bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of a Radioimmunoprecipitation Assay to Immunoblotting and ELISA for Detection of Antibody to African Swine Fever Virus
Authors: Alcaraz Carlos , De Diego Maribel , Pastor Maria J. , Escribano José M.
Published: May 2011

A radioimmunoprecipitation assay (RIPA) has been developed for detection of antibody to African swine fever virus (ASFV) and compared with the immunoblot assay with regard to sensitivity and specificity.

Two hundred seven field sera, obtained from pigs in Spain from different geographic areas between 1975 and 1986, that were positive by ASFV enzyme-linked immunosorbent assay (ELISA) were also analysed by immunoblot assay and RIPA. By serum dilution experiments, the RIPA appeared at least as sensitive as the ELISA and immunoblotting tests, although ELISA and RIPA detected antibodies to ASFV earlier in natural infection than did the immunoblot assay, as disclosed by animal inoculation studies. The most antigenic ASFV-induced proteins in natural infection detected by RIPA were the viral proteins p243, p172, p73, p25.5, p15, and p12 and the infection proteins p30 and p23.5. In the immunoblot assay, the proteins that were most reactive with the same sera were the viral protein p25.5 and the infection proteins p30, p25, and p21.5. Only 1 serum, from an animal infected with ASFV, was negative by immunoblot assay but showed a positive result by RIPA. A modification of conventional RIPA was performed using a dot transference of immunoprecipitated proteins to a nitrocellulose filter. This modification simplified the conventional RIPA procedures by eliminating the electrophoresis of immunoprecipitated proteins without affecting sensitivity and specificity.

The ease of use, specificity, and the sensitivity comparable to that of the immunoblot assay make the RIPA a useful confirmatory assay for sera that yield conflicting results in other ASFV antibody assays.
Extracutaneous Viral Inclusions in Psittacine Beak and Feather Disease
Authors: Latimer Kenneth S. , Rakich Pauline M. , Kircher Ingrid M. , Ritchie Branson W. , Niagro Frank D. , Steffens W. L. , Lukert Phil D.
Published: May 2011

Thirty-five birds that died with naturally acquired psittacine beak and feather disease (PBFD) were necropsied to identify extracutaneous viral inclusions. Inclusions were found in various tissue sections from 34 of 35 birds. By immunoperoxidase staining, intranuclear and intracytoplasmic inclusion bodies were shown to contain PBFD viral antigen. Inclusion-bearing lesions were widely disseminated but often closely associated with the alimentary tract. Lesions within the palate, esophagus, crop, intestine, bursa of Fabricius, and liver probably serve as sources for viral shedding into the feces.
Fumonisin B1 Levels Associated with an Epizootic of Equine Leukoencephalomalacia
Authors: Wilson Terrance M. , Ross P. Frank , Rice Larry G. , Osweiler Gary D. , Nelson Hillman A. , Owens Debra L. , Plattner Ronald D. , Reggiardo Carlos , Noon Ted H. , Pickrell James W.
Published: May 2011

During the fall of 1989, an episode of equine leukoencephalomalacia involved 18 of 66 purebred Arabian horses at a breeding/training stable in Arizona. Of the 18 horses affected, the condition was fatal in 14. These horses, as well as 48 unaffected horses, had been fed a diet containing a substantial amount of white corn screenings. Gross pathologic findings included liquefactive necrosis in parts of the cerebral white matter and hemorrhagic foci of various sizes in the brain stem. Histopathologic findings included rarefied white matter with pyknotic nuclei and eosinophilic cytoplasm. Thin-layer chromatography, high-performance liquid chromatography, and gas chromatography/mass spectroscopy were utilized to identify and quantitate fumonisin B1 in 3 samples of corn from the farm. Concentrations of fumonisin B1 range from 37 to 122 ppm. Fumonisin B1 was also detected. Using information on diet, animal weights, and feeding practices, estimates of total fumonisin B1 dosage were determined. This is the first definitive report on equine leukoencephalomalacia and associated fumonisin B1 concentrations.
Lead Concentrations in Blood and Milk from Periparturient Dairy Heifers Seven Months after an Episode of Acute Lead Toxicosis
Authors: Galey Francis D. , Slenning Barrett D. , Anderson Mark L. , Breneman Perlina C. , Littlefield E. Sue , Melton Larry A. , Tracy Mark L.
Published: May 2011

In September 1988, 100 of 300 yearling dairy heifers developed blindness, tachypnea, foaming at the mouth, chewing, and facial fasciculations. Twenty-five animals died. Lead toxicosis was diagnosed based on the clinical signs and the presence of excessive concentrations of lead in whole blood, liver, kidney, and rumen contents of affected animals. The source of the lead was Sudan grass silage that had been contaminated by soil that contained up to 77,000 mg/kg of lead. Lead concentrations were determined approximately 7 months after the acute episode of lead toxicosis. Whole blood and milk samples were obtained from heifers and a group of control cows 2 weeks prior to (blood only), at the time of, and 2 and 4 weeks after freshening. No lead was found in any of the milk samples (detection limit = 0.055 mg/liter). Animals that had been severely affected by lead toxicosis experienced a transient increase in whole blood lead concentrations at freshening that was not high enough to be considered toxic. No similar increases in blood lead were observed for control cows or heifers that had experienced milder toxicosis. These findings suggest that at parturition lead is mobilized into the blood of cattle previously exposed to excessive lead.
A Survey of Causes of Bovine Abortion Occurring in the San Joaquin Valley, California
Authors: Anderson Mark L. , Blanchard Pat C. , Barr Bradd C. , Hoffman Rick L.
Published: May 2011

