1
|
Mazwi KD, Kolo FB, Jaja IF, Byaruhanga C, Hassim A, van Heerden H. Polyphasic Characterization of Brucella spp. in Livestock Slaughtered from Abattoirs in Eastern Cape, South Africa. Microorganisms 2024; 12:223. [PMID: 38276208 PMCID: PMC10819803 DOI: 10.3390/microorganisms12010223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/04/2024] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
In livestock, brucellosis is mainly an asymptomatic disease except when abortion occurs; therefore, two serological tests are used for diagnosis as no single test is suitable. Abattoir samples enable a combination of culture, molecular, and serological tests to detect brucellosis. This study assessed Brucella-specific PCR (ITS-PCR) to detect brucellosis and to conduct a molecular characterization of Brucella spp. isolated from PCR-positive livestock (n = 565) slaughtered at abattoirs and the appropriate sample tissue(s). ITS-PCR detected Brucella DNA in 33.6% of cattle, 14.5% of sheep, and 4.7% of pig tissues. Impure Brucella cultures from PCR-positive tissues were 43.6% (44/94) of cattle, 51.7% (15/29) of sheep, and 50% (2/4) of pigs with predominantly B. abortus identification with AMOS-PCR and low isolation of mixed B. abortus and B. melitensis in all species. In cattle, 33% of isolates were from lymph nodes, while in sheep 38.0% were from the liver and kidney and only from tonsils in pigs (2/4). Brucella infections identified with AMOS-PCR were present in seropositive and mainly seronegative (75.6-100%) livestock with the potential to cause brucellosis during pregnancy or breeding. This study demonstrated the value of the polyphasic approach, especially with chronic infections and the potential risk of these asymptomatic animals.
Collapse
Affiliation(s)
- Koketso Desiree Mazwi
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0002, South Africa
| | - Francis Babaman Kolo
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0002, South Africa
| | - Ishmael Festus Jaja
- Department of Livestock and Pasture Science, Faculty of Science and Agriculture, University of Fort Hare, Alice 5700, South Africa
- Department of Agriculture and Animal Health, University of South Africa, Roodepoort, Johannesburg 1709, South Africa
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0002, South Africa
- National Agricultural Research Organisation, Entebbe P.O. Box 259, Uganda
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0002, South Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0002, South Africa
| |
Collapse
|
2
|
Kolo FB, Adesiyun AA, Fasina FO, Harris BN, Rossouw J, Byaruhanga C, Geyer HDW, Blumberg L, Frean J, van Heerden H. Brucellosis Seropositivity Using Three Serological Tests and Associated Risk Factors in Abattoir Workers in Gauteng Province, South Africa. Pathogens 2024; 13:64. [PMID: 38251371 PMCID: PMC10821213 DOI: 10.3390/pathogens13010064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/21/2023] [Accepted: 01/04/2024] [Indexed: 01/23/2024] Open
Abstract
Abattoir workers are liable to zoonotic infections from animals and animal products, primarily to diseases with asymptomatic and chronic clinical manifestations in animals, such as brucellosis. No published reports exist on the seroprevalence of brucellosis in abattoir workers in South Africa. Therefore, this cross-sectional study was conducted to estimate the occurrence and risk factors for Brucella exposure in abattoir workers in Gauteng Province. A total of 103 abattoir workers and managers from 6 abattoirs, where brucellosis-positive slaughtered cattle and sheep were previously detected, were interviewed and tested with serological assays using the Rose Bengal test (RBT), BrucellaCapt, and IgG-ELISA. A pre-tested questionnaire was administered to consenting respondents to obtain information on risk factors for brucellosis. Of the 103 respondents tested, the distribution of female and male workers was 16 (15.5%) and 87 (84.5%), respectively. The seroprevalence for exposure to brucellosis was 21/103 (20.4%, 95%CI: 13.1-29.5) using a combination of RBT, BrucellaCapt, or IgG-ELISA. For test-specific results, seroprevalences by RBT, BrucellaCapt, and IgG-ELISA were 13/103 (12.6%, 95%CI: 6.9-20.6), 9/103 (8.74%, 95%CI: 4.1-15.9), and 18/103 (17.5%, 95%CI: 10.7-26.2), respectively. Low-throughput abattoirs were identified as associated risks, as 29.3% of workers were seropositive compared with 12.7% of workers in high-throughput abattoirs, which highlights that direct contact at abattoirs poses higher risk to workers than indirect and direct contact outside abattoirs. This study confirms the occurrence of Brucella spp. antibodies among abattoir workers in South Africa, possibly due to occupational exposure to Brucella spp., and highlights the occupational hazard to workers. Furthermore, findings underscore that abattoir facilities can serve as points for active and passive surveillance for indicators of diseases of public health importance. We recommend periodic implementation of brucellosis testing of abattoir workers country-wide to establish baseline data for informing appropriate preventive practices and reducing the potential burden of infection rates among these high-risk workers.
