High Incidence of Related across Unrelated Leaf-Mining Diptera.

The maternally inherited endosymbiont, plays an important role in the ecology and evolution of many of its hosts by affecting host reproduction and fitness. Here, we investigated 13 dipteran leaf-mining species to characterize infections and the potential for this endosymbiont in biocontrol. infections were present in 12 species, including 10 species where the infection was at or near fixation.

A molecular method for biomonitoring of an exotic plant-pest: Leafmining for environmental DNA.

Understanding how invasive species respond to novel environments is limited by a lack of sensitivity and throughput in conventional biomonitoring methods. Arthropods in particular are often difficult to monitor due to their small size, rapid lifecycles, and/or visual similarities with co-occurring species. This is true for the agromyzid leafminer fly, Liriomyza sativae, a global pest of vegetable and nursery industries that has recently established in Australia.

The origin and maintenance of metabolic allometry in animals.

Organisms vary widely in size, from microbes weighing 0.1 pg to trees weighing thousands of megagrams - a 10-fold range similar to the difference in mass between an elephant and the Earth. Mass has a pervasive influence on biological processes, but the effect is usually non-proportional; for example, a tenfold increase in mass is typically accompanied by just a four- to sevenfold increase in metabolic rate.

Trial of Heat Inactivation of Selected Viruses Following Irradiation.

Four selected viruses were irradiated in ground pork with an electron beam at absorbed doses of 4.4 to 5.27 kG.

Studies of porcine reproductive and respiratory syndrome (PRRS) virus infection in avian species.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a recently recognized virus of swine. As a newly emerging virus, much of the basic information regarding PRRSV is in the process of discovery. We report three experiments with PRRSV in birds, and a fourth experiment to evaluate the infectivity and transmissibility of avian-derived PRRSV in swine.

Stability of porcine reproductive and respiratory syndrome virus in the presence of fomites commonly found on farms.

Objective: To determine the survival of porcine reproductive and respiratory syndrome virus (PRRSV) on nonliving substances (fomites) at 25 to 27 C.

Design: Prospective controlled study.

Sample Population: 3 solid, 6 porous, and 7 liquid fomites.

Prevalence of pseudorabies (Aujeszky's disease) virus antibodies in feral swine in Florida.

Serum samples collected from feral swine (Sus scrofa) throughout Florida (USA) from 1980 to 1989 were tested for antibodies to pseudorabies virus (PRV) by the serum neutralization test, the latex agglutination test, or by the enzyme-linked immunosorbent assay. Seropositive swine were detected at 11 of 13 sites with a composite seroprevalence of 34.8% (579 of 1,662 samples; range = 5.

Seroprevalence of infectious disease agents in free-ranging Florida panthers (Felis concolor coryi).

Serum samples obtained from 38 free-ranging Florida panthers (Felis concolor coryi) in southern Florida, March 1978 through February 1991, were tested for antibodies against eight bacterial, parasitic, and viral disease agents. Sera were positive for antibodies against feline panleukopenia virus (FPV) (78%), feline calicivirus (56%), feline immunodeficiency virus/puma lentivirus (37%), feline enteric coronavirus/feline infectious peritonitis virus (19%), and Toxoplasma gondii (9%). All samples were seronegative for Brucella spp.

Virus survival in the environment.

Viruses pass into the environment from clinically ill or carrier hosts; although they do not replicate outside living animals or people, they are maintained and transported to susceptible hosts. Population concentrations and movement, both animal and human, have been steadily increasing in this century, enhancing transmission of respiratory and enteric viruses and compounding the difficulty of preventing environmental transmission. Studies on environmental survival factors of viruses have been most definitive for polioviruses, foot and mouth disease viruses and Aujeszky's disease virus.

Serologic survey for transmissible gastroenteritis virus neutralizing antibodies in selected feral and domestic swine sera in the southern United States.

Serum samples collected from feral and domestic swine (Sus scrofa) in Florida and feral swine in Georgia and Texas were assayed by plaque reduction for their virus neutralizing (VN) antibodies against the porcine transmissible gastroenteritis virus (TGE). None of 560 samples collected from feral swine contained VN antibodies for TGE virus, but experimentally infected feral swine seroconverted. None of 665 samples from domestic swine contained TGE-VN antibodies.

Sequential changes in the humoral immune response of pigs to pseudorabies virus after vaccination, exposure to virulent virus, and reactivation of latent virus.

Sequential changes in the humoral immune response of pigs to pseudorabies virus (PRV) after each of several exposures to the virus were evaluated by determining virus neutralization (VN) and radioimmunoprecipitation (RIP) activities of sera collected at selected intervals. Pigs were vaccinated intramuscularly with live attenuated virus (6 pigs), inactivated attenuated virus (6 pigs), or inactivated virulent virus (6 pigs). All pigs were challenged oronasally with virulent virus 3 weeks later and 12 (4 pigs of each vaccine group) were subsequently treated with dexamethasone in an attempt to reactivate latent virus.

Prevalence and transmission of pseudorabies virus in an isolated population of feral swine.

Six hundred sixty-one feral swine (Sus scrofa) from Ossabaw Island, Georgia (USA) were captured, bled, and their sera tested for pseudorabies virus (PRV) antibody during a 6 yr period. Prevalence of seroconversion in females was somewhat higher than in males (10% versus 7%), but the difference was not statistically significant. Adults had a significantly higher prevalence than juveniles (29% versus 1%).

Immunological surveillance in a pseudorabies quarantined herd using gilts and their progeny as sentinels.