The causes of abortion in cattle in the San Joaquin Valley of California were surveyed from submissions to the California Veterinary Diagnostic Laboratory at Tulare. Four hundred sixty-eight abortion cases were examined. Most submissions (89%) were from large drylot dairies, milking an average of 814 cows. Abortion evaluations included necropsy, histopathology, bacteriology, virology, and other immunologic and serologic tests. A specific cause was identified in 29.5% of the abortions. Bacterial infections, most of which were sporadic, accounted for 16% of all abortions. Viral causes and protozoal infections were diagnosed in 5.6% and 3.2% of the abortions, respectively. Fetuses with protozoal infection had histologic lesions of focal nonsuppurative necrotizing encephalitis, and protozoa were detected. Similar histologic lesions were seen in 80 additional fetuses (17.1%), and although an etiologic agent was not identified for these cases, a protozoal infection was suspected.
Papillomavirus Infection of Aged Persian Cats
Authors: Carney Hazel C. , England James J. , Hodgin E. Clay , Whiteley Herbert E. , Adkison Daniel L. , Sundberg John P.
Published: May 2011

Papillomavirus infection was confirmed in 2 Persian cats with sessile hyperkeratotic skin lesions. Skin lesions were not typical papillomas as found in other species. Papillomavirus virions were demonstrated in negative stain preparations of homogenized tissue and within nuclei of cells in the stratum granulosum. Papillomavirus group-specific antigens were detected within nuclei corresponding to those containing virions. Attempts to transmit this disease to other cats or propagate the virus in tissue cultures were unsuccessful. A 7.8-kilobase DNA molecule was present in low-stringency Southern blots using a bovine papillomavirus type 1 cloned DNA probe. In reverse Southern blots, the cat papillomavirus hybridized under conditions of low stringency with all papillomavirus genomes tested. Combined with limited restriction endonuclease restriction mapping, the above information indicates that the feline cutaneous papillomavirus is a unique virus type and thus expands the list of hosts known to be infected by papillomaviruses.
Diagnosis of Bovine Viral Diarrhea Virus Infection using Monoclonal Antibodies
Authors: Vickers Mary L. , Minocha Harish C.
Published: May 2011

The monoclonal antibody (MAb) D89 against bovine viral diarrhea virus (BVDV) was used in conjunction with fluorescein-conjugated anti-mouse immunoglobulin in an indirect fluorescent antibody (IFA) procedure on frozen tissue sections and cell culture. During the 2-year study, BVDV was isolated from specimens submitted in 460 cases. The D89 Mab detected all but 2 BVDV isolates, both cytopathic. In 316 of the cases in which BVD virus was detected by IFA, specimens were inoculated on bovine turbinate cells and examined for BVDV antigens at 3–5, 10, and 20 days postinoculation. The BVDV was detected in 238/316 cases (75%) after 3–5 days incubation. The remainder were not detected until 10 or 20 days postinoculation. Virus isolation was enhanced in the early test if plates were centrifuged at the time of inoculation. Results suggest that D89 monoclonal antibody is a suitable diagnostic reagent for the detection of BVDV isolated from diagnostic specimens.

The D89 MAb can be used for the detection of BVDV in both cell culture and tissues. Combination of D89 with another BVDV MAb (C 17) did not improve the ability to detect BVDV in tissues compared to using D89 only, and the combined Mab's resulted in an increase in nonspecific fluorescence when used on tissues. Although pooling of different BVDV monoclonal antibodies may be necessary to detect all strains of BVDV in cell culture, pooling should be used with caution on tissues.

Early detection of BVDV in cell culture by this IFA procedure permits faster confirmation of BVDV diagnosis when compared to the usual routine testing for noncytopathic BVDV at termination of first passage in cell culture.
Evaluation of Four Commercial Anaerobic Systems for Identification of Eubacterium Suis
Authors: Walker Richard L. , Greene Russell T. , Gerig Thomas M.
Published: May 2011

Four commercial anaerobic systems (CASs) were evaluated for usefulness in identification of Eubacterium suis. Twelve strains were evaluated in each system in triplicate, and results were interpreted independently by 5 individuals. Statistically significant differences (P < 0.01) due to strain variation and reader interpretation accounted for discrepancies encountered. The reactivity, repeatability, and unique profiles generated made both CAS-1 and CAS-2 suitable adjuncts for identification of E. suis when colony morphology and Gram reaction were considered. Limited reactivity in CAS-3 limited its use as an aid in identification. Variability in test observations and the large number of numerical profiles generated precluded use of CAS-4.
Mycoplasma Iowae Species-Specific DNA Probe
Authors: Zhao Shaohua , Yamamoto Richard
Published: May 2011

A Mycoplasma iowae (MI) species-specific DNA probe (designated pMI-2) of 6.0 kbp (kilobase pairs) was isolated from an MI strain I-695 genomic library prepared in plasmid pUC8 and Escherichia coli strain JM83. When labeled with [32]P by nick translation, the probe hybridized in dot blot assays with 6 reference strains and 8 field isolates of MI but not with 16 other known species of avian mycoplasmas. The pMI-2 probe detected a minimum of 1.5 ng of MI strain I-695 chromosomal DNA. Under identical conditions of hybridization, the probe did not hybridize with a high concentration (200 ng) of M. gallisepticum or M. synoviae chromosomal DNA.
Detection of IgM Antibodies against Canine Distemper Virus in Dog and Mink Sera Employing Enzyme-Linked Immunosorbent Assay (ELISA)
Authors: Blixenkrone-Moller Merete , Pedersen Ib Rode , Appel Max J. , Griot Christian
Published: May 2011

An enzyme-linked immunosorbent assay (ELISA) for the detection of IgM antibodies against canine distemper virus (CDV) in canine and mink serum is described. The diagnostic potential of this technique was evaluated by analyzing sera from natural or experimental infections in dog and mink and negative control sera. These results were compared with results obtained in the developed CDV IgG ELISA and in the virus neutralization test. The IgM test, which requires only a single serum specimen, is a useful method for diagnosing current or recent CDV infections in dog and mink.
Neospora-Like Encephalomyelitis in a Calf: Pathology, Ultrastructure, and Immunoreactivity
Authors: Barr Bradd C. , Conrad Patricia A. , Dubey J. P. , Anderson Mark L.
Published: May 2011