Collapse
Affiliation(s)
- Francis B. Kolo
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria 0182, South Africa; (F.O.F.); (C.B.); (H.v.H.)
| | - Abiodun A. Adesiyun
- Faculty of Veterinary Science, Department of Production Animal Studies, University of Pretoria, Pretoria 0182, South Africa;
| | - Folorunso O. Fasina
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria 0182, South Africa; (F.O.F.); (C.B.); (H.v.H.)
| | - Bernice N. Harris
- School of Health Systems and Public Health, Faculty of Health Science, University of Pretoria, Pretoria 0084, South Africa;
| | - Jennifer Rossouw
- Centre for Emerging, Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg 2132, South Africa; (J.R.); (H.D.W.G.); (L.B.); (J.F.)
| | - Charles Byaruhanga
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria 0182, South Africa; (F.O.F.); (C.B.); (H.v.H.)
| | - Hermanus De Wet Geyer
- Centre for Emerging, Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg 2132, South Africa; (J.R.); (H.D.W.G.); (L.B.); (J.F.)
| | - Lucille Blumberg
- Centre for Emerging, Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg 2132, South Africa; (J.R.); (H.D.W.G.); (L.B.); (J.F.)
| | - John Frean
- Centre for Emerging, Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg 2132, South Africa; (J.R.); (H.D.W.G.); (L.B.); (J.F.)
- Faculty of Health Sciences, University of Witwatersrand, Johannesburg 2050, South Africa
| | - Henriette van Heerden
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria 0182, South Africa; (F.O.F.); (C.B.); (H.v.H.)
| |
Collapse
|
3
|
Huang YH, Owen-Smith N, Henley MD, Kilian JW, Kamath PL, Ochai SO, van Heerden H, Mfune JKE, Getz WM, Turner WC. Variation in herbivore space use: comparing two savanna ecosystems with different anthrax outbreak patterns in southern Africa. Mov Ecol 2023; 11:46. [PMID: 37525286 PMCID: PMC10392021 DOI: 10.1186/s40462-023-00385-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 04/16/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND The distribution of resources can affect animal range sizes, which in turn may alter infectious disease dynamics in heterogenous environments. The risk of pathogen exposure or the spatial extent of outbreaks may vary with host range size. This study examined the range sizes of herbivorous anthrax host species in two ecosystems and relationships between spatial movement behavior and patterns of disease outbreaks for a multi-host environmentally transmitted pathogen. METHODS We examined range sizes for seven host species and the spatial extent of anthrax outbreaks in Etosha National Park, Namibia and Kruger National Park, South Africa, where the main host species and outbreak sizes differ. We evaluated host range sizes using the local convex hull method at different temporal scales, within-individual temporal range overlap, and relationships between ranging behavior and species contributions to anthrax cases in each park. We estimated the spatial extent of annual anthrax mortalities and evaluated whether the extent was correlated with case numbers of a given host species. RESULTS Range size differences among species were not linearly related to anthrax case numbers. In Kruger the main host species had small range sizes and high range overlap, which may heighten exposure when outbreaks occur within their ranges. However, different patterns were observed in Etosha, where the main host species had large range sizes and relatively little overlap. The spatial extent of anthrax mortalities was similar between parks but less variable in Etosha than Kruger. In Kruger outbreaks varied from small local clusters to large areas and the spatial extent correlated with case numbers and species affected. Secondary host species contributed relatively few cases to outbreaks; however, for these species with large range sizes, case numbers positively correlated with outbreak extent. CONCLUSIONS Our results provide new information on the spatiotemporal structuring of ranging movements of anthrax host species in two ecosystems. The results linking anthrax dynamics to host space use are correlative, yet suggest that, though partial and proximate, host range size and overlap may be contributing factors in outbreak characteristics for environmentally transmitted pathogens.
Collapse
Affiliation(s)
- Yen-Hua Huang
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Norman Owen-Smith
- Centre for African Ecology, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Wits, 2050, South Africa
| | - Michelle D Henley
- Applied Behavioural Ecology and Ecosystem Research Unit, School of Environmental Sciences, University of South Africa, Florida, Johannesburg, 1710, South Africa
- Elephants Alive, Ekuthuleni Shareblock Ltd, Hoedspruit, 1380, South Africa
- Department of Philosophy, Faculty of Humanities, University of Johannesburg, Auckland Park, 2006, South Africa
| | - J Werner Kilian
- Etosha Ecological Institute (retired), Etosha National Park, Ministry of Environment, Forestry and Tourism, Okaukuejo, Namibia
| | - Pauline L Kamath
- School of Food and Agriculture, University of Maine, Orono, ME, 04469, USA
| | - Sunday O Ochai
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | - John K E Mfune
- Department of Environmental Science, University of Namibia, Windhoek, Namibia
| | - Wayne M Getz
- Department of Environmental Science, Policy & Management, University of California, Berkeley, CA, 94704, USA
- School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Wendy C Turner
- Wisconsin Cooperative Wildlife Research Unit, U.S. Geological Survey, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| |
Collapse
|
4
|
Ochai SO, Crafford JE, Kamath PL, Turner WC, van Heerden H. Development of conjugated secondary antibodies for wildlife disease surveillance. Front Immunol 2023; 14:1221071. [PMID: 37503338 PMCID: PMC10368751 DOI: 10.3389/fimmu.2023.1221071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 06/14/2023] [Indexed: 07/29/2023] Open
Abstract
Disease monitoring in free-ranging wildlife is a challenge and often relies on passive surveillance. Alternatively, proactive surveillance that relies on the detection of specific antibodies could give more reliable and timely insight into disease presence and prevalence in a population, especially if the evidence of disease occurs below detection thresholds for passive surveillance. Primary binding assays, like the indirect ELISA for antibody detection in wildlife, are hampered by a lack of species-specific conjugates. In this study, we developed anti-kudu (Tragelaphus strepsiceros) and anti-impala (Aepyceros melampus) immunoglobulin-specific conjugates in chickens and compared them to the binding of commercially available protein-G and protein-AG conjugates, using an ELISA-based avidity index. The conjugates were evaluated for cross-reaction with sera from other wild herbivores to assess future use in ELISAs. The developed conjugates had a high avidity of >70% against kudu and impala sera. The commercial conjugates (protein-G and protein-AG) had significantly low relative avidity (<20%) against these species. Eighteen other wildlife species demonstrated cross-reactivity with a mean relative avidity of >50% with the impala and kudu conjugates and <40% with the commercial conjugates. These results demonstrate that species-specific conjugates are important tools for the development and validation of immunoassays in wildlife and for the surveillance of zoonotic agents along the livestock-wildlife-human interface.
