Paola Sechi

Toxoplasma in Animals, Food, and Humans: An Old Parasite of New Concern

All hosts, including humans, can be infected by any one of the three forms of the parasite Toxoplasma gondii that correspond to three morphological stages: tachyzoite, bradyzoite, and sporozoite form. Felids are definitive hosts for T. gondii, which is an intracellular pathogen that infects a wide range of warm-blooded intermediate hosts. Toxoplasmosis is a disease where the interest of the diverse medical and veterinary specialties converge. Awareness needs to be increased that toxoplasmosis can induce clinical disease not only in immunocompromised patients or through congenital infections, but also in healthy patients. This is a review article that aims at illustrating why toxoplasmosis should be regarded a veterinary public health issue and how veterinary practitioners can contribute in controlling the infection.

Effect of selected dairy starter cultures on microbiological, chemical and sensory characteristics of swine and venison (Dama dama) nitrite-free dry-cured sausages

The aim of this study was the evaluation of selected lactic acid bacteria (LAB) starter culture of dairy origin in the production of nitrite-free low-acid fermented venison (Dama dama) sausage (salame di daino) produced in a small-scale plant in Umbria (Italy), and their effect on microbiological, physico-chemical and sensorial properties of the products. Salame di daino was obtained with two different processes: with and without the addition of selected LAB starter cultures. Microbial counts of Enterobacteriaceae, coliform organisms and Pseudomonas spp. were lower in salami made with the addition of starter cultures. Staphylococcus aureus, Salmonella spp, and Listeria monocytogenes after the first week of ripening were only detected from control salami. Control salami were paler and harder, whereas those made with the addition of starter cultures were slightly saltier, juicier and in general more acceptable. Selected dairy-origin starter (SDS) cultures did prevent the growth of both indicators of food safety and of process hygiene and increased the acceptability of full-ripened salami.

Seroprevalence and risk factors for Toxoplasma gondii in sheep in Grosseto district, Tuscany, Italy

BackgroundSerum samples from 630 milk sheep, in 33 dairy flocks representative of the southern area of the Tuscany region, were tested for the presence of antibodies to Toxoplasma gondii using an indirect immunofluorescence antibody test (IFAT). Questionnaires exploring the management system were completed by the veterinarian in charge of the flocks.ResultsAt least one seropositive animal was found in 32 of the 33 flocks tested (97.0%; 95% CI: 84.2%, 99.9%). In the positive flocks, median seroprevalence was 29.4% (interquartile range: 15.9%-46.1%). Overall animal-level seroprevalence, adjusted for sampling weights and test sensitivity and specificity, was 33.3% (95% CI: 24.8%, 42.7%). In a multivariable negative binomial regression model the number of seropositive animals in a flock decreased with increasing flock size (for >400 vs. <300 animals: count ratio (CR) = 0.62; 95% CI: 0.41, 0.95; P = 0.028) and was greater on farms where stray cats had access to animals’ water (CR = 1.54; 95% CI: 1.05, 2.26; P = 0.027).ConclusionsSmall flock size and access of cats to water are potential risk factors for Toxoplasma infection in sheep in the Grosseto district in Tuscany, Italy. Sheep could be an important source of T. gondii infection in humans, since we estimate that between 25% and 43% of sheep in the district were seropositive. Toxoplasmosis is also likely to be an important cause of abortion in sheep in the district. Control and prophylactic measures must be adopted to improve the rearing system and the implementation of health promoting programmes in a joint effort between sheep farmers, farmers’ associations and veterinarians to inform about the means of transmission of the infection and for a better understanding of the disease.

Effects of UV irradiation in a continuous turbulent flow UV reactor on microbiological and sensory characteristics of cow's milk.

