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Jiang D, Li S, Liang Y, Ma J, Wang B, Zhang C. Protective effects of the fructooligosaccharide on the growth performance, biochemical indexes, and intestinal morphology of blunt snout bream (Megalobrama amblycephala) infected by Aeromonas hydrophila. FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:139-153. [PMID: 36538149 DOI: 10.1007/s10695-022-01162-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
The purpose of the study was to investigate the effects of dietary fructooligosaccharide (FOS) on growth performance, biochemical indexes, intestinal morphology, and growth-related gene expression of blunt snout bream (Megalobrama amblycephala) infected by Aeromonas hydrophila (AH). Two hundred twenty-five healthy blunt snout bream with an initial body weight of 38.41 ± 0.88 g were randomly divided into five groups with three replicates: control (basal diet), model (AH + basal diet), SFOS (AH + 2 g/kg FOS), MFOS (AH + 4 g/kg FOS), LFOS (AH + 6 g/kg FOS). After 9 weeks of feeding, the results showed that the FOS-added diet abrogated AH-induced retardation, hemorrhage, and inflammatory infiltration. FOS supplementation enhanced the growth performance degradation caused by AH, and the highest growth performance was observed at MFOS. Meanwhile, the addition of FOS to feed improved the blood immunity reduced by AH. In expansion, the mucosal epithelium of intestinal villi exfoliated, exposing the lamina propria, and a few villi were genuinely harmed in the model group. Fish fed with MFOS ameliorated the damaged intestine, evidenced by well-preserved intestine architecture. Furthermore, the model group downregulated the expression of growth-related genes (growth hormone receptor (GHR), insulin-like growth factor 1 (IGF-1)). Fish fed with 2 g/kg or 4 g/kg FOS upregulated the genes specified above expressions in the liver compared with the model group. In conclusion, the results mentioned above suggested that the dietary FOS could relieve the pressure to elevate the immune damage and intestine injury induced by AH and enhance the hepatic expression of IGF-1 and GHR.
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Affiliation(s)
- Dongxue Jiang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471003, People's Republic of China
| | - Shengnan Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471003, People's Republic of China
| | - Yuexia Liang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471003, People's Republic of China
| | - Junqi Ma
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471003, People's Republic of China
| | - Bingke Wang
- Henan Academy of Fishery Sciences, Zhengzhou, 450040, People's Republic of China
| | - Chunnuan Zhang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471003, People's Republic of China.
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Diagnostic Approach to Enteric Disorders in Pigs. Animals (Basel) 2023; 13:ani13030338. [PMID: 36766227 PMCID: PMC9913336 DOI: 10.3390/ani13030338] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/21/2023] Open
Abstract
The diagnosis of enteric disorders in pigs is extremely challenging, at any age. Outbreaks of enteric disease in pigs are frequently multifactorial and multiple microorganisms can co-exist and interact. Furthermore, several pathogens, such as Clostridium perfrigens type A, Rotavirus and Lawsonia intracellularis, may be present in the gut in the absence of clinical signs. Thus, diagnosis must be based on a differential approach in order to develop a tailored control strategy, considering that treatment and control programs for enteric diseases are pathogen-specific. Correct sampling for laboratory analyses is fundamental for the diagnostic work-up of enteric disease in pigs. For example, histology is the diagnostic gold standard for several enteric disorders, and sampling must ensure the collection of representative and optimal intestinal samples. The aim of this paper is to focus on the diagnostic approach, from sampling to the aetiological diagnosis, of enteric disorders in pigs due to different pathogens during the different phases of production.
