Kenneth E. Nusbaum

Protective immunity induced by DNA vaccination of channel catfish with early and late transcripts of the channel catfish herpesvirus (IHV-1)

Seven full-length transcripts encoding four early and three late genes of the channel catfish virus (CCV), ictalurid herpesvirus I (IHV-1), have been cloned following rt-PCR amplification and DNA sequencing. Transcripts were selected based on their predicted association with membrane structures, identification as an envelope glycoprotein, or as a viral capsid protein. The transcripts derived from ORF 6, ORF 7, ORF 8a, ORF 10, ORF 51, ORF 53, and ORF 59 were all shown to be complete and unspliced. Each of the seven ORFs was cloned into a vaccine expression vector designed to support high levels of expression of the inserted sequence in catfish tissues. Solutions of DNA containing one each of the seven CCV ORFs, vector alone or PBS were injected intramuscularly into 4-8 cm catfish. Four to 6 weeks after injection each experimental group was challenged with one LD(50) of CCV. Single injections of DNA expression constructs containing ORF 59, encoding the envelope glycoprotein, or ORF 6, encoding a presumptive membrane protein, were found to elicit the strongest resistance to challenge compared to uninjected, PBS injected or vector injected groups. Even more effective was a combination vaccine pair in which both ORF 59 and ORF 6 expression constructs were injected. Other ORFs did not provide consistent protection to challenge above that observed in control fish. Both percent survival and kinetics of cumulative deaths were improved using the combination DNA vaccine encoding ORF 6 and ORF 59. Both ORF 6 and ORF 59 were able to elicit virus neutralizing antibodies capable of an anamnestic response on viral challenge. We believe this evidence provides adequate proof of principle for the use of DNA vaccines in channel catfish and the effectiveness of the resistance to viral infection they elicit.

Absence of humoral response in flamingos and red-tailed hawks to experimental vaccination with a killed West Nile virus vaccine.

Abstract Sixteen Chilean flamingos, Phoenicopterus chilensis, and 10 red-tailed hawks, Buteo jamacensis, were vaccinated in the pectoral muscle with 0.2 ml of a commercially produced killed West Nile virus vaccine intended for use in horses. Half the birds of each species received a booster vaccination 3 weeks after the first injection. Three weeks after the booster vaccination, none of 13 birds surveyed had detectable antibody to West Nile virus.

Preliminary Studies of a Newly Developed Subunit Vaccine for Channel Catfish Virus Disease

Abstract The soluble channel catfish virus (CCV) envelope was harvested and used as a vaccine for channel catfish virus disease. Three- to four-day-old eggs of channel catfish Ictalurus punctatus and 1-week-old fry were vaccinated by immersion. A booster was given to subgroups of fry 2 weeks after vaccination. Vaccinated and nonvaccinated control groups were challenged with viable CCV 8 weeks after vaccination. All challenged nonvaccinated control fry died during the first experiment, and 56% died in the second experiment. Survival offish vaccinated as eggs or fry was 31 and 82%, respectively; survival of groups given a booster dose was 81 and 89%, respectively.

Model based on weather variables to predict seroconversion to bluetongue virus in Alabama cattle

Abstract A model for the prediction of bluetongue virus seroconversion was developed using weather variables and results from serum samples collected from a research herd of Hereford, Angus, Holstein and mixed breed beef cows at 12 different times over 2 years. The six weather variables analyzed were: mean daily air temperature; mean daily soil temperature at a depth of 10 cm; mean daily hours of wet vegetation; total days of rainfall ≥ 0.13 cm; total rainfall for each 7 day period; mean daily solar energy (W m −2 ). A maximum R 2 multiple linear regression technique was applied to meteorological data collected during the four weekly intervals prior to each sample collection date (48 sets of weekly meteorological data). The best predictors for seroconversion were mean daily hours of wet vegetation and total rain days during the second weekly period prior to sample collection. The bluetongue virus seroconversion was related to mean daily hours of wet vegetation, total rain days, and total precipitation as expressed by the equation: Seroconversion=7.1+4.0 (mean daily hours of wet vegetation)−1.3 (total precipitation) (R 2 =0.62, P

Keratoconjunctivitis associated with Neisseria ovis infection in a herd of goats

Clinical signs appeared in a herd of 18 goats 6 weeks after being collected and placed in a research holding facility. Three goats developed bilateral epiphora, photophobia, and blepharospasm. One goat walked into objects in the pen. Affected animals were not separated from normal ones because of housing limitations. Twelve days after the initial signs were observed, there was 100% morbidity. An ophthalmic examination and consultation were requested. Each goat had bilateral ocular disease, but severity varied among animals. Photophobia, blepharospasm, and a serous discharge from the medial canthus were present. Several 0.5to 1-mm raised, transparent conjunctival follicles were present at the dorsal limbus (Fig. 1). Increased peripheral cornea1 relucency from stromal edema and subepithelial cornea1 neovascularization was present (Fig. 2). One severely affected doe had full thickness cornea1 edema that prohibited observation of the left anterior chamber by focal penlight examination. In the right cornea, there was superficial uptake of fluorescein stain. a The pupils were normal in goats with only conjunctivitis but were miotic in goats with keratitis. All goats with severe cornea1 involvement were examined by direct ophthalmoscopy and were normal. No other abnormality was found on physical examination. Etiologic agents considered in this herd included 1) Mycoplasma spp. (M. agalactia, M. mycoides mycoides), 1,8,12 2)

