Prevention of Salmonella Typhimurium colonization and organ invasion by combination treatment in broiler chicks.

The effects in broiler chicks of treatment with a competitive exclusion (CE) product, an experimental dietary probiotic, and the abiotic beta-glucan on cecal colonization, organ invasion, and serum and intestinal IgG and IgA levels to Salmonella challenge was evaluated. Four groups of 1-d-old chicks were treated by oral gavage on d 1 with an appropriate dose of a commercial CE product. Three groups received daily doses of probiotic, beta-glucan, or both, for 6 d. Three other groups were fed daily from d 1 onwards with probiotic, beta-glucan, or both. Subgroups of 30 chicks from each group were challenged on d 1, 9, 16, or 23 with 10(7) cfu/ mL of Salmonella Typhimurium (1769NR) and killed 7 d later. Control groups were maintained untreated and remained unchallenged (negative control), or were challenged with Salmonella Typhimurium (1769NR; positive control), as described above. Cecum, liver, and spleen samples were examined for the presence of Salmonella, whereas serum and intestinal fluid samples were assayed for total antibody (IgG and IgA) concentrations. Data were analyzed by 1-way ANOVA, and means were compared using Duncan's multiple range test. In comparison with other treatments, those involving CE product and beta-glucan, with or without probiotic during the first week, resulted in a superior inhibition of cecal colonization and organ invasion by Salmonella and also offered a higher level of protection (P < 0.05). During the second week, treatments containing experimental dietary probiotic and beta-glucan, with or without CE product, resulted in an inhibition of liver invasion (P < 0.05). The IgA levels were significantly higher (P < 0.05) in intestinal fluid compared with serum, whereas IgG had low levels. The results in the first and third week indicate that combination treatments involving CE product, probiotic, and beta-glucan are a more effective control of Salmonella colonization than the corresponding individual preparations.

Comparison of three commercial competitive-exclusion products for controlling Salmonella colonization of broilers in Brazil.

In this study, a new competitive-exclusion (CE) product, Mucosal Starter Culture (MSC), was compared with two other CE products (Aviguard and Avifree) commercially available in Brazil to evaluate their ability to protect newly hatched chicks against colonization by a strain of Salmonella Kedougou. This study was based on a previously published and recommended method for such products. Separate groups of the chicks were dosed orally with the respective treatment materials and challenged 24 h later, and their ceca were examined for Salmonella 5 days after challenge. Under the test conditions, only MSC and Aviguard gave statistically significant (P < 0.05) protection to the chicks, but the MSC treatment yielded the lowest mean level of cecal carriage and the smallest proportion of Salmonella-positive birds.

Virulence and molecular aspects of Bordetella avium isolated from cockatiel chicks (Nymphicus hollandicus) in Brazil.

Bordetella avium is an opportunistic pathogen that presents tropism for ciliated epithelia, leading to upper respiratory tract disease in turkeys. This agent has also been associated with Lockjaw Syndrome in psittacine birds, but literatures describing the importance of this agent in such species are rare. The purpose of the present study was to report the first outbreak of B. avium infection in juvenile cockatiels demonstrating the Lockjaw Syndrome in Brazil and to investigate the antimicrobial resistance profile and phenotypic and genotypic characteristics of these strains. Surprising, the strains obtained from five infected cockatiel chicks from three different breeders from different Brazilian states showed a clonal relationship using the Pulsed Field Gel Electrophoresis and Single Enzyme Amplified Fragment Length Polymorphism techniques. The virulence potentials of the B. avium strains were assessed using tracheal adherence and cytotoxic effects on a VERO cell monolayer.

BCG infection induces responsiveness to dead Mycobacterium leprae in hamsters. A mitsuda-like reaction

Hamsters inoculated with BCG become responsive to dead Mycobacterium leprae. The response is characerized by a typical perineural granulomatous reaction, observed 16 days after the injection of a suspension of dead M. leprae into the foot pad of animals previously sensitized with BCG