Objective-To evaluate cross protection provided by administration of contagious ecthyma vaccines against strains of orf virus in goats. Animals-126 Boer-Spanish crossbred goats (3 to 20 days old). Procedures-85 goats were vaccinated with a goat-derived contagious ecthyma vaccine. Of these, 41 were challenge exposed with the virus strain for the contagious ecthyma vaccine, 40 were challenge exposed with a more virulent field strain of orf virus, and 4 were lost to predation or died. Another 41 goats were vaccinated with a vaccine produced from a more virulent field strain of orf virus; of these, 18 were challenge exposed with the virus strain of the goat-derived contagious ecthyma vaccine, 18 were challenge exposed with the more virulent field strain of orf virus, and 5 were lost to predation or died. Results-Vaccination with the goat-derived contagious ecthyma vaccine did not significantly reduce the number of goats with lesions or lesion severity caused by challenge exposure with the more virulent field strain of orf virus. Vaccination with the vaccine produced from the more virulent field strain of orf virus significantly reduced the number of goats with lesions attributable to challenge exposure with the virus strain of the goat-derived contagious ecthyma vaccine, but it failed to significantly reduce lesion severity. Conclusions and Clinical Relevance-Vaccination did not result in cross protection for the 2 strains of orf virus. This may have been attributable to antigenic differences and may be a factor in outbreaks of contagious ecthyma in vaccinated goats.

The objective of this study was to determine the potential of Bdellovibrio bacteriovorus 109J as an alternative non-chemotherapeutic treatment of infectious bovine keratoconjunctivitis (IBK). To accomplish this, various parameters of B. bacteriovorus predation of Moraxella bovis were determined in vitro. Initial passage of B. bacteriovorus using M. bovis as prey required 10 d for active cultures to develop compared with 2 d for culture on normal Escherichia coli prey; however by the 5th passage, time to active predatory morphology was reduced to 2 d. This high passage B. bacteriovorus culture [1 × 10(10) plaque forming units (PFU)/mL] killed 76% of M. bovis [1 × 10(7) colony forming units (CFU)/mL] present in suspension broth in a 4 h assay. The minimal level of M. bovis supporting B. bacteriovorus predation was 1 × 10(4) CFU/mL. To assess the ability of B. bacteriovorus to kill M. bovis on an epithelial surface mimicking IBK, an in vitro assay with Madin-Darby bovine kidney (MDBK) cells inoculated with 4 × 10(7) CFU/mL M. bovis was used. Treatment with a B. bacteriovorus suspension (1.6 × 10(11) PFU/mL) decreased adherence of M. bovis to MDBK cells by 6-fold at 12 h of treatment, as well as decreased the number of unattached M. bovis cells by 1.4-fold. This study demonstrates that B. bacteriovorus has potential as an effective biological control of M. bovis at levels likely present in IBK-infected corneal epithelia and ocular secretions.

The objective of this study was to evaluate the in vivo predatory viability of the nematophagous fungus, Duddingtonia flagrans, after storage (36 months) and refrigeration (2-8 °C). This viability was evaluated using the infective larvae of gastrointestinal nematodes of sheep in the Northeastern semi-arid region of Brazil. Sixteen Santa Inês sheep with negative counting of eggs per gram of feces (EPG) were divided into four experimental groups, each group comprised of four animals. The pellets were administered at the dose of 3 g/10 kg of live weight (20% fungal micelyum), and a single administration was performed for each animal. Group I was administered pellets that had been stored for 36 months; Group II, freshly produced pellets; Group III, freshly produced pellets that did not contain fungi; and Group IV, pellets were not administered, and this was the control group. Feces were collected for 5 days, every 24 h for analysis. There was a significant decrease in the number of infective larvae of sheep nematodes that received D. flagrans pellets in a sodium alginate matrix, 82% was observed for Group I and 71% for Group II, compared to the control group. It is therefore concluded that the fungus, D. flagrans, pelleted in sodium alginate matrix after 36 months of storage at 2-8 °C, showed efficacy in reducing the number of infective larvae of gastrointestinal nematodes of sheep.