Evaluation of bacterins containing three predominant phage types of Salmonella enteritidis for prevention of infection in egg-laying chickens.

Six Salmonella enteritidis bacterin formulations differing in adjuvant content and whole-cell inactivation procedures were evaluated in egg-laying chickens. Chickens given S enteritidis bacterins containing modified Freund's incomplete adjuvant had greater humoral immune responses to S enteritidis than did birds given other bacterin formulations (P < 0.05). Better protection against infection by S enteritidis phage types 8, 13a, and 23 was obtained in birds vaccinated with bacterin 5. Bacterin 5 contained S enteritidis cells inactivated by 20% acetone and modified Freund's incomplete adjuvant.

Description of osteomyelitis lesions associated with Actinomyces pyogenes infection in the proximal tibia of adult male turkeys.

Actinomyces pyogenes was isolated from osteomyelitis lesions from the proximal tibia of mature tom turkeys. Gram-stained impression smears of the lesions resulted in bacteria that appeared as club-shaped, gram-positive pleomorphic rods. The bacteria grew better in a reduced-oxygen environment. The lesions were well demarcated and cavernous, ranging from purulent to caseous in consistency.

Evaluation of cell culture propagated and in vivo propagated hemorrhagic enteritis vaccines in turkeys.

The immune response of turkeys to a liquid, was compared with a previously frozen, cell culture propagated hemorrhagic enteritis (HE) vaccine. The liquid cell culture propagated HE vaccine was able to induce 100% seroconversion in turkeys 4 weeks after being vaccinated at 3.5 weeks of age; however, the previously frozen cell culture propagated HE vaccine induced 80% seroconversion 4 weeks post vaccination (P < 0.05). The average seroconversion in turkey flocks administered the liquid cell culture propagated HE was 97% in comparison with 98.5% in flocks given the splenic vaccine (P > 0.05). The complete absence of HE antigens in spleens of birds 5 days after being challenged with the virulent HE virus (40,000 TCID50 per bird) at an age of 9.5 weeks, was used as a model for successful protection against HE disease. The HE antigens were absent from spleens of all challenged birds that were previously vaccinated by the liquid cell culture propagated HE vaccine or splenic vaccine.

An enzyme-linked immunosorbent assay for detection of Bordetella avium infection in turkey flocks: sensitivity, specificity, and reproducibility.

An enzyme-linked immunosorbent assay (ELISA) for detection of Bordetella avium infection in turkey poults was developed. One-week-old poults challenged intratracheally with 10(12) colony-forming units of B. avium had detectable titers (greater than or equal to 11), with an average of 13.6% positive samples when the birds were 6 to 11 weeks old. The method was sensitive enough to detect maternal antibodies to B. avium in poults up to 3 weeks of age. The same poults challenged at 1 week of age had 100% tracheal infection up to 3 weeks of age, which dropped to 0% by 6 weeks. The method resulted in no false-positive samples (titer = 0) from birds not infected with B. avium and tested weekly between 4 and 11 weeks of age. Antibodies in turkey flocks infected with Newcastle disease virus, hemorrhagic enteritis virus, and Mycoplasma meleagridis, and birds infected with Escherichia coli had no apparent cross-reactivity to the B. avium antigens used in the ELISA. The percentages of B. avium-positive serum samples collected from different turkey flocks did not significantly differ (P greater than 0.05) when samples were tested by the developed ELISA at different times, an indication of the reproducibility of the method.

Characteristics of Actinomyces pyogenes involved in lameness of male turkeys in north-central United States.

A new condition of clinical lameness in 20 male turkey flocks of North-Central United States, associated with isolation of gram-positive rod bacteria from lesions of osteomyelitis, is characterized. The characterization confirmed the randomly selected isolates as Actinomyces pyogenes based on macroscopic and microscopic observations and 17 biochemical tests. The disease was reproduced within 3 weeks in all male turkeys, following an intravenous challenge at 15 weeks of age. The agar gel precipitin test and immunoblotting confirmed the antigenic similarity of the isolates recovered from the osteomyelitis lesions of lame birds.