Protozoal encephalomyelitis was diagnosed in a 3-day-old calf that was stunted, weak, and recumbent. Grossly, the calf had contracted tendons in the forelegs, a slightly domed skull, a porencephalic cyst in the cerebellum, ulcerative esophagitis, and abomasitis. Histologically, there was a multifocal nonsuppurative encephalomyelitis with clusters of protozoal tachyzoites and numerous protozoal cysts. The porencephalic cyst and gastrointestinal lesions appeared to be unrelated to the protozoal infection and were suggestive of a concurrent bovine virus diarrhea infection. A few groups of protozoal tachyzoites and numerous tissue cysts were found in neuropile, particularily in neurons of the spinal cord. By light microscopy, smaller tissue cysts were found in the brain (majority from 14 to 20 pm) than in the spinal cord (majority from 20 to 48 pm). The cyst walls ranged in thickness from < 1 pm to a maximum of 2 pm wide. Bradyzoites contained PAS-positive slender bradyzoites (5–8 × 1–2 μm). Tissue cysts reacted positively to anti-Neospora caninum sera; but unlike N. caninum, they were positive to 2 of 4 antisera against Toxoplasma gondii and to antisera to H. hammondi. Ultrastructurally, tissue cysts closely resembled a Neospora-like organism, including the finding of intemeuronal protozoal cysts, thick cyst walls, a lack of micropores in the bradyzoites, and the presence of numerous micronemes oriented perpendicular to the pellicle. Ultrastructural features in the calf protozoan that have not been reported for N. caninum in dogs included the presence of numerous tubulovesicular structures in the cyst ground substance and bradyzoite vesicles that contained small vesicular structures and short, flat membrane segments. The differences in antigenic reactivity and the minor morphologic differences between this bovine protozoan and N. caninum may reflect variations of a single organism dependent on factors such as the hosts species infected, the tissue infective stage studied, etc., or may indicate protozoal species/strain differences. The results also demonstrate antigenic cross-reactivity between this bovine apicomplexan, N. caninum, and T. gondii.
Isolation and Characterization of Streptococcrcs Suis Capsular Types 9-22
Authors: Gottschalk Marcelo , Higgins Robert , Jacques Mario , Beaudoin Marc , Henrichsen Jorgen
Published: May 2011

The incidence and biochemical patterns of Streptococcus suis capsular types 9-22 are presented. Of 148 untypeable (with types 1-8 antisera) isolates of S. suis recovered from diseased pigs, 10% were not capsulated. Of the remaining 134 isolates, only 53% belonged to capsular types 9-22; capsular types 22 and 9 were the most prevalent, representing 19% and 13%, respectively. Capsular type 15 (de Moor's group T Strep tococcus) is reported here for the first time in North America since it was described in 1963 in Europe. Of 188 untypeable isolates recovered from clinically healthy pigs, 25% were noncapsulated. Of the remaining 141 isolates, 90% belonged to the new capsular types, and 87% were identified as 1 of 4 types: 17, 18, 19, and 21. Capsular types 12 and 20 were not detected among the Canadian isolates. Almost half of strains were arginine dihydrolase-negative, and 45% fermented mannitol, which is seldom a positive test with capsular types 1–8. Although some strains were negative with salicin or trehalose, none were negative for both sugars. Only 54% of isolates tested with 1 rapid multitest system were correctly identified as S. suis. A tentative biochemical profile that might be used with a microplate identification system is also presented. Biochemical identification using the conventional system instead of the rapid multitest system is preferable.
Comparison of Seroagglutination, ELISA, and Indirect Fluorescent Antibody Staining for the Detection of K99, K88, and 987P Pilus Antigens of Escherichia Coli
Authors: Mullaney Christine D. , Francis David H. , Willgohs JoAnn A.
Published: May 2011

Seroagglutination (SAT), enzyme-linked immunosorbent assay (ELISA), and indirect fluorescent antibody staining tests (IFAT) were compared for reliability in the detection of pilus antigens K99, K88, and 987P of Escherichia coli. Test sensitivities were compared using mixtures of piliated bacteria of several strains diluted to a constant optical density with a nonpiliated strain. Relative sensitivities and specificities of the 3 tests were also compared using 55 E. coli strains that had previously been serotyped and characterized for pilus genes by DNA probe. Although specificity was not a serious problem with any of the tests, the SAT was relatively nonsensitive. The IFAT showed the greatest sensitivity of the 3 tests in detecting K88, K99, and 987P E. coli.
A Capture-Enzyme Immunoassay for Rapid Diagnosis of Transmissible Gastroenteritis Virus
Authors: Lu Wei , Osorio Fernando A. , Rhodes Marvin B. , Moxley Rodney A.
Published: May 2011

Two enzyme immunoassays (EIA) were developed for the detection of swine transmissible gastroenteritis virus (TGEV) antigens. The 2 EIAs used the same detecting system, a monoclonal antibody conjugated to horseradish peroxidase, but used different capture systems including a monoclonal antibody (m-EIA) or a polyclonal antibody (p-EIA). The EIAs were compared with the fluorescent antibody test (FAT) and electron microscopy (EM) for the detection of TGEV in intestinal samples of experimentally inoculated gnotobiotic piglets and of conventional diarrheic pigs submitted for diagnosis.

