Verocytotoxin-producing Escherichia coli O157 in minced beef and dairy products in Italy.

A total of 3879 samples of foodstuffs were examined for the presence of Verocytotoxin-producing Escherichia coli O157 (VTEC O157). The survey was conducted by 9 of the 10 Italian Veterinary Public Health Laboratories. Samples were collected between May 2000 and September 2001 in 14 regions and comprised 931 minced beef specimens and 2948 dairy products (DP) with less than 60 days of ripening. The DP included 657 pasteurised and 811 unpasteurised bovine DP, 477 pasteurised and 502 unpasteurised ovine DP, and 501 water-buffalo's milk mozzarella cheese. Samples were collected at retail level, from plants processing minced beef and dairy plants and from farms directly manufacturing cheeses. All the samples were tested using a sensitive procedure based on ISO/DIS 16654:1999 (later ISO 16654:2001), which includes an immunomagnetic separation step. A preliminary inter-laboratory trial was organised with artificially contaminated samples to assess the ability of all the participating laboratories to isolate E. coli O157 by the established procedure. VTEC O157 was isolated from four (0.43%) of the minced beef samples, collected in four different regions and during different months, but was not detected in any of the dairy products. E. coli O157 VT-eae+ was isolated from one raw cow's milk cheese. This survey provided national data on the presence of VTEC O157 in foodstuffs, demonstrating a low prevalence of the organism. The survey also encouraged updating of knowledge and procedures on VTEC O157 in laboratories with official responsibility for microbiological testing of foods of animal origin.

Antibacterial properties of grapefruit seed extract against Paenibacillus larvae subsp. larvae.

Twenty-one samples of grapefruit seed extract (GSE) either from marketed products or provided by an apiculturist were analysed to verify their inhibition activity, in particular against Paenibacillus larvae subsp. larvae, responsible for American foulbrood. The bactericide capacity of GSE has been measured in Bacillus subtilis BGA, Bacillus cereus 11778, Bacillus cereus K250 and Micrococcus luteus 9341a; these bacteria are normally used in the laboratory to study inhibitors. The results showed that not all GSE have the same inhibitory activity and two of those analysed do not inhibit the five bacteria used. Considering that 19 samples inhibited American foulbrood bacillus, the authors conclude that the use of a natural product (such as GSE) to control this important disease of bees, can be used as a substitute for chemotherapeutic products, after appropriate expedients.

[How to improve the appropriate application of stress test]. / Come migliorare l'appropriatezza all'esecuzione del test da sforzo.

A brief self administered questionnaire (Veterans Specific Activity Questionnaire VSAQ) should be used to estimate exercise tolerance on the basis of symptoms during daily activities to individualize ramp rates on the treadmill, so that the test duration would be approximately 10 minutes in according with guidelines for exercise testing for correct determination of oxygen uptake. In a recent study the responses to the VSAQ and age were the strongest predictors of both measured and predicted exercise capacity. This approach allows to individualize ramp rates on the treadmill and appropriately targets the exercise test duration (8-12 minutes). Further studies are need for validating the role different questionnares in different populations, including women, patients with low grade of work activity and with diabetes.

[A morphological analysis and assessment of the dentinal permeability of detergents and liners]. / Analisi morfologica e valutazione della permeabilità dentinale di detergenti e liners.

In this study we evaluated the morphological aspect at scanning electron microscopy (SEM) and the degree of permeability of the dentinal surface after treatment with different detergent solutions, liners and cleansers. In particular we tested new potassium oxalate products. The results obtained with in vitro tests showed that many detergents, liners and cleansers are able to maintain almost unaltered the smear layer, causing small modifications for the diameter and the number of dentinal tubules which are partially exposed. The materials we used were able to deterge the dentinal surface, as demonstrated by SEM analysis, but one of them was able to stabilize and to protect the surface. All tested products, except potassium oxalate, caused an increase in dentinal permeability, proving to exercise a potential by damaging action towards the dentine and the pulpal tissue. Only DDS was able to reduce the dentinal permeability, causing the formation of calcium oxalate precipitates which occlude the dentinal tubules.

[The marginal leakage of amalgam and Vitrebond restorations after an occlusal load test]. / Infiltrazione marginale di restauri in amalgama e Vitrebond dopo test da carico occlusale.

The use of adhesive liners in amalgam fillings and restorations is a recent form of conservative dentistry. The aim of our study was to assess marginal microleakage in amalgam and Vitrebond restorations after occlusal load test. Using extracted teeth, we prepared 16 class II amalgam restorations, (Valiant ICQ, Caulk). Adhesive liner, (Vitrebond, 3M USA), was used in half of these. The samples then had first a cyclic load test, (27 kg per 7,000 cycles), followed by a microleakage test, (sample immersed in 2% erythrosin solution for 24 hours). The results showed that, in samples with adhesive liner, color penetrated to a statistically lesser extent than in the control group without Vitrebond.

Clinical results obtained in cattle and swine by means of biological immunostimulators.

The conditioned infections due to opportunistic organisms, can be controlled by biological immunostimulators. The POLI-IF (Newcastle virus plus endotoxin of E. coli and Freund's incomplete adjuvant) rapidly induces the aspecific immunity. Given twice with 7-10 days interval in between, on occasion of a programmed stress (weaning, transport, crowding) it proved its efficacy in artificially suckled calves and in weaning piglets. The field trials, carried out on 2,782 treated calves in comparison with 2,909 untreated controls and on 4,387 piglets in comparison with 4,461 untreated controls, revealed statistically significant differences for P less than 0.005 among the groups of treated and control animals. The immunostimulator reduced the incidence of the disease, dead and discarded animals, as well as it shortened the mean duration of the disease in single heads. Though the way the POLI-IF acts is not perfectly known so far, yet it increases the serum bactericidal activity and the circulating leukocytes, while it induces high levels of IFN. In our opinion the activity of the POLI-IF is bound to 3 factors at least: activation of the complementary fractions, mobilization of the immunocompetent cells, induction of IFN.