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Brangsch H, Saqib M, Sial AUR, Melzer F, Linde J, Elschner MC. Sequencing-Based Genotyping of Pakistani Burkholderia mallei Strains: A Useful Way for Investigating Glanders Outbreaks. Pathogens 2022; 11:pathogens11060614. [PMID: 35745468 PMCID: PMC9227068 DOI: 10.3390/pathogens11060614] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 04/13/2022] [Revised: 05/05/2022] [Accepted: 05/19/2022] [Indexed: 12/10/2022] Open
Abstract
Burkholderia (B.) mallei is a host-adapted equine pathogen that causes glanders, a re-emerging zoonotic disease, which is endemic in Pakistan and other developing countries and seriously impacts the global equine movement. Due to globalization, the geographical restriction of diseases vanishes and the lack of awareness of and experience with eradicated diseases in industrialized countries also promotes the re-introduction of infections in these regions. Owing to the high equine population, the Pakistani province Punjab is a potential hotspot where several glanders outbreaks have been seen over last two decades. For determining the genomic diversity of B. mallei in this and other equine-populated prefectures, the genomes of 19 B. mallei strains isolated between 1999 and 2020 in different locations were sequenced and their genotypes were determined. Particularly, for genetically highly homogenous pathogens like B. mallei genotyping techniques require a high discriminatory power for enabling differentiation on the strain level. Thus, core-genome single nucleotide polymorphism (cgSNP) analysis was applied for distinguishing the highly similar strains. Furthermore, a whole-genome sequence-based core genome multi locus sequence typing (cgMLST) scheme, specific to B. mallei, was developed and additionally applied to the data. It was found that B. mallei genotypes in Pakistan persisted over time and space and genotype clusters preferred connection with a time point rather than the place of isolation, probably due to frequent equine movement, which promotes the spread of glanders. The cgMLST approach proved to work in accord with SNP typing and may help to investigate future glanders outbreaks.
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Affiliation(s)
- Hanka Brangsch
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Naumburger Str. 96a, 07743 Jena, Thuringia, Germany; (F.M.); (J.L.); (M.C.E.)
- Correspondence:
| | - Muhammad Saqib
- Veterinary Preventive Medicine and Public Health Laboratory, Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad 38000, Pakistan;
| | - Awais ur Rehman Sial
- Department of Clinical Studies, Faculty of Veterinary and Animal Science, Pir Mehr Ali Shah, Arid Agriculture University Rawalpindi, Rawalpindi 46000, Pakistan;
| | - Falk Melzer
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Naumburger Str. 96a, 07743 Jena, Thuringia, Germany; (F.M.); (J.L.); (M.C.E.)
| | - Jörg Linde
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Naumburger Str. 96a, 07743 Jena, Thuringia, Germany; (F.M.); (J.L.); (M.C.E.)
| | - Mandy Carolina Elschner
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Naumburger Str. 96a, 07743 Jena, Thuringia, Germany; (F.M.); (J.L.); (M.C.E.)
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Brangsch H, Golovko A, Pinchuk N, Deriabin O, Kyselova T, Linde J, Melzer F, Elschner MC. Molecular Typing of Ukrainian Bacillus anthracis Strains by Combining Whole-Genome Sequencing Techniques. Microorganisms 2022; 10:microorganisms10020461. [PMID: 35208915 PMCID: PMC8875922 DOI: 10.3390/microorganisms10020461] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 01/04/2022] [Revised: 02/09/2022] [Accepted: 02/14/2022] [Indexed: 01/27/2023] Open
Abstract
Anthrax is a recurrent zoonosis in the Ukraine with outbreaks occurring repeatedly in certain areas. For determining whether several Bacillus anthracis genotypes are circulating in this region, four strains from various sources isolated from different regions of the Ukraine were investigated. By combining long- and short-read next-generation sequencing techniques, highly accurate genomes were reconstructed, enabling detailed in silico genotyping. Thus, the strains could be assigned to the Tsiankovskii subgroup of the “TransEurAsia” clade, which is commonly found in this region. Their high genetic similarity suggests that the four strains are members of the endemic population whose progenitor was once introduced in the Ukraine and bordering regions. This study provides information on B. anthracis strains from a region where there is little knowledge of the local population, thereby adding to the picture of global B. anthracis genotype distribution. We also emphasize the importance of surveillance and prevention methods regarding anthrax outbreaks, as other studies predicted a higher number of cases in the future due to global warming.
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Affiliation(s)
- Hanka Brangsch
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96a, 07743 Jena, Germany; (J.L.); (F.M.); (M.C.E.)
