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Wencel P, Smith SH, Couck L, Hellebuyck T, Scott PC, McOrist S. Infection of juvenile falcons (Falco spp.) with intestinal Lawsonia intracellularis. Vet Med Sci 2023; 9:744-747. [PMID: 36639945 PMCID: PMC10029905 DOI: 10.1002/vms3.1063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Intestinal infection of many host species with Lawsonia intracellularis are widely reported. Analyses of infections among carnivorous falcons have not previously been reported. Fifty juvenile captive falcons (Falco spp.) with or without Lawsonia infection were investigated in the United Arab Emirates, including clinical laboratory methods. Fresh intestinal biopsy samples were analysed by microbiological techniques for Lawsonia and other bacteria and by standard parasitological and pathological methods. Lawsonia intracellularis infection was diagnosed by microbiological examination and qPCR in 10 of 50 juvenile falcons at case examination. Seven of these 10 falcons were of normal clinical appearance, and the other three had other contributing factors to ill-thrift. A range of other conditions were noted in 40 case control falcons. This first report of Lawsonia infection in falcons suggests that the agent may have a limited contribution to clinical disease in these birds, including ill-thrift syndromes. This lack of clinical disease association mimics that noted among Lawsonia infections recorded in other avian families.
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Affiliation(s)
- Peter Wencel
- Al Aseefa Falcon Hospital, Dubai, United Arab Emirates
| | - Sionagh H Smith
- Royal (Dick) School of Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Liesbeth Couck
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Tom Hellebuyck
- Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Peter C Scott
- Scolexia Avian and Animal Consultancy Co., Moonee Ponds, Victoria, Australia
| | - Steven McOrist
- Scolexia Avian and Animal Consultancy Co., Moonee Ponds, Victoria, Australia
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2
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Van TTH, Phung C, Anwar A, Wilson TB, Scott PC, Moore RJ. Campylobacter bilis, the second novel Campylobacter species isolated from chickens with Spotty Liver Disease, can cause the disease. Vet Microbiol 2023; 276:109603. [PMID: 36423482 DOI: 10.1016/j.vetmic.2022.109603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/18/2022] [Indexed: 11/21/2022]
Abstract
Spotty Liver Disease (SLD) is a significant disease of commercial layer hens. It can cause up to 10 % flock mortalities and reduce egg production by 25 %. Campylobacter hepaticus has been identified as the main cause of the disease, although it also appears that predisposing factors, such as some form of stress, may increase the likelihood of clinical disease occurring. Recently, a newly identified species, Campylobacter bilis, was isolated from bile samples of clinical SLD affected chickens. To investigate the pathogenic potential of C. bilis two independent isolates were used in infection trials of layer hens. Within 6 days of oral challenge birds developed typical SLD liver lesions, demonstrating that both strains induced SLD. C. bilis could be recovered from all the challenged birds that developed SLD. Thus, each of the steps in Koch's postulates have been fulfilled, confirming that C. bilis is an additional cause of SLD. A PCR method was developed which can specifically detect C. bilis from samples with complex microbiota. The identification of this newly discovered Campylobacter species as a second cause of SLD and the provision of a rapid method to detect the SLD causing bacterium will help with SLD vaccine development and epidemiology, thus assisting in the control of this important disease of poultry.
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Affiliation(s)
- Thi Thu Hao Van
- School of Science, RMIT University, Bundoora West Campus, Bundoora, Victoria, Australia
| | - Canh Phung
- School of Science, RMIT University, Bundoora West Campus, Bundoora, Victoria, Australia
| | - Arif Anwar
- Scolexia Pty Ltd., Moonee Ponds, Victoria, Australia
| | | | - Peter C Scott
- Scolexia Pty Ltd., Moonee Ponds, Victoria, Australia
| | - Robert J Moore
- School of Science, RMIT University, Bundoora West Campus, Bundoora, Victoria, Australia.
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3
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Muralidharan C, Quinteros JA, Anwar A, Wilson TB, Scott PC, Moore RJ, Van TTH. The use of filamentous hemagglutinin adhesin to detect immune responses to Campylobacter hepaticus infections in layer hens. Front Vet Sci 2022; 9:1082358. [PMID: 36619951 PMCID: PMC9811313 DOI: 10.3389/fvets.2022.1082358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Campylobacter hepaticus is the aetiological agent of Spotty Liver Disease (SLD). SLD can cause significant production loss and mortalities among layer hens at and around peak of lay. We previously developed an enzyme linked immunosorbent assay (ELISA), SLD-ELISA1, to detect C. hepaticus specific antibodies from bird sera using C. hepaticus total proteins and sera pre-absorbed with Campylobacter jejuni proteins. The high specificity achieved with SLD-ELISA1 indicated the presence of C. hepaticus specific antibodies in sera of infected birds. However, some of the reagents used in SLD-ELISA1 are time consuming to prepare and difficult to quality control. This understanding led to the search for C. hepaticus specific immunogenic proteins that could be used in recombinant forms as antibody capture antigens in immunoassay design. In this study, an immunoproteomic approach that combined bioinformatics analysis, western blotting, and LC MS/MS protein profiling was used, and a fragment of filamentous hemagglutinin adhesin (FHA), FHA1,628-1,899 with C. hepaticus specific antigenicity was identified. Recombinant FHA1,628-1,899 was used as antigen coating on ELISA plates to capture FHA1,628-1,899 specific antibodies in sera of infected birds. SLD-ELISA2, based on the purified recombinant FHA fragment, is more user-friendly and standardizable than SLD-ELISA1 for screening antibody responses to C. hepaticus exposure in hens. This study is the first report of the use of FHA from a Campylobacter species in immunoassays, and it also opens future research directions to investigate the role of FHA in C. hepaticus pathogenesis and its effectiveness as a vaccine candidate.
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Affiliation(s)
| | | | - Arif Anwar
- Scolexia Pty Ltd., Moonee Ponds, VIC, Australia
| | | | | | - Robert J. Moore
- School of Science, Royal Melbourne Institute of Technology University, Bundoora, VIC, Australia
| | - Thi Thu Hao Van
- School of Science, Royal Melbourne Institute of Technology University, Bundoora, VIC, Australia,*Correspondence: Thi Thu Hao Van ✉
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Muralidharan C, Huang J, Anwar A, Scott PC, Moore RJ, Van TTH. Prevalence of Campylobacter hepaticus specific antibodies among commercial free-range layers in Australia. Front Vet Sci 2022; 9:1058110. [DOI: 10.3389/fvets.2022.1058110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022] Open
Abstract
Spotty liver disease (SLD) caused by Campylobacter hepaticus affects the health and productivity of layer hens and is a disease of concern in poultry. In this study, blood and cloacal swab samples were collected from 709 birds across 11 free-range layer farms from different regions of Australia. The prevalence of C. hepaticus specific antibodies and DNA was assessed using a C. hepaticus specific ELISA and PCR and its correlation with mortalities and changes in egg production was analyzed to better understand the seroprevalence of C. hepaticus in Australian free-range layer farms. C. hepaticus specific antibodies were detected from birds in four of the five farms that had no history of SLD with seroprevalence as high as 41% in one of the farms. Seroprevalence of anti-C. hepaticus antibodies among flocks that had an active or previous SLD outbreak varied between 2 and 64%. C. hepaticus DNA was detected from birds in three farms with no known SLD history and five farms with confirmed SLD outbreaks. A good correlation was observed between the ELISA and PCR results with a Pearson correlation coefficient value of 0.85 (p-value = 0.001). No correlation was observed between the flock size or flock age and ELISA or PCR outcomes, and no significant difference between the seroprevalence of anti-C. hepaticus antibodies among flocks with or without a known history of SLD was established (p = 0.143). This study demonstrates the usefulness of C. hepaticus specific ELISA and PCR in identifying the occurrence of mild or sub-clinical SLD and provides a broader and more complete understanding of SLD epidemiology that will inform future research aimed at the development of methods to control SLD, such as appropriate biosecurity measures, vaccines, and feed additives.
