Experimental infection of wildebeest with the herpesvirus of infectious bovine rhinotracheitis/infectious pustular vulvovaginitis.

Intravaginal inoculation of a wildebeest (Connochaetes taurinus) with a wildebeest strain of the infectious bovine rhinotracheitis/infectious pustular vulvovaginitis herpesvirus induced only mild vulvovaginitis. The same virus did not produce any disease in another wildebeest exposed intranasally. A wildebeest bull which was inoculated by preputial instillation developed mild posthitis. The virus was reisolated only from the sites of inoculation. A carrier state was initiated in a wildebeest inoculated only once, intravaginally. The presence of this virus in the various secretions is a potential source for venereal transmission.     

Improved Sensitivity of the IPV/IBR Virus-Serum Neutralization Test

The serum neutralization (SN) test is still the most important method for the demonstration of infectious pustular vulvovaginitis/infectious bovine rhinotracheitis (IPV/IBR) antibodies. However, several authors have reported a relatively low sensitivity of the SN test, titers often being very low.     

The pathogenicity of bovine strains of foot and mouth disease virus for impala and wildebeest.

Impala (Aepyceros melampus) and wildebeest (Connochaetes taurinus) were infected with bovine strains of foot and mouth disease virus by intradermolingual inoculation. No clinical signs developed in the impala but mild atypical lesions developed in the tongues of the wildebeest with generalized spread to one foot in two of the eight animals exposed. All the impala but only some of the wildebeest developed viraemia. No virus could be isolated from any tissues in either species after the 7th day following virus inoculation. Immune response occurred in both species. A field survey revealed few animals of either species with significant antibody titers and no virus 'carriers' were found.     

Epidemiology and eradication of infectious bovine rhinotracheitis/infectious pustular vulvovaginitis (IBR/IPV) virus in Finland

Background  

Infectious bovine rhinotracheitis/infectious pustular vulvovaginitis (IBR/IPV) is a significant disease among domestic and wild cattle. The BHV-1 infection was first detected in Finland in 1970; presumably it was imported in 1968. The infection reappeared in the large-scale bulk-tank milk surveillances which started in 1990, and was eradicated in 1994. Our aim is to describe the epidemiology of this infection in Finland, and its eradication.     

Transmission of IBR/IPV virus in bovine semen: A case report

The transmission of IBR/IPV virus in imported semen is reported. Some of the inseminated animals showed seroconversion and, in accordance with Swiss law, had to be eliminated. To avoid such cases in international sperm exchange, methods of detecting IBR/IPV virus need to be improved. In the longer term, AI centres must be established in which all bovine stock is seronegative for IBR/IPV.     

Neutralizing Antibodies to Bovine Herpesvirus 1 in Reindeer

Serum samples from cattle and reindeer in Lapland were examined for neutralizing antibodies to the IBR/IPV virus. All the bovine sera tested were negative. The reindeer sera were tested using 2 different virus neutralization methods differing in the serum-virus incubation time prior to inoculation into tissue culture tubes. 12.6 % of the samples tested with a preincubation of 1 h at 37°C were positive, whereas 23 % of those tested with a preincubation time of 24 h at 37°C were positive. The fairly high prevalence of antibodies to IBR/IPV in the reindeer population in Finland indicates the occurrence of the IBR/IPV virus or a closely related cross-reacting herpesvirus.     

Effect of interferons on the replication of alcelaphine herpesvirus-1 of malignant catarrhal fever

Four isolates of alcelaphine herpesvirus-1 of malignant catarrhal fever (MCF) were tested for their inducibility of and sensitivity to various interferons. Viral isolates from an Indian gaur (Bos gaurus), a greater kudu (Tragelaphus strepsiceros) and two wildebeest (Connochaetes gnou) calves did not induce measurable interferon (IFN) in bovine fetal kidney cells. However, these low passages of each virus were all highly cell-associated and viral replication was inhibited at these passages by IFN at 14 IFN units/0.05 ml recovered from NDV-infected MDBK cells and at 7.6 IFN units/0.05 ml of IFN from NDV-infected bovine macrophages. The herpesvirus from the Indian gaur and greater kudu and high passages (greater than 50) of the cell-free WC-11 strain of alcelaphine herpesvirus-1 also were inhibited in their replication by recombinant IFN of bovine and human origins as determined by a fluorescent focus unit (FFU) reduction assay. The concentrations of IFN required to produce a 50% reduction in herpesvirus-produced FFU ranged between 6.4 and 480 IFN units. These findings promote the use of IFN as part of the regimens of treatment of captive endangered ruminant species with clinical MCF.     

