Investigation of possible vaccine-induced epizootics of infectious bovine rhinotracheitis, using restriction endonuclease analysis of viral DNA

Viral DNA was extracted from each of 14 modified-live (ML) bovine herpesvirus 1 vaccines, representing all of the ML infectious bovine rhinotracheitis virus (IBRV) vaccines licensed by the US Department of Agriculture for use in cattle. Restriction endonucleases Pst I and Bgl II were used to establish restriction enzyme patterns for the vaccinal viruses. Viral DNA from isolates obtained from 6 field samples of IBRV (1 from Colorado, 1 from West Virginia, 3 from Wisconsin, 1 from South Dakota) were digested with restriction endonucleases, and patterns were compared to evaluate the role of vaccinal virus in these field epizootics of infectious bovine rhinotracheitis. Animals from which field samples were obtained had been vaccinated with ML IBRV vaccine before the epizootic of infectious bovine rhinotracheitis occurred in the herds. In 2 of the 6 field samples, DNA restriction endonuclease analyses patterns from the isolates were indistinguishable from the pattern for the vaccinal viruses used. In the remaining 4 field samples, DNA restriction endonuclease analyses patterns of the IBRV from isolates were different from those of the vaccinal viruses.     

Isolation of caprine herpesvirus type 1 in Spain

Two strains of caprine herpesvirus type 1 (CpHV-1) were isolated after the experimental reactivation of two seropositive goats in Spain. Viral DNA from these isolates was compared with DNA from bovine herpesvirus type 1 and CpHV-1 reference strains by restriction endonuclease analysis. The two Spanish isolates were closely related but could easily be distinguished from each other and from the reference strains.     

A comparison of polypeptides and restriction endonuclease sites of BHV-1 isolates and identification of IPV virus in Japan

Bovine herpesvirus 1 (BHV-1) isolates from respiratory tract and from vagina of bovine in Japan were analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and the DNA restriction endonuclease cleavage pattern, and compared with European BHV-1 strains. Both protein profile and DNA cleavaged pattern of BHV-1 isolates from respiratory tract were the same as those of European infectious bovine rhinotracheitis (IBR) virus, whereas the protein profile and DNA cleavage patterns of one isolate (M1) from vagina was the same as those of the European infectious pustular vulvovaginitis (IPV) virus. The facts indicate that IPV virus has existed in Japan.     

Genetic and serologic analysis of feline cell-associated herpesvirus-induced infection of the urinary tract in conventionally reared cats

The genetic and antigenic nature of feline cell-associated herpesvirus (FeCAHV) was characterized by use of DNA restriction endonuclease analysis, and direct and indirect fluorescent antibody (FA) techniques. Serologic responses of 6 conventionally reared cats with induced FeCAHV urinary tract infection were retrospectively evaluated, using an indirect FA test. The EcoRI, HindIII, and Pst I restriction endonuclease cleavage patterns of FeCAHV DNA were similar to those of bovid herpesvirus 4 (BHV-4; DN599 strain) DNA. Specific fluorescence was observed when FeCAHV-inoculated cell monolayers were reacted with fluorescein-conjugated BHV-4 (DN599 strain) antiserum. Conversely, specific fluorescence was also observed when feline anti-FeCAHV serum and fluorescein-conjugated caprine anti-feline IgG was reacted with BHV-4 (DN599 strain)-infected cell monolayers. At postinoculation week 10, serum antibody titer in cats with FeCAHV-induced urinary tract infection ranged from 1:2,560 to 1:10,240, as measured by use of indirect FA testing. It was concluded that FeCAHV is a member of the BHV-4 group. In addition, the FeCAHV indirect FA test provides a sensitive and specific means of evaluating FeCAHV antibody concentration in exposed cats.     