Specific pathogen free gilts and their progeny were evaluated to use as sentinels in a pseudorabies virus (PRV) infected herd by immunologically monitoring for PRV seroconversions. Time intervals targeted were pre- and post-PRV vaccinations, herd exposure, and farrowing to finishing. Post-PRV vaccinations, gilts showed low PRV lymphocyte stimulation and humoral responses.

A necrotizing pneumonia in lambs caused by pseudorabies virus (Aujesky's disease virus).

An outbreak of pseudorabies occurred in sheep housed with swine in the same building. Although the sheep and swine were not in physical contact, the lambs and ewes were exposed to air from the sows' section. Three dead lambs were submitted to the Iowa State University Veterinary Diagnostic Laboratory for necropsy.

Antiviral effectiveness of butylated hydroxytoluene against pseudorabies (Aujeszky's disease) virus in cell culture, mice, and swine.

Butylated hydroxytoluene (BHT) was evaluated for antiviral effectiveness on pseudorabies virus (PRV) in cell culture, mice, and swine. When relatively small amounts of BHT were mixed with PRV and incubated at 37 C for 30 or 60 minutes before inoculation into cell cultures, the cell cultures did not become infected with virus. The PRV was not infectious when the virus was treated with BHT and then inoculated intraperitoneally into mice, but was infectious when BHT and PRV were inoculated simultaneously or when BHT was inoculated either 30 or 60 minutes before PRV.

Evaluation of a diagnostic antigen for the detection of Aujeszky's disease virus-infected subunit-vaccinated pigs.

An early virus protein complex that is found in the maintenance medium of Aujeszky's disease (AD) virus-infected cells was evaluated as a subunit diagnostic antigen (SUDA) in the enzyme-linked immunosorbent assay (ELISA). This antigen was found in purer form and in larger quantities for up to 12 h post-infection in the maintenance medium of AD virus-infected MDBK cell cultures than in the maintenance medium of virus-infected porcine Fallopian tube (PFT) and PK1a cell cultures. The SUDA was shown to be compatible with a lectin-derived subunit vaccine by the absence of positive ELISA reactions for antibody to this antigen in 25 AD virus-free subunit-vaccinated pigs.

Production and characterization of monoclonal antibodies directed against pseudorabies virus.

Hybridoma cell lines producing monoclonal antibodies to pseudorabies virus (PRV) were established. The monoclonal antibodies were characterized with respect to their antigenic specifications and biological activities. Two monoclonal antibodies immunoprecipitated the 50 kDa PRV glycoprotein (gp50) and two immunoprecipitated the 82 kDa glycoprotein (gp82).

Attenuated properties of thymidine kinase-negative deletion mutant of pseudorabies virus.

A thymidine kinase (TK)-negative (TK-) deletion mutant of the Bucharest (BUK) strain of pseudorabies virus (PRV) was isolated. The mutant, designated as PRV (BUK d13), did not revert to TK-positive (TK+), even when propagated in medium that selected for TK+ viruses. The mutant also replicated equally well at 39.

Evaluation of field isolates of pseudorabies (Aujeszky's disease) virus as determined by restriction endonuclease analysis and hybridization.

Sixty-seven isolates of pseudorabies virus (PRV) from 13 states were cleaved with 4 restriction endonucleases (RE), and after electrophoresis in agarose, their banding patterns were photographed and evaluated. The deoxyribonucleic acid (DNA) cleavage fragments were designated into regions specified by molecular weight ranges based on lambda phage DNA as a size marker. The 67 PRV isolates were evaluated according to the total number of cleavage fragments, by the number of fragments within designated molecular weight regions, and finally, by the migration of fragments within regions.

Stability of the pseudorabies virus genome after in vivo serial passage.

Restriction endonuclease patterns of pseudorabies virus (PRV) DNA were examined after each of 11 serial passages of the virus through pigs. Minor variations in the electrophoretic mobility of certain restriction enzyme fragments were observed by the sixth passage. This variability was similar to some of the minor variability observed in field isolates.

Stability of virulent pseudorabies (Aujeszky's disease) viral genome after single passage through nonswine animal species.

This experiment was done to determine the effect(s) of single passage of pseudorabies virus in dead-end hosts on the stability of the pseudorabies virus genome. Calves, dogs, rabbits and cats were inoculated with a virulent strain of pseudorabies virus and the virus was reisolated from each animal and restriction endonuclease analysis was used to determine possible alterations in the DNA banding patterns. The restriction fragment migration profile of the pseudorabies virus DNA isolated from the animals was indistinguishable from the DNA profile of the original pseudorabies virus inoculum.

Comparison of a modified counterimmunoelectrophoresis test and a microimmunodiffusion test for detection of pseudorabies virus antibodies in porcine sera.

The correlation of a modified counterimmunoelectrophoresis (CIE) test and a microimmunodiffusion test for detecting pseudorabies virus antibodies in porcine sera was investigated, using as reference a standard virus neutralization test. The counterimmunoelectrophoresis test exhibited a sensitivity comparable to the microimmunodiffusion test but was not as sensitive as the virus neutralization test. The best feature of the modified counterimmunoelectrophoresis test is that it is a rapid test.

Development of a nonneuronal cell line derived from porcine spinal ganglia.

A cell line from porcine spinal ganglion (PSPG) tissue was initiated and characterized. The PSPG cell line contained epithelioid, fibroblast-like, and stellate-like cells. There were numerous intercellular communications between cells in the culture.

Restriction endonuclease analysis of the pseudorabies (Aujeszky's disease) virus before and after serial passage in vivo and in vitro.

The deoxyribonucleic acid (DNA) of pseudorabies virus (PRV) was examined by restriction endonuclease analysis before and after various treatments: namely 1. plaque purification of stock virus, 2. serial passage of virus in cell culture at high (H) and low (L) multiplicity of infection (MOI), and 3.