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3
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Baldasso DZ, Guizzo JA, Dazzi CC, Paraboni Frandoloso GC, Feronato C, von Berg S, Carvalho Guedes RM, Wilson HL, Kreutz LC, Frandoloso R. Development and validation of a flow cytometry antibody test for Lawsonia intracellularis. Front Immunol 2023; 14:1145072. [PMID: 37033985 PMCID: PMC10073966 DOI: 10.3389/fimmu.2023.1145072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Lawsonia intracellularis is the etiologic agent of porcine proliferative enteropathy (PPE), an inflammatory bowel disease with a major economic impact on the pig industry. The serological diagnosis of PPE can be performed using Blocking or Indirect ELISA, Immunoperoxidase Monolayer Assay (IPMA) and Indirect Fluorescence Antibody Test (IFAT). Here, we designed a most sophisticated immunological method for the detection of porcine anti-L. intracellularis IgGs, named Flow Cytometry Antibody Test - FCAT. This assay uses whole, live-attenuated L. intracellularis bacteria derived from a commercial vaccine. For the assay, we set up the optimal antigen concentration (106 bacterium/assay), primary antibody dilution (1:100), time of incubation (20 min), antigen stability (15 days), precision (coefficient of variation - CV < 10%), reproducibility (CV ≤ 13%) and Receiver Operating Characteristic (ROC). When using a cut-off of >15.15% for FCAT, we determined that it showed a sensitivity of 98.8% and specificity of 100%. The rate of agreement with IPMA was 84.09% with a kappa index of 0.66. FCAT was used to screen 1,000 sera from non-vaccinated pigs housed in 22 different farms and we found that 730 pigs (73%) from 16 farms (72.7%) had L. intracellularis IgG. This high prevalence confirms that L. intracellularis is endemic on Brazilian pig farms. Finally, we determined that FCAT is an easy to perform diagnostic assay and we would highly recommend it for: i) seroepidemiological studies; ii) evaluation of infection dynamics; and iii) characterization of the humoral response profile induced by vaccines.
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Affiliation(s)
- Débora Zini Baldasso
- Laboratory of Microbiology and Advanced Immunology, Faculty of Veterinary Medicine, University of Passo Fundo, Passo Fundo, Brazil
| | | | - Cláudia Cerutti Dazzi
- Laboratory of Microbiology and Advanced Immunology, Faculty of Veterinary Medicine, University of Passo Fundo, Passo Fundo, Brazil
- Section of Immunology, AFK Imunotech, Passo Fundo, Brazil
| | | | - César Feronato
- Swine Technical Department, Merck Sharp & Dohme (MSD), São Paulo, Brazil
| | - Stephan von Berg
- Global Marketing Swine, Merck Sharp & Dohme (MSD), Animal Health, Munich, Germany
| | | | - Heather Lynne Wilson
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, SK, Canada
| | - Luiz Carlos Kreutz
- Laboratory of Microbiology and Advanced Immunology, Faculty of Veterinary Medicine, University of Passo Fundo, Passo Fundo, Brazil
- Section of Immunology, AFK Imunotech, Passo Fundo, Brazil
| | - Rafael Frandoloso
- Laboratory of Microbiology and Advanced Immunology, Faculty of Veterinary Medicine, University of Passo Fundo, Passo Fundo, Brazil
- Section of Immunology, AFK Imunotech, Passo Fundo, Brazil
- *Correspondence: Rafael Frandoloso,
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Li M, Xiao N, Li J, Lin H, Fan H. Evaluation of immune efficacy of Omp2 protein against Lawsonia intracellularis in mice. Vet Microbiol 2021; 263:109274. [PMID: 34781192 DOI: 10.1016/j.vetmic.2021.109274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/31/2021] [Accepted: 10/29/2021] [Indexed: 11/16/2022]
Abstract
Porcine proliferative enteropathy (PPE) is caused by the obligate intracellular bacterium Lawsonia intracellularis. Infection results in an enteric disease characterised by decreased growth performance of pigs, and presents a major economic burden for swine industries worldwide. Since vaccination is an effective technique for controlling PPE, novel effective vaccine platforms are need to be developed. In this study, five proteins of L. intracellularis were screened through animal experiments and the highly immunoprotective Omp2 protein was identified. Then, the immune efficacy of Omp2 was further evaluated based on humoral and cell mediated immune (CMI) responses, faecal bacterial shedding, histopathological lesions, immune barrier function of intestinal mucosa as well as digestive and absorptive capacity following challenge of mice with L. intracellularis. Mice immunised with Omp2 had reduced faecal shedding, fewer histopathological lesions and reduced bacteria colonisation of the ileum. Additionally, Omp2 immunised mice showed stronger serum IgG and IFN-γ levels, up-regulated Occludin and zonula occludens-1 (ZO-1) mRNA levels, as well as increased numbers of intestinal intraepithelial lymphocytes (IELs) and levels of sIgA. On the contrary, the activities of LPS, α-AMS and AKP were significantly increased. Our investigation indicated that immunization with Omp2 reduced the severity of clinical signs and provided efficacious immunoprotection for target animals against L. intracellularis infection in mouse model.