Hydrolysis-resynthesis equilibrium of the lysine-15--alanine-16 peptide bond in bovine trypsin inhibitor (Kunitz).

Catalytic amounts of bovine beta-trypsin, bovine alpha-chymotrypsin and porcine plasmin establish a true thermodynamic equilibrium between virgin (I) (reactive site Lys15-Ala16 peptide bond intact) and modified (I) (this bond hydrolyzed) bovine trypsin/kallikrein inhibitor (Kunitz). The very slow reaction rates for attaining equilibrium are pH-dependent and differ for different enzymes. Optimal rates are for beta-trypsin at pH 3.75, for alpha-chymotrypsin at pH 5.5, and for plasmin at pH 5.0. Under conditions of optimum pH the equilibrium is reached with the highest rate by plasmin. In 10(-5)M inhibitor solutions the equilibrium concentrations of virgin and modified inhibitor are established by plasmin after almost 300 days starting from either pure virgin or pure modified inhibitor. Thus, the hydrolysis constant KHyd = [I]/[I] is determined to be 0.33 at pH 5.0. In spite of many unsuccessful attempts, this demonstrates that the reactive site peptide bond Lys15-Ala16 in the bovine trypsin inhibitor (Kunitz) can be hydrolyzed by catalytic amounts of endopeptidase. It further confirms that the hydrolyzed Lys15-Ala16 peptide bond in modified inhibitor is subject to thermodynamic control resynthesis.     

Intestinal trypsin can significantly modify antigenic properties of polioviruses: implications for the use of inactivated poliovirus vaccine.

It was recently reported that the intestinal protease trypsin cleaves in vitro the VP1 protein of type 3 poliovirus at antigenic site 1 (J. P. Icenogle, P. D. Minor, M. Ferguson, and J. M. Hogle, J. Virol. 60:297-301, 1986). We found that incubation of purified or crude type 3 poliovirus preparations with specimens of human intestinal fluid brings about a similar change in the virion structure. Sera from children immunized solely with the regular inactivated poliovirus vaccine (IPV) neutralized trypsin-cleaved Sabin 3 virus poorly, if at all, despite moderate levels of antibodies to the corresponding intact virus. Sera containing very high titers of the intact virus also neutralized the trypsin-cleaved virus but at a relatively weaker capacity. Most sera from older persons who may have been exposed to a natural poliovirus infection before the introduction of the poliovirus vaccines as well as sera from children infected with type 3 poliovirus during the recent outbreak in Finland were able to neutralize the trypsin-cleaved type 3 polioviruses. Serum specimens collected 1 month after a single dose of live poliovirus vaccine from children previously immunized with IPV were able to neutralize the trypsin-cleaved virus as well. During natural infection and after live poliovirus vaccine administration polioviruses are exposed to proteolytic enzymes in the gut. Our results may offer an alternative explanation for the relatively weak mucosal immunity obtained with IPV. Improvement of IPV preparations by incorporation of trypsin-treated type 3 polioviruses in the vaccine should be studied.     

Epidemiologic and pathologic aspects of an epizootic of malignant catarrhal fever in exotic hoofstock

An epizootic of malignant catarrhal fever (MCF) occurred at the Los Angeles Zoological Park which resulted in the deaths of four exotic ungulates. The source of infection was considered to be a newly purchased wildebeest bull (Connochaetes taurinus taurinus) that had been negative for antibody to MCF virus by an indirect immunofluorescent test. The need to re-evaluate regulations for the transportation and housing of young wildebeest is emphasized by this MCF outbreak. The diagnostic technology now available for identifying asymptomatic carriers of MCF virus and the present understanding of the behavior and pathogenesis of this highly cell-associated herpesvirus in exotic ruminants should provide a basis for the prevention and control of MCF in zoological parks.     

