Antigenic relationship of non-serotype 1 turkey infectious bursal disease viruses from the United States and United Kingdom

Cross-neutralization tests showed that non-serotype 1 infectious bursal disease viruses originating from turkeys in the United States and the United Kingdom belong to the same serotype. It is proposed that this serotype be designated serotype 2.     

Anticoccidial efficacy of diclazuril against recent field isolates of Eimeria from turkey farms in the United States.

In a series of laboratory tests, diclazuril was evaluated for efficacy against Eimeria adenoeides, E. meleagrimitis, E. gallopavonis, and a mixture of the three species. Four isolates of each of the species were tested. When given at 0.5, 1.0, and 1.5 ppm in the feed, diclazuril was highly efficacious against all three species and against mixtures of the three, as judged by protection against mortality from coccidiosis, reduction in droppings scores, and improvement of weight gains compared with unmedicated controls. When diclazuril was given at 1.0 ppm, the improvement in droppings scores and weight gains was better than when 0.5 ppm of diclazuril was given. Increasing the dosage to 1.5 ppm did not appear to offer any consistent or significant improvement over 1.0 ppm.     

Antigenic relationship among field isolates of Tritrichomonas foetus from cattle

Analysis of protein and antigen profiles of Tritrichomonas foetus isolates from cattle from 5 western states was accomplished by sodium dodecyl sulfate polyacrylamide-gel electrophoresis, immunoblot, immunoprecipitation, and fluorography techniques. Total protein profiles of all isolates were compared by Coomassie brilliant blue staining of T foetus protein samples prepared by 4 protein-extraction methods. Antigenic tritrichomonas proteins were identified by immunoblot assay with polyclonal bovine or rabbit anti-T foetus serum. Additionally, [14C]glucosamine-labeled T foetus was used for total and antigenic glycoprotein analyses. Detectable differences in the composition of total proteins or antigenic tritrichomonal proteins were not observed among all isolates. However, intensity differences in some antigenic protein bands were apparent. Bovine and rabbit sera from immunized animals possessed antibodies to the same antigenic tritrichomonal proteins. Each T foetus isolate contained 4 to 7 molecular weight size classes of glycoprotein, which were labeled by [14C]glucosamine; however, only 3 to 4 glycoproteins were identified as antigens by bovine or rabbit antiserum.     

Characterization of turkey coronavirus from turkey poults with acute enteritis.

The present study was to characterize turkey coronavirus associated with turkey poult enteritis and mortality. Intestinal contents or intestines from affected turkey poults and inoculated turkey embryos contained coronaviruses as revealed by electron microscopy or were positive for turkey coronavirus by immunofluorescent antibody assay. Sucrose density gradient ultracentrifugation of the virus-containing intestinal homogenate yielded two opalescent bands corresponding to the buoyant densities of 1.14-1.15 and 1.18-1.20 g/ml, respectively. Coronaviral particles from intestinal contents or the sucrose density gradient preparation were mainly spherical in shape and had envelope and central depression. They were surrounded by a fringe of regularly spaced petal-shaped projections attached to the particles by a short stalk. Purified viruses hemagglutinated rabbit erythrocytes with a titer of 16. Major protein bands of purified viruses analyzed by SDS-PAGE were located at 200, 100-110, 50-60, and 30-35 kDa. The patterns of protein bands were consistent with those of Minnesota or Quebec turkey coronavirus isolates. A 568 bp nucleotide fragment of turkey coronavirus spike protein gene was amplified from RNA of inoculated turkey embryo intestine or purified virus. Sequence analysis of the 568 bp PCR product revealed high degree of identity with the corresponding spike protein gene sequence of human and bovine coronaviruses. The results indicated that turkey coronavirus was associated with turkey poults with acute enteritis.     