Collapse
Affiliation(s)
- Sunday O. Ochai
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Jan E. Crafford
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Pauline L. Kamath
- School of Food and Agriculture, University of Maine, Orono, ME, United States
| | - Wendy C. Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, United States
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| |
Collapse
|
5
|
Barandongo ZR, Dolfi AC, Bruce SA, Rysava K, Huang YH, Joel H, Hassim A, Kamath PL, van Heerden H, Turner WC. The persistence of time: the lifespan of Bacillus anthracis spores in environmental reservoirs. Res Microbiol 2023; 174:104029. [PMID: 36720294 DOI: 10.1016/j.resmic.2023.104029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/12/2023] [Accepted: 01/13/2023] [Indexed: 01/30/2023]
Abstract
Anthrax is a lethal bacterial zoonosis primarily affecting herbivorous wildlife and livestock. Upon host death Bacillus anthracis vegetative cells form spores capable of surviving for years in soil. Anthrax transmission requires host exposure to large spore doses. Thus, conditions that facilitate higher spore concentrations or promote spore survival will increase the probability that a pathogen reservoir infects future hosts. We investigated abiotic and pathogen genomic variation in relation to spore concentrations in surface soils (0-1 cm depth) at 40 plains zebra (Equus quagga) anthrax carcass sites in Namibia. Specifically, how initial spore concentrations and spore survival were affected by seasonality associated with the timing of host mortality, local soil characteristics, and pathogen genomic variation. Zebras dying of anthrax in wet seasons-the peak season for anthrax in Etosha National Park-had soil spore concentrations 1.36 orders of magnitude higher than those that died in dry seasons. No other variables considered affected spore concentrations, and spore survival rates did not differ among sites. Surface soils at these pathogen reservoirs remained culture positive for a range of 3.8-10.4 years after host death. Future research could evaluate if seasonal patterns in spore concentrations are driven by differences in sporulation success or levels of terminal bacteremia.
Collapse
Affiliation(s)
- Zoë R Barandongo
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Amélie C Dolfi
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Spencer A Bruce
- Department of Biological Sciences, State University of New York, Albany, NY 12222, USA.
| | - Kristyna Rysava
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Yen-Hua Huang
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Hendrina Joel
- Department of Environmental Science, Faculty of Science, University of Namibia, Private Bag 13301, Windhoek, Namibia.
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
| | - Pauline L Kamath
- School of Food and Agriculture, University of Maine, Orono, ME, USA.
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
| | - Wendy C Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| |
Collapse
|
6
|
Madzingira O, Aikukutu G, Kandongo F, Kolo FB, Khaiseb S, Tjipura-Zaire G, Kabajani JN, Musilika-Shilongo A, van Heerden H. Seroprevalence, and molecular detection of Brucella abortus in cattle tissues from an abattoir in Namibia. Infect Ecol Epidemiol 2023; 13:2229589. [PMID: 37398877 PMCID: PMC10308871 DOI: 10.1080/20008686.2023.2229589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/21/2023] [Indexed: 07/04/2023] Open
Abstract
Brucellosis is a worldwide zoonosis that is endemic in Namibia. This study estimated seroprevalence of brucellosis, and determined the presence of Brucella infection in slaughtered cattle using the genus-specific 16-23S rRNA interspacer PCR (ITS-PCR), and the species-specific AMOS-PCR. Between December 2018 and May 2019, sera (n = 304), pooled lymph nodes (n = 304), and individual spleen (n = 304) were collected from slaughtered cattle from 52 farms. Sera were tested for anti-Brucella antibodies using the Rose Bengal test (RBT), and the complement fixation test (CFT). Seroprevalence was 2.3% (7/304) (RBT) and 1.6% (5/304) (CFT). Prevalence of positive herds was 9.6% (5/52). Lymph node (n = 200) and spleen (n = 200) samples from seronegative cattle tested negative for Brucella spp. DNA on ITS-PCR, but Brucella spp. DNA was detected in lymph nodes (85.7%, 6/7) and spleen (85.7%, 6/7) from RBT positive cattle. ITS-PCR confirmed isolates from lymph node (51.4%, 4/7) and spleen (85.7%, 6/7) as Brucella spp.; while AMOS-PCR and Brucella abortus species specific (BaSS) PCR confirmed the isolates as Brucella abortus, and field strains, respectively. Provision of adequate protective gear, and the promotion of brucellosis awareness among abattoir workers is recommended to prevent zoonotic infection.