In the gnotobiotic piglets experimentally inoculated with TGEV, 81.8% (9/11) were positive for TGEV by p-EIA, and 72.7% (8/11) were positive by m-EIA. In comparison, 81.8% (9/11) were positive by FAT and 27.2% (3/11) were positive by EM. Three noninfected controls were negative by all tests. In the diagnostic samples, 86.0% (43/50) were positive by p-EIA, 68.2% (30/44) were positive by m-EIA, 28.6% (14/49) were positive by IFA, and 38.0% (19/50) were positive by EM. The m-EIA had a higher agreement with FAT and EM than did p-EIA.
Reproductive Failure Associated with Leptospira Interrogans Serovar Bratislava Infection of Swine
Authors: Bolin Carole A. , Cassells James A. , Hill Howard T. , Frantz Joseph C. , Nielsen Judith N.
Published: May 2011

Specimens from 17 swine herds experiencing reproductive failure were examined for Leptospira interrogans serovar bratislava. Clinical signs observed in these herds included stillborn pigs, weak neonatal pigs, and abortion. Diagnostic tests used to determine L. interrogans serovar bratislava infection were bacteriologic culture, serologic assays to detect antibodies, and immunofluorescence. Examination of fetal serum for antibodies against serovar bratislava and a fluorescent antibody test were the most practical diagnostic procedures.
Copper Toxicosis in Veal Calves
Authors: Sullivan John M. , Janovitz Evan B. , Robinson Farrel R.
Published: May 2011

Copper toxicosis was diagnosed in 7 veal calves, 10–16 weeks old, from 5 separate farms. All calves died without specific clinical signs, although 4 of the calves were icteric. The calves' dietary rations had been supplemented with various copper-containing hematinics. Peritoneal hemorrhage was reported at postmortem in 2 calves. Microscopic evidence of hepatopathy consisted of hepatocellular degeneration and necrosis, hemorrhage, and fibrosis. Concentrations of copper in livers from intoxicated calves ranged from 277 to 684 ppm and in kidneys from 1.1 to 82.0 ppm. The extent and severity of lesions in livers appeared to correlate with concentrations of copper. Nephrosis was minimal, without evidence of hemoglobinuria.
Isolation of Adenovirus from Lambs with Upper Respiratory Syndrome
Authors: Pommer Jerry , Schamber George
Published: May 2011

The role of viruses in the etiology of recurrent upper respiratory disease in newly weaned lambs was studied during 1984–1985 at the North Dakota Sheep Experiment Station. Serum samples collected from lambs at weaning, from lambs with signs of respiratory disease, and 3 weeks following the onset of clinical signs were tested for antibodies to ovine adenovirus (OAV), respiratory syncytial virus (RSV), and Parainfluenza type-3 virus (PI-3). Virus isolation studies were performed on nasal secretions samples taken at the same time. Parainfluenza type-3 was isolated from 1 of 275 lambs tested, and there was 2.5% overall 4-fold increase in antibody titer to PI-3 during the 2-year study. An adenovirus with a different restriction endonuclease digestion pattern from that of previously reported adenovirus strains in the United States was isolated from 13 of 275 nasal secretions collected from lambs at the time of weaning. There was a 17.6% overall 4-fold increase in seroconversion to the adenovirus isolated from the lambs with clinical disease.
Fumonisin B1 Concentrations in Feeds from 45 Confirmed Equine Leukoencephalomalacia Cases
Authors: Ross P. F. , Rice L. G. , Reagor J. C. , Osweiler G. D. , Wilson T. M. , Nelson H. A. , Owens D. L. , Plattner R. D. , Harlin K. A. , Richard J. L. , Colvin B. M. , Banton M. I.
Published: May 2011

During the fall of 1989 and winter of 1990, numerous reports of equine leukoencephalomalacia (ELEM) occurred from many regions of the United States. Typically, horses were consuming feed partially or entirely composed of corn and/or corn screenings. From October 1989 through May 1990, samples from 55 confirmed or suspected ELEM cases were received at the National Veterinary Services Laboratories, Ames, Iowa, for fumonisin B1 analysis. Samples from 9 cases in 1984–1985 were also obtained. Fumonisin B1, a mycotoxin produced by Fusarium moniliforme, causes ELEM, but little is known of naturally occurring toxic or safe levels in feeds. To determine what levels of fumonisin B1 in feeds are associated with ELEM, 45 selected cases were studied. The fumonisin B1 concentrations ranged from <1 ppm to 126 ppm, with the majority of the samples above 10 ppm. All types of feeds were included: corn, screenings, sweet feeds, and commercially pelleted rations. The length of exposure varied from 7 to >35 days. Horse feed samples not associated with ELEM were also collected and analyzed. None of the nonproblem feed samples contained fumonisin B, levels >8 ppm.
An Immunofluorescence Test to Determine the Occurrence of Type II Collagen in Muscle Biopsies from Cattle with Rectovaginal Constriction
Authors: Dawe Donald L. , Lindl Patricia A. , Wallace Charles E. , Brown John
Published: May 2011

Type II collagen occurs in the muscles of rectovaginal constriction (RVC) affected and carrier cattle but not in normal cattle. Muscle biopsies from known RVC affected and carrier cattle and normal cattle were examined for the presence of Type II collagen using affinity purified goat anti-collagen II serum in a fluorescent antibody test. Type II collagen was consistently found in RVC affected animals (22 of 23 samples score positive). Rectovaginal constriction carrier animals had variable staining for the Type II collagen (25 of 47 samples scored positive). Some positive staining was also observed in the control animals (8 of 34 samples scored positive). Because of the variable occurrence of Type II collagen, the value of fluorescent antibody staining to identify RVC carrier animals is uncertain.
Identification of Immunoglobulin Light Chains in Canine Extramedullary Plasmacytomas by Thioflavine T and Immunohistochemistry
Authors: Brunnert Steven R. , Altman Norman H.
Published: May 2011