Restriction endonuclease patterns of bovine herpesvirus type 1 isolated from bovine mammary glands

Restriction endonuclease analysis was used, in conjunction with viral neutralization and growth-curve experiments, to compare a bovine herpesvirus type 1 (BHV-1) isolate, originally obtained from bovine mammary gland lesions, with a standard BHV-1 strain, infectious bovine rhinotracheitis virus. Although differences were not detected by viral neutralization or growth-curve experiments, restriction fragment patterns generated by Bam HI, Eco RI, Hind III, and Hpa I, revealed definite differences between the isolate and the prototype strain. Additionally, Eco RI, Hind III, and Hpa I patterns revealed that the mammary gland isolate had DNA-fragment patterns characteristic of infectious pustular vulvovaginitis strain of BHV-1, type 2b. Seemingly, type-2b isolates, similar to types 1 and 2a, may be capable of causing divergent types of infection of variable severity in cattle.     

A serological comparison of some animal herpesviruses

Bovine herpesvirus 1 (BHV-1) isolates (Cooper-type strain 4975 and Oxford) were compared in neutralization tests with the bovine herpesvirus 4 (BHV-4) isolate (85/16 TV) and the herpesviruses of red deer (D2839/1) and goats (E/CH). Hyperimmune antiserum was prepared in rabbits against the plaque-selected viruses and endpoint and kinetic neutralization test were made. BHV-4 was clearly different from the other four viruses. The closely-related BHV-1 strains were also related in these tests to the red deer herpesvirus. The Oxford strain seemed rather closer antigenically than the Cooper-type strain to the red deer herpesvirus. Antiserum to the caprine herpesvirus failed to neutralize either BHV-1 strain or red deer virus, but antiserum to the Cooper-type and red deer herpesviruses did neutralize caprine virus to a limited extent.     

Vulvovaginitis of goats due to a herpesvirus

Two concurrent outbreaks of genital disease in goats were associated with infection by a herpesvirus that was isolated from vulval and vaginal lesions of affected does. Serum neutralising antibody to the virus was present both in goats with the clinical disease and some unaffected goats. Of 19 goat herds examined only 4 had serum neutralising antibody positive goats with low (5%) to high (60%) incidence of infection. The virus isolate was characterised as a herpesvirus on its physico-chemical and morphological features. It contained DNA and was inactivated at low pH and by treatment with lipid solvents and trypsin. The virus particles were icosahedral, consisting of a nucleocapsid surrounded by an envelope membrane and measured approximately 150 nm in diameter. The virus was serologically related to a New Zealand isolate of caprine herpesvirus (NZ-CpHV), associated with similar genital disease, and was distinct from bovine herpes virus-1 (BHV-1) showing a one way neutralisation pattern.     

Occurrence of caprine herpesvirus (BHV-6) infection in goat population of the GDR

To clarify the occurrence of the caprine herpesvirus (BHV-6) infection in the goat population in the GDR, 175 sera, collected from the agricultural research station of Karl-Marx-Universit?t at Probstheida were tested for the presence of neutralizing antibodies against BHV-6. BHV-6 antibodies were present in 12% of the sera examined. The titer was low. Cross-neutralization of BHV-6 could not be determined with any other bovine herpesvirus. The goat sera tested were free of neutralizing antibodies against BHV-1 and BHV-3. The indirect immunofluorescence antibody test revealed cross-reactivity only between BHV-6 and BHV-1.     

Restriction endonuclease analysis of BHV-1 and BHV-5 strains isolated in Argentina.

The genomes of 10 bovine herpesvirus 1 and 5 strains isolated in Argentina from 1989 to 1994, recovered from animals showing different clinical signs, and two reference strains (Los Angeles and A663) were compared by restriction endonuclease analysis. Four restriction enzymes, HindIII, BamHI, EcoRI and PstI, were used and analysis of the restriction patterns used to assign the isolate to either the BHV-1.1, BHV-1.2 or BHV-5 genotype. There was a correlationship between restriction pattern and clinical signs in six out of ten Argentinian isolates.     