Tuberculosis in Tanzanian wildlife

Bovine tuberculosis, caused by Mycobacterium bovis, is a pathogen of growing concern in free-ranging wildlife in Africa, but little is known about the disease in Tanzanian wildlife. Here, we report the infection status of Mycobacterium bovis in a range of wildlife species sampled from protected areas in northern Tanzania. M. bovis was isolated from 11.1% (2/18) migratory wildebeest (Connochaetes taurinus) and 11.1% (1/9) topi (Damaliscus lunatus) sampled systematically in 2000 during a meat cropping program in the Serengeti ecosystem, and from one wildebeest and one lesser kudu (Tragelaphus imberbis) killed by sport hunters adjacent to Tarangire National Park. A tuberculosis antibody enzyme immunoassay (EIA) was used to screen serum samples collected from 184 Serengeti lions (Panthera leo) and 19 lions from Ngorongoro Crater sampled between 1985 and 2000. Samples from 212 ungulates collected throughout the protected area network between 1998 and 2001 also were tested by EIA. Serological assays detected antibodies to M. bovis in 4% of Serengeti lions; one positive lion was sampled in 1984. Antibodies were detected in one of 17 (6%) buffalo (Syncerus caffer) in Tarangire and one of 41 (2%) wildebeest in the Serengeti. This study confirms for the first time the presence of bovine tuberculosis in wildlife of northern Tanzania, but further investigation is required to assess the impact on wildlife populations and the role of different wildlife species in maintenance and transmission.     

Effect of simultaneous administration of betamethasone and triiodothyronine (T3) on the development of functional pulmonary maturation in fetal rabbit

Recent experimental evidence suggests that a combination of glucocorticoid and thyroid hormone may be more effective than either hormone alone in accelerating morphologic as well as biochemical mammalian fetal lung maturation. We have demonstrated that IM administration of T3 to the rabbit doe is associated with enhanced functional fetal lung maturation. We investigated the effect of simultaneous administration of T3 and betamethasone on the development of functional fetal lung maturation and the duration of survival after premature delivery. On day 25 and 26 of pregnancy, T3 (175 micrograms/kg/dose) betamethasone (85 micrograms/kg/dose), T3 plus betamethasone or the appropriate amount of the vehicles were injected. The functional fetal pulmonary maturity and the duration of survival after premature delivery were assessed on day 27 of gestation. Although enhanced functional fetal lung maturation was observed after T3 or betamethasone administration, there was no additive effect after simultaneous administration of both. The duration of survival on premature delivery was enhanced in betamethasone but not T3 or T3 plus betamethasone group when compared to control. Further animal experimentation seems necessary before a clinical trial of T3 plus betamethasone therapy is considered.     

Assessing introgressive hybridization between blue wildebeest (<Emphasis Type="Italic">Connochaetes taurinus</Emphasis>) and black wildebeest (<Emphasis Type="Italic">Connochaetes gnou</Emphasis>) from South Africa

Introgressive hybridization poses a threat to the genetic integrity of black wildebeest (Connochaetes gnou) and blue wildebeest (Connochaetes taurinus) populations in South Africa. Black wildebeest is endemic to South Africa and was driven to near extinction in the early 1900s due to habitat destruction, hunting pressure and disease outbreaks. Blue wildebeest on the other hand are widely distributed in southern and east Africa. In South Africa the natural distribution ranges of both species overlap, however, extensive translocation of black wildebeest outside of its normal distribution range in South Africa have led to potential hybridization between the two species. The molecular identification of pure and admixed populations is necessary to design viable and sustainable conservation strategies, since phenotypic evidence of hybridization is inconclusive after successive generations of backcrossing. The aim of this study was to assess levels of hybridization in wildebeest using both species-specific and cross-species microsatellite markers. Black wildebeest (157) and blue wildebeest (122) from provincial and national parks and private localities were included as reference material, with 180 putative hybrid animals also screened. A molecular marker panel consisting of 13 cross-species and 11 species-specific microsatellite markers was developed. We used a Bayesian clustering model to confirm the uniqueness of blue- and black wildebeest reference groups, assign individuals to each of the two clusters, and determine levels of admixture. Results indicated a clear partition between black wildebeest and blue wildebeest (the average proportions of membership to black wildebeest and blue wildebeest clusters were QI?=?0.994 and QI?=?0.955 respectively). From the putative hybrid samples, only five hybrid individuals were confirmed. However, high levels of linkage disequilibrium were observed in the putative hybrid populations which may indicate historical hybridization. Measures of genetic diversity in the black wildebeest populations were found to be lower than that of the blue wildebeest. The observed lower level of genetic diversity was expected due to the demographic history of the specie. This study will make a significant contribution to inform a national conservation strategy to conserve the genetic integrity of both species.     