Antigenic characterization of Anaplasma marginale isolates from different regions of Brazil

Antigenic characterization of A. marginale isolates has contributed to identifying the presence of common and restricts epitopes of major surface proteins (MSPs). The data may improve vaccine development to protect against A. marginale isolates from different regions. Brazilian A. marginale isolates were characterized antigenically by Western blot with monoclonal antibodies (MAbs) against MSPs and rabbit anti-MSP-4 from Florida strain. Six A. marginale isolates from MS, MG (AUFV1), SP, PR-L1, PR-HV, RS and Florida strain were tested with ANA22B1 to MSP-1a, AMR36A6 to MSP-1b, ANAF19E2 to MSP-2, AMG75C1 and AMG76B2 to MSP-3 and ANAF16C1 to MSP-5. ANA22B1 recognized MSP-1a epitope in all A. marginale isolates, and reacted with polypeptides of different size ranging 46-105kDa. MSP2 was not detected in MS and SP isolates by ANAF19E2, and only PR-L1 and MG (AUFV1) isolates reacted with MAbs which recognize MSP3 epitope. MSP4 and MSP5 were detected in all A. marginale isolates analyzed. The results revealed conservation of MSP-1a and MSP-5 epitopes among all Brazilian isolates, and showed antigenic variability to MSP-1b, MSP-2 and MSP-3 proteins, agreeing with recent data about the genetic diversity found in the polimorphic multigene family responsible for these proteins.     

Characterization of bovine coronavirus isolates/from eight different states in the USA.

Bovine coronavirus isolates from eight different states of the USA were compared for their antigenic properties and susceptibility to hygromycin B. Antigenic differences were observed among the isolates in a one-way hemagglutination-inhibition (HI) test using a polyclonal antiserum against the Mebus bovine coronavirus isolate. Differences were observed on isoelectric focusing among viral proteins with isoelectric points between 4.45-4.65. Most of the BCV isolates were susceptible to hygromycin B (0.5 mM) whereas a few hygromycin B resistant isolates were also found.     

Serologic classification of two ovine adenovirus isolates from the central United States

Two ovine adenovirus (OAV) strains (RTS-42 and RTS-151), isolated from lambs in the central United States, were compared using 2-way cross-neutralization tests with the 6 recognized OAV species, 9 bovine adenovirus species, and 4 porcine species. Virus RTS-42 was identified as OAV type 5, confirming previous results. Virus RTS-151 was identified as OAV type 6, although the serologic crossing was largely one-sided.     

Comparative investigation on different turkey rhinotracheitis (TRT) virus isolates from different countries.

The present investigation was carried out to compare the antigenic relationship between TRT virus isolates from different countries. The obtained results showed that all virus isolates shared similar physiochemical properties. In virus neutralisation tests marked two way cross reactions between BUT 1 = 8544 (England), STG 761/88 and STG 854/88 (Germany) could be detected. On the other hand VCO 3 isolate (France) showed only partial reaction. Also the SDS-poly acrylamide gel electrophoresis (SDS-PAGE) profiles of three TRT viruses (one from England and two from Germany) were very similar, while the VCO 3 strain from France showed some variation.     

Prevalence and geographic distribution of Fanconi syndrome in Basenjis in the United States

A survey was conducted to ascertain the prevalence of Fanconi syndrome in Basenjis and to determine in which geographic regions the greatest number of affected dogs resided. A thousand questionnaires were distributed nationally, and 624 (62%) were returned. Through this survey, prevalence, geographic distribution, and breeder involvement were successfully correlated with the overall association of the disease with the Basenji breed. Ten percent (96/959) of all Basenjis involved in the survey had Fanconi syndrome. Half (50%; 48/96) of the Basenjis affected were between 4 and 8 years old. Seventy-six percent (44/58) of owners of Basenjis with Fanconi syndrome were breeding their dogs, and 93% (52/56) had owned other Basenjis before the survey was conducted. Females outnumbered males (3:1) in frequency of the disease. This ratio reflected the higher breeder participation in the survey, rather than being a true gender predilection for the disease.     