Collapse
Affiliation(s)
- Oscar Madzingira
- Department of Paraclinical Sciences, School of Veterinary Medicine, Faculty of Health Sciences and Veterinary Medicine, University of Namibia, Windhoek, Namibia
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Gottlieb Aikukutu
- Central Veterinary Laboratory, Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia
| | - Fidelis Kandongo
- Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia
| | - Francis B. Kolo
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Siegfried Khaiseb
- Central Veterinary Laboratory, Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia
| | - Georgina Tjipura-Zaire
- Central Veterinary Laboratory, Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia
| | - Juliet N. Kabajani
- Central Veterinary Laboratory, Directorate of Veterinary Services, Ministry of Agriculture, Water and Land Reform, Windhoek, Namibia
| | | | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| |
Collapse
|
7
|
Dogonyaro BB, van Heerden H, Potts AD, Fasina FO, Casanovas-Massana A, Kolo FB, Lötter C, Byaruhanga C, Ko AI, Wunder EA, Adesiyun AA. Molecular Characterization of Leptospira Species Detected in the Kidneys of Slaughtered Livestock in Abattoirs in Gauteng Province, South Africa. Pathogens 2023; 12:666. [PMID: 37242336 PMCID: PMC10223745 DOI: 10.3390/pathogens12050666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
Leptospira was investigated in kidneys (n = 305) from slaughtered livestock in the Gauteng Province abattoirs, South Africa, using a culture medium to isolate Leptospira, followed by the LipL32 qPCR to detect Leptospira DNA. The SecY gene region was amplified, sequenced, and analyzed for LipL32 qPCR-positive samples or Leptospira isolates. The overall frequency of isolation of Leptospira spp. was 3.9% (12/305), comprising 4.8% (9/186), 4.1% (3/74), and 0% (0/45) from cattle, pigs, and sheep, respectively (p > 0.05). However, with LipL32 qPCR, the overall frequency of Leptospira DNA was 27.5%, consisting of 26.9%, 20.3%, and 42.2% for cattle, pigs, and sheep, respectively (p = 0.03). Based on 22 SecY sequences, the phylogenetic tree identified the L. interrogans cluster with serovar Icterohaemorrhagiae and the L. borgpetersenii cluster with serovar Hardjo bovis strain Lely 607. This study is the first molecular characterization of Leptospira spp. from livestock in South Africa. The reference laboratory uses an eight-serovar microscopic agglutination test panel for leptospirosis diagnosis, of which L. borgpetersenii serovar Hardjo bovis is not part. Our data show that pathogenic L. interrogans and L. borgpetersenii are circulating in the livestock population. Diagnostic use of molecular methods will eliminate or reduce the under-reporting of leptospirosis in livestock, particularly sheep, in South Africa.
Collapse
Affiliation(s)
- Banenat B. Dogonyaro
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, CT 06520, USA
- National Veterinary Research Institute, Virology Department, Vom 930101, Nigeria
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - Andrew D. Potts
- Bacterial Serology Laboratory, ARC-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa
| | - Folorunso O. Fasina
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
- ECTAD, Food and Agriculture Organization of the United Nations, Nairobi 00100, Kenya
| | - Arnau Casanovas-Massana
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, CT 06520, USA
| | - Francis B. Kolo
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - Christine Lötter
- Bacterial Serology Laboratory, ARC-Onderstepoort Veterinary Research, Onderstepoort 0110, South Africa
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - Albert I. Ko
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, CT 06520, USA
- Gonçalo Moniz Research Center, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Salvador 40081, Brazil
| | - Elsio A. Wunder
- Department of Epidemiology of Microbial Diseases, School of Public Health, Yale University, New Haven, CT 06520, USA
- Gonçalo Moniz Research Center, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Salvador 40081, Brazil
| | - Abiodun A. Adesiyun
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
- Department of Paraclinical Sciences, School of Veterinary Medicine, The University of West Indies, St. Augustine 685509, Trinidad and Tobago
| |
Collapse
|
8
|