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Affiliation(s)
- Minxue Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ning Xiao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jiannan Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huixing Lin
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hongjie Fan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, China.
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Campillo M, Smith SH, Gally DL, Opriessnig T. Review of methods for the detection of Lawsonia intracellularis infection in pigs. J Vet Diagn Invest 2021; 33:621-631. [PMID: 33739176 PMCID: PMC8225690 DOI: 10.1177/10406387211003551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Lawsonia intracellularis is an obligate intracellular bacterium
associated with enteric disease in pigs. Clinical signs include weight loss,
diarrhea, and, in some cases, sudden death. The hallmark lesion is the
thickening of the intestinal mucosa caused by increased epithelial cell
replication, known as proliferative enteropathy. The immune response to
L. intracellularis is not well defined, and detection of
the infection, especially in the early stages, is still a significant challenge.
We review here the main approaches used to identify this important but poorly
understood pathogen. Detection of L. intracellularis infection
as the cause of clinical disease is confounded by the high prevalence of the
pathogen in many countries and that several other pathogens can produce similar
clinical signs. A single L. intracellularis–specific ELISA and
several amplification assays are available commercially to aid detection and
surveillance, although histopathology remains the primary way to reach a
conclusive diagnosis. There are major gaps in our understanding of L.
intracellularis pathogenesis, especially how the host responds to
infection and the factors that drive infection toward different clinical
outcomes. Knowledge of pathogenesis will increase the predictive value of
antemortem tests to guide appropriate interventions, including identification
and treatment of subclinically affected pigs in the early stages of disease,
given that this important manifestation reduces pig productivity and contributes
to the economic burden of L. intracellularis worldwide.
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Affiliation(s)
- Marta Campillo
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Sionagh H Smith
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - David L Gally
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
| | - Tanja Opriessnig
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
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Draskovic V, Bosnjak-Neumuller J, Vasiljevic M, Petrujkic B, Aleksic N, Kukolj V, Stanimirovic Z. Influence of phytogenic feed additive on Lawsonia intracellularis infection in pigs. Prev Vet Med 2018; 151:46-51. [PMID: 29496105 DOI: 10.1016/j.prevetmed.2018.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/04/2018] [Accepted: 01/04/2018] [Indexed: 11/30/2022]
Abstract
Lawsonia intracellularis is known to cause proliferative enteropathy (PE), one of the economically most important swine diseases with global distribution. Not unlike other enteric diseases, PE is a frequent indication for antibiotic therapy. However, their unjustified use leads to an emerging problem - antimicrobial resistance. Thus, the aim of this research was to assess if a phytogenic additive may replace antibiotics in the control of PE in 144 weaned piglets (72 treated and 72 controls) naturally infected with L. intracellularis. The quantity of L. intracellularis faecal shedding was monitored by real-time polymerase chain reaction (PCR) assay in faecal samples on day 0, 14 and 28, whilst the level of the ileum damage was determined by immunohistochemistry (IHC) assay performed on gut sections. Real-time PCR assay revealed that cycle-threshold (Ct) values in the treatment group increased significantly over time and were higher than in the control. These results indicate that the use of the phytogenic additive decreases the faecal excretion of L. intracellularis both throughout the experiment and in comparison to the control. The expression of the L. intracellularis antigen in IHC assay was lower in treated animals, implying that the additive leads to the decrease in the pathogen quantity in the ileum. Significantly higher feed conversion ratio was recorded in the treatment group. The results indicate that the phytogenic additive may be beneficial in the control of PE, but additional research is necessary to assess its use in various pig categories and define the optimum concentrations.
