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Kulathunga DGRS, Harding JCS, Rubin JE. Antimicrobial susceptibility of western Canadian Brachyspira isolates: Development and standardization of an agar dilution susceptibility test method. PLoS One 2023; 18:e0286594. [PMID: 37390052 PMCID: PMC10313021 DOI: 10.1371/journal.pone.0286594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 05/19/2023] [Indexed: 07/02/2023] Open
Abstract
The re-emergence of Brachyspira-associated disease in pigs since the late 2000s has illuminated some of the diagnostic challenges associated with this genus; notably, the lack of standardized antimicrobial susceptibility testing (AST) methods and interpretive criteria. Consequently, laboratories have relied heavily on highly variable in-house developed methods. There are currently no published investigations describing the antimicrobial susceptibility of Brachyspira isolates collected from pigs in Canada. The first objective of this study was therefore to develop a standardized protocol for conducting agar dilution susceptibility testing of Brachyspira spp., including determining the optimal standardized inoculum density, a key test variable that impacts test performance. The second objective was to determine the susceptibility of a collection of western Canadian Brachyspira isolates using the standardized methodology. After assessing multiple media, an agar dilution test was standardized in terms of starting inoculum (1-2 × 108 CFU/ml), incubation temperature and time, and assessed for repeatability. The antimicrobial susceptibility of a collection of clinical porcine Brachyspira isolates (n = 87) collected between 2009-2016 was then determined. This method was highly reproducible; repeat susceptibility testing yielded identical results 92% of the time. Although most of the isolates had very low MICs to the commonly used antimicrobials to treat Brachyspira-associated infections, several isolates with elevated MICs (>32 μg/ml) for tiamulin, valnemulin, tylosin, tylvalosin, and lincomycin were identified. Overall, this study underscores the importance of establishing CLSI approved clinical breakpoints for Brachyspira to facilitate the interpretation of test results and support the evidence-based selection of antimicrobials in swine industry.
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Affiliation(s)
- D. G. R. S. Kulathunga
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - John C. S. Harding
- Department of Large Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Joseph E. Rubin
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Parra-Aguirre J, Nosach R, Fernando C, Hill JE, Wilson HL, Harding JCS. Experimental natural transmission (seeder pig) models for reproduction of swine dysentery. PLoS One 2022; 17:e0275173. [PMID: 36166423 PMCID: PMC9514633 DOI: 10.1371/journal.pone.0275173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 09/07/2022] [Indexed: 11/19/2022] Open
Abstract
Swine dysentery is causally associated with Brachyspira hampsonii and B. hyodysenteriae infection. Given the importance of transmission models in understanding re-emergent diseases and developing control strategies such as vaccines, the objective of this experiment was to evaluate two experimental natural transmission (seeder pig) models in grower pigs, each with 24 animals. Seeder pigs were intragastrically inoculated using broth cultures of either B. hampsonii strain 30446 (genomovar II) or B. hyodysenteriae strain G44. In trial 1, three seeder pigs were placed into two pens containing nine susceptible contact pigs creating a 1:3 seeder:contact ratio. This was sufficient to achieve natural B. hampsonii infection of 13/18 (72%) contact pigs, however, the incidence of mucoid or mucohemorrhagic diarrhea (MMHD) in contact pigs differed significantly between pens (4/9 versus 9/9; P = 0.03). In trial 2, eight seeder pigs inoculated intragastrically with B. hampsonii did not develop MMHD but when re-inoculated with B. hyodysenteriae 14 days later, all developed mucohemorrhagic diarrhea within 13 days of re-inoculation. Two seeder pigs were placed into each of 4 contact pens each containing 4 pigs. This 1:2 seeder:contact ratio resulted in natural infection of 14/16 (87%) contact pigs with incubation period ranging from 9–15 days. There were no significant differences among pens in incubation period, duration, clinical period or severity of diarrhea. These trials demonstrated that a 1:2 seeder:contact ratio with groups of six grower pigs per pen sustained natural transmission of B. hyodysenteriae G44 with greater consistency in the incidence of MMHD among pens compared to a B. hampsonii 30446 transmission model using 1:3 seeder:contact ratio in pens of 12. Understanding why B. hampsonii intragastric inoculation failed in one experiment warrants additional research.
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Affiliation(s)
- Juan Parra-Aguirre
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Roman Nosach
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Champika Fernando
- Department of Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Janet E. Hill
- Department of Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Heather L. Wilson
- Department of Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- VIDO/Intervac, University of Saskatchewan, Saskatoon, SK, Canada
| | - John C. S. Harding
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- * E-mail:
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3
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Scherrer S, Stephan R. Novel multiplex TaqMan assay for differentiation of the four major pathogenic Brachyspira species in swine. Microbiologyopen 2021; 10:e1169. [PMID: 33650802 PMCID: PMC7887428 DOI: 10.1002/mbo3.1169] [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] [Received: 11/04/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 01/24/2023] Open
Abstract
A novel TaqMan 5-plex real-time PCR using a combination of locked nucleic acid-modified (LNA)- and minor groove binding (MGB)-conjugated DNA probes was developed for identification and differentiation between the four main pathogenic Brachyspira species in swine. B. hyodysenteriae, B. pilosicoli, and B. suanatina are identified using three hydrolysis probes targeting cpn60, while B. hampsonii is recognized by another nox specific probe. The assay also includes an exogenous internal control simultaneously verifying the PCR competency of the DNA samples. Validation of the novel assay was performed using DNA samples from 18 Brachyspira reference strains and 477 clinical samples obtained from porcine rectal swabs by comparing them with different PCR-based methods targeting nox, 16S rDNA, and 23S rDNA. The specificity of the assay was 100% without cross-reactivity or detection of different pathogens. Depending on the Brachyspira species, the limit of detection was between 10 and 20 genome equivalents with a cut-off threshold cycle (Ct) value of 37. The developed highly sensitive and specific 5-plex real-time PCR assay is easy to implement in routine veterinary diagnostic laboratories and enables rapid differentiation between the main four pathogenic Brachyspira species recognized in pigs using a single-tube approach.