Ntivuguruzwa JB, Babaman Kolo F, Mwikarago EI, van Heerden H. Seroprevalence of brucellosis and molecular characterization of Brucella spp. from slaughtered cattle in Rwanda. PLoS One 2022; 17:e0261595. [PMID: 36413520 PMCID: PMC9681097 DOI: 10.1371/journal.pone.0261595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 11/06/2022] [Indexed: 11/23/2022] Open
Abstract
Bovine brucellosis is endemic in Rwanda, although, there is a paucity of documented evidence about the disease in slaughtered cattle. A cross-sectional study was conducted in slaughtered cattle (n = 300) to determine the seroprevalence of anti-Brucella antibodies using the Rose Bengal Test (RBT), and indirect enzyme-linked immunosorbent assay (i-ELISA). Corresponding tissues were cultured onto a modified Centro de Investigación y Tecnología Agroalimentaria (CITA) selective medium and analysed for Brucella spp. using the 16S-23S ribosomal interspacer region (ITS), AMOS, and Bruce-ladder PCR assays. The seroprevalence was 20.7% (62/300) with RBT, 2.9% (8/300) with i-ELISA, and 2.9% (8/300) using both tests in series. Brucella-specific 16S-23S ribosomal DNA interspace region (ITS) PCR detected Brucella DNA in 5.6% (17/300; Brucella culture prevalence). AMOS-PCR assay identified mixed B. abortus and B. melitensis (n = 3), B. abortus (n = 3) and B. melitensis (n = 5) while Bruce-ladder PCR also identified B. abortus (n = 5) and B. melitensis (n = 6). The gold standard culture method combined with PCR confirmation identified 5.6% Brucella cultures and this culture prevalence is higher than the more sensitive seroprevalence of 2.9%. This emphasizes the need to validate the serological tests in Rwanda. The mixed infection caused by B. abortus and B. melitensis in slaughtered cattle indicates cross-infection and poses a risk of exposure potential to abattoir workers. It is essential to urgently strengthen a coordinated national bovine brucellosis vaccination and initiate a test-and-slaughter program that is not presently applicable in Rwanda.
Collapse
Affiliation(s)
- Jean Bosco Ntivuguruzwa
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
- Department of Veterinary Medicine, College of Veterinary Medicine, University of Rwanda, Kigali, Rwanda
- * E-mail:
| | - Francis Babaman Kolo
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Emil Ivan Mwikarago
- Department of Biomedical Services, National Reference Laboratory Division, Rwanda Biomedical Centre, Kigali, Rwanda
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
9
|
Madzingira O, Byaruhanga C, Fasina FO, van Heerden H. Assessment of knowledge, attitudes and practices relating to brucellosis among cattle farmers, meat handlers and medical professionals in Namibia. Vet Med Sci 2022; 9:535-547. [PMID: 36382350 PMCID: PMC9857002 DOI: 10.1002/vms3.937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Brucellosis is a re-emerging zoonosis of significant socio-economic, animal and public health importance. It is principally a foodborne or occupation-associated infection of humans, whose effective control depends on maximum cooperation of high-risk populations. OBJECTIVES The study assessed knowledge, attitudes and practices relating to brucellosis among cattle farmers (communal and commercial), meat handlers (abattoir and butchery workers) and medical professionals (nurses and doctors) in Namibia. METHODS Between June 2019 and September 2020, self-administered questionnaires and questionnaire interviews were carried out in cattle farmers (n = 264), meat handlers (n = 143) and medical professionals (n = 124) in Namibia. RESULTS Overall, 43.50% (231/531) of respondents were aware of brucellosis, with the highest awareness among medical professionals (73.39%, 91/124) and the least in meat handlers (13.99%, 20/143). Awareness of brucellosis was associated with tertiary education (p < 0.001) and the medical profession (p < 0.001). However, most medical professionals (98.39%, 122/124) did not consider brucellosis as a differential diagnosis in cases of persistent febrile illness. A proportion of communal (85.60%) and commercial (71.00%) farmers; abattoir workers (44.40%); butchers (53.50%); nurses (55.60%); and medical doctors (28.00%) consumed raw milk. CONCLUSIONS The study identified the purchase of animals of unknown health status; assisting cow delivery; handling of aborted fetuses with no protective wear; consumption of raw milk, homemade cheese, cattle testes and undercooked livers, as risk factors for Brucella infection in cattle and humans. Thus, intensified risk communication, including public health education, is recommended, in particular, among meat handlers and communal farmers, to promote awareness and discourage risky practices.