The dairy industry under current pasteurization conditions (15 s at 72°C) and sanitary standards achieves a safe product with excellent quality. In an ever-competitive market there is still a need to improve product quality and extend shelf life of dairy products to increase competitiveness and open up new markets. In an attempt to test the effect of UV irradiation on microbiota of fluid milk, a continuous flow UV system at 254 nm was used to treat 3.5 and 2% fat milk at two UV doses (880 and 1,760 J liter(-1)). Milk was obtained from three processors, and two lots from each processor were assessed. To assess the impact on the most descriptive native microbiota in pasteurized milk after UV illumination, the product was held at two storage temperatures (4 and 7°C) and tested weekly for 5 weeks for aerobic plate counts (psychrotrophic and mesophilic bacteria), laboratory pasteurization counts, aerobic sporeformers, coliform organisms, and titratable acidity. Microbial counts for all tested microorganisms were lower in UV-treated milk when compared with control throughout storage at 4 and 7°C in both 3.5 and 2% fat milk. Sensory analysis indicated that there is a sensory defect associated with UV treatment at the wavelength used.

Acceptability of Electrical Stunning and Post-Cut Stunning Among Muslim Communities: A Possible Dialogue

Abstract Current technical-scientific advances allow a reappraisal of some practices used during religious slaughter without compromising its deep and essential meaning, through to the identification of techniques that limit the nonhuman animal vigilance without causing any lesion that may impair its integrity. All this in respect of religious principles of the Jewish and Muslim community and in respect of animal welfare, minimizing as much as possible the risk of causing useless suffering to the animals. A demonstrative slaughter was performed in a slaughterhouse of the Modena province (Italy): ritual incision of the neck vessels was preceded by stunning to explore the feasibility that lessening animal suffering could conform to religious prescriptions, as it does in other countries. Two alternative methods to classical ritual slaughter without prior stunning were illustrated in order to limit animal suffering during killing and comply with Islamic ritual requirements.

Meat spoilage: a critical review of a neglected alteration due to ropy slime producing bacteria

The shelf-life of a product is the period of time during which the food retains its qualitative characteristics. Bacteria associated with meat spoilage produce unattractive odours and flavours, discolouration, gas and slime. There are several neglected alterations that deserve more attention from food business operators and competent authorities. Ropy slime is a typical alteration of the surface of vacuum and modified atmosphere packed cooked meat products, that causes major economic losses due to the increasingly sophisticated consumer requirements. This is a review article that aims at raising awareness of an old problem of new concern, in the light of new advances and trends for understanding the aetiology of the phenomenon, the origins of contamination and the prevention measures.

Evolution under different storage conditions of anomalous blue coloration of Mozzarella cheese intentionally contaminated with a pigment-producing strain of Pseudomonas fluorescens.

Several widespread occurrences of anomalous blue coloration of Mozzarella cheese have been recorded in the United States and some European countries. Official laboratory analysis and health authorities have linked the occurrences to contamination of the processing water with strains of Pseudomonas fluorescens, although several experts questioned how to unequivocally link the blue color to the presence of the microorganism. To establish a method to determine whether a given Pseudomonas spp. strain is responsible for the defect and study the evolution of the coloration under different storage conditions, we developed an in vitro system for the evaluation of blue coloration of Mozzarella cheese intentionally contaminated with strains of P. fluorescens. The purpose of the system was to determine whether P.fluorescens strains, isolated from Mozzarella cheese with anomalous blue coloration, were able to reproduce the blue coloration under controlled experimental conditions. Thirty-six trials of experimental inoculation of Mozzarella cheese in different preservation liquids were conducted using various suspensions of P.fluorescens (P. fluorescens ATCC 13525, P.fluorescens CFBP 3150, and P. fluorescens 349 field strain isolated from blue-colored Mozzarella cheese) at different concentrations and incubated at different temperatures. Growth curves of all tested P.fluorescens strains demonstrated that after 3 d of incubation the concentration was generally >10(6) cfu/g of Mozzarella cheese incubated in either tryptic soy broth (control) or conditioning brine. Prolonged incubation for 5 d at either 20 °C or 8 °C led to concentrations up to 10(9) cfu/g of Mozzarella cheese incubated in tryptic soy broth and up to 10(8) cfu/g of Mozzarella cheese incubated in preservation liquid. All Mozzarella cheeses inoculated with the field strain of P. fluorescens, except those opened 1h after packaging and stored at 8 °C, showed the characteristic anomalous blue coloration, which appeared from 1 to 72 h after opening the packaging, and was proportional to colony count, duration of storage, and storage temperature. With the proposed system, which enabled a larger number of samples to be analyzed under controlled experimental conditions and a large amount of data to be generated in a short time, we described precisely how and under which conditions the presence of P. fluorescens in Mozzarella cheese is responsible for the anomalous blue coloration. The system will help producers intercept contaminated batches and help consumers avoid the conditions under which the defect can appear.