Extramedullary plasmacytomas were studied in 29 dogs. The site at which tumors occurred and the age and sex of the dogs were similar to those in previous reports. The skin of the digits, chin, ear, and lip represented the most common (17/29) tumor sites. Males and females were equally represented, and tumors occurred in middle-aged to old dogs (mean age, 9.0 years). A breed predilection was seen in the Cocker Spaniel (n = 7; 24%); Cocker Spaniels represented only 4% (210/4,725) of the submissions during the same period. Tumors were stained with immunohistochemical markers (λ light chain, K light chain) and thioflavine T. Immunoreactivity was limited to either λ or K light chains, consistent with a monoclonal plasma cell population. The majority of tumors expressed λ light chains, consistent with previously reported canine plasma cell dyscrasias. Thioflavine T cytoplasmic fluorescence was seen in the majority (18/29) of plasmacytomas and with inflammatory plasma cells present in control specimens. Other round cell neoplasms (lymphosarcoma, histiocytoma, and mastocytoma) were negative with thioflavine T, indicating that positive staining with thioflavine T was specific for plasma cells (neoplastic and inflammatory). This study confirms by immunohistochemistry that canine extramedullary plasmacytomas disproportionately express λ light chains and establishes thioflavine T staining as a rapid histochemical method for diagnosis of these tumors.
Development and Evaluation of an Enzyme-Linked Immunosorbent Assay for Detection, Typing, and Subtyping of Vesicular Stomatitis Virus
Authors: Alonso Albino , Martins Mauricio A. , da Penha D. Gomes Maria , Allende Rossana , Söndahl Magnus S.
Published: May 2011

An indirect sandwich enzyme-linked immunosorbent assay (ELISA) has been used for vesicular stomatitis virus (VSV) typing using sets of monovalent and polyvalent rabbit/guinea pig antisera for identification of VSV types New Jersey (VNJ) and Indiana (VIND). The VIND polyvalent antiserum (VIND-P) detects any strain of the 3 subtypes of the VIND type (VIND-1, VIND-2, and VIND-3) with the same strong reactivity. It is also possible to subtype the VIND strains using VIND-P rabbit antiserum as capture antibody and monovalent VIND-1, VIND-2, or VIND-3 guinea pig antisera as detector. The ELISA proposed has about 10 times more sensitivity and provides 10% more positive results than does the complement fixation 50% (CF,) test when epithelial samples are tested.
Sensitivity of the Standardized Pseudorabies Virus Neutralization Test Varies with the Test Strain Used
Authors: Scherba Gail , Weigel Ronald M. , Jin Ling , Hall William , Zuckermann Federico A.
Published: May 2011

The effect of altering the strain of the test virus used in the standardized pseudorabies virus neutralization (VN) test on the sensitivity of the assay was evaluated. Comparative VN tests were performed using 4 different strains: the avirulent Bartha parental, the avirulent recombinant Bartha gIIIKa, the moderately virulent Shope (currently used for the VN test at the National Veterinary Services Laboratory, Ames, IA), and the highly virulent P2208 (Funkhauser). A radioimmunoassay and a Western immunoblotting technique were employed to verify the presence of anti-pseudorabies virus (PrV) antibodies in sera. Statistical analysis indicated that replacement of the Shope strain by the Bartha gIIIKa or the P2208 strain resulted in VN titers that were 4.23- and 2.00-fold higher, respectively. Despite these differences, specificity with regard to PrV diagnosis was unaltered. This apparent enhancement of the sensitivity of the PrV VN test would be beneficial for the serologic identification of PrV-infected animals during an eradication effort.
Development of an Immunocytochemical Procedure to Detect Adenoviral Antigens in Chicken Tissues
Authors: Saifuddin Md. , Wilks Colin R. , Birtles Mervyn J.
Published: May 2011

An immunocytochemical technique utilizing an avidin-biotin peroxidase complex was developed to detect viral antigens in various tissues following oral administration of a locally isolated serotype 8 avian adenovirus (AAV) in specific pathogen-free (SPF) chickens. A strong color reaction was obtained with tissues from infected birds that contained a minimal amount of AAV antigens as determined by an indirect enzyme-linked immunosorbent assay. No reaction was detected in sections of tissues obtained from SPF chickens, and the reactivity with infected tissues could be removed by prior absorption of the primary antibody with purified AAV. A group-specific antigen common to the 12 serotypes of AAV was demonstrated by this technique. Because of the high sensitivity and broad-spectrum reactivity, this technique could be useful for studying the pathogenesis and laboratory diagnosis of inclusion body hepatitis caused by several serotypes of AAV.
Patterns of Bovine Dairy Submissions to the California Veterinary Diagnostic Laboratory System
Authors: Peauroi John R. , Case James T. , Hird David W.
Published: May 2011

Dairy cattle submissions to the California Veterinary Diagnostic Laboratory System (CVDLS) were analyzed to determine submitter statistics. Eligible submissions were those received July 1, 1987 through December 31, 1989 for reasons other than regulatory brucellosis serology. A comprehensive list frame of California dairies was constructed from Brucella Ring Test information and served as the comparison population for the study. Analyses were performed based on geographic location, herd size, proximity to a CVDLS laboratory, and frequency of submission. Thirty-nine percent of the 2,490 California dairies in the reference population had submitted specimens 21 time to the CVDLS during the study period. Twenty-three percent of the reference population had submitted 22 times. Specimens were more likely to be submitted from larger herds than smaller herds. Larger dairies also submitted specimens more frequently. Dairies in the northern part of the state were more likely to submit specimens and submitted more frequently than southern herds when herd size was accounted for in the analysis. Mean submission rate (&SD) for the 970 submitting dairies was 1.4 (± 1.8) submissions/year. Forty-six percent of the dairies accounted for 80% of submissions, whereas only 14% of dairies accounted for 50% of all diagnostic dairy submissions.
Detection of Bluetongue Virus Using a cDNA Probe Derived from Genome Segment 4 of Bluetongue Virus Serotype 2
Authors: Chinsangaram Jarasvech , Hammami Salah , Osburn Bennie I.
Published: May 2011

