Bovine antibody against Streptococcus agalactiae, type Ia, produced by preparturient intramammary and systemic vaccination.

Four pregnant heifers were immunized by the intramammary route with killed or live Streptococcus agalactiae vaccine, and a 5th heifer was vaccinated by the intramuscular route with killed vaccine. Antibody in the colostrum from vaccinated and non-vaccinated glands was compared. Antibacterial glands was compared. Antibacterial antibody titers of the 4 immunoglobulin classes were determined by indirect fluorescent antibody assay. Although the content of immunoglobulin G1 (IgG1), IgG2, and IgM in the colostrum from the vaccinated glands was not substantially different from the nonvaccinated glands, IgA content was considerably greater in the former. Antibody specific to S agalactiae was isolated from all colostrum samples. The mouse passive protection test and Ouchterlony analysis were used to demonstrate the presence of type-specific antibody to Ia strain used for vaccination. The passive mouse protection test also was useful to compare the protective capacity of specific S agalactiae, type Ia, antibodies of immunoglobulin classes IgG, IgM, and IgA. Increased protective capacity of IgM and IgA over IgG1, on a weight basis, was demonstrated. The present study indicates that S agalactiae preparations, when introduced into the mammary gland, can give rise to local antibody synthesis in the vaccinated glands.     

PERINATAL FOAL MORTALITY ASSOCIATED WITH A HERPESVIRUS

An outbreak of perinatal foal mortality associated with a herpesvirus is described. Twenty two foals either were still-born, or died soon after birth, or were weak and soon developed severe respiratory signs, or were normal at birth and developed respiratory symptoms 18 to 24 hours later. Elevated temperatures, heart and respiratory rates were constant features. The animals were severely leucopaenic, and showed an absolute neutropaenia. At autopsy the lungs were enlarged, and showed varying degrees of aeration and moderate to severe oedema and congestion. Histopathology showed an acute focal necrotising bronchiolitis with the presence of intranuclear eosinophilic inclusion bodies. Herpesvirus was recovered from 9 foals in cell culture and identified by electron microscopy.     

INTERACTION BETWEEN INFECTIOUS BURSAL DISEASE VIRUS AND NEWCASTLE DISEASE VIRUS IN CHICKENS

The Australian strain of infectious bursal disease virus (IBDV), 002/73, affected the response of chickens to Newcastle disease virus (NDV). The titre of serum antibodies to NDV in chickens infected with IBDV was significantly lower than that of birds infected with NDV alone. It also appeared that IBDV affected NDV excretion from chickens as NDV was more frequently isolated from chickens infected with IBDV, IBDV infection did not alter the pathogenicity of NDV in chickens. This Australian strain of IBDV therefore appeared to be immunodepressive in one-day-old chickens.     

Salmonella serotypes encountered in animal feed additives in Lebanon.

Animal feed-additive samples (n = 300) were examined for the presence of salmonellae, using the selenite-F broth-enrichment method followed by subculturing on Salmonella-Shigella and brilliant green agar with sulfadiazine selective agar plates. Samples consisted of a variety of feed additives: 119 bone meal samples, 77 meat meal samples, 40 fish meal samples, and 64 miscellaneous meal samples. Results of examination found 49 (41.2%) of the bone meal samples, 6 (7.8%) of the meat meal samples and 2 (5%) of the fish meal samples contained salmonellae. Of 57 isolates representing 24 serotypes, 4 most frequently isolated serotypes were Salmonella meleagridis (35.1%), Salmonella tennessee (7%), Salmonella chester (5.2%), and Salmonella senftenberg (5.2%). This study shows a high Salmonella-contamination rate of bone meal compared with meat meal and fish meal samples. Of 12 known positive bone meal samples that were examined, 100% of 25-g samples, compared with 70% to 100% of 2.5-g samples and 30% to 90% of 0.25-g samples and 30% to 90% of 0.25-g samples, were positive for salmonellae.     

Differentiation of influenza virus antigens using enzyme immunoassay]

Reported is a microprocess of enzyme immune assay in which slipformed air pockets of polyvinylchloride (PVC), as used in the pharmaceutical industry, are used as carriers of antigens or antibody. Two methods, the anti-globulin and the double-antibody methods, are based on antibody which had been coupled with alkaline phosphatase. Tests in which various sub-types of influenza virus were used have shown the double-antibody method to be a sensitive technique which can be successfully used in the differentiation of envelope antigens.     

THE PATHOGENESIS OF INFECTIOUS AVIAN ENCEPHALOMYELITIS

Infectious avian encephalomyelitis virus (IAEV) maternal antibody was detected in the serum of chickens for up to 21 days following hatching. This antibody protected chickens against clinical IAE after intracerebral inoculation with van Roekel strain or oral administration of the NSW-1 strain of IAEV. Maternal antibody to IAEV also protected testosterone bursectomised chickens against the development of clinical disease. IAEV maternal antibody also influeced the pattern of virus excretion in faeces and serological responsiveness. This influence on antibody responses persisted beyond the time that IAEV maternal antibody could be detected. The importance of IAEV maternal antibody on the strategy of vaccination against IAE is discussed.