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Publications (19)33.9 Total impact

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    ABSTRACT: The isolation, serological classification and growth properties of adenoviruses isolated from fatal cases of haemorrhagic enterocolitis in calves are described. Four viruses, from different submissions, were isolated in cultures of calf testis cells and were identified as adenoviruses by electron microscopy. The four isolates were serologically identical and were classified as bovine adenovirus type 10 in cross-neutralisation tests with other bovine, ovine and porcine adenovirus species. Their growth in the nucleus of infected cells was accompanied by the production of typical adenovirus-associated inclusions. A serological survey to determine the incidence of infection with the virus in cattle in Northern Ireland demonstrated the presence of low levels of neutralising antibodies in 55 per cent of cattle over two years old, although only 8 per cent were positive at a 1/500 dilution of serum.
    The Veterinary record 04/1996; 138(11):250-2. · 1.80 Impact Factor
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    ABSTRACT: Outbreaks of clinical avian encephalomyelitis (AE) which developed after vaccination of 14-week-old birds by the oral route are reported. Mortality during weeks 2 to 5 following vaccination reached 2%. Experimental studies showed that, in contrast to popular opinion, AE vaccine virus given orally can spread to the central nervous system and produce encephalomyelitis (mild). The severity of the vaccine induced lesions was not affected by chicken anaemia virus (CAV) infection 2 weeks before AE vaccination. It is postulated that non-CAV-induced immunosuppression allowed vaccine virus to produce the severe lesions and deaths occurring during the disease outbreaks, and that in one case, Marek's disease virus was the immunosuppressive agent.
    Avian Pathology 10/1994; 23(3):435-45. · 1.73 Impact Factor
  • B M Adair, D Todd, E R McKillop, M S McNulty
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    ABSTRACT: An ELISA test for detection of influenza A virus type-specific antibodies in chicken and turkey sera is described. Antigen was prepared from infected allantoic fluids using an H7N1 virus. Virus particles were disrupted using sodium deoxycholate to release internal antigens and tests were standardised by testing batches of sera from influenza-free birds. A negative antigen was included in the test and was shown to be effective in eliminating the non-specific increase in absorbance values observed with influenza-negative sera from older birds. Sensitivity and group-specificity were demonstrated by infection of chickens and turkeys with influenza subtypes unrelated to the H7N1 virus from which the antigen was prepared, so that only type A specific responses were being detected. The sensitivity was equivalent to the haemagglutination-inhibition test. Antisera to all 13 haemagglutinin subtypes, prepared in chickens, were strongly positive, again highlighting the group reactivity of the test and demonstrating its suitability as a screening test.
    Avian Pathology 08/1989; 18(3):455-63. · 1.73 Impact Factor
  • B M Adair, K Burns, E R McKillop
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    ABSTRACT: Fluorescent antibody (FA) studies with avian reoviruses in chickens, turkeys and ducks are described. Detection of the group-specific antigen by FA test was investigated by titrating a reovirus antiserum on chick embryo liver cell cultures infected with 18 reovirus strains fixed on multitest slides. With 16 of the viruses, test titres were similar, indicating presence of a common antigen. The titre observed with a duck reovirus isolate was considerably lower, suggesting partial cross-reactivity. One virus (Kosters) was not stained. A comparison of the agar gel immuno-diffusion (AGID) test with the FA test on serial dilutions of antiserum demonstrated the greater sensitivity of the FA test. In a survey of chicken and turkey sera for reovirus antibodies by both tests, a higher percentage positive was recorded by immunofluorescence with CS108 virus as antigen. No antibodies to this virus were detected in 46 duck sera but 4 sera were positive for the duck reovirus isolate. Of 100 chicken sera, 19 were positive for duck reovirus and 6 for Kosters virus. No antibodies to either of these viruses were found in turkey sera. The results demonstrate the usefulness of the indirect FA test with multitest slides for avian reovirus serology and indicate the existence of atypical strains with no or partial group antigen reactivity.
    Journal of Comparative Pathology 10/1987; 97(5):495-501. · 1.38 Impact Factor
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    ABSTRACT: Eleven bovine, 19 porcine, and 3 ovine picornaviruses were tested for their ability to grow in the presence of the viral inhibitors 2-(alpha-hydroxy-benzyl)- benzimidazole (HBB) and guanidine-HC1 (GHC1). The nature of the lesions produced by inoculation of newborn mice with these viruses was also investigated. Nine bovine viruses were inhibited by both compounds, and produced skeletal myonecrosis in mice, suggesting similarities to the human coxsackie group B viruses and indicating potential pathogenicity for bovine species. One bovine virus (VH7) was inhibited by GHC1 but not by HBB and caused widespread skeletal muscle damage in mice typical of coxsackie group A viruses. Another bovine virus (F266a) was inhibited only by HBB. None of the porcine or ovine viruses showed significant inhibition by either compound nor produced lesions in mice.