Growth inhibition of selected microorganisms by an association of dairy starter cultures and probiotics

Several growth curves for selected pathogens and hygiene indicators alone and vs selected dairy starter cultures (LAB) and commercial probiotics have been performed. All strains for LAB and commercial probiotics were inoculated as pure cultures into skim milk to get an initial cocci:bacilli:enterocci ratio of 2:1:1 and a concentration of approx 107 cfu mL–1 until challenge vs selected pathogens and hygiene indicators. Selected pathogens came from the collection of the Laboratorio di Ispezione degli Alimenti di O.A. or were reference strains (Escherichia coli, CSH26 K12, Staphylococcus aureus, 27R, Salmonella Derby 27, Pseudomonas fluorescens ATCC 13525, Listeria innocua ATCC 33090). Each strain was inoculated into skim milk to get an initial concentration of approx 106 cfu mL–1. Growth curves in skim milk for the following challenges were studied: i) sterility control; ii) association LAB; iii) association of LAB vs each selected pathogen or hygiene indicator; iv) selected pathogen or hygiene indicator alone. The challenges were carried out in BHI broth and in skim milk at 37°C. The highest reduction was observed in milk but in general the association of LAB and the probiotic was able to limit the growth of pathogens and hygiene indicators.

Religious Slaughter: Data from Surveys and Spot-Check Visits in Italy and Animal Welfare Issues

Abstract The public is becoming increasingly concerned about how nonhuman animals are treated, and many studies show that European citizens are concerned about farm animal welfare. Religious slaughter has always been a controversial and emotive subject, caught between animal welfare considerations, cultural and human rights issues. There is considerable variation in current practices, and the rules regarding religious requirements are still confusing. Similarly, consumer demands and concerns also need to be addressed. Therefore, there is a need for information relating to slaughter techniques as well as product range, consumer expectations, market share, and socioeconomic issues. This research aims at identifying the procedures for current methods of religious slaughter in Italy. Conventional slaughter is performed with prior stunning; kosher slaughter is practiced without stunning. Halal slaughter is performed for most of the animals without stunning. Halal slaughter with prior stunning is accepted for 5.9% of small ruminants. Questionnaires were sent to regional health authorities, and spot-check visits were conducted on cattle, sheep, and poultry abattoirs in Italy from October 2008 to March 2009. The observed parameters are discussed in regards to the risk to animal welfare. Observations not only on restraining methods, but also on post-cut, clinical indicators of consciousness are considered. This research is the first, systematic attempt to analyze the methods of religious slaughter and to discuss the implications for animal welfare.

Effect of a novel starter culture and specific ripening conditions on microbiological characteristics of nitrate-free dry-cured pork sausages

Abstract This study evaluated the effect of a ‘formulation of selected dairy starter cultures and commercial probiotics’, associated with ‘specific ripening conditions’ in the production of nitrite and nitrate-free, low-acid, fermented pork sausage, produced in a small-scale plant in Umbria (Italy), and their effect on microbiological, physico-chemical and sensorial properties of the products. The following conditions were investigated throughout the experiment: (i) the use of the ‘formulation of selected dairy starter cultures and commercial probiotics’ vs no starter; (ii) the use of ‘specific ripening conditions’ vs ‘classic ripening conditions’; (iii) the use of nitrate vs nitrite and nitrate-free sausages. Sensory properties were improved and pathogen control was greater in salami to which a ‘formulation of selected dairy starter cultures and commercial probiotics’ had been added, especially under ‘specific ripening conditions’. The proposed formulation, together with the specific ripening conditions, greatly inhibited the growth of undesirable microbiota, reduced the isolation rate of pathogens and preserved the acceptability of the salami.