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Affiliation(s)
- Simone Scherrer
- Department of Veterinary Bacteriology, Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Roger Stephan
- Department of Veterinary Bacteriology, Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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4
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Carranza A, Parada J, Tamiozzo P, León MF, Camacho P, Cola GD, Corona-Barrera E, Ambrogi A, Zielinski G. Identification and distribution of Brachyspira species in feces from finishing pigs in Argentina. Vet World 2021; 14:607-613. [PMID: 33935405 PMCID: PMC8076473 DOI: 10.14202/vetworld.2021.607-613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 01/22/2021] [Indexed: 12/03/2022] Open
Abstract
Background and Aim: Brachyspira are Gram-negative, aerotolerant spirochetes that colonize the large intestine of various species of domestic animals and humans. The aim of this study was to determine the presence and distribution of different species of Brachyspira presents in feces from finishing pigs in Argentina. Materials and Methods: Fecal samples (n=1550) were collected from finishing pigs in 53 farms of the most important swine production areas of Argentina, and Brachyspiras species were identified by bacteriological and molecular methods. Results: The regional prevalence of Brachyspira spp. was at the level of 75.5% (confidence interval 95%, 62.9-87.9), and it was lower among those farms with >1001 sows. One hundred and twenty-eight isolates of Brachyspira were properly identified and the species found were: Brachyspira hyodysenteriae, Brachyspira pilosicoli, Brachyspira innocens, and Brachyspira murdochii. B. hyodysenteriae and B. pilosicoli had low prevalence (1.9% and 7.5%, respectively), B. innocens was isolated from 34% of the farms and B. murdochii was found in 39.6%. Conclusion: The present study provides epidemiological data about herd prevalence of the different Brachyspira species in Argentina, showing that the prevalence figure seems to be higher than that reported in other countries.
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Affiliation(s)
- Alicia Carranza
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina
| | - Julián Parada
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina.,National Scientific and Technical Research Council (CONICET), Córdoba, Argentina
| | - Pablo Tamiozzo
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina
| | - Malena Flores León
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina
| | - Pablo Camacho
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina
| | - Gabriel Di Cola
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina
| | - Enrique Corona-Barrera
- Faculty of Veterinary Medicine and Animal Science, Autonomous University of Tamaulipas, Victoria, México
| | - Arnaldo Ambrogi
- Department of Animal Pathology, Faculty of Agronomy and Veterinary, National University of Rio Cuarto, Río Cuarto, Argentina
| | - Gustavo Zielinski
- National Agricultural Technology Institute (INTA), Marcos Juárez, Córdoba, Argentina
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5
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David J H. Distribution and transmission of aetiological agents of swine dysentery. Vet Rec 2019; 182:192-194. [PMID: 30970310 DOI: 10.1136/vr.k571] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Hampson David J
- Department of Infectious Diseases and Public Health, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
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6
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Isolation of Brachyspira hyodysenteriae from a crow ( Corvus corone ) in close proximity to commercial pigs. Vet J 2018; 236:111-112. [DOI: 10.1016/j.tvjl.2018.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/29/2018] [Accepted: 05/01/2018] [Indexed: 11/18/2022]
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7
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Willems H, Heuser J, Ewers C, Herbst W. Isolation and antimicrobial susceptibility of Brachy -spira species from feces of layer chickens in Germany. Tierarztl Prax Ausg G Grosstiere Nutztiere 2018; 46:29-34. [DOI: 10.15653/tpg-170168] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
SummaryObjective: Anaerobic spirochetes of the genus Brachyspira are important pathogens causing swine dysentery (Brachyspira [B.] hyodysenteriae) and porcine intestinal spirochetosis (B. pilosicoli, PIS). In addition, avian intestinal spirochetosis (AIS) is caused by B. pilosicoli, B. intermedia and B. alvinipulli. Despite the economic impact of AIS, the disease has not received appropriate attention in Germany. This study was aimed at identifying Brachyspira spp. in Germany and determining their antimicrobial susceptibility. Material and methods: From 2009 to 2013, a total of 71 fecal swabs were obtained from clinically healthy layer hens from eight different commercial flocks. Brachyspira spp. culture was performed in trypticase soybean agar added with 5% sheep blood. Species determination was conducted by PCRs targeting the NADH-gen and the 16S rDNA or by nox-gene sequencing. Antimicrobial susceptibility to macrolides, lincosamides and pleuromutilins was tested by a microdilution assay. Results: Brachyspira spp. were isolated from 40 (56.3%) swabs distributed over all eight flocks. In 26 cases, the following species were determined by PCR: B. pilosicoli (n = 16), B. intermedia (2), B. innocens (3), B. murdochii (1), mixtures of B. pilosicoli/B. intermedia (2), B. innocens/B. intermedia (1), B. innocens/B. murdochii (1). Remaining isolates were characterized by noxgene sequencing as B. “pulli” (n = 9), B. alvinipulli (3), B. intermedia (1) and as not identifiable (1). Antimicrobial susceptibility testing of 37 isolates revealed minimal inhibitory concentrations 90 (MIC90) of > 128 mg/l (tylosin), 64 mg/l (lincomycin), 8 mg/l (tiamulin) and 4 mg/l (valnemulin), respectively. Comparing to breakpoints applied to pigs, these values lie within the range of resistance. Conclusion The demonstration of different Brachyspira spp., particularly B. pilosicoli, intermedia and alvinipulli in commercial layers, indicates the need of further research to assess their potential role in causing AIS in German poultry flocks. The increased antimicrobial resistance of Brachyspira spp. isolates to tylosin and pleuromutilins is likely associated with extensive use of these drugs in poultry medicine.