    Archives of Virology 02/1987; 97(1-2):49-59. · 2.03 Impact Factor
  • B M Adair, E R McKillop, B H Coackley
    Australian Veterinary Journal 06/1986; 63(5):162. · 0.92 Impact Factor
  • B M Adair, D Todd, J B McFerran, E R McKillop
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    ABSTRACT: The sensitivities of five serological tests (haemagglutination inhibition, ELISA, serum neutralisation, fluorescent antibody and agar gel immunodiffusion) for detection of Egg Drop Syndrome virus antibody were compared. In experimentally inoculated birds seroconversion was first detected at five days post-inoculation using haemagglutination inhibition, ELISA, serum neutralisation and fluorescent antibody test, and at seven days post-inoculation using agar gel immunodiffusion. Sera from birds experimentally infected with two or more different fowl adenovirus serotypes gave positive reactions in some of these tests, as did a small percentage of haemagglutination inhibition negative field sera. It is concluded that only haemagglutination inhibition or serum neutralisation should be used for detection of infection in commercial birds.
    Avian Pathology 02/1986; 15(4):677-85. · 1.73 Impact Factor
  • B M Adair, D Todd, E R McKillop, K Burns
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    ABSTRACT: Four serological tests i.e. ELISA, serum neutralisation (SN), fluorescent antibody (FA), and agar gel immunodiffusion (AGID) were compared for sensitivity using several criteria, for detection and titration of infectious laryngotracheitis (ILT) virus antibodies in chicken sera. In the ELISA test, sera were tested in parallel on virus positive and negative control antigens with results expressed as positive-negative difference. Non-specific binding was not a problem in this test. SN tests were performed in microtitre plates using chick embryo liver cells, while sera for FA tests were titrated on multispot slides on which were fixed ILT virus-infected chick embryo liver cell cultures. The AGID test was the standard test still widely used for serological diagnosis of ILT. The four tests were compared using (1) sera from experimentally inoculated birds bled regularly at intervals from 4 to 35 days post-inoculation, (2) convalescent sera from a natural outbreak of ILT, and (3) serial dilutions of an ILT positive serum. In all experiments the ELISA test was of slightly greater sensitivity than SN and was comparable to the FA test. In the experimentally infected birds ELISA and FA test detected sero-conversion in more birds at 7 days than SN. In tests with the serially diluted hyperimmune ILT serum, ELISA, FA and SN tests were comparable. SN however was the most useful test for quantification of ILT antibodies. ILT-SN titres in birds were never high, the highest titre recorded in experimental birds and in convalescent sera was 1/48. AGID was found to be less sensitive than ELISA, FA or SN test but was considered useful for detection of antibodies on a flock basis, since, with the convalescent sera AGID detected a significant proportion of positives.
    Avian Pathology 11/1985; 14(4):461-9. · 1.73 Impact Factor
  • B M Adair, E R McKillop, K Burns
    The Veterinary record 10/1985; 117(11):275-6. · 1.80 Impact Factor
  • B M Adair, E R McKillop, J B McFerran
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    ABSTRACT: 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.
    American Journal of Veterinary Research 05/1985; 46(4):945-6. · 1.35 Impact Factor
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    ABSTRACT: Two hundred serum samples from Texel and Texel crossbred sheep (non-indigenous breeds) and 200 from indigenous Northern Ireland breeds (mainly Blackface, Cheviot and Border Leicester crosses) were tested for antibodies to parainfluenza virus types 1, 2 and 3, respiratory syncytial virus, bovine adenovirus (subgroups 1 and 2), influenza type A, maedi-visna virus and bovine virus diarrhoea virus. The percentage of animals with antibodies to parainfluenza virus 3 (50 to 56 per cent) and adenovirus subgroups 1 and 2 (70 to 90 per cent) was comparable in both groups. Infection of sheep with subgroup 2 adenoviruses has not previously been reported. In the case of respiratory syncytial virus and bovine virus diarrhoea virus, the percentage of animals positive was higher in the non-indigenous group (55.5 and 53 per cent, respectively) than in indigenous breeds (18.5 and 11 per cent, respectively). No antibodies were detected to parainfluenza virus 1 or 2, influenza A or maedivisna virus.