- Correspondence:
| | - Anatolii Golovko
- Department of Bacteriological Research and Quality Control of Veterinary Immunobiological Preparations, SSCIBSM, 30, Donetskaya St., 03151 Kyiv, Ukraine; (A.G.); (N.P.); (O.D.); (T.K.)
| | - Nataliia Pinchuk
- Department of Bacteriological Research and Quality Control of Veterinary Immunobiological Preparations, SSCIBSM, 30, Donetskaya St., 03151 Kyiv, Ukraine; (A.G.); (N.P.); (O.D.); (T.K.)
| | - Oleg Deriabin
- Department of Bacteriological Research and Quality Control of Veterinary Immunobiological Preparations, SSCIBSM, 30, Donetskaya St., 03151 Kyiv, Ukraine; (A.G.); (N.P.); (O.D.); (T.K.)
| | - Tetiana Kyselova
- Department of Bacteriological Research and Quality Control of Veterinary Immunobiological Preparations, SSCIBSM, 30, Donetskaya St., 03151 Kyiv, Ukraine; (A.G.); (N.P.); (O.D.); (T.K.)
| | - Jörg Linde
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96a, 07743 Jena, Germany; (J.L.); (F.M.); (M.C.E.)
| | - Falk Melzer
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96a, 07743 Jena, Germany; (J.L.); (F.M.); (M.C.E.)
| | - Mandy Carolina Elschner
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96a, 07743 Jena, Germany; (J.L.); (F.M.); (M.C.E.)
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Kostoulas P, Gardner IA, Elschner MC, Denwood M J, Meletis L, Nielsen SS. Examples of proper reporting for evaluation (Stage 2 validation) of diagnostic tests for diseases listed by the World Organisation for Animal Health. REV SCI TECH OIE 2021; 40:287-298. [PMID: 34140743 DOI: 10.20506/rst.40.1.3225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Reporting and design standards are key indicators of the quality of diagnostic accuracy (validation) studies but, with the exception of aquatic animal diseases and paratuberculosis in ruminants, there is limited guidance for designing these studies in animals. There is, therefore, a need for generic guidelines that are based on disease characteristics, such as mode of transmission, latent period and pathogenesis. Comprehensive, clear and transparent reporting of primary test accuracy studies for diseases listed by the World Organisation for Animal Health (OIE) has value for the end users of diagnostic tests and, ultimately, for decision-makers, who require systematic reviews and meta-analysis of multiple tests for specified diseases and testing purposes. The recent publication of reporting standards for Bayesian latent class models, to analyse test-accuracy data from naturally occurring disease events, fills an important gap as these methods are being increasingly used for OIE-listed diseases. Adherence to design and reporting standards, as well as to guidelines, helps to ensure that research funding for test validation studies is used appropriately and that the strengths and limitations of single tests or test combinations are made clear to test users. The authors provide a review of key points that are often overlooked or misinterpreted in test validation studies, as well as two concrete examples of good practice for use as a reference point for future studies.
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Elschner MC, Melzer F, Singha H, Muhammad S, Gardner I, Neubauer H. Validation of a Commercial Glanders ELISA as an Alternative to the CFT in International Trade of Equidae. Front Vet Sci 2021; 8:628389. [PMID: 33665218 PMCID: PMC7920956 DOI: 10.3389/fvets.2021.628389] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/15/2021] [Indexed: 11/13/2022] Open
Abstract
Glanders, caused by Burkholderia (B.) mallei is a notifiable zoonotic disease in equidae. For international trade and movement of equids, certificates of negative serological test results for antibodies against B. mallei are required. To date, the complement fixation test (CFT) is the mandatory test to issue these health certificates. The CFT is difficult to standardize and, due to its poor specificity, often leads to false-positive reactions resulting in trade restrictions with considerable financial consequences. In the present study, the new ID Screen Glanders Double Antigen Multispecies ELISA (GLANDA- ELISA) (IDvet, Grabels, France) was evaluated using 400 negative and 370 glanders positive field samples of equidae. The GLANDA-ELISA was significantly more specific (99.8%) than the CFT (97.0%). Considering the comparable sensitivities of CFT (96.5%) and ELISA (98.1%), this new GLANDA-ELISA test appears a suitable confirmatory test and a realistic alternative for serological testing of horses for trade or movement.