Restriction endonuclease and monoclonal antibody analysis of Brazilian isolates of bovine herpesviruses types 1 and 5

Twelve Brazilian isolates and three reference strains of bovine herpesviruses (BHVs) were subjected to restriction endonuclease analysis (REA) and monoclonal antibody (MAb) analysis. Viral DNA was cleaved with BamHI, BstEII, EcoRI, HindIII and PstI. The monoclonal antibody panel allowed the differentiation between types 1 and 5 viruses, while REA with BstEII and HindIII showed the distinction between BHV-1 and -5 subtypes. Typical 1.1 and 1.2a patterns were observed with two isolates from respiratory disease. An isolate from semen of a clinically healthy bull displayed 1.2b profile, whereas another displayed a clear 5a pattern, which was never reported before. Seven out of nine Brazilian type 5 (BHV-5) isolates displayed REA patterns similar to the Australian BHV-5 strain N569 (BHV-5a), and differing from the Argentinean A663 strain (BHV-5b) virus. Another two BHV-5 isolates, which displayed an unusual MAb pattern of reactivity, showed a BstEII profile different from both reference strains of BHV-5. These two viruses were considered BHV-5 "non-a/non-b" subtype.     

Genetic characterisation of bovine herpesvirus 1 in New Zealand

AIM: To genotype bovine herpesvirus type 1 (BHV-1) isolates from cattle in New Zealand. METHODS: Twenty-eight BHV-1 isolates were collected from clinical samples from cattle over 28 years. They were characterised and compared using restriction endonuclease analysis (REA), and polymerase chain reaction (PCR) and DNA sequencing. RESULTS: Twenty-four isolates were classified as bovine herpesvirus subtype 1.2b (BHV-1.2b) by REA. The remaining four isolates were distinct from the others in REA profiles of one of the major enzymes (HindIII) by which the classification was made. However, these four isolates were closely related to others when the REA profiles of other restriction enzymes were studied, and therefore were regarded as divergent strains of BHV- 1.2b. All BHV-1 isolates were detectable by PCR, and sequence analysis of selected PCR products did not indicate any significant differences between isolates. CONCLUSION: BHV-1.2b appears to be the predominant strain of BHV-1 in cattle in New Zealand. There was no evidence that more virulent strains of BHV-1, e.g. subtype 1.1 and BHV type 5, are, or have been, present in New Zealand. Genetic variations exist among these BHV-1.2b isolates.     

Genetic relatedness of disease-associated field isolates of bovid herpesvirus type 4

Eight field isolates of bovid herpesvirus type 4 (BHV-4) were examined by restriction analysis and Southern blot hybridization with respect to their relatedness to one another and to the BHV-4 prototype strain DN-599. Isolates were obtained from cattle exhibiting a range of disease states including abortion, pneumonia, enteritis, metritis, and vaginal blisters. Initial growth studies of all 9 viruses were performed and revealed that the overall rate of virus growth was slow when compared with that of other herpesviruses. Infection with each virus also resulted in the formation of large fused cells, which in addition to the slow growth rate, indicated that the isolates were of the cytomegalovirus type. Further studies to characterize and compare the various BHV-4 isolates were undertaken by obtaining cell-free virus from infected cell populations. Viral isolates were purified and used as a source of BHV-4 DNA. Purified DNA, representing each of the 8 field isolates and the prototype strain DN-599, were each cleaved with 3 restriction enzymes and were separated by agarose-gel electrophoresis, and the resultant fragment patterns were compared. In general, genomic fragments of the field isolates corresponded to those generated by cleavage of DN-599 DNA, with the exception of the abortion-associated isolate 83-3572. Additional minor differences were also seen between DN-599 DNA and DNA from the other field isolates, but the overall restriction patterns were similar. To confirm that all isolates were members of the BHV-4 type, hybridization studies were performed using DN-599.(ABSTRACT TRUNCATED AT 250 WORDS)     

Restriction endonuclease analysis of BHV-1 and BHV-5 strains isolated in argentina

The genomes of 10 bovine herpesvirus 1 and 5 strains isolated in Argentina from 1989 to 1994, recovered from animals showing different clinical signs, and two reference strains (Los Angeles and A663) were compared by restriction endonuclease analysis. Four restriction enzymes, HindIII, BamHI, EcoRI and PstI, were used and analysis of the restriction patterns used to assign the isolate to either the BHV-1.1, BHV-1.2 or BHV-5 genotype. There was a correlationship between restriction pattern and clinical signs in six out of ten Argentinian isolates.     