    The Veterinary record 11/1984; 115(16):403-6. · 1.80 Impact Factor
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    ABSTRACT: Twelve herds were investigated where outbreaks of clinical Aujeszky's disease had occurred. Clinical Aujeszky's disease was eliminated from all farms following vaccination. After vaccination was stopped in two of the six fattening herds virus was also apparently eradicated, judging from serological examination. These two herds were the smallest of the six fattening farms and size and the throughput of pigs may have contributed to apparent eradication of virus. In two of six breeding farms where controlled vaccination is still practised unvaccinated gilts and boars were seronegative. In this case possible eradication of infection may have resulted from either no excretion or insufficient production of virus from vaccinates to infect susceptible non-vaccinates. It is postulated that a properly controlled and monitored vaccination and culling programme may result in the eradication of disease and perhaps also infection from breeding herds experiencing Aujeszky's disease.
    The Veterinary record 11/1984; 115(14):348-52. · 1.80 Impact Factor
  • B M Adair, E R McKillop, J B McFerran, D Todd
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    ABSTRACT: In double immunodiffusion tests between a bovine subgroup 2 adenovirus (serotype 8) and other mammalian adenoviruses, no group-specific crossing was demonstrated. However, in cross-fluorescent antibody tests (FAT) between bovine subgroup 2 viruses (serotypes 5, 7 and 8) and conventional (non-subgroup 2) adenoviruses from several species (bovine adenovirus serotypes 1 and 2, ovine serotypes 1, 4 and 5, porcine serotype 1, and human serotypes 2 and 5) sharing of antigens was demonstrated. The FAT titres observed when rabbit antisera to conventional adenoviruses were used to stain bovine subgroup 2 viruses were, however, much lower than titres with other non-subgroup 2 viruses. The converse was also true. The crossing was also predominantly one-sided. The low level cross was confirmed using antisera to selected viruses prepared in chickens to exclude interference by possible natural adenovirus infections in the rabbits used to prepare the antisera in the initial experiments.
    Veterinary Microbiology 04/1983; 8(2):121-8. · 3.13 Impact Factor
  • B M Adair, J B McFerran, E R McKillop
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    ABSTRACT: Two adenoviruses (WV419/75 and WV757/75), isolated from lambs in New Zealand were compared using neutralisation tests with the five recognised ovine adenovirus species, NINE bovine and four porcine adenoviruses. WV419/75 did not cross-react with any of the viruses tested and represents a new ovine adenovirus species (OAV-6). WV757/75 cross-reacted with bovine adenovirus type 7 (BAV-7) with a homologous to heterologous titre ratio of 16 in one direction only, and also showed a substantial one-way cross reaction in haemagglutination-inhibition tests (WV757 antiserum inhibiting haemagglutination by BAV-7). There was therefore insufficient distinction from BAV-7 virus to allow designation as a separate species. Fluorescent antibody studies with WV419 and WV757 demonstrated virus inclusions in the nuclei of infected cells. These were stained by antiserum to OAV-4 indicating presence of the mammalian group antigen. Thin section electron microscope studies showed typical adenovirus particles and associated inclusions in cell nuclei. The similarity of the two viruses to the bovine subgroup 2 adenoviruses in several of their properties is discussed.
    Archives of Virology 02/1982; 74(4):269-75. · 2.03 Impact Factor
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    ABSTRACT: Six isolates of rotavirus were made from turkeys and two from chickens. Three of these required trypsin treatment for isolation and serial passage in cell cultures. The remainder were isolated without trypsin treatment. Most of these viruses were isolated in chick embryo liver cell cultures from the faeces of birds aged under 1 week. In six of the eight instances, rotavirus isolation was associated with enteric disturbance, characterised by signs such as diarrhoea, poor or abnormal appetite, abnormally fluid or gaseous intestinal contents or increased mortality. Cross immunofluorescence tests showed that while avian and mammalian rotaviruses shared a common group antigen, the avian viruses were more closely related to each other than to the Nebraska calf rotavirus isolate. On the basis of serum neutralisation tests seven of the eight avian rotaviruses were grouped into three serotypes, with two turkey isolates (Ty1 and Ty3) and a chicken (Ch1) virus being the prototype strains. The remaining virus, Ty2, was intermediate in type between Ty1 and Ch1. Analysis of the RNA of these viruses by polyacrylamide gel electrophoresis showed that they could also be grouped into a number of electropherotypes. The isolates which were serologically distinct were also electrophoretically distinct. Similarly the five isolates which belonged to the Ty3 sero-type were electrophoretically identical. Analysis of the serological and electrophoretic differences suggested that RNA segment 5 may code for a type-specific antigen.