Prevalence of capsular serotypes among Staphylococcus aureus isolates from cows with mastitis in the United States

Development of an appropriate Staphylococcus aureus vaccine for bovine mastitis has eluded researchers for decades. The ability of S. aureus to form a protective exopolysaccharide capsule has posed a major obstacle because of the multiple serotypes and the poor immune response elicited by exopolysaccharides. This study characterized S. aureus serotypes isolated from cases of bovine mastitis obtained from veterinary diagnostic laboratories that service 44% of the dairy cattle in the United States. Major milk producing areas of the northeast, north central, Pacific coast and southwest were proportionately represented. Sub-samples of mastitic milk that contained S. aureus were frozen and sent to our laboratory for strain serotyping. The only other regional serotyping of S. aureus from bovine mastitis to date was done in France. The primary serotypes found were types 5 (51%) and 8 (18%) and 31% were non-typeable. In the current study, serotype 5 accounted for 18% of the isolates and serotype 8 for 23%. More importantly 59% of the isolates were not typeable with either type 5 or 8 antisera. These data indicate that S. aureus vaccines employing serotypes 5 and 8 would only be marginally effective in the United States. These data also suggest that development of a S. aureus vaccine for bovine mastitis should take into account regional variation in S. aureus serotypes.     

Pathogenicity of turkey coronavirus in turkeys and chickens

We designed this study to compare the replication potential of turkey coronavirus (TCV) and its effect in chickens and turkeys and to study the effect of singleand combined infection of turkey poults with TCV and astrovirus. We studied the pathogenicity of TCV in experimentally inoculated turkey poults and chickens by observing the dinical signs and gross lesions. Two trials were conducted with 1-day-old and 4-wk-old specific-pathogen-free turkey poults and chickens. One-day-old turkey poults developed diarrhea at 48 hr postinoculation. Poults euthanatized at 3, 5, and 7 days postinoculation had flaccid, pale, and thin-walled intestines with watery contents. The 4-wk-old turkeys had no clinical signs or gross lesions. One-day-old and 4-wk-old chicks developed no clinical signs or gross lesions although the TCV was detected in gut contents of the birds throughout the experimental period (14 days). In another experiment, mean plasma D-xylose concentrations in 3-day-old turkey poults inoculated with TCV, turkey astrovirus, or a combination of both viruses were significantly lower than in the uninoculated controls.     

Serotyping of Mannheimia (Pasteurella) haemolytica isolates from the upper Midwest United States.

Mannheimia (Pasteurella) haemolytica biotype A serotype1 (A1) is the primary bacterial agent responsible for the clinical signs and pathophysiologic events in bovine pneumonic pasteurellosis. The goal of this study was to determine the prevalence of other serotypes of M. haemolytica biotype A organisms obtained from the upper Midwest diagnostic laboratories. A total of 147 M. haemolytica isolates were collected from Minnesota, South Dakota, and Michigan. Isolates were tested against M. haemolytica antisera obtained from the National Animal Disease Center, Ames, Iowa. Results indicated that M. haemolytica serotype 1 represented approximately 60%, serotype 6 represented 26%, and serotype 2 represented 7% of the total examined isolates. In addition, 7% of the isolates were serotype 9, 11, or untypable. This finding suggests that M. haemolytica serotypes other than serotype 1 can be isolated from the lung lesions of diseased cattle and seem to be capable of causing the pathologic changes observed in the lung with pneumonic pasteurellosis.     

Serotypes of previously unclassified isolates of Erysipelothrix rhusiopathiae from swine in the United States and Puerto Rico

Serotypes of 46 previously unclassified isolates of Erysipelothrix rhusiopathiae from porcine tissues in the United States and serotypes of 31 isolates of the organism from porcine tissues received from Puerto Rico were determined. The 46 isolates from the United States were classified in serotype 21. Four isolates (from Georgia, Minnesota, Ohio, and Oklahoma) were tested and found to be pathogenic for swine. Serotypes 1 (subtypes 1a and 1b), 2, 5, 6, and 21 were found in porcine tissues from Puerto Rico. The relative frequency of the various serotypes was similar to that previously reported in the United States.     