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Rohde J, Majzoub-Altweck M, Falkenau A, Hermanns W, Burrough ER, Ritzmann M, Stadler J. Occurrence of dysentery-like diarrhoea associated with Brachyspira suanatina
infection on a German fattening pig farm. Vet Rec 2018; 182:195. [DOI: 10.1136/vr.104705] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/24/2017] [Accepted: 12/24/2017] [Indexed: 11/04/2022]
Affiliation(s)
- Judith Rohde
- Institute for Microbiology, University of Veterinary Medicine, Foundation; Hannover Germany
| | - Monir Majzoub-Altweck
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich; Munich Germany
| | - Almuth Falkenau
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich; Munich Germany
| | - Walter Hermanns
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich; Munich Germany
| | - Eric R Burrough
- Department of Veterinary Diagnostic and Production Animal Medicine; College of Veterinary Medicine, Iowa State University; Ames USA
| | - Mathias Ritzmann
- Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich; Oberschleissheim Germany
| | - Julia Stadler
- Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich; Oberschleissheim Germany
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Joerling J, Barth SA, Schlez K, Willems H, Herbst W, Ewers C. Phylogenetic diversity, antimicrobial susceptibility and virulence gene profiles of Brachyspira hyodysenteriae isolates from pigs in Germany. PLoS One 2018; 13:e0190928. [PMID: 29324785 PMCID: PMC5764319 DOI: 10.1371/journal.pone.0190928] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 12/24/2017] [Indexed: 11/19/2022] Open
Abstract
Swine dysentery (SD) is an economically important diarrheal disease in pigs caused by different strongly hemolytic Brachyspira (B.) species, such as B. hyodysenteriae, B. suanatina and B. hampsonii. Possible associations of epidemiologic data, such as multilocus sequence types (STs) to virulence gene profiles and antimicrobial susceptibility are rather scarce, particularly for B. hyodysenteriae isolates from Germany. In this study, B. hyodysenteriae (n = 116) isolated from diarrheic pigs between 1990 and 2016 in Germany were investigated for their STs, susceptibility to the major drugs used for treatment of SD (tiamulin and valnemulin) and genes that were previously linked with virulence and encode for hemolysins (tlyA, tlyB, tlyC, hlyA, BHWA1_RS02885, BHWA1_RS09085, BHWA1_RS04705, and BHWA1_RS02195), outer membrane proteins (OMPs) (bhlp16, bhlp17.6, bhlp29.7, bhmp39f, and bhmp39h) as well as iron acquisition factors (ftnA and bitC). Multilocus sequence typing (MLST) revealed that 79.4% of the isolates belonged to only three STs, namely ST52 (41.4%), ST8 (12.1%), and ST112 (25.9%) which have been observed in other European countries before. Another 24 isolates belonged to twelve new STs (ST113-118, ST120-123, ST131, and ST193). The temporal distribution of STs revealed the presence of new STs as well as the regular presence of ST52 over three decades (1990s-2000s). The proportion of strains that showed resistance to both tiamulin und valnemulin (39.1%) varied considerably among the most frequent STs ranging from 0% (0/14 isolates resistant) in ST8 isolates to 46.7% (14/30), 52.1% (25/48), and 85.7% (6/7) in isolates belonging to ST112, ST52, and ST114, respectively. All hemolysin genes as well as the iron-related gene ftnA and the OMP gene bhlp29.7 were regularly present in the isolates, while the OMP genes bhlp17.6 and bhmp39h could not be detected. Sequence analysis of hemolysin genes of selected isolates revealed co-evolution of tlyB, BHWA1_RS02885, BHWA1_RS09085, and BHWA1_RS02195 with the core genome and suggested independent evolution of tlyA, tlyC, and hlyA. Our data indicate that in Germany, swine dysentery might be caused by a limited number of B. hyodysenteriae clonal groups. Major STs (ST8, ST52, and ST112) are shared with other countries in Europe suggesting a possible role of the European intra-Community trade of pigs in the dissemination of certain clones. The identification of several novel STs, some of which are single or double locus variants of ST52, may on the other hand hint towards an ongoing diversification of the pathogen in the studied area. The linkage of pleuromutilin susceptibility and sequence type of an isolate might reflect a clonal expansion of the underlying resistance mechanism, namely mutations in the ribosomal RNA genes. A linkage between single virulence-associated genes (VAGs) or even VAG patterns and the phylogenetic background of the isolates could not be established, since almost all VAGs were regularly present in the isolates.