Comparison of the herpesviruses of cattle by DNA restriction endonuclease analysis and serologic analysis

Reference strains and field isolates of herpesviruses recovered from cattle in the United States were compared by restriction endonuclease (RE) analysis and the indirect fluorescent antibody test. As a result of these comparisons, 5 major biotypes of bovine herpesvirus (BHV) were defined. These types were (i) infectious bovine rhinotracheitis virus (BHV-1), (ii) bovine herpes mammillitis virus (BHV-2), (iii) malignant catarrhal fever (MCF) virus (herpesvirus alcelaphinae), (iv) the group of slow-growth isolates represented by the prototype strain Movar 33/63 (bovine cytomegalovirus candidate), and (v) the syncytia-forming Pennsylvania 47 strain. Bovine herpesvirus-1 and BHV-2 did not cross-react serologically with any other type of BHV tested. A low, but consistent level of serologic cross-reactivity was detected among MCF virus, the Movar group, and Pennsylvania 47. Several nonsyncytial, slow-growth strains, which were recovered from dissimilar clinical syndromes and were serologically related to Movar 33/63, exhibited similar DNA RE cleavage patterns, confirming their identity as members of a single type. There was no isolate from American domestic cattle similar to the African MCF virus, which has been sporadically isolated from exotic ruminants in the United States. The African MCF virus isolated during a MCF epizootic in a United States zoo exhibited some DNA RE cleavage differences in comparison with the MCF virus world prototype strain WC 11, indicating that strain diversity exists within this biotype.     

Pathogenicity of a caprine herpesvirus.

A herpesvirus isolated from neonatal Angora kids (Capra hircus) with a relatively severe generalized infection was shown to be infective for adult goats as well as for kids. However, the virus lacked pathogenicity for either lambs or calves. Although a nonreciprocating serologic overlap exists between the caprine virus and the antibody to bovine herpesvirus (BHV-1), results of cross immunity tests in calves indicated that the 2 viruses are immunologically distinct. On the basis of these findings, the caprine virus seems to be a specific pathogen of goats. Accordingly, the designation of Herpesvirus caprae or caprine herpesvirus 1 seems taxonomically appropriate.     

DNA restriction enzyme analysis of a bovine herpesvirus 1 strain isolated from encephalitis in Hungary

The DNA of a bovine herpesvirus 1 (BHV-1) strain isolated from calf encephalitis in Hungary was analysed with restriction enzymes. The cleavage pattern of the encephalitis strain Na/67 differed from those of all the other Hungarian BHV-1 isolates investigated so far. The EcoRI and HindIII cleavage patterns of virus strain Na/67 were found to be similar to the patterns of two other encephalitis strains (N569 and A663 from Australia and Argentina, respectively) characterized earlier. Strain Na/67 is the first isolate in Europe which showed the restriction enzyme pattern of BHV-1.3 previously supposed to be characteristic of encephalitis strains.     

Molecular diagnosis of alcelaphine herpesvirus (malignant catarrhal fever) infections by nested amplification of viral DNA in bovine blood buffy coat specimens

A fragment of alcelaphine herpesvirus-1 (AHV-1; malignant catarrhal fever) DNA was subcloned into pUC 18 and sequenced. The subclone hybridized strongly to AHV-1 DNA, weakly to alcelaphine herpesvirus-2 (AHV-2) DNA, and not at all to DNA from bovine herpesvirus-1 (BHV-1; infectious bovine rhinotracheitis [IBR] virus), bovine herpesvirus-2 (BHV-2; bovine herpes mamillitis [BHM] virus), and bovine herpesvirus-4 (BHV-4; isolate DN599). A 2-stage (nested) polymerase chain reaction (PCR) diagnostic test was devised based on a portion of the subcloned AHV-1 DNA sequence. First and second stage amplified AHV-1 DNA targets were 487 and 172 base pairs (bp) in length, respectively. Unique Pvu II and Stu I restriction endonuclease cleavage sites confirmed the identity of amplified AHV-1 DNA. Five AHV-1 and 2 AHV-2 isolates were identically and specifically PCR positive. BHV-1, BHV-2, and BHV-4 viruses were negative by the same procedure. As little as 0.01 TCID50 AHV-1 was detected using the nested amplification procedure. Simple methods of buffy coat isolation from bovine blood were employed to prepare specimens for PCR. An AHV-1-infected calf was PCR positive from 3 to 77 days postinoculation (PI), with rising seroconversion first noted 14 days PI. The AHV-1 DNA sequence was 62% homologous to a portion of the Epstein-Barr virus genome. The nested PCR procedure may improve the viral diagnosis of clinical and subclinical alcelaphine herpesvirus infections.     