The relationship of pathogenicity to the growth of Pasteurella multocida serotype 3,4 isolates in normal turkey plasma

The percent mortality (M%) caused by various isolates of Pasteurella multocida serotypes 3,4 in turkeys challenged with these organisms was significantly associated with the growth curve when these organisms were grown in normal turkey plasma. The organisms that lysed the most caused the least mortality. In turn, the longer it took for an organism to reach the lowest point on its growth curve, the lower the M%. The highest point on the growth curve and the time that it took to reach that point were analyzed in normal and heat-treated plasma (HTP). The isolates with the maximum growth had the highest M%. The isolates that reached their maximum growth faster also had the greatest M%.     

Comparison of growth rates of Tritrichomonas foetus isolates from various geographic regions using three different culture media

The growth rates of 16 isolates of Tritrichomonas foetus from three distinct geographic regions were investigated in modified Diamond's medium, liver infusion broth medium and a commercially available culture kit. While some differences in growth characteristics were detected for different isolates and in the three different media, all isolates grew. Trichomonads reached peak concentrations from an initial concentration of 10(4) trichomonads/ml on Days 2, 3 and 4 in modified Diamond's medium, on Days 2-6 (excluding CAPTF102) in the commercial culture kit and on Days 2-7 in liver infusion broth medium. Viable parasites were detectable for longer periods in liver infusion broth medium and the commercial culture kit than in Diamond's medium. Peak concentrations for isolates tended to be higher in modified Diamond's medium than in liver infusion broth medium or the commercial culture kit. Results show that these three media are suitable for the growth of all 16 T. foetus isolates from three continents and suggest that these media could be used effectively throughout the world.     

Antigenic characterisation of virus isolates from vaccinated dogs dying of rabies

Four rabies virus isolates from dogs that succumbed to rabies infection in Nigeria within one year of anti-rabies vaccination were characterised by monoclonal antibodies (MAbs). The samples were screened for rabies and rabies-related viral antigens by the indirect fluorescent antibody test, performed with MAb 502-2, which recognises the nucleocapsid (NC) protein of all known Lyssaviruses and with MAb 422-5 which identifies African rabies-related viruses. All four canine virus isolates displayed positive fluorescence with MAb 502-2 and were negative with MAb 422-5. In the anti-NC MAb characterisation with a panel of 34 additional MAbs, all isolates displayed positive staining with 32 of the MAbs, were negative with MAb 102-27 and all displayed poor immunofluorescence with MAb 377-7. On the basis of reactivity with a panel of 40 anti-glycoprotein (G) MAbs the isolates were separated into four distinct viral subtypes. None of these canine isolates was identified as the common attenuated Flury LEP rabies strain used for domestic animal vaccination and none resembled other previously characterised rabies viruses from Nigeria.     

Detection of turkey enteric coronavirus by enzyme-linked immunosorbent assay and differentiation from other coronaviruses

A double-antibody ELISA for the detection of coronaviruses in intestinal contents from turkey poults with diarrhea was developed. Antibodies were raised in rabbits and guinea pigs against a Minnesota isolate of turkey enteric coronavirus (TCV) propagated in embryonating turkey eggs and were purified by density-gradient centrifugation. The specificity of antisera was confirmed by hemagglutination-inhibition and immunoelectron microscopy. Absorption of anti-TCV hyperimmune sera with egg extracts or egg ovalbumin and the use of different dilution and blocking buffers influenced the sensitivity and specificity of the ELISA. Reciprocal cross-reactivity was detected among turkey, chicken, bovine, and murine coronaviruses. Antisera to the transmissible gastroenteritis virus of swine, the rabbit enteric coronavirus, or the human coronavirus strain 299E failed to react with TCV. The TCV cross-reacted only moderately with the avian infectious bronchitis virus and the hemagglutinating encephalomyelitis virus of swine. Investigations with samples from 47 commercial turkey flocks in Quebec with episodes of transmissible enteritis revealed that the ELISA was more sensitive than was electron microscopy for detection of TCV.