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Van TTH, Lee Nen That LFM, Perera R, Anwar A, Wilson TB, Scott PC, Stanley D, Moore RJ. Spotty liver disease adversely affect the gut microbiota of layers hen. Front Vet Sci 2022; 9:1039774. [PMID: 36387407 PMCID: PMC9650437 DOI: 10.3389/fvets.2022.1039774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/10/2022] [Indexed: 11/27/2022] Open
Abstract
Spotty Liver Disease (SLD) is a serious infectious disease which occurs mainly in laying chickens in free range production systems. SLD outbreaks can increase mortality and decrease egg production of chickens, adversely impact welfare and cause economic hardship for poultry producers. The bacterium Campylobacter hepaticus is the primary cause of the disease. This study aimed to identify the effects of C. hepaticus on chicken gut microbiota and gut structure. Three C. hepaticus strains (HV10T, NSW44L and QLD19L), isolated from different states of Australia, were used in the study. Chickens at 26-weeks post-hatch were orally dosed with one of the C. hepaticus strains (challenged groups) or Brucella broth (unchallenged or control group). Six days after the challenge, birds were necropsied to assess liver damage, and caecal content and tissue samples were collected for histology, microbiology, and 16S rRNA gene amplicon sequencing to characterize the composition of the bacterial microbiota. Strain C. hepaticus NSW44L produced significantly more disease compared to the other C. hepaticus strains and this coincided with more adverse changes observed in the caecal microbiota of the birds challenged with this strain compared to the control group. Microbial diversity determined by Shannon and Simpson alpha diversity indices was lower in the NSW44L challenged groups compared to the control group (p = 0.009 and 0.0233 respectively, at genus level). Short-chain fatty acids (SCFAs) producing bacteria Faecalibacterium, Bifidobacterium and Megamonas were significantly reduced in the challenged groups compared to the unchallenged control group. Although SLD-induction affected the gut microbiota of chickens, their small intestine morphology was not noticeably affected as there were no significant differences in the villus height or ratio of villus height and crypt depth. As gut health plays a pivotal role in the overall health and productivity of chickens, approaches to improve the gut health of the birds during SLD outbreaks such as through diet and keeping the causes of stress to a minimum, may represent significant ways to alleviate the impact of SLD.
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Affiliation(s)
- Thi Thu Hao Van
- School of Science, RMIT University, Bundoora, VIC, Australia
- *Correspondence: Thi Thu Hao Van
| | | | - Rachelle Perera
- School of Science, RMIT University, Bundoora, VIC, Australia
| | - Arif Anwar
- Scolexia Pty Ltd., Moonee Ponds, VIC, Australia
| | | | | | - Dragana Stanley
- Institute for Future Farming Systems, Central Queensland University, Rockhampton, QLD, Australia
| | - Robert J. Moore
- School of Science, RMIT University, Bundoora, VIC, Australia
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McOrist S, Scott PC, Jendza J, Paynter D, Certoma A, Izzard L, Williams DT. Analysis of acidified feed components containing African swine fever virus. Res Vet Sci 2022; 152:248-260. [PMID: 36055134 DOI: 10.1016/j.rvsc.2022.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 07/06/2022] [Accepted: 08/15/2022] [Indexed: 10/15/2022]
Abstract
Mitigation of African swine fever (ASF) virus in contaminated feed materials would assist control activities. Various finely-ground pig feed ingredients (5 cereals, 4 plant proteins, 2 animal proteins, 1 oil, 1 compound) were sprayed and mixed thoroughly with a buffered formic acid formulation (0, 1 or 2% vol/vol) to produce a consistent and durable level of formate (1% or 2%) with consistent acidification of cereal ingredients to less than pH 4. No such acidification was noted in other ingredients. Selected representative feed ingredients were further mixed with infectious ASF virus (106 TCID50) or media alone and incubated for 0, 6, 12, 24, 48, 72 or 168 h. The residual ASF virus at each timepoint was quantified using qPCR and a cell culture based TCID50 assay to determine survivability. Maize, rice bran and compound feed (with or without formate) all reduced infectious ASF virus to levels below the detection threshold of the cell culture assay (101.3 TCID50/mL). A consistent reduction in ASF virus DNA levels was observed by qPCR assay when maize containing ASF virus was mixed with 1% or 2% buffered formic acid. This reduction in viral DNA corresponded to the acidifying pH effect measured. No such reduction in ASF virus DNA levels was noted in non-cereal ingredients containing ASF virus, in which the pH had not been lowered below pH 4 following treatment. Interestingly, residual ASF virus levels in spiked meat/bone meal were greater than control levels, suggesting a buffering effect of that feed ingredient.
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Affiliation(s)
- Steven McOrist
- Scolexia Animal and Avian Health Consultancy, 19 Norwood Crescent, Moonee Ponds, Victoria 3039, Australia.
| | - Peter C Scott
- Scolexia Animal and Avian Health Consultancy, 19 Norwood Crescent, Moonee Ponds, Victoria 3039, Australia
| | - Joshua Jendza
- BASF Lampertheim GmbH, Chemiestraße 22, Lampertheim 68623, Germany
| | - David Paynter
- Regional Laboratory Services, Samaria Road, Benalla, Victoria 3672, Australia
| | - Andrea Certoma
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria 3220, Australia
| | - Leonard Izzard
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria 3220, Australia
| | - David T Williams
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria 3220, Australia
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Abstract
A novel species of Campylobacter was isolated from bile samples of chickens with spotty liver disease in Australia, making it the second novel species isolated from chickens with the disease, after Campylobacter hepaticus was isolated and described in 2016. Six independently derived isolates were obtained. They were Gram-stain-negative, microaerobic, catalase-positive, oxidase-positive and urease-negative. Unlike most other species of the genus Campylobacter, more than half of the tested strains of this novel species hydrolysed hippurate and most of them could not reduce nitrate. Distinct from C. hepaticus, many of the isolates were sensitive to 2,3,5-triphenyltetrazolium chloride (0.04%) and metronidazole (4 mg ml-1), and all strains were sensitive to nalidixic acid. Phylogenetic analysis using 16S rRNA and hsp60 gene sequences demonstrated that the strains formed a robust clade that was clearly distinct from recognized Campylobacter species. Whole genome sequence analysis of the strains showed that the average nucleotide identity and the genome blast distance phylogeny values compared to other Campylobacter species were less than 86 and 66%, respectively, which are below the cut-off values generally recognized for isolates of the same species. The genome of the novel species has a DNA G+C content of 30.6 mol%, while that of C. hepaticus is 27.9 mol%. Electron microscopy showed that the cells were spiral-shaped, with bipolar unsheathed flagella. The protein spectra generated from matrix-assisted laser desorption/ionization time of flight analysis demonstrated that they are different from the most closely related Campylobacter species. These data indicate that the isolates belong to a novel Campylobacter species, for which the name Campylobacter bilis sp. nov. is proposed. The type strain is VicNov18T (=ATCC TSD-231T=NCTC 14611T).