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Affiliation(s)
- Vladimir Draskovic
- Department of Biology, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000 Belgrade, Serbia.
| | | | | | - Branko Petrujkic
- Department of Nutrition and Botany, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000 Belgrade, Serbia
| | - Nevenka Aleksic
- Department of Parasitology, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000 Belgrade, Serbia
| | - Vladimir Kukolj
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000 Belgrade, Serbia
| | - Zoran Stanimirovic
- Department of Biology, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000 Belgrade, Serbia
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7
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Kim J, Won G, Park S, Lee JH. Identification of Lawsonia intracellularis putative hemolysin protein A and characterization of its immunoreactivity. Vet Microbiol 2017. [PMID: 28622862 DOI: 10.1016/j.vetmic.2017.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Despite the recent global increase in fatal endemic outbreaks of proliferative enteropathy (PE) caused by the obligate intracellular bacterium Lawsonia intracelluralis (LI) in the swine industry, development of effective prevention strategies or immunodiagnostic tests has been delayed due to the difficulty of cultivating this pathogen in vitro. Although several genetic analyses have been performed at the level of gene transcription after the complete genome sequence of LI was made available, the mechanism of LI infection and virulence genes remain unidentified. In the present study, we assessed the antigenic features of the LI0004 protein, which we putatively defined as Lawsonia hemolysin A (LhlyA), by employing bioinformatics tools and in vivo and in vitro protein-based molecular assays. The amino acid sequence of LhlyA showed approximately 60% homology to the hemolysin-like proteins of Bilophila wadsworthia and Desulfovibrio piger. Presence of computationally predicted linear antigenic B-cell epitopes on the LhlyA protein was demonstrated by immunoblotting; a band with a molecular mass corresponding to the predicted size of the protein was strongly recognized by sera collected from artificially infected mice. Further, in an in vivo cytotoxicity assay, no splenomegaly was observed in mice inoculated with purified LhlyA. Collectively, the data presented here suggest that the LhlyA protein is a highly immuno-reactive antigen of L. intracellullaris and can potentially be used to develop effective protection strategies against PE.
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Affiliation(s)
- Jehyung Kim
- College of Veterinary Medicine, Chonbuk National University, Iksan Campus, Gobong-ro 79, Iksan, 54596, Republic of Korea
| | - Gayeon Won
- College of Veterinary Medicine, Chonbuk National University, Iksan Campus, Gobong-ro 79, Iksan, 54596, Republic of Korea
| | - Suyeon Park
- College of Veterinary Medicine, Chonbuk National University, Iksan Campus, Gobong-ro 79, Iksan, 54596, Republic of Korea
| | - John Hwa Lee
- College of Veterinary Medicine, Chonbuk National University, Iksan Campus, Gobong-ro 79, Iksan, 54596, Republic of Korea.
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Smith SH, Wilson AD, Van Ettinger I, MacIntyre N, Archibald AL, Ait-Ali T. Down-regulation of mechanisms involved in cell transport and maintenance of mucosal integrity in pigs infected with Lawsonia intracellularis. Vet Res 2014; 45:55. [PMID: 24885874 PMCID: PMC4031155 DOI: 10.1186/1297-9716-45-55] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 04/22/2014] [Indexed: 11/10/2022] Open
Abstract
Lawsonia intracellularis is an obligate intracellular bacterium, responsible for the disease complex known as proliferative enteropathy (PE). L. intracellularis is associated with intestinal crypt epithelial cell proliferation but the mechanisms responsible are yet to be defined. Microarray analysis was used to investigate the host-pathogen interaction in experimentally infected pigs to identify pathways that may be involved. Ileal samples originating from twenty-eight weaner pigs experimentally challenged with a pure culture of L. intracellularis (strain LR189/5/83) were subjected to microarray analysis. Microarray transcriptional signatures were validated using immunohistochemistry and quantitative real time PCR of selected genes at various time points post challenge. At peak of infection (14 days post challenge) 86% of altered transcripts were down regulated, particularly those involved in maintenance of mucosal integrity and regulation of cell transport. Among the up-regulated transcripts, CD163 and CDK1 were novel findings and considered to be important, due to their respective roles in innate immunity and cellular proliferation. Overall, targeted cellular mechanisms included those that are important in epithelial restitution, migration and protection; maintenance of stable inter-epithelial cell relationships; cell transport of nutrients and electrolytes; innate immunity; and cell cycle.