Differentiation of vaccine and field strains of bovine herpesvirus type 1 by restriction endonuclease analysis

Bovine herpesvirus type 1 (BHV-1) DNA molecules obtained from a limited number of infected cells were cleaved with a variety of restriction endonucleases. By use of selected DNA fragments in Bgl 1, Pst 1, Pvu 1 and Pvu 11 restriction patterns, one reference, two vaccine and three wild-type strains of BHV-1 were distinguished from one another. The simplified DNA fingerprinting method described here should be most useful, not only to control the genetic stability of BHV-1 vaccines during production, but also to differentiate the vaccine strains from other isolates in clinical cases.     

Bovine herpesvirus-1 (BHV-1) recombinant expressing pseudorabies virus (PrV) glycoproteins B and C induces type 1 immune response in BALB/c mice

Bovine herpesvirus 1 (BHV-1) attached poorly and penetrated into a mouse cell line, BALB 3T3/A31, but a recombinant BHV-1/TF7-6, which expresses pseudorabies virus (PrV) gB and gC genes, did attach and penetrated into cells more efficiently. In this study the gene green fluorescent protein (GFP) has been integrated into genome of BHV-1/TF7-6 and its parental line of BHV-1. When the mouse mesenteries were incubated in vitro and infected with BHV-1/TF7-6/GFP, strong fluorescence was observed while BHV-1/GFP infection hardly demonstrated fluorescence, suggesting that BHV-1 recombinant expressing PrV gB and gC can infect mouse tissue cells more efficiently than the parental BHV-1 does. When BALB/c mice were inoculated with purified BHV-1/TF7-6 or its parental BHV-1, the former induced lower level of anti-BHV-1 immunoglobulin G (IgG) than the latter did. When sub-classes of anti-BHV-1 IgG were analyzed, it was found that mice immunized with BHV-1/TF7-6 or the parental BHV-1 demonstrated the same level of IgG2a. Since anti-BHV-1 IgG1 level was lower in mice inoculated with BHV-1/TF7-6, the IgG2a:IgG1 ratio was higher in BHV-1/TF7-6 inoculated mice than in the parental BHV-1 inoculated ones. These results indicate that BHV-1/TF7-6 induces type 1 predominant immune to BALB/c mice.     

Study of bovine herpesvirus type 1 strains with monoclonal antibodies.

Fourteen strains of bovine herpesvirus type 1 (BHV-1, IBRV) representing all three groups of BHV-1 (BHV-1.1, BHV-1.2, BHV-1.3) were studied by ELISA using 106 monoclonal antibodies (Mabs) produced against BHV-1. On the basis of the ELISA, the Mabs could be divided into three groups. The first group (40 Mabs, 38%) reacted with all strains, the second group (43 Mabs, 41%) with the respiratory and genital strains (BHV-1.1 and BHV-1.2) while the third group (23 Mabs, 22%) only with the respiratory strains. Only 5 out of the antibodies neutralized respiratory and genital strains, and none of them neutralized the encephalitogenic strains (1.3). Three Mabs selected from each of the 3 groups, and the above five neutralizing strains were studied by Western blot. Antibodies of groups 1 and 3, and two neutralizing antibodies bound to a 90k protein (gpIII), whereas members of group 2 and 3 neutralizing antibodies reacted with a 74k and a 130k protein (both gpl). The results indicate that reactivity with monoclonal antibodies is as suitable for the classification of BHV-1 strains as is restriction endonuclease (RE) analysis but it cannot distinguish between subgroups within the groups.