The development of genome-wide single nucleotide polymorphisms in blue wildebeest using the DArTseq platform

Blue wildebeest (Connochaetes taurinus taurinus) are economically important antelope that are widely utilised in the South African wildlife industry. However, very few genomic resources are available for blue wildebeest that can assist in breeding management and facilitate research. This study aimed to develop a set of genome-wide single nucleotide polymorphism (SNP) markers for blue wildebeest. The DArTseq genotyping platform, commonly used in polyploid plant species, was selected for SNP discovery. A limited number of published articles have described the use of the DArTseq platform in animals and, therefore, this study also provided a unique opportunity to assess the performance of the DArTseq platform in an animal species. A total of 20,563 SNPs, each located within a 69 bp sequence, were generated. The developed SNP markers had a high average scoring reproducibility (>99%) and a low percentage missing data (~9.21%) compared to other reduced representation sequencing approaches that have been used in animal studies. Furthermore, the number of candidate SNPs per nucleotide position decreased towards the 3′ end of sequence reads, and the ratio of transitions (Ts) to transversions (Tv) remained similar for each read position. These observations indicate that there was no read position bias, such as the identification of false SNPs due to low sequencing quality, towards the tail-end of sequencing reads. The DArTseq platform was also successful in identifying a large number of informative SNPs with desirable polymorphism parameters such as a high minor allele frequency (MAF). The Bos taurus genome was used for the in silico mapping of the marker sequences and a total of 6020 (29.28%) sequences were successfully mapped against the bovine genome. The marker sequences mapped to all of the bovine chromosomes establishing the genome-wide distribution of the SNPs. Moreover, the high observed Ts:Tv ratio (2.84:1) indicate that the DArTseq platform targeted gene-rich regions of the blue wildebeest genome. Finally, functional annotation of the marker sequences revealed a wide range of different putative functions indicating that these SNP markers can be useful in functional gene studies. The DArTseq platform, therefore, represents a high-throughput, robust and cost-effective genotyping platform, which may find adoption in several other African antelope and animal species.     

Alcelaphine Herpesvirus-1 (Malignant Catarrhal Fever Virus) in Wildebeest Placenta: Genetic Variation of ORF50 and A9.5 Alleles

Alcelaphine herpesvirus–1 (AlHV-1), a causative agent of malignant catarrhal fever in cattle, was detected in wildebeest (Connochaetes taurinus) placenta tissue for the first time. Although viral load was low, the finding of viral DNA in over 50% of 94 samples tested lends support to the possibility that placental tissue could play a role in disease transmission and that wildebeest calves are infected in utero. Two viral loci were sequenced to examine variation among virus samples obtained from wildebeest and cattle: the ORF50 gene, encoding the lytic cycle transactivator protein, and the A9.5 gene, encoding a novel polymorphic viral glycoprotein. ORF50 was well conserved with six newly discovered alleles differing at only one or two base positions. In contrast, while only three new A9.5 alleles were discovered, these differed by up to 13% at the nucleotide level and up to 20% at the amino acid level. Structural homology searching performed with the additional A9.5 sequences determined in this study adds power to recent analysis identifying the four-helix bundle cytokine interleukin-4 (IL4) as the major homologue. The majority of MCF virus samples obtained from Tanzanian cattle and wildebeest encoded A9.5 polypeptides identical to the previously characterized A9.5 allele present in the laboratory maintained AlHV-1 C500 strain. This supports the view that AlHV-1 C500 is suitable for the development of a vaccine for wildebeest-associated MCF.     

FIELD IMMOBILIZATION OF YOUNG WILDEBEEST WITH SUCCINYLCHOLINE CHLORIDE

The results of 112 cases of field immobilization of wildebeest, Gorgon taurinus hecki (Neumann), * with succinylcholine chloride are given, and compared with the results given by Talbot and Lamprey (1961), who reported field dose rates of 0.023 mg/lb. body weight as ineffective, 0.028–0.029 mg/lb. as effective, and 0.036 mg/lb. as lethal, when given to adult wildebeest. Doses in the present series were determined empirically in the field and it was found that the youngest age group of wildebeest tried with the drug (49 cases, 6–12 months old) survived 'lethal' doses of 0.036–0.037 mg/lb. Field experience suggested that not only were young wildebeest capable of surviving greater doses of succinylcholine than adults, but there was an absence of secondary complications. Adult animals suffered from regurgitation of ruminal contents and difficulty with breathing.
In the field it proved easier to produce consistent results with young wildebeest, and it is suggested that in testing the possible use of succinylcholine for immobilizing other game animals the effect of the drug on both young and old animals should be compared.
Use of an effective marking method, by branding, followed by field recording of marked animals has shown that six animals out of a total of 87 disappeared shortly after release. The casualty rate associated with the field marking is given.     