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Affiliation(s)
| | | | | | | | | | - Tahar Ait-Ali
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK.
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Jensen T, Boesen H, Vigre H, Boye M. Detection of Lawsonia intracellularis in Formalin-fixed Porcine Intestinal Tissue Samples: Comparison of Immunofluorescence and In-situ Hybridization, and Evaluation of the Effects of Controlled Autolysis. J Comp Pathol 2010; 142:1-8. [DOI: 10.1016/j.jcpa.2009.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 04/02/2009] [Indexed: 10/20/2022]
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Guimarães-Ladeira CV, Palhares MS, Oliveira JSV, Ramirez MA, Guedes RMC. Faecal shedding and serological cross-sectional study of Lawsonia intracellularis in horses in the state of Minas Gerais, Brazil. Equine Vet J 2009; 41:593-6. [PMID: 19803056 DOI: 10.2746/042516409x407639] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
REASON FOR PERFORMING THE STUDY Proliferative enteropathy, caused by the intracellular bacterium Lawsonia intracellularis, has been described in horses in Australia, the USA, Canada and European countries but has not been reported in Latin America. The prevalence of the disease in horses worldwide is unknown. OBJECTIVE To evaluate the presence of subclinical L. intracellularis infection in horses in the state of Minas Gerais, Brazil. METHODS A longitudinal study using serology and PCR for detecting antibodies (IgG) and shedding of L. intracellularis in faecal samples, respectively, was conducted using a total of 223 horses from 14 different horse farms in Minas Gerais, and from the Veterinary School of UFMG equine herds in Minas Gerais. The immunoperoxidase technique in glass slides was used as the serological test. RESULTS Twenty-one horse sera had immunoglobulin G titres of 1:60 and were considered positive. The PCR technique in faeces for L. intracellularis DNA identified 7 horses as faecal shedders. Horses shedding the organism appeared healthy, indicating that subclinical infection of L. intracellularis occurred in the horses. CONCLUSION Seropositivity and detection of faecal shedding of L. intracellularis indicates the presence of the agent in the equine population in Minas Gerais. POTENTIAL RELEVANCE Results of this study should alert clinicians in countries where proliferative enteropthy in horses has not been reported to consider this disease as a possible cause of enteric disease.
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Affiliation(s)
- C V Guimarães-Ladeira
- Department of Clinic and Surgery, Veterinary School, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627 - Pampulha, PO Box 567, Belo Horizonte, MG 31.270-901, Brazil
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Kokubo T, Matsushita S. Evaluation of new cage lid with partitioning barrier based on transmission of CAR bacillus in mice. Exp Anim 2009; 58:189-92. [PMID: 19448343 DOI: 10.1538/expanim.58.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
We developed a new cage lid made of stainless steel wire mesh and having a screen barrier for partitioning a small laboratory animal cage into compartments. To evaluate the effectiveness of the lid, we tested the transmissibility of Cilia-Associated Respiratory (CAR) bacillus from infected mice to uninfected sentinel mice, which were kept in separate compartments using this lid. Infection from the infected mice to the uninfected mice was confirmed by microbiological, serological, pathological, and molecular diagnostic examinations, as previously observed in an intra-cage contact route. The cage lid that we developed is very useful when uninfected mice are used in quarantine and contagion experiments to prevent fighting among the mice.