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Affiliation(s)
- Canh Phung
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | | | - Chaitali Dekiwadia
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | - Robert J Moore
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | - Thi Thu Hao Van
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
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Phung C, Wilson TB, Quinteros JA, Scott PC, Moore RJ, Van TTH. Enhancement of Campylobacter hepaticus culturing to facilitate downstream applications. Sci Rep 2021; 11:20802. [PMID: 34675257 PMCID: PMC8531295 DOI: 10.1038/s41598-021-00277-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Campylobacter hepaticus causes Spotty Liver Disease (SLD) in chickens. C. hepaticus is fastidious and slow-growing, presenting difficulties when growing this bacterium for the preparation of bacterin vaccines and experimental disease challenge trials. This study applied genomic analysis and in vitro experiments to develop an enhanced C. hepaticus liquid culture method. In silico analysis of the anabolic pathways encoded by C. hepaticus revealed that the bacterium is unable to biosynthesise L-cysteine, L-lysine and L-arginine. It was found that L-cysteine added to Brucella broth, significantly enhanced the growth of C. hepaticus, but L-lysine or L-arginine addition did not enhance growth. Brucella broth supplemented with L-cysteine (0.4 mM), L-glutamine (4 mM), and sodium pyruvate (10 mM) gave high-density growth of C. hepaticus and resulted in an almost tenfold increase in culture density compared to the growth in Brucella broth alone (log10 = 9.3 vs 8.4 CFU/mL). The type of culture flask used also significantly affected C. hepaticus culture density. An SLD challenge trial demonstrated that C. hepaticus grown in the enhanced culture conditions retained full virulence. The enhanced liquid culture method developed in this study enables the efficient production of bacterial biomass and therefore facilitates further studies of SLD biology and vaccine development.
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Affiliation(s)
- Canh Phung
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | | | | | | | - Robert J Moore
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia.
| | - Thi Thu Hao Van
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
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Quinteros JA, Scott PC, Wilson TB, Anwar AM, Scott T, Muralidharan C, Van TTH, Moore RJ. Isoquinoline alkaloids induce partial protection of laying hens from the impact of Campylobacter hepaticus (spotty liver disease) challenge. Poult Sci 2021; 100:101423. [PMID: 34534853 PMCID: PMC8449056 DOI: 10.1016/j.psj.2021.101423] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 12/26/2022] Open
Abstract
Spotty liver disease (SLD) is a serious condition affecting extensively housed laying hens. The causative bacterium was described in 2015 and characterized in 2016 and named Campylobacter hepaticus. Antibiotics are the only tool currently available to combat SLD. However, antimicrobial resistance has already been detected, so finding therapeutic alternatives is imperative. Isoquinoline alkaloids (IQA), such as sanguinarine and chelerythrine, have been shown to have immunomodulatory effects. It has been hypothesized that IQA could ameliorate some of the deleterious effects of SLD. This study aimed to address that hypothesis in an experimental disease induction model. Birds were fed with diets containing 2 different doses of an IQA containing product, 100 mg of product/kg of feed (0.5 ppm of sanguinarine) and 200 mg of product/kg of feed (1.0 ppm of sanguinarine). Two additional groups remained untreated (a challenged positive control and an unchallenged negative control). After 4 wk of treatment, birds from all groups except the negative control group were exposed to C. hepaticus strain HV10. The IQA treated groups showed a reduction in the number of miliary lesions on the liver surface and reduced lesion scores compared with untreated hens. A significant reduction of egg mass was detected 6 d after exposure to C. hepaticus in the untreated group (P = 0.02). However, there was not a significant drop in egg-mass in the IQA groups, especially those fed with a high dose of IQA (P = 0.93). IQA supplementation did not produce significant changes in intestinal villus height and crypt depth but did result in a significant reduction in the proinflammatory cytokine, interleukin-8, in the blood (P < 0.01). Microbiota analysis showed that IQA treatment did not alter the alpha diversity of the cecal microbiota but did produce changes in the phylogenetic structure, with the higher dose of IQA increasing the Firmicutes/Bacteroidetes ratio. Other minor changes in production indicators included an increase in feed consumption (P < 0.01) and an increase in body weight of the treated hens (P < 0.0001). The present study has demonstrated that IQA confers some protection of chickens from the impact of SLD.
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Affiliation(s)
| | | | | | - Arif M Anwar
- Scolexia Pty Ltd, Moonee Ponds, VIC 3039, Australia
| | - Tyrone Scott
- Scolexia Pty Ltd, Moonee Ponds, VIC 3039, Australia
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Wilson TB, Stevenson G, Crough R, de Araujo J, Fernando N, Anwar A, Scott T, Quinteros JA, Scott PC, Archer MJG. Evaluation of Residues in Hen Eggs After Exposure of Laying Hens to Water Containing Per- and Polyfluoroalkyl Substances. Environ Toxicol Chem 2021; 40:735-743. [PMID: 32274818 DOI: 10.1002/etc.4723] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/04/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) have been used in aqueous film-forming foams used in firefighting, resulting in soil and groundwater contamination and leading to human exposure via animal products grown in contaminated areas. The present study reports the relationship between PFAS intake by hens and the PFAS concentrations in the edible parts of eggs. Laying hens were exposed via drinking water to different concentrations of 4 PFAS compounds (perfluorooctane sulfonate [PFOS], perfluorohexane sulfonate [PFHxS], perfluorooctanoic acid [PFOA], and perfluorohexanoic acid) over 61 d. Egg PFAS residues were assessed for a further 30 d after exposure ceased. The target concentrations of PFAS were 0, 0.3, 3, 30, and 300 µg/L for the treatment groups T1-T5, respectively; and PFAS residues were determined from the eggs collected every second day. There was a linear correlation between the PFAS concentrations in the drinking water of hens and those detected in the egg, which could be useful in estimating PFAS concentrations in the egg by measuring water concentrations. Exposure of hens to drinking water with PFAS concentrations below the Australian Government Department of Health limits (PFOS and PFHxS, 0.07 µg/L; PFOA, 0.56 µg/L), and with no other sources of PFAS exposure, is unlikely to result in egg PFAS concentrations that would exceed the 10% limit set by Food Standards Australia New Zealand for human consumption. Environ Toxicol Chem 2021;40:735-743. © 2020 SETAC.
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Affiliation(s)
| | - Gavin Stevenson
- National Measurement Institute, Lindfield, New South Wales, Australia
| | - Robert Crough
- National Measurement Institute, Lindfield, New South Wales, Australia
| | - Jesuina de Araujo
- National Measurement Institute, Lindfield, New South Wales, Australia
| | | | - Arif Anwar
- Scolexia, Moonee Ponds, Victoria, Australia
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Muralidharan C, Anwar A, Wilson TB, Scott PC, Moore RJ, Van TTH. Development of an enzyme-linked immunosorbent assay for detecting Campylobacter hepaticus specific antibodies in chicken sera - a key tool in Spotty Liver Disease screening and vaccine development. Avian Pathol 2020; 49:658-665. [PMID: 32835491 DOI: 10.1080/03079457.2020.1813252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Spotty Liver Disease (SLD) is an emerging disease of serious concern in the egg production industry, as it causes significant egg loss and mortality in layer hens. The causative agent is a newly identified Gram-negative bacterium, Campylobacter hepaticus, and knowledge about C. hepaticus pathogenesis and the potential for vaccine development is still in its infancy. Current detection methods for SLD, such as PCR and culturing, only detect an active infection and will not give any indication of a past infection from which the bacteria have been cleared. An immunological assay, on the other hand, can provide information on previous infections and therefore is crucial in vaccine development against SLD. In the present study, we have developed the first immunoassay capable of detecting C. hepaticus-specific antibodies present in the sera of infected birds. The assay uses C. hepaticus total protein extract (TPE) as the antigen coating on enzyme-linked immunosorbent assay (ELISA) plates. The cross reactivity of C. hepaticus antibodies with closely related C. jejuni and C. coli antigens was successfully overcome by pre-absorbing the sera using C. jejuni cell extracts. The assay was validated using sera samples from both naturally- and experimentally-infected birds, birds vaccinated with formalin-killed bacteria, and serum samples from SLD-negative birds (control group). The optimized ELISA assay had 95.5% specificity and 97.6% sensitivity. The immunoassay provides a useful tool for monitoring the exposure of poultry flocks to C. hepaticus infection and can be used to direct and support vaccine development. HIGHLIGHTS The first immunoassay developed for Spotty Liver Disease (SLD). A useful method for detecting C. hepaticus-specific antibodies in birds. Highly specific (95.5%) and sensitive (97.6%) assay. A key tool for use in epidemiological studies and vaccine development.