    Avian Pathology 08/1980; 9(3):363-75. · 1.73 Impact Factor
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    ABSTRACT: The isolation of a number of strains of infectious bursal disease (IBD) virus from fowl, turkeys and ducks is described. These isolates could be grouped into two serotypes using the neutralisation test. It is proposed that the cell culture adapted vaccine strain from fowl should be the prototype virus for serotype 1 and that the TY89 isolate from a turkey should be the prototype for serotype 2. The isolates in serotype 2 consisted of an antigenically homogeneous group of viruses from turkeys and fowl. However, within serotype 1, which represented isolates from fowl and ducks, some isolates showed only a 30% cross reaction with the vaccine strain. If cross protection mirrors cross neutralisation, then infection with viruses belonging to serotype 2 or with antigenically distant strains from serotype 1 provides one explanation for the apparent failure of the vaccine on certain sites. However, if cross protection does not mirror cross neutralisation, then a virus from serotype 2 could be used as a heterotypic vaccine for young birds with high levels of maternally derived antibody to serotype 1.
    Avian Pathology 08/1980; 9(3):395-404. · 1.73 Impact Factor
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    ABSTRACT: The biological and physical properties of strain 127 virus, a haemagglutinating virus associated with the egg drop syndrome 1976, are described. Haematoxylin and eosin and immunofluorescent studies demonstrated that virus multiplication took place in the nucleus of cells with production of typical adenovirus inclusions. Thin section electron microscopy showed typical adenovirus particles and associated inclusions accumulating in nuclei. Strain 127 infectivity was stable in monovalent but not divalent cations, and stable to ether treatment and extremes of pH. IDU inhibition indicated presence of DNA. Growth of 127 as evidenced by HA production was better in duck kidney, fibroblast and liver cells, than in fowl cell cultures, while growth in turkey cells was limited to kidney and liver cultures. There was no evidence of growth in a range of mammalian cells. Strain 127 agglutinated erythrocytes from avian but not mammalian species and the haemagglutinin was stable to heating and freezing. There was no crossing in neutralisation or haemagglutination-inhibition tests between 127 and 11 fowl adenoviruses, and no cross-immunofluorescence between 127 and FAV-1. It is concluded that 127 is an avian adenovirus, possibly originating from ducks.
    Avian Pathology 08/1979; 8(3):249-64. · 1.73 Impact Factor
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    ABSTRACT: An adenovirus and a spherical virus 20--24 nm diameter were isolated from ovine faeces. The small virus replicated in the nucleus, and was associated especially with the nucleolus. It haemagglutinated guinea pig and human erythrocytes, was thermostable and required an adenovirus for replication. It is concluded that this represents the first recorded isolate of an ovine AAV.
    Archives of Virology 02/1979; 60(2):171-6. · 2.03 Impact Factor
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    ABSTRACT: A syndrome causing depressed egg production is described. It is characterised either by a failure to attain predicted production targets or by a fall in egg numbers. The depression in production can reach 30% and it may or may not return to normal. For a short period the eggs produced are smaller, lose colour, have poor egg shell strength and many soft shelled eggs are laid. The birds remain apparently healthy and there is a marked age incidence, with most flocks starting this depression in egg production at 29-31 weeks of age. This syndrome has been recently recorded in the Netherlands, but has not been seen before in Northern Ireland. Viruses which agglutinated fowl erythrocytes to very high titres were isolated in chick embryo liver cells from six affected flocks. Three of these isolates were from the oviduct, two from the upper respiratory tract and one from the faeces. These agents are similar to adenoviruses, but were not neutralised by antisera to 11 prototype fowl adenoviruses. In addition, 17 adenoviruses were also isolated from the flocks showing the syndrome described. These isolates fell into five serological types, in addition to nine which could not be typed using antisera to 11 prototype adenoviruses. Investigations of flocks with falls in egg production not conforming to this syndrome yielded five isolates. Six adenoviruses were also isolated from birds with diarrhoea.
    Avian Pathology 02/1978; 7(1):35-47. · 1.73 Impact Factor