Collapse
Affiliation(s)
- Oscar Madzingira
- Faculty of Agriculture and Natural Resources, School of Veterinary MedicineUniversity of NamibiaWindhoekNamibia,Department of Veterinary Tropical DiseasesFaculty of Veterinary Science, University of PretoriaOnderstepoortSouth Africa
| | - Charles Byaruhanga
- Department of Veterinary Tropical DiseasesFaculty of Veterinary Science, University of PretoriaOnderstepoortSouth Africa
| | - Folorunso Oludayo Fasina
- Emergency Centre for Transboundary Animal Diseases‐Food and Agriculture Organisation of the United Nations (ECTAD‐FAO)Dar es SalaamTanzania
| | - Henriette van Heerden
- Department of Veterinary Tropical DiseasesFaculty of Veterinary Science, University of PretoriaOnderstepoortSouth Africa
| |
Collapse
|
10
|
Ntivuguruzwa JB, Kolo FB, Gashururu R, Uwibambe E, Musanayire V, Ingabire A, Umurerwa L, Mwikarago EI, van Heerden H. Molecular characterization of Brucella spp. from seropositive herds of cattle farmed at the wildlife-livestock-human interface in Rwanda. Front Vet Sci 2022; 9:1017851. [PMID: 36304409 PMCID: PMC9592924 DOI: 10.3389/fvets.2022.1017851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 09/20/2022] [Indexed: 11/04/2022] Open
Abstract
Seroprevalence studies showed that brucellosis is prevalent in cattle in Rwanda with no recent study on the characterization of Brucella spp. Therefore, this study aimed to characterize Brucella spp. in seropositive herds of cattle farmed at the wildlife–livestock–human interface. Whole blood samples (n = 118), milk (n = 41), and vaginal swabs (n = 51) were collected from 64 seropositive herds. All samples (n = 210) were inoculated onto modified Centro de Investigacion y Tecnologia Agroalimentaria (CITA) selective medium. Cultures were analyzed to detect Brucella spp. using 16S−23S ribosomal DNA interspacer region (ITS) PCR, the Brucella cultures were speciated using AMOS and Bruce-ladder PCR assays. Brucella spp. were detected in 16.7% (35/210) of the samples established from the samples using ITS-PCR. The AMOS PCR assay identified mixed Brucella abortus and B. melitensis (n = 6), B. abortus (n = 7), and B. melitensis (n = 1) from cultures from blood samples; mixed B. abortus and B. melitensis (n = 1) and B. abortus (n = 4) from cultures from milk samples; mixed B. abortus and B. melitensis (n = 6), B. abortus (n = 8), and B. melitensis (n = 1) from cultures from vaginal swabs. Bruce-ladder PCR assay confirmed B. abortus and B. melitensis cultures. The isolation of Brucella spp. was significantly associated with districts, with the Nyagatare district having more isolates than other districts (p = 0.01). This study identified single or mixed B. abortus and B. melitensis infections in cattle samples in Rwanda, which emphasizes the need to improve brucellosis control at the wildlife–livestock–human interface and raise the awareness of cattle keepers, abattoir workers, laboratory personnel, and consumers of cattle products.
Collapse
Affiliation(s)
- Jean Bosco Ntivuguruzwa
- Bovine Tuberculosis and Brucellosis Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa,Department of Veterinary Medicine, School of Veterinary Medicine, University of Rwanda, Kigali, Rwanda,*Correspondence: Jean Bosco Ntivuguruzwa
| | - Francis Babaman Kolo
- Department of Veterinary Medicine, School of Veterinary Medicine, University of Rwanda, Kigali, Rwanda
| | - Richard Gashururu
- Department of Veterinary Medicine, School of Veterinary Medicine, University of Rwanda, Kigali, Rwanda
| | - Evodie Uwibambe
- Department of Veterinary Medicine, School of Veterinary Medicine, University of Rwanda, Kigali, Rwanda
| | - Vestine Musanayire
- Department of Animal Resources and Veterinary Services, Rwanda Agriculture and Animal Resources Board, Kigali, Rwanda
| | - Angelique Ingabire
- Department of Animal Resources and Veterinary Services, Rwanda Agriculture and Animal Resources Board, Kigali, Rwanda
| | - Lydia Umurerwa
- Department of Animal Resources and Veterinary Services, Rwanda Agriculture and Animal Resources Board, Kigali, Rwanda
| | - Emil Ivan Mwikarago
- National Reference Laboratory Division, Department of Biomedical Services, Rwanda Biomedical Centre, Kigali, Rwanda
| | - Henriette van Heerden
- Bovine Tuberculosis and Brucellosis Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
11
|
Ntivuguruzwa JB, Michel AL, Kolo FB, Mwikarago IE, Ngabonziza JCS, van Heerden H. Prevalence of bovine tuberculosis and characterization of the members of the Mycobacterium tuberculosis complex from slaughtered cattle in Rwanda. PLoS Negl Trop Dis 2022; 16:e0009964. [PMID: 35921351 PMCID: PMC9377585 DOI: 10.1371/journal.pntd.0009964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 11/05/2021] [Revised: 08/15/2022] [Accepted: 07/08/2022] [Indexed: 11/24/2022] Open
Abstract
Background Bovine tuberculosis (bTB) is an endemic disease in Rwanda, but little is known about its prevalence and causative mycobacterial species. The disease causes tremendous losses in livestock and wildlife and remains a significant threat to public health. Materials and methods A cross-sectional study employing a systematic random sampling of cattle (n = 300) with the collection of retropharyngeal lymph nodes and tonsils (n = 300) irrespective of granulomatous lesions was carried out in six abattoirs to investigate the prevalence and identify mycobacterial species using culture, acid-fast bacteria staining, polymerase chain reaction, and GeneXpert assay. Individual risk factors and the origin of samples were analysed for association with the prevalence. Findings Of the 300 sample pools, six were collected with visible TB-like lesions. Our findings demonstrated the presence of Mycobacterium tuberculosis complex (MTBC) in 1.7% (5/300) of sampled slaughtered cattle. Mycobacterium bovis was isolated from 1.3% (4/300) animals while one case was caused by a rifampicin-resistant (RR) M. tuberculosis. Non-tuberculous mycobacteria were identified in 12.0% (36/300) of the sampled cattle. There were no significant associations between the prevalence and abattoir category, age, sex, and breeds of slaughtered cattle. Conclusions This study is the first in Rwanda to isolate both M. bovis and RR M. tuberculosis in slaughtered cattle indicating that bTB is present in Rwanda with a low prevalence. The isolation of RR M. tuberculosis from cattle indicates possible zooanthroponotic transmission of M. tuberculosis and close human-cattle contact. To protect humans against occupational zoonotic diseases, it is essential to control bTB in cattle and raise the awareness among all occupational groups as well as reinforce biosafety at the farm level and in the abattoirs. Tuberculosis in cattle (bTB) causes financial losses to livestock owners and is a disease transmissible to humans especially those with an occupational risk through exposure to infected animals and animal products. This study aimed to identify the prevalence of bTB and characterize the mycobacterial species from cattle slaughtered in the six abattoirs in Rwanda. Four M. bovis, as well as one rifampicin-resistant (RR) M. tuberculosis, were identified from slaughtered cattle and, thus, the apparent bTB prevalence was 1.7% (5/300). Likely, the RR M. tuberculosis isolate was mostly likely of human origin and transmitted to cattle during close human-cattle contact. It is therefore essential to control bTB in cattle and reinforce the protection of farmworkers and abattoir workers who are always exposed to infected animals.