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Affiliation(s)
| | - Arif Anwar
- Scolexia Pty Ltd., Moonee Ponds, Australia
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12
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Phung C, Vezina B, Anwar A, Wilson T, Scott PC, Moore RJ, Van TTH. Campylobacter hepaticus, the Cause of Spotty Liver Disease in Chickens: Transmission and Routes of Infection. Front Vet Sci 2020; 6:505. [PMID: 32010715 PMCID: PMC6974796 DOI: 10.3389/fvets.2019.00505] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 12/20/2019] [Indexed: 01/26/2023] Open
Abstract
The epidemiology of Spotty Liver Disease (SLD) was investigated by assaying 1,840 samples collected from layer chickens and the environment in poultry farms across Australia for the presence of Campylobacter hepaticus, the agent responsible SLD in chickens. A C. hepaticus specific PCR and bacterial culture were used. Results showed that birds could be infected with C. hepaticus up to 8 weeks before clinical SLD was manifested. In addition, birds could be infected long before laying starts, as young as 12 weeks old, but the peak period for SLD outbreaks was when the birds were 26-27 weeks old. Campylobacter hepaticus DNA was detected in motile organisms such as wild birds and rats and so these organisms may be vectors for C. hepaticus dissemination. Moreover, water, soil, mites, flies, and dust samples from SLD infected farms were also found to be PCR-positive for C. hepaticus DNA. However, it still remains to be determined whether these environmental sources carry any viable C. hepaticus. The indications from this study are that environmental sources are a likely transmission source of C. hepaticus. Therefore, biosecurity practices need to be strictly followed to prevent the spread of SLD amongst and between flocks. Also, a rapid, molecular detection method such as PCR should be used as to monitor for C. hepaticus presence in flocks before clinical disease is apparent, and therefore inform the use of biosecurity and therapeutic measures to help prevent SLD outbreaks.
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Affiliation(s)
- Canh Phung
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | - Ben Vezina
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | - Arif Anwar
- Scolexia Pty Ltd., Moonee Ponds, VIC, Australia
| | | | | | - Robert J Moore
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
| | - Thi Thu Hao Van
- School of Science, RMIT University, Bundoora West Campus, Bundoora, VIC, Australia
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Steer-Cope PA, Sandy JR, O'Rourke D, Scott PC, Browning GF, Noormohammadi AH. Vaccination with FAdV-8a induces protection against inclusion body hepatitis caused by homologous and heterologous strains. Avian Pathol 2019; 48:396-405. [PMID: 31042049 DOI: 10.1080/03079457.2019.1612032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Fowl aviadenoviruses (FAdV) are important avian pathogens, responsible for several poultry diseases prevalent worldwide, including inclusion body hepatitis (IBH). FAdV intraspecies cross-protection has been clearly demonstrated, but there is little evidence that any interspecies cross-protection exists. The present study aimed to assess the inter- and intraspecies protection between three FAdV field isolates (FAdV-8a, FAdV-8b, FAdV-11) identified in association with severe IBH outbreaks. Inocula prepared using inactivated plaque-purified virus with adjuvant Montanide™ ISA 71VG, were injected intramuscularly into 3-week-old SPF chickens. At 6-weeks of age, the birds were challenged with 106 TCID50 of homologous or heterologous virus intraperitoneally, and full post mortem examination performed at 4 days post-challenge. Various tissues were examined for gross and histological lesions and assessed for the presence of virus by PCR-HRM. All homologous-type vaccine/challenge groups exhibited protection against IBH lesions with no virus detected in the tissues. Unvaccinated groups challenged with virus showed evidence of FAdV-induced lesions; however, FAdV-8a demonstrated lower pathogenicity compared with FAdV-8b and FAdV-11. In the heterologous-type vaccine/challenge groups, FAdV-8a vaccine was shown to protect against challenge with both FAdV-8b and FAdV-11. FAdV-8a and 8b belong to species E and were therefore anticipated to cross-protect. However, FAdV-11 belongs to species D and therefore cross-protection by FAdV-8a was an uncharacteristic and unique finding of this study. Further research is required to disseminate the molecular basis for the interspecies cross-protection between FAdV-8a and FAdV-11. Nonetheless, the FAdV-8a isolate was shown to have substantial potential as a vaccine candidate in countries where FAdV-8a, 8b or 11 are prevalent.
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Affiliation(s)
- Penelope A Steer-Cope
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne , Werribee , Australia.,Poultry CRC, University of New England , Armidale , Australia
| | - Jeanine R Sandy
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne , Werribee , Australia
| | - Denise O'Rourke
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne , Werribee , Australia
| | - Peter C Scott
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne , Werribee , Australia
| | - Glenn F Browning
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne , Werribee , Australia
| | - Amir H Noormohammadi
- Asia-Pacific Centre for Animal Health, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne , Werribee , Australia.,Poultry CRC, University of New England , Armidale , Australia
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Abstract
Campylobacter hepaticus was recently identified as the aetiological agent of Spotty Liver Disease (SLD). SLD causes significant health and productivity losses in the Australian egg industry and the disease is present in other countries. Following the isolation and characterization of C. hepaticus, molecular tools and refined culturing methods have been developed to identify the pathogen. It is suspected that the application of these tools will lead to identification of the pathogen in many poultry production systems throughout the world. As C. hepaticus has only recently been identified, little is known about the mechanisms of pathogenesis and, hence, new research needs to be directed towards understanding SLD epidemiology and C. hepaticus virulence mechanisms to inform efforts to develop intervention strategies.
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Affiliation(s)
- Robert J Moore
- a School of Science, RMIT University , Bundoora , Australia
| | | | - T T Hao Van
- a School of Science, RMIT University , Bundoora , Australia
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15
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Van TTH, Lacey JA, Vezina B, Phung C, Anwar A, Scott PC, Moore RJ. Survival Mechanisms of Campylobacter hepaticus Identified by Genomic Analysis and Comparative Transcriptomic Analysis of in vivo and in vitro Derived Bacteria. Front Microbiol 2019; 10:107. [PMID: 30804905 PMCID: PMC6371046 DOI: 10.3389/fmicb.2019.00107] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 01/18/2019] [Indexed: 01/01/2023] Open
Abstract
Chickens infected with Campylobacter jejuni or Campylobacter coli are largely asymptomatic, however, infection with the closely related species, Campylobacter hepaticus, can result in Spotty Liver Disease (SLD). C. hepaticus has been detected in the liver, bile, small intestine and caecum of SLD affected chickens. The survival and colonization mechanisms that C. hepaticus uses to colonize chickens remain unknown. In this study, we compared the genome sequences of 14 newly sequenced Australian isolates of C. hepaticus, isolates from outbreaks in the United Kingdom, and reference strains of C. jejuni and C. coli, with the aim of identifying virulence genes associated with SLD. We also carried out global comparative transcriptomic analysis between C. hepaticus recovered from the bile of SLD infected chickens and C. hepaticus grown in vitro. This revealed how the bacteria adapt to proliferate in the challenging host environment in which they are found. Additionally, biochemical experiments confirmed some in silico metabolic predictions. We found that, unlike other Campylobacter sp., C. hepaticus encodes glucose and polyhydroxybutyrate metabolism pathways. This study demonstrated the metabolic plasticity of C. hepaticus, which may contribute to survival in the competitive, nutrient and energy-limited environment of the chicken. Transcriptomic analysis indicated that gene clusters associated with glucose utilization, stress response, hydrogen metabolism, and sialic acid modification may play an important role in the pathogenicity of C. hepaticus. An understanding of the survival and virulence mechanisms that C. hepaticus uses will help to direct the development of effective intervention methods to protect birds from the debilitating effects of SLD.