The double-stranded (ds) RNA genome segment 4 of bluetongue virus (BTV) serotype 2 was cloned and used as a serogroup-specific complementary (c) DNA probe for BTV diagnosis. A cDNA representing a 60% copy of genome segment 4 of BTV-2 prototype was produced. The specificity of the cDNA probe was determined by hybridizing this probe to a northern blot of dsRNA (separated by polyacrylamide gel electrophoresis) of plaque-purified BTV-2 prototype. This cDNA probe was then used to hybridize to the RNA samples. Because the probe hybridized to all BTV samples but not to epizootic hemorrhagic disease virus samples, it appears to be a group-specific probe that could be used in BTV diagnosis.
Production and Characterization of Monoclonal Antibodies to Psittacine Beak and Feather Disease Virus
Authors: Ritchie Branson W. , Niagro Frank D. , Latimer Kenneth S. , Steffens W. L. , Pesti Denise , Aron Lorraine , Luketr Phil D.
Published: May 2011

Monoclonal antibodies specific for the virus that causes psittacine beak and feather disease (PBFD) were produced by fusing spleen cells from mice immunized with purified concentrated PBFD virus with mouse myeloma cell line Sp2/0. The resulting hybridomas were tested for reactivity against whole purified virus by an enzyme-linked immunosorbent assay (ELISA) system. Four clones, designated 15H8, 8E3, 11G12, and 2C3, were subcloned by limiting dilution. Isotyping indicated that clone 15H8 was secreting IgG, whereas the remaining clones secreted IgM. The secreted immunoglobulins were characterized by reactivity against purified PBFD virus using immunoblotting procedures, by immunohistochemical staining of virus-induced lesions in infected tissues, and by inhibition of PBFD virus agglutination of cockatoo erythrocytes. Antibodies secreted by clones 15H8 and 8E3 had the strongest activity against purified whole virus. Only immunoglobulin secreted by the clone 15H8 could be used to detect viral antigen in infected tissues. None of the monoclonal antibodies had hemagglutination-inhibition activity.
Aldicarb Toxicosis in a Flock of Sheep
Authors: Dorman David C. , Harlin Karen A. , Haschek Wanda M. , Ross Steven S. , Wisse Carl A. , Meerdink Gavin L.
Published: May 2011

Aldicarb toxicosis was diagnosed in 200 sheep that died suddenly. Carbamate insecticide toxicosis was suspected based on observed clinical signs (hypersalivation, diarrhea, urination, paddling, seizures, miosis, and deaths occurring within 1 hour). Tissue samples were submitted from 4 Columbian ewes for pathologic and analytical evaluation. Severe diffuse pulmonary edema was observed on gross and histologic examination. Inhibition of cholinesterase activity in retina (21.2–68.1% of normal activity, n = 3), brain (40.6–45.6% of normal activity, n = 3), and whole blood (27% of normal activity, n = 1) supported a diagnosis of carbamate toxicosis. Reversal of brain and whole blood cholinesterase activities (reactivation factor > 1.4) following an in vitro 1 hour incubation at 37 C was also consistent with carbamate poisoning. Aldicarb toxicosis was confirmed following its detection in rumen contents at 1.5, 5.5, and 334 ppm using both high-pressure liquid chromatography with UV detection and gas chromatography with nitrogen/phosphorus detection.
Characterization of an Epizootic of Pulmonary Edema in Swine Associated with Fumonisin in Corn Screenings
Authors: Osweiler Gary D. , Ross P. F. , Wilson T. M. , Nelson P. E. , Witte S. T. , Carson T. L. , Rice L. G. , Nelson H. A.
Published: May 2011

In 1989, corn screenings were associated with acute interstitial pulmonary edema, hydrothorax, and death in swine. Attack rate was 5–50%, case fatality rate was 50–90%, and clinical course was 1–2 days. Screenings from farms with pigs affected with pulmonary edema contained 20–330 μg fumonisin B1 per gram. Screenings containing 92 μg fumonisin B1 per gram fed to weanling pigs caused pulmonary edema and death. Sterilized corn inoculated with Fusarium moniliforme and diluted 1:1 with clean corn contained fumonisin B, (17 μg/g) and caused acute pulmonary edema when fed for 5 days. Survivors developed subacute hepatotoxicosis with individual hepatocellular necrosis, hepatomegalocytosis, and increased numbers of mitotic figures. Similar liver lesions occurred in pigs given fumonisin B1 intravenously at 0.8 mg/kg body weight for 14 days.
Isolation of a Cytopathic Virus from Weak Pigs on Farms with a History of Swine Infertility and Respiratory Syndrome
Authors: Yoon In J. , Joo Han S. , Christianson William T. , Kim Hyun S. , Collins James E. , Carlson Jack H. , Dee Scott A.
Published: May 2011