Predicted impact of barriers to migration on the Serengeti wildebeest population

The Serengeti wildebeest migration is a rare and spectacular example of a once-common biological phenomenon. A proposed road project threatens to bisect the Serengeti ecosystem and its integrity. The precautionary principle dictates that we consider the possible consequences of a road completely disrupting the migration. We used an existing spatially-explicit simulation model of wildebeest movement and population dynamics to explore how placing a barrier to migration across the proposed route (thus creating two disjoint but mobile subpopulations) might affect the long-term size of the wildebeest population. Our simulation results suggest that a barrier to migration--even without causing habitat loss--could cause the wildebeest population to decline by about a third. The driver of this decline is the effect of habitat fragmentation (even without habitat loss) on the ability of wildebeest to effectively track temporal shifts in high-quality forage resources across the landscape. Given the important role of the wildebeest migration for a number of key ecological processes, these findings have potentially important ramifications for ecosystem biodiversity, structure, and function in the Serengeti.     

Subspecific identity and a comparison of genetic diversity between wild and ex situ wildebeest

The original North American ex situ wildebeest population was believed to originate from the white-bearded wildebeest (Connochaetes taurinus albojubatus), which is both morphologically distinct and geographically separated from the brindled wildebeest (C. t. taurinus). However, after an import of wildebeest into North America in 2001, managers have suspected that white-bearded and brindled wildebeest were mixed in herds at multiple institutions. We sequenced the mitochondrial control region (d-loop) from a portion of the managed North American population and compared our sequences with previously published sequences from wild individuals to determine the subspecific identity and genetic diversity of our ex situ population. We were able to confidently identify C. t. albojubatus as the subspecies identity of the sampled portion of our population. Within our population, haplotype and nucleotide diversity were low (0.169 and 0.001, respectively) with a single common haplotype (H1) containing 41 of the 45 individuals sequenced, while two rare haplotypes (H2 and H3) were derived from three individuals and a single individual, respectively. Nucleotide and haplotype diversity were greater overall in the wild populations compared with our managed population. However, C. t. albojubatus was found to exhibit lower nucleotide diversity in both wild and ex situ populations when compared to other wild subspecies. Though the overall goal of the North American wildebeest population is for public education and not reintroduction, maintaining genetic diversity is vital for the long-term viability of this managed population, which may benefit from periodic supplementation of wild animals.     

Sample-based assessment of the microbial etiology of bovine necrotic vulvovaginitis

A semiquantitative evaluation of potential bacterial pathogens was correlated to the severity of lesions during an outbreak of bovine necrotic vulvovaginitis (BNVV) on an Israeli dairy herd. Bacteriologic examination of 287 vaginal swabs from 104 post-calving heifers showed a highly significant correlation between Porphyromonas levii colony forming unit numbers and the clinical scores of the lesions, when assessed by an ordinal regression statistical model. No such correlation was found for the other bacteria included in the study. Nineteen samples taken for virological examinations resulted negative for bovine herpes viruses 1, 2, 4 and 5. Thus the results of this study substantiate the essential role of P. levii in the etiology of BNVV and indicate that BHV4 is not required as a predisposing factor to the syndrome.     

Developments in the production and quality control of poliovirus vaccines -- historical perspectives.

Using virus grown in monkey kidney cells, Salk and his colleagues developed an inactivated poliovirus vaccine (IPV) in 1952. A large-scale field trial showed the vaccine to be safe and highly immunogenic in children, but soon after the vaccine became generally available in 1955, cases of paralytic disease were reported in recipients. Investigations showed that almost all the cases occurred in children who had received vaccine from one particular manufacturer. Extensive studies attributed the disaster to problems with inactivation. Addition of a Seitz filtration step midway during formalin inactivation and extension of the inactivation period resulted in a safe vaccine. No further paralytic cases were observed following the use of several hundred million doses of this improved vaccine. Thus, IPV was safe and caused a dramatic decline in the incidence of poliomyelitis in countries where it was used. A second generation IPV is produced in fermentors using well-characterized cell strains or continuous cell lines. The major breakthrough in the development of live poliovirus vaccine was the application of tissue culture methods for virus attenuation. By 1959 several candidate live oral poliovirus vaccines (OPV) had been developed. These were clinically tested in millions of individuals and found to be safe and effective. Since the attenuated virus strains developed by Koprowski and Cox were more neurotropic in monkeys than the Sabin strains, only the latter was licensed in the USA in 1961 and endorsed shortly after by the World Health Organization (WHO). The widespread use of Sabin's OPV in many countries hastened the development of International Requirements by WHO for OPV in 1962 to define the criteria that ensured the uniformity of batches produced by different manufacturers. These have been updated continuously in light of new information and quality control procedures. Extensive field trials have shown the risk of OPV associated polio to be less than 0.3 per million doses administered.