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Affiliation(s)
- Thi Thu Hao Van
- School of Science, RMIT University, Bundoora, VIC, Australia
| | - Jake A Lacey
- Doherty Department, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Ben Vezina
- School of Science, RMIT University, Bundoora, VIC, Australia
| | - Canh Phung
- School of Science, RMIT University, Bundoora, VIC, Australia
| | - Arif Anwar
- Scolexia Pty Ltd., Moonee Ponds, VIC, Australia
| | | | - Robert J Moore
- School of Science, RMIT University, Bundoora, VIC, Australia
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16
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Van TTH, Gor MC, Anwar A, Scott PC, Moore RJ. Campylobacter hepaticus, the cause of spotty liver disease in chickens, is present throughout the small intestine and caeca of infected birds. Vet Microbiol 2017; 207:226-230. [PMID: 28757028 DOI: 10.1016/j.vetmic.2017.06.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/29/2017] [Accepted: 06/29/2017] [Indexed: 11/29/2022]
Abstract
Spotty liver disease (SLD) causes significant egg production losses and mortality in chickens and is therefore a disease of concern for some sectors of the poultry industry. Although the first reports of the disease came from the United States in the 1950s it is only recently that the organism that causes the disease was identified, isolated, and characterised as a new bacterial species, Campylobacter hepaticus. The first isolations of C. hepaticus were from the livers and bile of SLD affected birds. Isolates could only be recovered from samples that had a monoculture of C. hepaticus in the tissues, as a selective culturing method has not yet been developed. In non-selective growth conditions the slow growing C. hepaticus is quickly outgrown by many other members of the chicken microbiota. Therefore, it is currently not possible to use a culturing approach to evaluate C. hepaticus carriage in tissues, such as the gastrointestinal tract (GIT), that also carry complex microbial populations. As it is suspected that birds become infected via the faecal-oral route it is important that pathogen carriage in the GIT is investigated. In the present study, a specific and sensitive quantitative real-time PCR assay, based on the glycerol kinase gene of C. hepaticus, was developed. The assay facilitated the detection and quantification of C. hepaticus in tissue samples from clinical cases of SLD. It was shown that in infected birds C. hepaticus colonises the small intestine, increasing in abundance from duodenum to ileum, and is at highest levels within the ceaca. C. hepaticus was also readily detected in cloacal swabs, indicating that thecl-oral infection.
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Affiliation(s)
- Thi Thu Hao Van
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia
| | - Mian-Chee Gor
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia
| | - Arif Anwar
- Scolexia Pty. Ltd., Moonee Ponds, Victoria 3039, Australia
| | - Peter C Scott
- Scolexia Pty. Ltd., Moonee Ponds, Victoria 3039, Australia; Poultry Cooperative Research Centre, Armidale, New South Wales 2351, Australia
| | - Robert J Moore
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia; Poultry Cooperative Research Centre, Armidale, New South Wales 2351, Australia.
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17
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Van TTH, Elshagmani E, Gor MC, Anwar A, Scott PC, Moore RJ. Induction of spotty liver disease in layer hens by infection with Campylobacter hepaticus. Vet Microbiol 2017; 199:85-90. [DOI: 10.1016/j.vetmic.2016.12.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/04/2016] [Accepted: 12/27/2016] [Indexed: 11/30/2022]
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18
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Van TTH, Elshagmani E, Gor MC, Scott PC, Moore RJ. Campylobacter hepaticus sp. nov., isolated from chickens with spotty liver disease. Int J Syst Evol Microbiol 2016; 66:4518-4524. [DOI: 10.1099/ijsem.0.001383] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Thi Thu Hao Van
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia
| | | | - Mian Chee Gor
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia
| | - Peter C. Scott
- Scolexia Pty Ltd, Moonee Ponds, Victoria 3039, Australia
- Poultry Cooperative Research Centre, Armidale, New South Wales 2351, Australia
| | - Robert J. Moore
- Poultry Cooperative Research Centre, Armidale, New South Wales 2351, Australia
- School of Science, RMIT University, Bundoora, Victoria 3083, Australia
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19
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Steer PA, Sandy JR, O'Rourke D, Scott PC, Browning GF, Noormohammadi AH. Chronological analysis of gross and histological lesions induced by field strains of fowl adenovirus serotypes 1, 8b and 11 in one-day-old chickens. Avian Pathol 2015; 44:106-13. [PMID: 25609454 DOI: 10.1080/03079457.2015.1007919] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Fowl adenoviruses (FAdVs) cause diseases in domestic chickens, including inclusion body hepatitis (IBH), with immunosuppression believed to play a role in their pathogenesis. To gain a better understanding of the pathogenesis and chronology of disease caused by FAdVs, the gross pathology, histopathology and dissemination of virus were examined at several different time points, after inoculation of one-day-old specific pathogen-free chickens with FAdV-1, FAdV-8b or FAdV-11 via the ocular route. FAdV-8b had a slightly greater virulence than FAdV-11, but both were primary pathogens. The presence and severity of hepatic lesions were used to define the three stages of the disease: incubation (1-3 days post-inoculation, PI), degeneration (4-7 days PI) and convalescence (14 days PI). Both viruses were detected in the liver, kidney, bursa, thymus and gizzard of most birds during the degenerative stage, and persisted in the gizzard into convalescence. The FAdV-1 isolate was found to be apathogenic, but virus was detected in the bursa and/or gizzard of several birds between 2 and 7 days PI. This is the first study examining the chronology of gross and microscopic lesions of pathogenic and apathogenic FAdVs in association with viral presence in multiple tissues. It was concluded that both FAdV-8b and FAdV-11 are primary pathogens, and that these strains may play a role in immunosuppression.
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Affiliation(s)
- Penelope A Steer
- a Poultry CRC , University of New England , Armidale , NSW , Australia
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20
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Scott PC, Wilson TB, Walker C. Serological and growth rate responses to the use of chicken Newcastle disease vaccines in pigeons. Aust Vet J 2013; 91:525-530. [DOI: 10.1111/avj.12127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2013] [Indexed: 11/29/2022]
Affiliation(s)
- PC Scott
- Scolexia Animal & Avian Health; Moonee Ponds Victoria Australia
| | - TB Wilson
- Scolexia Animal & Avian Health; Moonee Ponds Victoria Australia
| | - C Walker
- Melbourne Bird Veterinary Clinic; Scoresby Victoria Australia
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21
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Affiliation(s)
- Christina McCowan
- University of Melbourne Veterinary Clinical Centre; 250 Princes Hwy Werribee Vic. 3030 Australia
- Biosciences Research Division, Department of Primary Industries; Veterinary Diagnostics; 5 Ring Road Bundoora Vic. 3083 Australia
| | - Susan Bibby
- Aviagen ANZ; PO Box 1147 Griffith NSW 2680 Australia
| | - Peter C. Scott
- Asia Pacific Centre for Animal Health; 250 Princes Highway Werribee Vic. 3030 Australia
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22
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Hewson KA, Scott PC, Devlin JM, Ignjatovic J, Noormohammadi AH. The presence of viral subpopulations in an infectious bronchitis virus vaccine with differing pathogenicity--a preliminary study. Vaccine 2012; 30:4190-9. [PMID: 22542436 PMCID: PMC7115607 DOI: 10.1016/j.vaccine.2012.04.054] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 04/13/2012] [Accepted: 04/15/2012] [Indexed: 01/22/2023]
Abstract
There are currently four commercially available vaccines in Australia to protect chickens against infectious bronchitis virus (IBV). Predominantly, IBV causes clinical signs associated with respiratory or kidney disease, which subsequently cause an increase in mortality rate. Three of the current vaccines belong to the same subgroup (subgroup 1), however, the VicS vaccine has been reported to cause an increased vaccinal reaction compared to the other subgroup 1 vaccines. Molecular anomalies detected in VicS suggested the presence of two major subspecies, VicS-v and VicS-del, present in the commercial preparation of VicS. The most notable anomaly is the absence of a 40 bp sequence in the 3'UTR of VicS-del. In this investigation, the two subspecies were isolated and shown to grow independently and to similar titres in embryonated chicken eggs. An in vivo investigation involved 5 groups of 20 chickens each and found that VicS-del grew to a significantly lesser extent in the chicken tissues collected than did VicS-v. The group inoculated with an even ratio of the isolated subspecies scored the most severe clinical signs, with the longest duration. These results indicate the potential for a cooperative, instead of an expected competitive, relationship between VicS-v and VicS-del to infect a host, which is reminiscent of RNA viral quasi-species.