Severe clinical signs of swine infertility and respiratory syndrome (SIRS) of unknown cause were observed in several Minnesota swine farms between November 1990 and March 1991. Forty-five lung samples of weak pigs were collected from 13 swine farms, and virus isolation was attempted using swine alveolar macrophage (SAM) cultures. A cytopathic virus was isolated from 19 lung samples collected from 6 different farms. Four pregnant sows were infected intranasally with a tissue suspension from which virus was isolated, and 4 6-week-old pigs and 2 contact pigs were infected intranasally with 1 of the isolates. The 4 sows farrowed 12 stillborn and 32 normal pigs. Virus was recovered from 10 of 19 pigs examined. Infected 6-week-old pigs were clinically normal except for slightly elevated rectal temperatures and mild respiratory signs. No or mild interstitial pneumonic lesions were observed in inoculated pigs, but the lesion was obvious in the 2 contact pigs. Seroconversion was observed in sows and pigs as measured by indirect fluorescent antibody (IFA). Serologic identification of the isolates was carried out by IFA using reference serum prepared from an experimentally infected sow. A cytoplasmic fluorescence was observed on the SAM monolayers infected with each of the 19 different isolates. Fluorescence was also observed when the monolayers were tested with SIRS virus ATCC VR-2332-infected sow sera. Replication of the isolates was not affected in the medium containing 5-iodo-2'-deoxyuridine but was inhibited by treatment with ether. The isolates were relatively stable at 56 C and did not agglutinate with various erythrocytes tested. These results are similar to those of previous reports, and the isolates, designated as SIRS virus, were the cause of SIRS on the farms investigated.
Evaluation of the Sensitivity and Specificity of Two Diagnostic Tests for Antibodies to Pseudorabies Virus Glycoprotein X
Authors: Weigel Ronald M. , Hall William F. , Scherba Gail , Siegel Arthur M. , Hahn Edwin C. , Lehman James R.
Published: May 2011

The diagnostic performance of 2 enzyme-linked immunosorbent assays (gX-T, gX-H) for antibodies to pseudorabies virus (PRV) glycoprotein X (gX) were evaluated using 311 serum samples from a nonvaccinated quarantined herd. When the standardized virus neutralization (VN) test, which uses the Shope strain (VN Shope), was used as the comparative diagnostic standard, the gX-T test had a 7% false-negative rate and a 52% false-positive rate, and the gX-H test had a 19% false-negative rate and a 19% false-positive rate. When the VN test with a Bartha recombinant strain (VN Bartha gIIIKa) was used as the diagnostic standard, the gX-T test had a 9% false-negative rate and a 26% false-positive rate, and the gX-H test had a 24% false-negative rate and a 11% false-positive rate. Thus, the gX-T test was more sensitive and the gX-H test was more specific. Additional diagnostic tests on 79 serum samples from a noninfected herd did not produce false positives for the gX-H test, but there was an 8% false-positive rate for the gX-T test. Previous studies from our laboratory have demonstrated that VN Bartha gIIIKa has higher sensitivity than VN Shope, without losing specificity, and thus is a better comparative diagnostic standard. When adding a suspect range to the gX-T test, using the same criteria as the suspect range for the gX-H test, the false-positive rate of the gX-T test was reduced to 5% when evaluated versus VN Bartha gIIIKa in the infected herd and to 1% for the PRV-negative herd. However, 18% of the positive samples were classified as suspect (vs. 8% for the gX-H test). In PRV eradication programs, the cost of false negatives is greater than the cost of false positives; thus, the gX-T diagnostic used in this study is of greater diagnostic value.
Foot-and-Mouth Disease Virus Typing by Complement Fixation and Enzyme-Linked Immunosorbent Assay using Monovalent and Polyvalent Antisera
Authors: Alonso Albino , Martins Mauricio A. , Maria da Penha D. Gomes , Allende Rossana , Söndahl Magnus S.
Published: May 2011

An indirect “sandwich” enzyme-linked immunosorbent assay (ELISA) using polyvalent and monovalent antisera was compared with the 50% complement fixation (CF) test for the detection of foot-and-mouth disease (FMD) O, A, and C virus types. ELISA was more sensitive than CF tests when polyvalent antisera were used for detecting the 3 types of virus in epithelial samples, whereas ELISA using monovalent antisera was the least sensitive technique. The ELISA performed with polyvalent antisera was 9 times more sensitive for detecting FMD virus than that with monovalent antisera. However, viral isolation in cell culture was the most sensitive detection system. The combined use of ELISA with polyvalent antisera and cell culture inoculations was the most effective procedure for identifying FMD virus in epithelial samples from the field.
Dog Lymphocyte Cultures Facilitate the Isolation and Growth of Virulent Canine Distemper Virus
Authors: Appel Max J. G. , Pearce-Kelling Susan , Summers Brian A.
Published: May 2011

Optimal conditions for the isolation and growth of virulent canine distemper virus (CDV) in canine thymic and peripheral blood lymphocyte cultures were determined. Peak virus titers were seen from 3 to 6 days postinoculation of lymphocytes and depended on the multiplicity of infection. Dog lymphocytes were at least as susceptible as canine macrophages to infection with virulent CDV. Virus replication in lymphocytes resulted in higher virus titers than in dog lung macrophages. Peripheral blood lymphocytes (PBL) from CDV-immune dogs were as susceptible to CDV as were PBL from susceptible dogs.
Effect of Culture Media and Incubation Temperature on Growth of Selected Strains of Francisella Tularensis
Authors: Payne Marie P. , Morton Rebecca J.
Published: May 2011

The rate and amount of growth of 4 field isolates and reference strain ATCC 6223 of Francisella tularensis were evaluated on isolation media with 2 different agar bases and with different supplements and incubated at 25 C, 35 C, and 42 C. Biochemical reactions on conventional differential media with and without cysteine were evaluated. Two of the field isolates and the reference strain were F. tularensis subspecies tularensis (formerly biovar tularensis or Type A), and 2 isolates were subspecies holarctica (formerly subspecies palaearctica or Type B). Bacto cystine heart blood agar supplemented with 1% hemoglobin, glucose cystine heart blood agar, and brain-heart infusion blood agar supported good growth of all 4 field strains, with the most luxuriant growth occurring on Bacto cystine heart blood agar with hemoglobin. Heart infusion blood agar and trypticase soy blood agar supported growth of the field isolates, although growth was diminished and delayed. Strain 6223 was distinctly fastidious and failed to grow on heart infusion or trypticase soy blood agars. Growth of strain 6223 was best on Bacto cystine heart blood agar with hemoglobin. The agar base did not affect growth unless the supplements became limiting, in which case Bacto agar base generally supported growth better than BiTek agar base. Incubation at 35 C was optimum for all 5 strains. Growth at 42 C was slow, with the greatest decrease in the rate and amount of growth occurring with field isolates of F. tularensis subspecies tularensis. Strain 6223 did not grow at 25 C, and the 4 field isolates grew slowly at the lower temperature. The addition of cysteine did not alter any biochemical reactions with the exception of decreasing the detection time of H2S by subpsecies holarctica.
Evaluation of Commercially Available Antibodies to Cytokeratin Intermediate Filaments and Laminin in Normal Cat Pinna
Authors: Peaston Anne E. , Higgins Robert J. , Naydan Diane K. , Sokol Karen A.
Published: May 2011