Adherence of channel catfish virus to sperm and leukocytes

Abstract Although channel catfish virus (CCV) is thought to be vertically transmitted, no mechanism has been demonstrated for such a process. When contained in small volumes of saline, CCV associated rapidly with channel catfish leukocytes and sperm, associated slowly with a continuous cell line of channel catfish cells and did not adhere to channel catfish eggs. This virus-sperm adherence appeared to be a mechanism by which eggs might become infected with virus. However, virus-sperm adherence was not detected when sperm were added to 250 ml of CCV-containing water, indicating that sperm are probably not involved with transmitting CCV into eggs from water or ovarian fluid. Egg infections in channel catfish, if they occur, must be accomplished by mechanisms different from those thought to be involved in the infection of salmonid eggs by infectious hematopoietic necrosis virus.

Reported Rabies Pre-exposure Immunization of Students at US Colleges of Veterinary Medicine

In 2008, the US experienced a disruption in human rabies vaccine supplies, leading public health authorities to prioritize vaccine release for post-exposure prophylaxis (PEP) and limit vaccine supplies for pre-exposure prophylaxis (PreEP) in high-risk groups. In 2008, the Association of American Veterinary Medical Colleges (AAVMC) surveyed its member institutions on rabies vaccination policies and practices. Senior administrators at Colleges of Veterinary Medicine (CVMs) and departments of veterinary science and comparative medicine were asked to identify the person most knowledgeable about their institutions student rabies vaccination program. Respondents were asked to describe their policies and procedures for administering PreEP to veterinary medical students and staff and to estimate the annual demand for student and staff PreEP vaccine. Twenty-one CVMs responded. Twenty (95%) reported requiring PreEP of veterinary medical students and 16 (80%) of those 20 required vaccination upon matriculation. An estimated 7,309 doses of vaccine were required for PreEP of an estimated 2,436 first-year US veterinary medical students. Seventy-two percent of respondents administered PreEP in August, September, and October, coinciding with the highest public demand for PEP. CVMs should consider altering the timing of rabies vaccine administration to veterinary medical students and staff to other months, thereby helping to ensure that PEP rabies vaccine will be available to people with validated rabies exposures and to ensure that supplies will be available for PreEP of students and staff. AAVMC may wish to identify and support a point of coordination to facilitate the purchase and distribution of human rabies vaccine among its US member CVMs.

Detection and Distribution of Flavobacterium columnare in Experimentally-Infected Channel Catfish, Ictalurus punctatus Using Culture and Polymerase Chain Reaction

Abstract The authors examined the use of culture and polymerase chain reaction (PCR) to detect Flavobacterium columnare in experimentally-infected channel catfish, Ictalurus punctatus. Five treatments were utilized which included immersion exposure to 106, 107, 108 colony forming units (CFU)/mL for 30 minutes, intramuscular injection of 108 CFU/fish and a negative control (i.e., immersion in Cytophaga broth). Flavobacterium columnare was isolated and detected in mucus 30 minutes following exposure by microbiological culture and PCR in all treatments except the negative controls. Gills were positive by culture and by PCR in all treatments at 30 minutes post treatment except the 106 CFU/mL immersion treatment which did not yield positive culture and PCR results until 1 hour. Culture positive samples were observed in the internal organs (anterior and posterior kidney) and blood of the 1078 CFU/mL treatments although at low numbers (≤10 CFU). Results of PCR paralleled that of culture for the mucus and gill samples when analyzing all treatments together over time suggesting either method is useful in determination of the presence ofF. columnare. Polymerase chain reaction was significantly (P < 0.001) better at detection ofF. columnare from skin/muscle than was the use of microbiological culture. These results suggest that PCR may be useful for rapid detection of F. columnare in the mucus.

Seroepidemiologic study of bluetongue virus serotype 2 in Alabama

Abstract Sera from 1341 Alabama cattle representing 65 of 67 countries (97%) were tested for antibodies to bluetongue virus (BTV) using the agar gel precipitin (AGP) test. Those positive by AGP were tested of type-specific antibodies to BTV serotype 2 using the serum neutralization (SN) test. Four hundred and forty-six of the 1341 samples (33%) were positive by AGP. 446 samples (19%) were positive for antibodies to BTV serotype 2 (BTV-2). When these sera were tested using the SN test, 28 of the 84 (33%) had titers that were 4-fold greater to BTV-2 than to the other four serotypes of BTV present in the U.S.A. Sera positive for antibodies to BTV-2 were from 19 of Alabamas 67 counties.

What's your diagnosis: Fin Plaques and Hair-Like Structures on Wild-Caught Bluegill Fish (Lepomis macrochirus)

Whats your diagnosis: Fin Plaques and Hair-Like Structures on Wild-Caught Bluegill Fish ( Lepomis macrochirus )