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Affiliation(s)
- Kylie A Hewson
- The University of Melbourne, Veterinary Science, 250 Princes Hwy, Werribee, 3030, Victoria, Australia.
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23
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Abstract
Measurements were made during Shechita (kosher) slaughter of 692 meat chickens, including the behaviour of the birds during the procedure and the times from their removal from the crate, to neck cutting, bleed-out and shackling. Four of 100 birds showed a mild physical response to neck cutting but the others showed no response. Approximately 60 per cent of the birds showed a physical response to touching the eye or eyelid at up to 5 seconds after neck cutting, but by 15 seconds none showed this response. The birds became unable to retain their posture and suffered involuntary muscular contractions at 12 to 15 seconds after neck cutting and had lost approximately 40 per cent of their total blood volume by 30 seconds after neck cutting.
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Affiliation(s)
- J L Barnett
- Animal Welfare Science Centre, Department of Primary Industries, 600 Sneydes Road, Werribee, Victoria 3030, Australia
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24
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Jones JF, Whithear KG, Scott PC, Noormohammadi AH. Duration of Immunity with Mycoplasma synoviae: Comparison of the Live Attenuated Vaccine MS-H (Vaxsafe MS) with Its Wild-Type Parent Strain, 86079/7NS. Avian Dis 2006; 50:228-31. [PMID: 16863072 DOI: 10.1637/7465-103005r.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The duration of protective immunity elicited by the MS-H vaccine was evaluated by experimental challenge of chickens at 15 and 40 wk after eyedrop vaccination. Immunity induced by the parent strain of the vaccine, 86079/7NS, was also investigated for comparison. A serological response to Mycoplasma synoviae was detected in 89% to 100% of MS-H vaccinates and 86079/7NS inoculates at 15, 27, 30, 35, and 40 wk after inoculation. A significantly lower incidence of air-sac lesions and lower air-sac lesion severity were observed in both the MS-H vaccinated and the 86079/7NS inoculated groups, as compared to the unvaccinated controls, after both challenge points. Tracheal mucosal thicknesses in MS-H vaccinates was significantly lower in the upper, lower, and total trachea at 40 wk after vaccination, as compared to the controls. It was demonstrated in this experiment that protective immunity, as determined by protection against experimental challenge, was maintained to at least 40 wk after vaccination.
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Affiliation(s)
- Jillian F Jones
- School of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia
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25
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Jones JF, Whithear KG, Scott PC, Noormohammadi AH. Determination of the Effective Dose of the Live Mycoplasma synoviae Vaccine, Vaxsafe MS (Strain MS-H) by Protection Against Experimental Challenge. Avian Dis 2006; 50:88-91. [PMID: 16617988 DOI: 10.1637/7429-083005r.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The minimum effective dose of the Mycoplasma synoviae-H (MS-H) vaccine was determined through protection against experimental challenge. Chickens were vaccinated by eyedrop with the following doses of a vaccine: 1.2 x 10(5), 2.4 x 10(5) 4.8 x 10(5), 9.6 x 10(5), 1.92 X 10(6), and 3.84 X 10(6) color change units (CCU), then challenged 6 wk after vaccination. Rapid serum agglutination results indicated that 100% of birds receiving an MS-H dose of > or = 4.8 x 10(5) CCU had antibodies to MS and enzyme-linked immunosorbent assay results showed that 60% of birds receiving a dose of 4.8 x 10(5) or 9.6 x 10(5) CCU and 100% of birds receiving a dose of 1.92 x 10(6) or 3.84 x 10(6) had antibodies to MS. At postmortem after challenge, the following parameters were significantly lower in birds vaccinated with an MS-H dose of > or = 4.8 x 10(5) CCU: air sac (AS) lesion severity; incidence of AS lesions; mucosal thicknesses in the upper trachea, middle trachea, and lower trachea (LT); and MS colonization of the LT and AS. It was concluded that an MS-H dose of 4.8 x 10(5) CCU was sufficient to elicit an antibody response in birds, prevent MS colonization in the LT and AS, and protect against AS lesions caused by an experimental MS and infectious bronchitis virus challenge.
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Affiliation(s)
- Jillian F Jones
- School of Veterinary Science, The University of Melbourne, Werribee, Victoria, 3052, Australia
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26
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Jones JF, Whithear KG, Scott PC, Noormohammadi AH. Onset of Immunity with Mycoplasma synoviae: Comparison of the Live Attenuated Vaccine MS-H (Vaxsafe MS) with Its Wild-Type Parent Strain (86079/7NS). Avian Dis 2006; 50:82-7. [PMID: 16617987 DOI: 10.1637/7428-083005r.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The onset of protective immunity with MS-H was determined through experimental challenge and compared with the parent strain 86079/7NS. MS-H vaccinates and 86079/7NS inoculates were challenged at 1, 2, 3, 4, 5, and 6 wk after vaccination, then examined 2 wk after challenge for signs of respiratory disease. Serologic results indicated that 100% of MS-H vaccinates had antibodies to MS by 3 wk after vaccination and 100% of 86079/7NS inoculates were positive by 2 wk after inoculation. From 3 wk after vaccination, MS-H vaccinates had a significantly lower incidence of air sac lesions and, from 4 wk after vaccination, a significantly lower air sac lesion severity. In 86079/7NS-inoculated birds, a significantly lower incidence of air sac lesions was observed from 1 wk after inoculation, and air sac lesion severity was significantly lower than the unvaccinated controls at 3 wk after inoculation. It would appear that, under the conditions of this experiment, protective immunity elicited by MS-H appeared at 4 wk after vaccination, slightly later than the appearance of serum antibody. Although the MS-H vaccine was slower to establish protective immunity than 86079/7NS, there was no significant difference between the two strains by 4 wk after vaccination or inoculation.