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Affiliation(s)
- Jessica Joerling
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Giessen, Germany
| | - Stefanie A. Barth
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Giessen, Germany
- Friedrich-Loeffler-Institut/ Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Karen Schlez
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Giessen, Germany
| | - Hermann Willems
- Department of Veterinary Clinical Sciences, Clinic for Swine, Justus Liebig University Giessen, Giessen, Germany
| | - Werner Herbst
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Giessen, Germany
| | - Christa Ewers
- Institute of Hygiene and Infectious Diseases of Animals, Justus Liebig University Giessen, Giessen, Germany
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Diseases of the Alimentary Tract. Vet Med (Auckl) 2017. [PMCID: PMC7167529 DOI: 10.1016/b978-0-7020-5246-0.00007-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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La T, Phillips ND, Hampson DJ. An Investigation into the Etiological Agents of Swine Dysentery in Australian Pig Herds. PLoS One 2016; 11:e0167424. [PMID: 27907102 PMCID: PMC5131991 DOI: 10.1371/journal.pone.0167424] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/14/2016] [Indexed: 11/18/2022] Open
Abstract
Swine dysentery (SD) is a mucohemorrhagic colitis, classically seen in grower/finisher pigs and caused by infection with the anaerobic intestinal spirochete Brachyspira hyodysenteriae. More recently, however, the newly described species Brachyspira hampsonii and Brachyspira suanatina have been identified as causing SD in North America and/or Europe. Furthermore, there have been occasions where strains of B. hyodysenteriae have been recovered from healthy pigs, including in multiplier herds with high health status. This study investigated whether cases of SD in Australia may be caused by the newly described species; how isolates of B. hyodysenteriae recovered from healthy herds compared to isolates from herds with disease; and how contemporary isolates compare to those recovered in previous decades, including in their plasmid gene content and antimicrobial resistance profiles. In total 1103 fecal and colon samples from pigs in 97 Australian herds were collected and tested. Of the agents of SD only B. hyodysenteriae was found, being present in 34 (35.1%) of the herds, including in 14 of 24 (58%) herds that had been considered to be free of SD. Multilocus sequence typing applied to 96 isolates from 30 herds and to 53 Australian isolates dating from the 1980s through the early 2000s showed that they were diverse, distinct from those reported in other countries, and that the 2014/16 isolates generally were different from those from earlier decades. These findings provided evidence for ongoing evolution of B. hyodysenteriae strains in Australia. In seven of the 20 herds where multiple isolates were available, two to four different sequence types (STs) were identified. Isolates with the same STs also were found in some herds with epidemiological links. Analysis of a block of six plasmid virulence-associated genes showed a lack of consistency between their presence or absence and their origin from herds currently with or without disease; however, significantly fewer isolates from the 2000s and from 2014/16 had this block of genes compared to isolates from the 1980s and 1990s. It is speculated that loss of these genes may have been responsible for the occurrence of milder disease occurring in recent years. In addition, fewer isolates from 2014/16 were susceptible to the antimicrobials lincomycin, and to a lesser extent tiamulin, than those from earlier Australian studies. Four distinct multi-drug resistant strains were identified in five herds, posing a threat to disease control.
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Affiliation(s)
- Tom La
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Nyree D. Phillips
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - David J. Hampson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
- * E-mail:
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12
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La T, Rohde J, Phillips ND, Hampson DJ. Comparison of Brachyspira hyodysenteriae Isolates Recovered from Pigs in Apparently Healthy Multiplier Herds with Isolates from Herds with Swine Dysentery. PLoS One 2016; 11:e0160362. [PMID: 27489956 PMCID: PMC4973917 DOI: 10.1371/journal.pone.0160362] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 07/18/2016] [Indexed: 11/19/2022] Open
Abstract
Swine dysentery (SD) is a mucohaemorrhagic colitis of grower/finisher pigs classically resulting from infection by the anaerobic intestinal spirochaete Brachyspira hyodysenteriae. This study aimed to determine whether B. hyodysenteriae isolates from pigs in three healthy German multiplier herds supplying gilts to other farms differed from isolates from nine German production herds with SD. Isolates were subjected to whole genomic sequencing, and in silico multilocus sequence typing showed that those from the three multiplier herds were of previously undescribed sequence types (ST132, ST133 and ST134), with all isolates from the same herd having the same ST. All isolates were examined for the presence of 332 genes encoding predicted virulence or virulence lifestyle associated factors, and these were well conserved. Isolates from one multiplier herd were atypical in being weakly haemolytic: they had 10 amino acid substitutions in the haemolysin III protein and five in the haemolysin activation protein compared to reference strain WA1, and had a disruption in the promoter site of the hlyA gene. These changes likely contribute to the weakly haemolytic phenotype and putative lack of virulence. These same isolates also had nine base pair insertions in the iron metabolism genes bitB and bitC and lacked five of six plasmid genes that previously have been associated with colonisation. Other overall differences between isolates from the different herds were in genes from three of five outer membrane proteins, which were not found in all the isolates, and in members of a block of six plasmid genes. Isolates from three herds with SD had all six plasmid genes, while isolates lacking some of these genes were found in the three healthy herds-but also in isolates from six herds with SD. Other differences in genes of unknown function or in gene expression may contribute to variation in virulence; alternatively, superior husbandry and better general health may have made pigs in the two multiplier herds colonised by "typical" strongly haemolytic isolates less susceptible to disease expression.