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Affiliation(s)
- Mandy Carolina Elschner
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | - Falk Melzer
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | - Harisankar Singha
- Indian Council of Agricultural Research, National Research Centre on Equines, Hisar, India
| | - Saqib Muhammad
- Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad, Pakistan
| | - Ian Gardner
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island (UPEI), Charlottetown, PE, Canada
| | - Heinrich Neubauer
- Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Jena, Germany
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Elschner MC, Laroucau K, Singha H, Tripathi BN, Saqib M, Gardner I, Saini S, Kumar S, El-Adawy H, Melzer F, Khan I, Malik P, Sauter-Louis C, Neubauer H. Evaluation of the comparative accuracy of the complement fixation test, Western blot and five enzyme-linked immunosorbent assays for serodiagnosis of glanders. PLoS One 2019; 14:e0214963. [PMID: 30951554 PMCID: PMC6450644 DOI: 10.1371/journal.pone.0214963] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/23/2019] [Indexed: 01/25/2023] Open
Abstract
Glanders is a zoonotic contagious disease of equids caused by Burkholderia (B.) mallei. Serodiagnosis of the disease is challenging because of false-positive and false-negative test results. The accuracy of the complement fixation test (CFT) which is prescribed for international trade by the World Organisation for Animal Health (OIE), five ELISAs and a Western blot (WB) were compared for serodiagnosis of glanders using sera from 3,000 glanders-free and 254 glanderous equids. Four ELISA tests are based on recombinant antigens (TssA, TssB, BimA and Hcp1), the IDVet ELISA is based on a semi-purified fraction of B. mallei and WB makes use of a purified LPS-containing B. mallei-antigen. Sensitivity and specificity of tests were estimated using cut-off values recommended by the test developers. The WB and all ELISAs, except BimA, were significantly more specific than the CFT. ELISAs based on TssA, TssB, and BimA antigens had significantly lower sensitivity compared to CFT while the sensitivities of the Hcp1-ELISA, the IDVet-ELISA and the WB did not differ significantly from that of the CFT. Given their comparable sensitivities and specificities, the CFT (98.0%, 96.4%), the WB (96.8%, 99.4%), the Hcp1-ELISA (95.3%, 99.6%) and the IDVet-ELISA (92.5%, 99.5%) should be further developed to meet OIE requirements.
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Affiliation(s)
- Mandy Carolina Elschner
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Jena, Germany
- * E-mail:
| | - Karine Laroucau
- Paris Est University, Animal Health Laboratory, EU-Reference Laboratory for Glanders, Maisons Alfort Cedex, France
| | - Harisankar Singha
- Indian Council of Agricultural Research—National Research Centre on Equines, Hisar, India
| | | | - Muhammad Saqib
- Department of Clinical Medicine and Surgery, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Ian Gardner
- Department of Health Management, Atlantic Veterinary College, UPEI, Prince Edward Island, Canada
| | - Sheetal Saini
- Indian Council of Agricultural Research—National Research Centre on Equines, Hisar, India
| | - Subodh Kumar
- Defence Research and Development Establishment, Microbiology Division, Gwalior, India
| | - Hosny El-Adawy
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Jena, Germany
- Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh, Egypt
| | - Falk Melzer
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Jena, Germany
| | - Iahtasham Khan
- Section of Epidemiology and Public Health, College of Veterinary and Animal Sciences, Jhang, Pakistan
| | - Praveen Malik
- Chaudhary Charan Singh, National Institute of Animal Health, Department of Animal Husbandry, Dairying and Fisheries, Baghpat, India
| | - Carola Sauter-Louis
- Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Heinrich Neubauer
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Jena, Germany
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Ghori MT, Khan MS, Khan JA, Rabbani M, Shabbir MZ, Chaudhry HR, Ali MA, Muhammad J, Elschner MC, Jayarao BM. Seroprevalence and risk factors of glanders in working equines - Findings of a cross-sectional study in Punjab province of Pakistan. Acta Trop 2017; 176:134-139. [PMID: 28760480 DOI: 10.1016/j.actatropica.2017.07.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 12/17/2022]
Abstract
Glanders is an infectious and contagious bacterial disease of equines. A little is known about its seroprevalence and risk factors in working equines in countries where the disease is endemic. Also, there are no reports on prevalence of the disease in areas where there is a prior evidence of Burkholderia (B.) mallei detection in soil. A cross-sectional study was conducted in selected districts (n=09) of Punjab province of Pakistan during 2014-2015. A total of 1008 serum samples were screened for detection of antibodies to B. mallei with complement fixation test followed by western blot. The overall seroprevalence was found to be 3.17% (95% CI: 2.25-4.44). The seropositivity was significantly higher from the sampling sites where B. mallei was detected in soil [OR: 10.66 (95% CI: 4.42-31.66), p=0.00]. Other risk factors significantly associated with animal seropositivity were: age group [OR: 1.78 (95% CI: 4.58-15.56), p=0.00], location in urban area [OR: 2.99 (95% CI: 1.46-6.51), p=0.00],body condition [OR: 3.47 (95% CI: 1.64-7.99), p=0.00], presence of farcy lesion[OR: 7.71 (95% CI: 3.47-19.50), p=0.00], proximity to water bodies [OR: 7.71 (95% CI: 3.47-19.50), p=0.00]; domestic animal population [OR: 3.20 (95% CI: 1.24-10.87), p=0.03] and number of households in sampling area [OR: 4.18 (95%CI: 1.82-11.30), p=0.00]. The study provides an estimate of prevalence of glanders and a potential link between animal seropositivity and presence of B. mallei in soil. The risk factors identified in this study can be used in surveillance and disease awareness. The high prevalence of disease in draught horses and contact of infected animals with their care-takers in developing countries signify need to initiate progressive control of the disease using one health approach.