Collapse
Affiliation(s)
- Jean Bosco Ntivuguruzwa
- Bovine Tuberculosis and Brucellosis Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria; Pretoria, South Africa
- Department of Veterinary Medicine, College of Veterinary Medicine, University of Rwanda, Kigali, Rwanda
- * E-mail:
| | - Anita L. Michel
- Bovine Tuberculosis and Brucellosis Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria; Pretoria, South Africa
| | - Francis Babaman Kolo
- Bovine Tuberculosis and Brucellosis Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria; Pretoria, South Africa
| | - Ivan Emil Mwikarago
- Department of Human Medicine and Device assessment and Registration, Rwanda Food and Drug Administration, Kigali, Rwanda
| | - Jean Claude Semuto Ngabonziza
- National Reference Laboratory Division, Department of Biomedical Services, Rwanda Biomedical Centre, Kigali, Rwanda
- Department of Clinical Biology, School of Medicine and Pharmacy, College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda
| | - Henriette van Heerden
- Bovine Tuberculosis and Brucellosis Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria; Pretoria, South Africa
| |
Collapse
|
12
|
Huang Y, Kausrud K, Hassim A, Ochai SO, van Schalkwyk OL, Dekker EH, Buyantuev A, Cloete CC, Kilian JW, Mfune JKE, Kamath PL, van Heerden H, Turner WC. Environmental drivers of biseasonal anthrax outbreak dynamics in two multihost savanna systems. ECOL MONOGR 2022. [DOI: 10.1002/ecm.1526] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yen‐Hua Huang
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology University of Wisconsin‐Madison Madison WI USA
| | - Kyrre Kausrud
- Norwegian Veterinary Institute, PO. box 64 Ås Norway
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases University of Pretoria Onderstepoort South Africa
| | - Sunday O. Ochai
- Department of Veterinary Tropical Diseases University of Pretoria Onderstepoort South Africa
| | - O. Louis van Schalkwyk
- Department of Veterinary Tropical Diseases University of Pretoria Onderstepoort South Africa
- Office of the State Veterinarian, Department of Agriculture, Land Reform and Rural Development Government of South Africa Skukuza South Africa
- Department of Migration Max Planck Institute of Animal Behavior Radolfzell Germany
| | - Edgar H. Dekker
- Office of the State Veterinarian, Department of Agriculture, Land Reform and Rural Development Government of South Africa Skukuza South Africa
| | - Alexander Buyantuev
- Department of Geography and Planning, University at Albany State University of New York Albany NY USA
| | - Claudine C. Cloete
- Etosha Ecological Institute, Etosha National Park, Ministry of Environment, Forestry and Tourism Namibia
| | - J. Werner Kilian
- Etosha Ecological Institute, Etosha National Park, Ministry of Environment, Forestry and Tourism Namibia
| | - John K. E. Mfune
- Department of Environmental Science University of Namibia Windhoek Namibia
| | | | - Henriette van Heerden
- Department of Veterinary Tropical Diseases University of Pretoria Onderstepoort South Africa
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases University of Pretoria Onderstepoort South Africa
| | - Wendy C. Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology University of Wisconsin‐Madison Madison WI USA
| |
Collapse
|
13
|
Ochai SO, Crafford JE, Hassim A, Byaruhanga C, Huang YH, Hartmann A, Dekker EH, van Schalkwyk OL, Kamath PL, Turner WC, van Heerden H. Immunological Evidence of Variation in Exposure and Immune Response to Bacillus anthracis in Herbivores of Kruger and Etosha National Parks. Front Immunol 2022; 13:814031. [PMID: 35237267 PMCID: PMC8882864 DOI: 10.3389/fimmu.2022.814031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/17/2022] [Indexed: 11/13/2022] Open
Abstract
Exposure and immunity to generalist pathogens differ among host species and vary across spatial scales. Anthrax, caused by a multi-host bacterial pathogen, Bacillus anthracis, is enzootic in Kruger National Park (KNP), South Africa and Etosha National Park (ENP), Namibia. These parks share many of the same potential host species, yet the main anthrax host in one (greater kudu (Tragelaphus strepsiceros) in KNP and plains zebra (Equus quagga) in ENP) is only a minor host in the other. We investigated species and spatial patterns in anthrax mortalities, B. anthracis exposure, and the ability to neutralize the anthrax lethal toxin to determine if observed host mortality differences between locations could be attributed to population-level variation in pathogen exposure and/or immune response. Using serum collected from zebra and kudu in high and low incidence areas of each park (18- 20 samples/species/area), we estimated pathogen exposure from anti-protective antigen (PA) antibody response using enzyme-linked immunosorbent assay (ELISA) and lethal toxin neutralization with a toxin neutralization assay (TNA). Serological evidence of pathogen exposure followed mortality patterns within each system (kudus: 95% positive in KNP versus 40% in ENP; zebras: 83% positive in ENP versus 63% in KNP). Animals in the high-incidence area of KNP had higher anti-PA responses than those in the low-incidence area, but there were no significant differences in exposure by area within ENP. Toxin neutralizing ability was higher for host populations with lower exposure prevalence, i.e., higher in ENP kudus and KNP zebras than their conspecifics in the other park. These results indicate that host species differ in their exposure to and adaptive immunity against B. anthracis in the two parks. These patterns may be due to environmental differences such as vegetation, rainfall patterns, landscape or forage availability between these systems and their interplay with host behavior (foraging or other risky behaviors), resulting in differences in exposure frequency and dose, and hence immune response.
