Atypical mycobacteria as the probable cause of positive tuberculin reactions in squirrel monkeys (Saimiri sciureus).

Three of 275 squirrel monkeys (Saimiri sciureus) demonstrated a positive reaction to Koch's old tuberculin within 72 hours after the test. The animals were again positive when retested 1 week later. Two of the monkeys were killed and necropsied. There was no gross nor histologic evidence of tuberculosis. Organisms were cultured from liver, spleen, and mediastinal lymph node. These were identified as Runyon Group II mycobacteria, Mycobacteria gordoneae.

Antibody response and resistance of turkeys to Newcastle disease vaccine strain LaSota.

Studies were undertaken to determine the influence of repeated revaccination on the immune response in immuno-competent turkeys as measured by humoral antibody and resistance to challenge. Protection was better in turkeys given the LaSota spray vaccine at 4 weeks and 30 days later than in turkeys given one vaccination by spray or intramuscular route or exposed 4 times at 10-day intervals by the aerosol route. The anamnestic response, as measured by the HI tests to revaccination with the same immunogen, was not evident by the 3rd day postrevaccination but was observed on the 7th day. The interval between primary and secondary vaccination was found to be important to a true and optimal anamnestic response. Response was greater, however, in vaccinated turkeys exposed to VVND, a more virulent virus antigenically different from the vaccine strain. Exposure to LaSota vaccine by the intramuscular route gave a poorer HI response than LaSota given by aerosol.

In vitro DNA synthesis in lymphocytes from turkeys vaccinated with LaSota, TC, and inactivated Newcastle disease vaccines.

In vitro cultures of peripheral blood lymphocytes from turkeys vaccinated and revaccinated with Newcastle disease (ND) vaccines were stimulated to transformation when exposed to the homologous and heterologous strains of ND virus. The mitogenesis was measured by the uptake of 3H-thymidine into newly synthesized DNA. There was considerable difference in DNA synthesis by lymphocytes drawn 0, 2, 5, and 10 days after vaccination and revaccination with the three vaccines. Stimulation of DNA synthesis, evident as early as the 2nd day, was highest in lymphocytes from turkeys vaccinated or revaccinated with TCND intramuscularly. Stimulation was least in lymphocytes from turkeys vaccinated and revaccinated with LaSota vaccine by aersol. Stimulation was intermediate from an inactivated vaccine given subcutaneously. DNA synthesis was greater with the homologous than with the heterologous strains of NDV. Synthesis was even greater when the same strain was used as a viral suspension in allantoic or cell-culture fluid than the commercial vaccine. The bovine paramyxovirus (PI3) resulted in a minimum DNA synthesis or completely inhibited it. A many-fold (order of magnitude) stimulatory effect was observed when PHA was used as an antigen. The stimulation of DNA synthesis did not parallel the HI antibody response.