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Affiliation(s)
| | | | - Jawaria Ali Khan
- University of Veterinary and Animal Sciences, P.O. Box 54000, Lahore, Pakistan
| | - Masood Rabbani
- University of Veterinary and Animal Sciences, P.O. Box 54000, Lahore, Pakistan
| | | | | | - Muhammad Asad Ali
- University of Veterinary and Animal Sciences, P.O. Box 54000, Lahore, Pakistan
| | - Javed Muhammad
- University of Veterinary and Animal Sciences, P.O. Box 54000, Lahore, Pakistan
| | - Mandy Carolina Elschner
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a 07743, Jena, Germany
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Khan I, Wieler LH, Saqib M, Melzer F, Santana VLDA, Neubauer H, Elschner MC. Effect of incubation temperature on the diagnostic sensitivity of the glanders complement fixation test. REV SCI TECH OIE 2015; 33:869-75. [PMID: 25812210 DOI: 10.20506/rst.33.3.2324] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The complement fixation test (CFT) is the only serological test prescribed by the World Organisation for Animal Health (OIE) for the diagnosis of glanders in international trading of equids. However, false-positive reactions have caused financial losses to the animal owners in the past, and false-negative tests have resulted in the introduction of glanders into healthy equine populations in previously glanders-free areas. Both warm (incubation at 37°C for 1 h) and cold (overnight incubation at 4°C) procedures are recommended by the OIE for serodiagnosis of glanders. In a comparison of the sensitivity and specificity of the two techniques, using the United States Department of Agriculture antigen, warm CFT was found to be significantly less sensitive (56.8%; p < 0.0005) than the cold CFT (83.6%). Cold CFT thus increases the detection rate of glanders but a lower diagnostic specificity has to be accepted. The immunoblot was used as the gold standard.
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Hänsel C, Mertens K, Elschner MC, Melzer F. Novel real-time PCR detection assay for Brucella suis. Vet Rec Open 2015; 2:e000084. [PMID: 26392898 PMCID: PMC4567156 DOI: 10.1136/vetreco-2014-000084] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [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: 08/19/2014] [Revised: 01/30/2015] [Accepted: 02/11/2015] [Indexed: 11/03/2022] Open
Abstract
INTRODUCTION Brucella suis is the causative agent of brucellosis in suidae and is differentiated into five biovars (bv). Biovars 1 and 3 possess zoonotic potential and can infect humans, whereas biovar 2 represents the main source of brucellosis in feral and domestic pigs in Europe. Both aspects, the zoonotic threat and the economic loss, emphasize the necessity to monitor feral and domestic pig populations. Available serological or PCR based methods lack sensitivity and specificity. RESULTS Here a bioinformatics approach was used to identify a B. suis specific 17 bp repeat on chromosome II (BS1330_II0657 locus). This repeat is common for B. suis bv 1 to 4 and was used to develop a TaqMan probe assay. The average PCR efficiency was determined as 95% and the limit of detection as 12,5 fg/µl of DNA, equally to 3.7 bacterial genomes. This assay has the highest sensitivity of all previously described B. suis specific PCR assays, making it possible to detect 3-4 bacterial genomes per 1 µl of sample. The assay was tested 100% specific for B. suis and negative for other Brucella spp. and closely related non-Brucella species. CONCLUSIONS This novel qPCR assay could become a rapid, inexpensive and reliable screening method for large sample pools of B. suis 1 to 4. This method will be applicable for field samples after validation.