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Affiliation(s)
- Jillian F Jones
- School of Veterinary Science, The University of Melbourne, Werribee, Victoria, 3030, Australia
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27
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Affiliation(s)
- H K Brown
- Department of Microbiology and Immunology, University of Melbourne, Victoria
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28
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Scott PC, Markham JF, Whithear KG. Safety and efficacy of two live Pasteurella multocida aro-A mutant vaccines in chickens. Avian Dis 1999; 43:83-8. [PMID: 10216763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Two auxotrophic aro-A mutants of Pasteurella multocida designated PMP1 (serotype 1) and PMP3 (serotype 3) were tested as vaccine candidates to protect chickens against fowl cholera. A reliable intratracheal challenge method was established that resulted in > or = 75% mortality in both specific-pathogen-free chickens and commercial broiler breeders 24 hr after challenge. Dose protection studies indicated that at least 10(6) colony-forming units (CFU) of PMP1 and 10(8) CFU of PMP3 were required to provide complete protection against challenge in all birds. Although high doses of 10(9) CFU of the vaccine strains produced some endotoxinlike reactions, lower but protective dose levels produced no clinical sign or lesion in any chicken. Both vaccine strains provided cross-protection with a heterologous challenge strain PM206 (serotype 4). Future studies will examine the duration of protective immunity induced by the two vaccine candidates, PMP1 and PMP3, and cross-protection against other serovars.
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Affiliation(s)
- P C Scott
- School of Veterinary Science, University of Melbourne, Victoria, Australia
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29
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Markham JF, Morrow CJ, Scott PC, Whithear KG. Safety of a Temperature-Sensitive Clone of Mycoplasma synoviae as a Live Vaccine. Avian Dis 1998. [DOI: 10.2307/1592702] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Markham JF, Scott PC, Whithear KG. Field Evaluation of the Safety and Efficacy of a Temperature-Sensitive Mycoplasma synoviae Live Vaccine. Avian Dis 1998. [DOI: 10.2307/1592703] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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31
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Markham JF, Scott PC, Whithear KG. Field evaluation of the safety and efficacy of a temperature-sensitive Mycoplasma synoviae live vaccine. Avian Dis 1998; 42:682-9. [PMID: 9876836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Mycoplasma synoviae (MS) strain MS-H was used in three separate commercial flocks for large-scale evaluation of the safety and efficacy of the vaccine under commercial conditions. MS-H successfully colonized meat and layer-breeders vaccinated by eyedrop and persisted for up to 55 wk after vaccination. Restriction fragment length polymorphism analysis showed that MS-H was the only strain isolated from two vaccinated flocks. In a third flock, challenge with a wild-type MS occurred, and this strain was isolated from both vaccinated and unvaccinated birds. Vertical transmission of MS-H was investigated by culturing pipped embryos and testing broiler progeny for MS antibody at processing (56 days old). No evidence of vertical transmission was detected. Lateral transmission of MS-H strain from vaccinated to unvaccinated birds occurred in one of the commercial flocks. Forty-one of 50 isolates of MS-H obtained from vaccinated flocks maintained their temperature-sensitive phenotype, but nine isolates showed a nontemperature-sensitive phenotype.
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Affiliation(s)
- J F Markham
- School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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32
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Markham JF, Morrow CJ, Scott PC, Whithear KG. Safety of a temperature-sensitive clone of Mycoplasma synoviae as a live vaccine. Avian Dis 1998; 42:677-81. [PMID: 9876835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A temperature-sensitive (ts+) clone derived from the Australian Mycoplasma synoviae (MS) field isolate 86079/7NS was produced by chemical mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine and assessed for safety as a live vaccine. This clone, designated MS-H, was assessed for pathogenicity in three different models with air sac lesions as the criterion. No air sac lesions were observed when MS-H was administered to specific-pathogen-free hybrid white leghorn (HWL) chickens by eyedrop at 10 times the normal dose or directly into the thoracic air sacs or as an aerosol administered to specific-pathogen-free Webster white leghorn chickens with concurrent intratracheal T-strain infectious bronchitis virus (IBV). MS-H did not revert to virulence or lose the ts+ phenotype when passaged through five in vivo and 10 in vitro passages. No adverse effects were seen when HWL chickens were vaccinated concurrently with MS-H and combinations of Mycoplasma gallisepticum ts-11 vaccine, IBV vaccine, and infectious laryngotracheitis virus vaccine. Lateral transmission of MS-H was found to occur when vaccinated HWL chickens were mixed with unvaccinated chickens 2 wk after vaccination. At 1 wk after mixing, one out of two unvaccinated chickens had seroconverted to MS and was culture positive for MS. At 2 wk after mixing, both contact chickens were positive for MS by culture and serology.
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Affiliation(s)
- J F Markham
- School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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Vaiano SA, Azuolas JK, Parkinson GB, Scott PC. Serum total calcium, phosphorus, 1,25-dihydroxycholecalciferol, and endochondral ossification defects in commercial broiler chickens. Poult Sci 1994; 73:1296-305. [PMID: 7971674 DOI: 10.3382/ps.0731296] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The research described in this paper relates the changes in serum concentration of calcium, phosphorus, and 1,25-dihydroxycholecalciferol [1,25(OH)2D3] to changes in tibial ash percentage and the incidence of endochondral ossification defects (EOD) in flocks of commercially reared broiler chickens at 14 d of age. Sequential studies of six Australian broiler flocks representing three major genetic lines were undertaken at weekly intervals from 1 to 28 d of age. Serum collected from birds was analyzed for total calcium, inorganic phosphorus, and 1,25(OH)2D3. Tibial ash percentage was also determined at weekly intervals, and the incidence of EOD was determined at 14 d of age by examining sagittal sections of the proximal tibiotarsus. The EOD observed in the 14-d-old broiler chickens were characterized by enlarged zones of proliferating chondrocytes, similar to that which occurs during calcium- or vitamin D-dependent rickets. Three flocks had a 50% incidence of EOD at 14 d of age and were classified as severely affected. The other three flocks had incidences ranging from 12 to 16% and were classified as mildly affected. Broiler flocks severely affected with EOD (50% incidence at Day 14) had lower (P < or = .05) concentrations of 1,25(OH)2D3 than flocks mildly affected (12 to 16% incidence). Tibial ash percentages were lower (P < or = .05) in the severely affected flocks between Days 14 to 28, and it is likely that a lower rate of ash accretion between Days 7 to 14 precedes the development of the EOD.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S A Vaiano
- Victorian Institute of Animal Science, Attwood, Australia
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Abstract
The following unusual diseases were diagnosed in birds submitted to the Veterinary Research Institute, Victoria, between 1978 and 1987: the viral diseases beak and feather disease of psittacines, infectious laryngotracheitis in peafowls, a papovavirus-like inclusion body disease in psittacines, and pox; chlamydiosis; the bacterial diseases actinomycosis, listeriosis and mycobacteriosis; the fungal diseases favus, yeast infections and systemic zygomycosis; the protozoan diseases cryptosporidiosis, hexamitiasis, suspected leucocytozoonosis, sarcosporidiosis, toxoplasmosis, trichomoniasis and an unidentified protozoan-like organism which caused pneumonia in ducks; a variety of parasites; the metabolic disorders curled-toe paralysis in pheasant poults, encephalomalacia and parenchymatous goitre; toxicity due to dimetridazole and the ingestion of the leaves of the tobacco tree; and other non-infectious conditions including asphyxiation, burns, cataracts, cerebellar degeneration and atrophy, cystic right oviducts and exertional rhabdomyolysis.
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Affiliation(s)
- R L Reece
- Department of Agricultural and Rural Affairs, Veterinary Research Institute, Attwood, Victoria, Australia
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Affiliation(s)
- P C Scott
- Centre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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Abstract
The nucleotide sequences of one Ovar-DQB gene, excluding exon 1 and parts of the introns, and one Ovar-DRB pseudogene are presented. The structure of the Ovar-DQB gene is typical of a major histocompatibility complex (MHC) class II B gene and demonstrates considerable sequence similarity with that of humans including such characteristics as the less common polyadenylation signal, ATTAAA. The ovine sequence has a typical 5' acceptor splice signal for exon 5, thus potentially encoding a full length cytoplasmic tail. The Ovar-DRB gene identified in this study was found to be a pseudogene, lacking a defined exon 2 and containing premature termination codons in both exons 3 and 4. The 3' donor splice site of exon 3 is also atypical. A purine-pyrimidine microsatellite repeat, (dC.dA)15, in the 3' region of the pseudogene may be a hotspot for recombination within the ovine DR subregion.