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Affiliation(s)
- Tom La
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - Judith Rohde
- Institute for Microbiology, University of Veterinary Medicine, Hannover, Germany
| | - Nyree Dale Phillips
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
| | - David J. Hampson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
- * E-mail:
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13
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Löbert S, Zimmermann W, Bürki S, Frey J, Nathues H, Scheer P, Doherr MG, Stalder U, Zeeh F. Occurrence of Brachyspira hyodysenteriae in multiplier pig herds in Switzerland. Tierarztl Prax Ausg G Grosstiere Nutztiere 2016; 44:13-8. [PMID: 26757784 DOI: 10.15653/tpg-150674] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/23/2015] [Indexed: 01/07/2023]
Abstract
OBJECTIVE This research was aimed to determine the occurrence of Brachyspira (B.) hyodysenteriae in Swiss multiplier pig herds. MATERIALS AND METHODS In a pilot study a direct real-time polymerase chain reaction (PCR) method for B. hyodysenteriae was compared to culture followed by PCR on 106 samples from three herds. Subsequently 40 multiplier herds were epidemiologically characterized and analysed for the presence of B. hyodysenteriae using direct PCR on 1412 rectal swabs. For external validation 20 swabs obtained from two positive conventional herds were analysed. RESULTS The comparison of direct PCR with culture followed by PCR resulted in a moderate agreement (kappa index: 0.58). In the two conventional herds, 35% of the samples (7/20) tested positive. Samples from 39 multipliers tested negative. In one multiplier herd, 25% (9/36) of the samples tested PCR positive. Risk factors in the multiplier herd may have been rodents or birds, but not pig purchase. CONCLUSION AND CLINICAL RELEVANCE B. hyodysenteriae have been detected in a Swiss multiplier herd, which underlines the threat of potential spread by replacement pigs. Consequently, a Brachyspira monitoring programme was established for Swiss multiplier herds.
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Affiliation(s)
| | | | | | | | | | | | | | | | - F Zeeh
- Dr. Friederike Zeeh, Clinic for Swine, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, 3001 Bern, Switzerland,
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Mushtaq M, Zubair S, Råsbäck T, Bongcam-Rudloff E, Jansson DS. Brachyspira suanatina sp. nov., an enteropathogenic intestinal spirochaete isolated from pigs and mallards: genomic and phenotypic characteristics. BMC Microbiol 2015; 15:208. [PMID: 26458507 PMCID: PMC4603578 DOI: 10.1186/s12866-015-0537-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 09/25/2015] [Indexed: 11/10/2022] Open
Abstract
Background The genus Brachyspira currently encompasses seven valid species that colonize the intestines of mammals and birds. In a previous study a group of strongly haemolytic isolates from pigs and mallards was provisionally described as a new species within genus Brachyspira, “B. suanatina”, and enteropathogenic properties were demonstrated in a porcine challenge model. Methods In the current study characterization of B. suanatina was performed on the basis of cell morphology, growth characteristics, enzyme profiles, DNA-DNA hybridization (DDH) and whole genome comparisons. The draft genome sequence of B. suanatina strain AN4859/03 was determined and compared with the available genomes of all valid species of Brachyspira. Results According to morphological traits, growth characteristics and enzymatic profiles, B. suanatina was similar to the type strain of B. hyodysenteriae, but using the recommended threshold value of 70 % similarity by DDH it did not belong to any of the recognized Brachyspira species (range 16–64 % similarity). This was further supported by average nucleotide identity values. Phylogenetic analysis performed using housekeeping genes and core genomes of all valid Brachyspira sp. and “B. hampsonii” revealed that B. suanatina and B. intermedia formed a clade distinct from B. hyodysenteriae. By comparing the genomes of the three closely related species B. intermedia, B. hyodysenteriae and B. suanatina similar profiles of general genomic features and distribution of genes in different functional categories were obtained. However, the genome size of B. hyodysenteriae was smallest among the species, suggesting the possibility of reductive evolution in the divergence of this species. A bacteriophage region and a putative plasmid sequence were also found in the genome of B. suanatina strain AN4859/03. Conclusions The results of our study suggest that despite being similar to B. hyodysenteriae phenotypically, B. suanatina should be regarded as a separate species based on its genetic characteristics. Based on characteristics presented in this report we propose that strains AN4859/03, AN1681:1/04, AN2384/04 and Dk12570-2 from pigs in Sweden and Denmark, and strains AN3949:2/02 and AN1418:2/01 isolated from mallards in Sweden, represent a unique species within genus Brachyspira. For this new species we propose the name B. suanatina for which the type strain is AN4859/03T (=ATCC® BAA-2592™ = DSM 100974T). Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0537-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mamoona Mushtaq
- Department of Animal Breeding and Genetics, Global Bioinformatics Centre, Swedish University of Agricultural Sciences (SLU), SE750 07, Uppsala, Sweden.
| | - Saima Zubair
- Department of Animal Breeding and Genetics, Global Bioinformatics Centre, Swedish University of Agricultural Sciences (SLU), SE750 07, Uppsala, Sweden.
| | - Therese Råsbäck
- Department of Bacteriology, National Veterinary Institute (SVA), SE751 89, Uppsala, Sweden.
| | - Erik Bongcam-Rudloff
- Department of Animal Breeding and Genetics, Global Bioinformatics Centre, Swedish University of Agricultural Sciences (SLU), SE750 07, Uppsala, Sweden.
| | - Désirée S Jansson
- Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute (SVA), SE751 89, Uppsala, Sweden. .,Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE750 07, Uppsala, Sweden.