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Affiliation(s)
- Toshiaki Kokubo
- Laboratory Animal Sciences Section, Department of Technical Support and Development, Fundamental Technology Center, National Institute of Radiological Sciences, Inage-ku, Chiba, Japan
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Ladinig A, Sommerfeld-Stur I, Weissenböck H. Comparative evaluation of diagnostic methods for Lawsonia intracellularis infection in pigs, with emphasis on cases lacking characteristic lesions. J Comp Pathol 2008; 140:140-8. [PMID: 19108850 DOI: 10.1016/j.jcpa.2008.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Accepted: 09/30/2008] [Indexed: 11/15/2022]
Abstract
In this study the following methods for the diagnosis of Lawsonia intracellularis infection in pigs were compared in relation to a reference method (examination of ileal mucosal scrapings by the polymerase chain reaction [PCR]): Warthin-Starry (WS) staining of tissue sections, immunohistochemistry (IHC), in-situ hybridization (ISH), and PCR examination of faeces and of paraffin wax-embedded samples of ileum. Of 204 pigs examined, 32 were considered on the basis of the PCR to be infected. Gross and histopathological examination, including the use of WS staining, were of limited value. PCR examination of faeces proved to be the most sensitive (sensitivity 70%) of the methods used but, due to the occurrence of false positives, its specificity (95%) was the lowest. IHC (sensitivity 66%, specificity 99%) and ISH (sensitivity 54%, specificity 100%) were clearly superior to examination of WS-stained sections (sensitivity 34%, specificity 100%) for routine diagnosis; although less sensitive than the PCR, they indicated only cases of clinical relevance and, moreover, were capable of distinguishing different stages and levels of infection. Because examination of paraffin wax-embedded tissue by the PCR was shown to be associated with low sensitivity (41%), IHC was regarded as the method of choice for retrospective studies.
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Affiliation(s)
- A Ladinig
- Institute of Pathology and Forensic Veterinary Medicine, Department of Pathobiology, University of Veterinary Medicine, Vienna, Austria
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13
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Weissenböck H, Mrakovcic M, Ladinig A, Fragner K. In situ hybridization for Lawsonia intracellularis--specific 16s rRNA sequence in paraffin-embedded tissue using a digoxigenin-labeled oligonucleotide probe. J Vet Diagn Invest 2007; 19:282-5. [PMID: 17459858 DOI: 10.1177/104063870701900309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An in situ hybridization (ISH) procedure with a digoxigenin-labeled oligonucleotide probe for detection of Lawsonia intracellularis in paraffin-embedded tissue is described. This technique recognized 71% of PCR-positive cases and was thus superior to Warthin-Starry silver stain, which only detected 41%. The presented ISH is of comparable sensitivity to previously published immunohistochemical assays and is recommended for laboratories wishing to diagnose L. intracellularis infections in tissue sections but without access to antibodies.
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Affiliation(s)
- Herbert Weissenböck
- Institute of Pathology and Forensic Veterinary Medicine, Department of Pathobiology, Veterinärplatz 1, A-1210 Vienna, Austria
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14
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Kroll JJ, Roof MB, Hoffman LJ, Dickson JS, Harris DLH. Proliferative enteropathy: a global enteric disease of pigs caused byLawsonia intracellularis. Anim Health Res Rev 2007; 6:173-97. [PMID: 16583781 DOI: 10.1079/ahr2005109] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
AbstractProliferative enteropathy (PE; ileitis) is a common intestinal disease affecting susceptible pigs raised under various management systems around the world. Major developments in the understanding of PE and its causative agent,Lawsonia intracellularis, have occurred that have led to advances in the detection of this disease and methods to control and prevent it. Diagnostic tools that have improved overall detection and early onset of PE in pigs include various serological and molecular-based assays. Histological tests such as immunohistochemistry continue to be the gold standard in confirmingLawsonia-specific lesions in pigspost mortem. Despite extreme difficulties in isolatingL. intracellularis, innovations in the cultivation and the development of pure culture challenge models, have opened doors to better characterization of the pathogenesis of PE throughin vivoandin vitro L. intracellularis–host interactions. Advancements in molecular research such as the genetic sequencing of the entireLawsoniagenome have provided ways to identify various immunogens, metabolic pathways and methods for understanding the epidemiology of this organism. The determinations of immunological responsiveness in pigs to virulent and attenuated isolates ofL. intracellularisand identification of various immunogens have led to progress in vaccine development.