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Affiliation(s)
- P C Scott
- Centre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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Abstract
The nucleotide sequence of all exons and introns, excluding exon 1, of the ovine major histocompatibility complex (MhcOvar) genes analogous to the HLA-DQA1 and -DQA2 genes has been determined and the gene structure found to be similar to that reported for other species. The predicted amino acid sequences of the Ovar-DQA genes have been compared with the equivalent DQA genes in man, mouse, rat, rabbit, and cattle and used to determine the evolutionary relationships of the sheep class II genes to these other species. Northern blot analysis of sheep mRNA using exon specific probes for each of the two Ovar-DQA genes show that both genes are transcribed, whereas in humans there is no evidence that HLA-DQA2 is transcriptionally active. Restriction fragment length polymorphisms (RFLPs) have been used to define a polymorphic series of alleles in both Ovar-DQA genes and have indicated that the number of DQA genes is not constant in sheep as it is in humans, but varies with the haplotype.
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Affiliation(s)
- P C Scott
- Centre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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Gogolin-Ewens KJ, Meeusen EN, Scott PC, Adams TE, Brandon MR. Genetic selection for disease resistance and traits of economic importance in animal production. REV SCI TECH OIE 1990; 9:865-96. [PMID: 1983434 DOI: 10.20506/rst.9.3.519] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Significant advances have been made in recent years in improving animal stocks by selective breeding. However, existing selection techniques still rely on laborious and time-consuming progeny-testing programs and often depend on subjective assessment of the phenotype. New techniques in molecular genetics are being developed, aimed at the isolation and identification of DNA markers linked to genes for economically important production traits and disease resistance. When available, these markers will provide animal breeders with an objective test system to identify, at birth or even earlier, animals carrying desirable genes. This review outlines some of these new techniques and how they may be applied to the animal industries. Consideration is also given to some of the recent advances in our understanding of the immune system and of possible mechanisms of genetic control of animal disease resistance or susceptibility. The current knowledge of major histocompatibility complex (MHC) and non-MHC associated disease resistance/susceptibility in domestic animals is summarised and mechanisms which may be responsible for these associations are presented. Genes that control such factors as macrophage activation, cytokines, cytokine receptors and gamma delta-T cell receptors are also presented as potential candidates for analysis in genetic disease association studies. Ultimately, the goal will be to identify genes or DNA markers which can be used to select for or to genetically engineer disease resistance and enhanced production traits.
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Affiliation(s)
- K J Gogolin-Ewens
- Centre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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Abstract
Ten free-living superb lyrebirds (Menura novaehollandiae) from forest habitat in southern Victoria, Australia were examined at necropsy over a 10 yr period. The acanthocephalan Plagiorhynchus menurae was identified in two lyrebirds from forest habitat in southern Victoria, Australia. There was necrotic enteritis in the duodenum associated with the acanthocephalans, with secondary bacterial involvement. The lesions probably resulted in the observed emaciation and debilitation of the birds. Probably the forest-floor habitat and insect diet of lyrebirds exposes them to these infections.
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Affiliation(s)
- S McOrist
- Veterinary Research Institute, Parkville, Victoria, Australia
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Abstract
A panel of monoclonal antibodies was used for structural and immunodepletion analysis of sheep MHC class II molecules. The results indicate the antibodies recognize molecules of molecular weight 32-34,000 (alpha chain) and 26-28,000 (beta chain). Immunodepletion analysis indicates that the antibodies may recognize up to four distinct class II molecules some of which are structurally distinguishable using SDS-PAGE. Southern blot analysis using HLA-D region DR, DQ, DP, DO and DZ cDNA probes showed that a number of the cDNA probes hybridized specifically to sheep DNA indicating the presence of closely related genes in sheep. Together the results suggest that the sheep MHC class II region contains distinct MHC class II genes similar to those found in man.
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Affiliation(s)
- N K Puri
- Department of Veterinary Preclinical Sciences, University of Melbourne, Parkville, Australia
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Abstract
To study the class II genes of the major histocompatibility region of the sheep genome, human HLA class II genes corresponding to the known subregions in man (DR, DQ, DP, DO, and DZ) were used for Southern hybridization analysis of sheep DNA and to probe a sheep genomic library. Hybridizing bands were noted for all probes except DP alpha. DQ alpha and beta and DR beta appear to be present as multicopy genes, while DR alpha-, DZ alpha-, and DO beta- like genes appear to be single copy. All bands detected with the DP beta probe were also detectable with other beta chain probes. From eight lambda-bacteriophage clones of a sheep genomic library nine distinct class II genes were identified. These genes were characterized by differential hybridization analysis and restriction mapping. Two genes were DR beta-like, three DQ alpha-like and four DQ beta-like. The extensive cross-hybridization observed with beta chain probes was not seen with alpha chain probes. The results of this study suggest that the major histocompatibility complex class II region of the sheep has a similar genetic organization to that of man, with the provisional exception of the DP subregion.
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Scott PC, Condron RJ, Reece RL. Inclusion body hepatitis associated with adenovirus-like particles in a cockatiel (Psittaciformes; Nymphicus hollandicus). Aust Vet J 1986; 63:337-8. [PMID: 3026296 DOI: 10.1111/j.1751-0813.1986.tb02879.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Reece RL, Scott PC, Forsyth WM, Gould JA, Barr DA. Toxicity episodes involving agricultural chemicals and other substances in birds in Victoria, Australia. Vet Rec 1985; 117:525-7. [PMID: 4082413 DOI: 10.1136/vr.117.20.525] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A series of case reports detailing observations on toxicity episodes in birds caused by a variety of agricultural chemicals and other substances is presented. These problems arose as a result of ignorance, accident and malicious intent. The episodes involved maldison, monocrotophos, fenitrothion, trichlorofon, dieldrin, chlordane, endrin, metaldehyde, bromadiolone, arsenic, lead and zinc. An unresolved episode where toxicity was implicated is also included.
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Barr DA, Smart IJ, Forsyth WM, Reece RL, Scott PC. The runting/stunting syndrome in meat chickens. Aust Vet J 1985. [DOI: 10.1111/j.1751-0813.1985.tb13929.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Reece RL, Barr DA, Forsyth WM, Scott PC. Investigations of toxicity episodes involving chemotherapeutic agents in Victorian poultry and pigeons. Avian Dis 1985; 29:1239-51. [PMID: 3833224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This series of case reports details observations on toxicity episodes in poultry due to a variety of chemotherapeutic agents. These problems arose owing to overdosage, variation in species susceptibility, potentiation of the toxic effects of one substance by the presence of another substance, and particular disease or other on-farm factors. Ignorance and accident were responsible for some of these situations. The episodes involved monensin, salinomycin, nicarbazin, sulphaquinoxaline, dinitolmide, dimetridazole, nitrofurans, streptomycin, and 3-nitro-4-hydroxyphenylarsonic acid.
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Reece RL, Hooper PT, Tate SH, Beddome VD, Forsyth WM, Scott PC, Barr DA. Field, clinical and pathological observations of a runting and stunting syndrome in broilers. Vet Rec 1984; 115:483-5. [PMID: 6516183 DOI: 10.1136/vr.115.19.483] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Observations on a runting and stunting syndrome in broiler chickens in Victoria, Australia, based on general observations from 1980 to 1983 on 2244 chickens from 109 affected broiler chicken flocks, are summarised. The details on 156 of these birds from five affected flocks with varying runting percentages are presented. Typically affected birds were presented with atrophy of the pancreas, the thymus and the bursa of Fabricius.
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