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Molecular Epidemiology of Novel Pathogen "Brachyspira hampsonii" Reveals Relationships between Diverse Genetic Groups, Regions, Host Species, and Other Pathogenic and Commensal Brachyspira Species. J Clin Microbiol 2015; 53:2908-18. [PMID: 26135863 DOI: 10.1128/jcm.01236-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 06/22/2015] [Indexed: 11/20/2022] Open
Abstract
Outbreaks of bloody diarrhea in swine herds in the late 2000s signaled the reemergence of an economically significant disease, swine dysentery, in the United States. Investigations confirmed the emergence of a novel spirochete in swine, provisionally designated "Brachyspira hampsonii," with two genetically distinct clades. Although it has since been detected in swine and migratory birds in Europe and North America, little is known about its genetic diversity or its relationships with other Brachyspira species. This study characterizes B. hampsonii using a newly developed multilocus sequence typing (MLST) approach and elucidates the diversity, distribution, population structure, and genetic relationships of this pathogen from diverse epidemiological sources globally. Genetic characterization of 81 B. hampsonii isolates, originating from six countries, with our newly established MLST scheme identified a total of 20 sequence types (STs) belonging to three clonal complexes (CCs). B. hampsonii showed a heterogeneous population structure with evidence of microevolution locally in swine production systems, while its clustering patterns showed associations with its epidemiological origins (country, swine production system, and host species). The close genetic relatedness of B. hampsonii isolates from different countries and host species highlights the importance of strict biosecurity control measures. A comparative analysis of 430 isolates representing seven Brachyspira species (pathogens and commensals) from 19 countries and 10 host species depicted clustering by microbial species. It revealed the close genetic relatedness of B. hampsonii with commensal Brachyspira species and also provided support for the two clades of B. hampsonii to be considered a single species.
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16
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Hampson DJ, La T, Phillips ND. Emergence of Brachyspira species and strains: reinforcing the need for surveillance. Porcine Health Manag 2015; 1:8. [PMID: 28694985 PMCID: PMC5499009 DOI: 10.1186/s40813-015-0002-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 06/05/2015] [Indexed: 11/24/2022] Open
Abstract
This short review discusses the increasing complexity that has developed around the understanding of Brachyspira species that infect pigs, and their ability to cause disease. It describes the recognition of new weakly haemolytic Brachyspira species, and the growing appreciation that Brachyspira pilosicoli and some other weakly haemolytic species may be pathogenic in pigs. It discusses swine dysentery (SD) caused by the strongly haemolytic Brachyspira hyodysenteriae, particularly the cyclical nature of the disease whereby it can largely disappear as a clinical problem from a farm or region, and re-emerge years later. The review then describes the recent emergence of two newly described strongly haemolytic pathogenic species, “Brachyspira suanatina” and “Brachyspira hampsonii” both of which appear to have reservoirs in migratory waterbirds, and which may be transmitted to and between pigs. “B. suanatina” seems to be confined to Scandinavia, whereas “B. hampsonii” has been reported in North America and Europe, causes a disease indistinguishable from SD, and has required the development of new routine diagnostic tests. Besides the emergence of new species, strains of known Brachyspira species have emerged that vary in important biological properties, including antimicrobial susceptibility and virulence. Strains can be tracked locally and at the national and international levels by identifying them using multilocus sequence typing (MLST) and comparing them against sequence data for strains in the PubMLST databases. Using MLST in conjunction with data on antimicrobial susceptibility can form the basis for surveillance programs to track the movement of resistant clones. In addition some strains of B. hyodysenteriae have low virulence potential, and some of these have been found to lack the B. hyodysenteriae 36 kB plasmid or certain genes on the plasmid whose activity may be associated with colonization. Lack of the plasmid or the genes can be identified using PCR testing, and this information can be added to the MLST and resistance data to undertake detailed surveillance. Strains of low virulence are particularly important where they occur in high health status breeding herds without causing obvious disease: potentially they could be transmitted to production herds where they may colonize more effectively and cause disease under stressful commercial conditions.
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Affiliation(s)
- David J Hampson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6112 Australia
| | - Tom La
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6112 Australia
| | - Nyree D Phillips
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA 6112 Australia
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17
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Cai HY, Caswell JL, Prescott JF. Nonculture Molecular Techniques for Diagnosis of Bacterial Disease in Animals. Vet Pathol 2014; 51:341-50. [DOI: 10.1177/0300985813511132] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The past decade has seen remarkable technical advances in infectious disease diagnosis, and the pace of innovation is likely to continue. Many of these techniques are well suited to pathogen identification directly from pathologic or clinical samples, which is the focus of this review. Polymerase chain reaction (PCR) and gene sequencing are now routinely performed on frozen or fixed tissues for diagnosis of bacterial infections of animals. These assays are most useful for pathogens that are difficult to culture or identify phenotypically, when propagation poses a biosafety hazard, or when suitable fresh tissue is not available. Multiplex PCR assays, DNA microarrays, in situ hybridization, massive parallel DNA sequencing, microbiome profiling, molecular typing of pathogens, identification of antimicrobial resistance genes, and mass spectrometry are additional emerging technologies for the diagnosis of bacterial infections from pathologic and clinical samples in animals. These technical advances come, however, with 2 caveats. First, in the age of molecular diagnosis, quality control has become more important than ever to identify and control for the presence of inhibitors, cross-contamination, inadequate templates from diagnostic specimens, and other causes of erroneous microbial identifications. Second, the attraction of these technologic advances can obscure the reality that medical diagnoses cannot be made on the basis of molecular testing alone but instead through integrated consideration of clinical, pathologic, and laboratory findings. Proper validation of the method is required. It is critical that veterinary diagnosticians understand not only the value but also the limitations of these technical advances for routine diagnosis of infectious disease.