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Affiliation(s)
- C Hänsel
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses , Jena, Thüringen , Germany
| | - K Mertens
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses , Jena, Thüringen , Germany
| | - M C Elschner
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses , Jena, Thüringen , Germany
| | - F Melzer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses , Jena, Thüringen , Germany
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Sting R, Schwabe I, Oehme R, Elschner MC, Melzer F. First report of a Brucella suis infection in roe deer (Capreolus capreolus). Berl Munch Tierarztl Wochenschr 2014; 127:120-122. [PMID: 24693656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the present case report the detection of Brucella (B.) suis biovar 2 in roe deer (Capreolus capreolus) is described for the first time. The roe deer fawn was found emaciated and moribund in a hunting ground in the district Hohenlohe in Baden-Württemberg, Germany, in February 2013. A post-mortem examination revealed particularly a high-grade fibrinous pleurisy caused by the pathogen which could be multiplied in a dense growth on sheep blood agar and confirmed and differentiated subsequently by PCR.
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Khan I, Wieler LH, Melzer F, Elschner MC, Muhammad G, Ali S, Sprague LD, Neubauer H, Saqib M. Glanders in animals: a review on epidemiology, clinical presentation, diagnosis and countermeasures. Transbound Emerg Dis 2012; 60:204-21. [PMID: 22630609 DOI: 10.1111/j.1865-1682.2012.01342.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glanders or farcy, caused by Burkholderia mallei, is an infectious and zoonotic disease of solipeds. Horses, donkeys and mules are the only known natural reservoir of B. mallei. Although glanders has been eradicated from most countries, it has regained the status of a re-emerging disease because of the numerous recent outbreaks. Pre-symptomatic or carrier animals are the potential source of infection for the healthy equine population and play a crucial role in the spreading of the infectious agent. Glanders is characterized by ulcerating nodular lesions of the skin and mucous membrane. Generalized symptoms include fever, malaise, depression, cough, anorexia and weight loss. Burkholderia mallei can invade its host through mucous membranes, gastrointestinal tract and the integument. Its virulence mechanisms and pathogenesis are not yet completely understood. A major problem when using serological tests for diagnosing glanders is the occurrence of false-positive and false-negative results leading to difficulties in international trade with equids and to the spread of glanders to disease-free regions. Moreover, poor tests critically result in poor control of disease. These tests are not only incapable of discriminating between B. mallei and B. pseudomallei antibodies, they are also unable to differentiate between malleinized and naturally infected animals. Combined use of both serological and molecular detection methods increases the detection rate of glanders. Countermeasures against glanders include early detection of disease in susceptible animals, stringent quarantine measures, testing and safe destruction of infected carcasses, adequate compensation to the animal owners, disinfection of infected premises and awareness about glanders and the zoonotic implications through veterinary extension services. An account of the clinical picture and successful experimental therapy of spontaneous equine glanders is also given.
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Affiliation(s)
- I Khan
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
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Khan I, Wieler LH, Melzer F, Gwida M, Santana VLDA, de Souza MMA, Saqib M, Elschner MC, Neubauer H. Comparative evaluation of three commercially available complement fixation test antigens for the diagnosis of glanders. Vet Rec 2011; 169:495. [PMID: 21896565 DOI: 10.1136/vr.d5410] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The sensitivity and specificity of three commercially available complement fixation test (CFT) antigens from c.c.pro (c.c.pro), Central Veterinary Institute of Wageningen UR (CIDC) and the United States Department of Agriculture (USDA) were comparatively evaluated by testing 410 sera collected from glanders-endemic and non-endemic areas (200 true-negative randomly collected sera and 210 sera collected from experimentally immunised animals (12 rabbits, 19 horses), clinically positive (135) and culture-positive (44) horses, donkeys and mules). Immunoblotting (IB) was used as the gold standard test. Highest sensitivity was shown for the CIDC antigen (100 per cent) followed by the c.c.pro antigen (99.39 per cent). However, the USDA antigen showed substantially less (p<0.05) sensitivity (62.19 per cent). Highest specificity was found for the USDA antigen (100 per cent) followed by the CIDC (97.5 per cent) and c.c.pro antigen (96.5 per cent). Positive and negative predictive values (assumed glanders prevalence of <0.1 per cent) for each antigen were calculated to be 95.88 and 99.48 (c.c.pro), 97.04 and 100 (CIDC), 100 and 76.33 per cent (USDA), respectively. Almost perfect agreement (0.96) was found between CFT using either c.c.pro or CIDC and IB.
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Affiliation(s)
- I Khan
- Federal Research Institute for Animal Health, Naumburger Strasse 96a, 07743 Jena, Germany.
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