The pattern of distribution of cytokeratin (CK) intermediate filaments can be used to characterize subsets of epithelial tissues. The purpose of the study was to examine the CK expression of feline pinna skin. Six normal feline pinnae were routinely processed in formalin. An immunohistochemical method was used to stain the pinnae with 8 commercially available anti-human CK antibodies (Abs) (PKK1, CAM 5.2, UCD 10/ 11, 35BH11, 34BE12, AE1/AE3, MAK 6, A575) and an anti-human laminin Ab. All the CK Abs selectively localized to epithelium except 35BH11, which did not react with any part of the pinna. Some epithelial subsets were identified by their unique staining pattern with CK Abs. Basal cells but not suprabasal cells of the epidermis stained with PKK1; basal but not lumenal cells of apocrine glands stained with 34BE12. Apocrine glands stained with all CK Abs except 35BH11. All epithelial structures were stained with A575. Basal lamina of epithelial and mesenchymal tissues was clearly identified by the anti-laminin Ab. The results indicate that in cat pinna some commercially available anti-human CK Abs selectively stain subsets of epithelium and adnexa. PKK1, 34BE12, and A575 were the CK Abs with the most consistent staining patterns, the other Abs stained more variably from pinna to pinna. The pattern of epithelial and adnexal staining was similar but not identical to that reported for humans.
Forestomach Papillomas in Flaky Skin and Steel-Dickie Mutant Mice
Authors: Sundberg John P. , Kenty George A. , Beamer Wesley G. , Adkison Daniel L.
Published: May 2011

Gastric papillomas were diagnosed in flaky skin ( fsn/fsn) and steel-Dickie ( Sl/Sld) mutant mice but not littermate controls. Both mutants suffer from severe anemia of differing causes. Immunohistochemical screening and Southern blot analyses failed to detect any evidence of a papillomavirus in the gastric lesions. Phenotypic expression of the fsn and Sld mutant genes may play an essential role in the spontaneous development of forestomach papillomas in these mouse mutants.
Hairy Vetch (Vicia Villosa Roth) Poisoning in Cattle: Update and Experimental Induction of Disease
Authors: Panciera Roger J. , Mosier Derek A. , Ritchey Jerry W.
Published: May 2011

Hairy vetch poisoning (vetch-associated disease) of cattle is a generalized disease characterized pathologically by infiltration of skin and many internal organs by monocytes, lymphocytes, plasma cells, and often eosinophils and multinucleated giant cells and clinically by dermatitis, pruritis, often diarrhea, wasting, and high mortality. The disease was experimentally reproduced in an adult Angus female that had recovered from the natural disease 1 year earlier. She developed dermatitis on the 11th day of vetch feeding, and despite withdrawal from the vetch diet on the 12th day, death occurred 24 days after first day of vetch feeding. The cow developed lymphocytosis and hyperproteinemia. The results of other hematologic evaluations, blood chemical profiles, urinalysis, and cutaneous hypersensitivity tests using vetch lectin were normal. Lymphocyte blastogenesis studies with vetch lectin were not interpretable. Necropsy revealed gross lesions characteristic of the disease in the skin, heart, kidney, adrenal, and lymphoid tissues. Microscopically there was typical cellular infiltration in those organs and in the thyroid, liver, pancreas, salivary and mammary glands, urinary bladder, corpus luteum, and cerebral meninges. Cutaneous apocrine gland necrosis was present. The inflammatory reaction has qualities of a type-IV hypersensitivity reaction. Hypersensitivity may occur when constituents of the ingested plant are absorbed and act as antigens that sensitize lymphocytes and evoke the multisystemic granulomatous inflammatory response that characterizes the disease. Alternatively, vetch lectin may directly activate T lymphocytes to initiate the cellular response. Vetch-like diseases have been associated with a variety of diets that did not contain hairy vetch. The gross and histopathologic lesions of the vetch-associated and the vetch-like diseases are not mimicked in quality and distribution by any other disease.
Arsenic Concentrations in Tissues and Body Fluids of Dogs on Chronic Low-Level Dietary Sodium Arsenite
Authors: Neiger Regg D. , Osweiler Gary D.
Published: May 2011

Twenty-four female Beagle dogs, 7–8 months old, were assigned to 4 groups. Control, low-dosage, medium-dosage, and high-dosage groups were offered 0, 1, 2, and 4 mg of sodium arsenite per kilogram of body weight per day (mg/kg/day), respectively, in their feed (equivalent to 0.0, 33.4, 66.7, and 133.4 μg/g in feed). On day 59, the dosage was doubled for the rest of the experiment, which ended on day 183. In general, arsenic concentrations in tissues and body fluids reflected arsenic levels in feed. Arsenic caused a dose-related decrease in food intake. Statistically significant differences in blood, liver, and kidney arsenic were detected, in most cases, between the 2 higher dosage groups and controls. The greatest differences in arsenic concentrations between groups were present in urine and hair. Results indicate that urine and hair would be the most useful specimens for chemical analysis when attempting to confirm low-level dietary inorganic arsenic exposure or poisoning.