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Affiliation(s)
- H. Y. Cai
- Animal Health Laboratory, University of Guelph, Guelph, Ontario, Canada
| | - J. L. Caswell
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - J. F. Prescott
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
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18
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Rohde J, Habighorst-Blome K, Seehusen F. “Brachyspira hampsonii” clade I isolated from Belgian pigs imported to Germany. Vet Microbiol 2014; 168:432-5. [DOI: 10.1016/j.vetmic.2013.11.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 11/08/2013] [Accepted: 11/09/2013] [Indexed: 11/17/2022]
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Martínez-Lobo FJ, Hidalgo Á, García M, Argüello H, Naharro G, Carvajal A, Rubio P. First identification of "Brachyspira hampsonii" in wild European waterfowl. PLoS One 2013; 8:e82626. [PMID: 24349322 PMCID: PMC3857821 DOI: 10.1371/journal.pone.0082626] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 10/25/2013] [Indexed: 11/18/2022] Open
Abstract
Anseriformes deserve special attention in the epidemiology of Brachyspira spp. because diverse Anseriformes species have been described to act as highly efficient carriers of several Brachyspira spp. that can also infect livestock. The aim of this study was to investigate the prevalence and diversity of Brachyspira spp. in waterfowl that winter in Spain. Brachyspira spp. were isolated from 51 of the 205 faecal samples collected from graylag geese and mallards in the Villafáfila Lagoons Nature Reserve (Northwestern Spain). The Brachyspira species identified through phenotyping, PCR and sequencing of the nox gene were B. pilosicoli (5.9%), B. alvinipulli (11.8%), "B. hampsonii" (19.6%), B. murdochii (23.5%) and B. innocens (39.2%). The most relevant finding of this study is the description of "B. hampsonii" in specimens from birds for the first time. Phylogenetic analysis of the nox gene sequences grouped all of the obtained "B. hampsonii" isolates into a cluster with Brachyspira strains previously identified by others as "B. hampsonii" and separated from other Brachyspira spp. isolates and reference strains. Additionally, this cluster was related to clades that grouped B. murdochii and B. innocens isolates. The identification of "B. hampsonii" was also achieved in 8 of the 10 isolates by sequencing the16S rRNA gene and tlyA gene. Regardless of the species identified, no antimicrobial resistance was observed in any of the enteropathogenic isolates recovered. This is the first description of "B. hampsonii" in European waterfowl, which might represent hosts that serve as natural reservoirs of this Brachyspira species. This finding indicates that this spirochete is not limited to North America, and its presence in wild birds in Europe poses a risk of transmission to livestock.
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Affiliation(s)
| | - Álvaro Hidalgo
- Infectious Diseases and Epidemiology Unit, Faculty of Veterinary Medicine, University of León, León, Spain
| | - Marta García
- Infectious Diseases and Epidemiology Unit, Faculty of Veterinary Medicine, University of León, León, Spain
| | - Héctor Argüello
- Infectious Diseases and Epidemiology Unit, Faculty of Veterinary Medicine, University of León, León, Spain
| | - Germán Naharro
- Infectious Diseases and Epidemiology Unit, Faculty of Veterinary Medicine, University of León, León, Spain
| | - Ana Carvajal
- Infectious Diseases and Epidemiology Unit, Faculty of Veterinary Medicine, University of León, León, Spain
| | - Pedro Rubio
- Infectious Diseases and Epidemiology Unit, Faculty of Veterinary Medicine, University of León, León, Spain
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20
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Mappley LJ, La Ragione RM, Woodward MJ. Brachyspira and its role in avian intestinal spirochaetosis. Vet Microbiol 2013; 168:245-60. [PMID: 24355534 DOI: 10.1016/j.vetmic.2013.11.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 11/17/2013] [Accepted: 11/18/2013] [Indexed: 10/26/2022]
Abstract
The fastidious, anaerobic spirochaete Brachyspira is capable of causing enteric disease in avian, porcine and human hosts, amongst others, with a potential for zoonotic transmission. Avian intestinal spirochaetosis (AIS), the resulting disease from colonisation of the caeca and colon of poultry by Brachyspira leads to production losses, with an estimated annual cost of circa £ 18 million to the commercial layer industry in the United Kingdom. Of seven known and several proposed species of Brachyspira, three are currently considered pathogenic to poultry; B. alvinipulli, B. intermedia and B. pilosicoli. Currently, AIS is primarily prevented by strict biosecurity controls and is treated using antimicrobials, including tiamulin. Other treatment strategies have been explored, including vaccination and probiotics, but such developments have been hindered by a limited understanding of the pathobiology of Brachyspira. A lack of knowledge of the metabolic capabilities and little genomic information for Brachyspira has resulted in a limited understanding of the pathobiology. In addition to an emergence of antibiotic resistance amongst Brachyspira, bans on the prophylactic use of antimicrobials in livestock are driving an urgent requirement for alternative treatment strategies for Brachyspira-related diseases, such as AIS. Advances in the molecular biology and genomics of Brachyspira heralds the potential for the development of tools for genetic manipulation to gain an improved understanding of the pathogenesis of Brachyspira.