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Affiliation(s)
- Jeremy J Kroll
- Department of Research and Development, Boehringer Ingelheim Vetmedica Inc., 2501 North Loop Drive, Ames, Iowa 50010, USA.
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15
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Boesen HT, Jensen TK, Møller K, Nielsen LH, Jungersen G. Evaluation of a novel enzyme-linked immunosorbent assay for serological diagnosis of porcine proliferative enteropathy. Vet Microbiol 2005; 109:105-12. [PMID: 15975740 DOI: 10.1016/j.vetmic.2005.05.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Revised: 05/09/2005] [Accepted: 05/12/2005] [Indexed: 11/28/2022]
Abstract
A specific enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to the porcine pathogen Lawsonia intracellularis was developed and evaluated using sera from naïve, naturally infected as well as experimentally infected pigs. On the basis of 37 serum samples collected from experimentally infected pigs and 62 serum samples from naturally infected pigs the sensitivity of the ELISA was calculated to 98.0%. The specificity of the test was 99.3%, calculated on the basis of 273 serum samples collected in six herds free of L. intracellularis after medicated eradication. The novel ELISA was a specific and sensitive method for detecting specific antibodies, and may be a good alternative to the existing serological tests for L. intracellularis. It may be usable for diagnosis of proliferative enteropathy and for determination of a herd's epidemiologic status.
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Affiliation(s)
- Henriette Toft Boesen
- Danish Institute for Food and Veterinary Research, Bülowsvej 27, DK-1790 Copenhagen V, Denmark.
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Jordan DM, Knittel JP, Knitted JP, Schwartz KJ, Roof MB, Hoffman LJ. A Lawsonia intracellularis transmission study using a pure culture inoculated seeder-pig sentinel model. Vet Microbiol 2005; 104:83-90. [PMID: 15530742 DOI: 10.1016/j.vetmic.2004.09.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2004] [Revised: 08/11/2004] [Accepted: 08/25/2004] [Indexed: 11/18/2022]
Abstract
Transmission of Lawsonia intracellularis from experimentally inoculated pigs to naive swine was demonstrated in this study. The study was conducted using conventional pigs divided into three groups as follows: principles inoculated with L. intracellularis, sentinels, and controls. The pigs were inoculated and paired on 13 and 9 days post-inoculation with a sentinel pig for 7 days. Fecal samples and serum samples were collected throughout the study for polymerase chain reaction (PCR) and antibody testing by indirect fluorescent antibody techniques. After co-mingling, the inoculated group was necropsied; sentinel and control pigs were necropsied 7-14 days later. The intestinal tracts were evaluated grossly and microscopically for lesions. PCR was performed on intestinal mucosal scrapings and feces. Warthin-Starry and fluorescent antibody staining procedures were conducted to confirm colonization with L. intracellularis. Gross and microscopic lesions typical of porcine proliferative enteropathy (PPE) were observed in both the inoculated and sentinel groups. Transmission was demonstrated from inoculated principle pigs to sentinel pigs. PCR results detected cyclical shedding of L. intracellularis in the feces. Seroconversion occurred in pigs that were exposed to L. intracellularis. From this study, it was demonstrated that transmission of L. intracellularis can occur easily in an environment with experimentally infected pigs and that PCR can be a useful tool to monitor fecal shedding of the organism.
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Affiliation(s)
- Dianna M Jordan
- Iowa State University, Veterinary Diagnostics and Production Animal Medicine, Ames, IA 50010, USA.
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