeptides, particularly vancomycin. In this regard, the food chain represents a possible source of vancomycin-resistant enterococci for humans, mainly as a result of the use of avoparcin, a vancomycin-like glycopeptide, as a feed additive for growth promotion of farm animals, as undoubtedly established by previous studies (Bates, 1997; Mc Donald et al., 1997). Although the utilization of avoparcin in animal husbandry has been banned since 1997, VRE have recently been isolated from foods of different typology (Giraffa et al., 2000; Knijff et al., 2002), therefore investigation into the frequency of recovery of VRE at this level is still recommendable. Thus, the present survey was carried out with the aim of evaluating the occurrence of VRE in foods of animal origin purchased in Tuscany, considering that these microorganisms could play a relevant role both directly as potential pathogens for humans, as well as in relation to their capability to spread antibiotic resistance genes to other pathogenic bacteria, such as Staphylococcus aureus.

Occurrence and antimicrobial susceptibility of aeromonads from maricultured gilthead seabream (Sparus aurata)

The understanding of the genetic mechanisms of livestock adaptation to environmental challenges is becoming an important research topic in this time of rapid climate change. New tools and approaches are now available to investigate this complex phenomenon. Low-cost high-throughput technologies have opened the genomic era to agricultural species. All major farm animals have been completely sequenced and HapMap projects are completed or in progress. Low, medium and high-density SNP panels are available or under construction. Molecular information on many thousand markers has initiated the era of population genomics, which is the application of genomic approaches to population genetics. The comparison of patterns of diversity along the genome in animals originating in different environments and new GIScience-based models able to associate molecular markers to environmental variables promise to discover genomic regions associated to traits important for adaptation and to pave the way to the identification of causative genes. Local breeds adapted to a sustainable production in extreme and harsh environments will play a fundamental role in this process. Domestication, adaptation and biodiversity Response mechanisms to environmental challenges have been evolving in livestock populations for millions of years, first in wild ancestor species and, since the Neolithic, in derived domesticates. The post-domestication colonization of the world, along with agriculture expansion and human migrations, have often taken livestock species well outside the agro-climatic range of adaptation of wild ancestors, so that nowadays livestock species count thousand local populations adapted to environments as different as sub-Saharan Africa and Yacutia. Adaptation to local agro-climatic conditions and husbandry systems, and human selection towards different use and morphology, have maintained and shaped the original diversity, sometimes increasing it by promptly capturing useful mutations that would have most probably been lost by genetic drift or reduced fitness (e.g. myostatin mutations causing double muscling in beef cattle). This diversity is a treasure to humankind and guarantees a genetic pool wide enough to direct breeding towards new selection objectives when necessary. In the medium term perspective, one of these objectives is to improve adaptation to higher temperatures, drought and diseases. Projections, in fact, indicate a rapid trend towards a warmer planet and shorter plant growing periods in a large part of the planet. The tropics and subtropics will be affected the most. In these regions, by the end of this century growing season temperatures are expected to exceed the most extreme seasonal temperatures recorded from 1900 to 2006 (Battisti and Naylor, 2009). The consequences of climate change on food security and agriculture socio-economy are difficult to predict and will vary considerably from site to site, however consensus is that the risk of a negative effect in these areas is high (Müller et al., 2011). Europe will be affected, as well: reduced water supplies and increased production vulnerability are expected in the South, while mainly positive effects are predicted in the North (Falloon and Betts, 2010). In any case, in a large part of the world, agriculture will have to change dramatically to adapt to new conditions. Variations may firstly occur in crop production, in terms of both species and yield. Livestock production systems will have to adapt to these changes and to a number of direct (heat, drought) and indirect (new diet, new disease pressure) effects of climate change. At the same time, breeding and husbandry practices et al. (eds.), OI 10.3920/978-90-8686-741-7_1,

Activity of selected essential oils on spoiling fungi cultured from Marzolino cheese

Microscopic fungi can be present on a variety of foodstuff, including cheese. They can be responsible for fungal spoilage, causing sensory changes making food unacceptable for human consumption, and posing severe health concerns. Furthermore, some of these organisms are able to resist antimicrobial preservatives provided for by law. Antifungal activity of 15 chemically defined EOs, alone and in mixture, were checked by a microdilution test against isolates of Penicillium funiculosum and Mucor racemosus cultured from rinds of Marzolino, a typical Italian fresh pecorino cheese. Origanum vulgare yielded the lowest MIC values, followed by Salvia sclarea, Ocimum basilicum and Cymbopogon citratus, while Citrus paradisi and Citrus limon were not active. All mixtures showed antifungal activity at lower concentration with respect to MIC values of each EO component, when not in combination. This study is the first to describe the setting up of EOs mixtures to limit spoiling moulds.