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Affiliation(s)
- Luke J Mappley
- Department of Bacteriology, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey KT15 3NB, UK; Department of Food and Nutritional Sciences, University of Reading, Reading, Berkshire RG6 6AP, UK.
| | - Roberto M La Ragione
- Department of Bacteriology, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey KT15 3NB, UK; School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Martin J Woodward
- Department of Food and Nutritional Sciences, University of Reading, Reading, Berkshire RG6 6AP, UK
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21
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Prohaska S, Pflüger V, Ziegler D, Scherrer S, Frei D, Lehmann A, Wittenbrink M, Huber H. MALDI-TOF MS for identification of porcine Brachyspira
species. Lett Appl Microbiol 2013; 58:292-8. [DOI: 10.1111/lam.12189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 10/09/2013] [Accepted: 10/28/2013] [Indexed: 12/01/2022]
Affiliation(s)
- S. Prohaska
- Vetsuisse Faculty; Institute of Veterinary Bacteriology; University of Zurich; Zurich Switzerland
| | | | | | - S. Scherrer
- Vetsuisse Faculty; Institute of Veterinary Bacteriology; University of Zurich; Zurich Switzerland
| | - D. Frei
- Vetsuisse Faculty; Institute of Veterinary Bacteriology; University of Zurich; Zurich Switzerland
| | - A. Lehmann
- Vetsuisse Faculty; Institute of Veterinary Bacteriology; University of Zurich; Zurich Switzerland
| | - M.M. Wittenbrink
- Vetsuisse Faculty; Institute of Veterinary Bacteriology; University of Zurich; Zurich Switzerland
| | - H. Huber
- Vetsuisse Faculty; Institute of Veterinary Bacteriology; University of Zurich; Zurich Switzerland
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22
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Rubin JE, Harms NJ, Fernando C, Soos C, Detmer SE, Harding JCS, Hill JE. Isolation and characterization of Brachyspira spp. including "Brachyspira hampsonii" from lesser snow geese (Chen caerulescens caerulescens) in the Canadian Arctic. MICROBIAL ECOLOGY 2013; 66:813-822. [PMID: 23933825 DOI: 10.1007/s00248-013-0273-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 07/24/2013] [Indexed: 06/02/2023]
Abstract
Brachyspira is associated with diarrhea and colitis in pigs, and control of these pathogens is complicated by their complex ecology. Identification of wildlife reservoirs of Brachyspira requires the discrimination of colonized animals and those simply contaminated through environmental exposure. Lesser snow geese (Chen caerulescens caerulescens) were sampled in the Canadian arctic during the summer of 2011, and cloacal swabs were cultured on selective media. Brachyspira isolates were obtained from 15/170 (8.8 %) samples, and 12/15 isolates were similar to isolates previously recovered from pigs, including "Brachyspira hampsonii", a recently characterized species associated with dysentery-like disease in pigs in North America. A pilot inoculation study with one strongly β-hemolytic B. hampsonii isolate resulted in fecal shedding of the isolate by inoculated pigs for up to 14 days post-inoculation, but no severe clinical disease. Results of this study indicate that lesser snow geese can be colonized by Brachyspira strains that can also colonize pigs. Millions of lesser snow geese (C. caerulescens caerulescens) travel through the major pork-producing areas of Canada and the USA during their annual migration, making them a potential factor in the continental distribution of these bacteria.
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Affiliation(s)
- Joseph E Rubin
- Department of Veterinary Microbiology, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada
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Osorio J, Carvajal A, Naharro G, Rubio P, La T, Phillips ND, Hampson DJ. Identification of weakly haemolytic Brachyspira isolates recovered from pigs with diarrhoea in Spain and Portugal and comparison with results from other countries. Res Vet Sci 2013; 95:861-9. [PMID: 23928181 DOI: 10.1016/j.rvsc.2013.07.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 07/02/2013] [Accepted: 07/13/2013] [Indexed: 10/26/2022]
Abstract
Weakly haemolytic anaerobic intestinal spirochaetes of the genus Brachyspira are commonly identified based on species-specific gene sequences. Apart from the pathogenic Brachyspira pilosicoli, the distribution and disease associations of the other weakly haemolytic Brachyspira species in pigs have not been comprehensively investigated. In this study weakly haemolytic Brachyspira isolates (n=67) from Spanish and Portuguese pigs with diarrhoea, negative in a routine diagnostic PCR for B. pilosicoli, were identified by sequencing their NADH oxidase genes (nox). Nearly half the isolates were identified as Brachyspira murdochii (n=31; 46.3%). The others were Brachyspira innocens (n=26; 38.8%), Brachyspira intermedia (n=7; 10.4%), "Brachyspira pulli" (n=1; 1.5%) and a potentially novel Brachyspira species (n=2; 3%). Multilocus sequence typing (MLST) on a subset of 18 isolates confirmed their species designations, including the potential new species, and identified similarities to strains from other countries.
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Affiliation(s)
- J Osorio
- Animal Health Department, Faculty of Veterinary Sciences, University of León, León 24071, Spain
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