Collapse
Affiliation(s)
- Sunday O. Ochai
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Jan E. Crafford
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Yen-Hua Huang
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, United States
| | - Axel Hartmann
- Etosha Ecological Institute, Ministry of Environment, Forestry and Tourism, Okaukuejo, Namibia
| | - Edgar H. Dekker
- Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Government of South Africa, Skukuza, South Africa
| | - O. Louis van Schalkwyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
- Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Government of South Africa, Skukuza, South Africa
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
| | - Pauline L. Kamath
- School of Food and Agriculture, University of Maine, Orono, ME, United States
| | - Wendy C. Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, United States
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| |
Collapse
|
14
|
Bruce SA, Huang YH, Kamath PL, van Heerden H, Turner WC. The roles of antimicrobial resistance, phage diversity, isolation source and selection in shaping the genomic architecture of Bacillus anthracis. Microb Genom 2021; 7. [PMID: 34402777 PMCID: PMC8549369 DOI: 10.1099/mgen.0.000616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacillus anthracis, the causative agent of anthrax disease, is a worldwide threat to livestock, wildlife and public health. While analyses of genetic data from across the globe have increased our understanding of this bacterium’s population genomic structure, the influence of selective pressures on this successful pathogen is not well understood. In this study, we investigate the effects of antimicrobial resistance, phage diversity, geography and isolation source in shaping population genomic structure. We also identify a suite of candidate genes potentially under selection, driving patterns of diversity across 356 globally extant B. anthracis genomes. We report ten antimicrobial resistance genes and 11 different prophage sequences, resulting in the first large-scale documentation of these genetic anomalies for this pathogen. Results of random forest classification suggest genomic structure may be driven by a combination of antimicrobial resistance, geography and isolation source, specific to the population cluster examined. We found strong evidence that a recombination event linked to a gene involved in protein synthesis may be responsible for phenotypic differences between comparatively disparate populations. We also offer a list of genes for further examination of B. anthracis evolution, based on high-impact single nucleotide polymorphisms (SNPs) and clustered mutations. The information presented here sheds new light on the factors driving genomic structure in this notorious pathogen and may act as a road map for future studies aimed at understanding functional differences in terms of B. anthracis biogeography, virulence and evolution.
Collapse
Affiliation(s)
- Spencer A Bruce
- Department of Biological Sciences, University at Albany - State University of New York, Albany, NY 12222, USA
| | - Yen-Hua Huang
- Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| | - Pauline L Kamath
- School of Food and Agriculture, University of Maine, Orono, ME 04469, USA
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | - Wendy C Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
15
|
Turner WC, Kamath PL, van Heerden H, Huang YH, Barandongo ZR, Bruce SA, Kausrud K. The roles of environmental variation and parasite survival in virulence-transmission relationships. R Soc Open Sci 2021; 8:210088. [PMID: 34109041 PMCID: PMC8170194 DOI: 10.1098/rsos.210088] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Disease outbreaks are a consequence of interactions among the three components of a host-parasite system: the infectious agent, the host and the environment. While virulence and transmission are widely investigated, most studies of parasite life-history trade-offs are conducted with theoretical models or tractable experimental systems where transmission is standardized and the environment controlled. Yet, biotic and abiotic environmental factors can strongly affect disease dynamics, and ultimately, host-parasite coevolution. Here, we review research on how environmental context alters virulence-transmission relationships, focusing on the off-host portion of the parasite life cycle, and how variation in parasite survival affects the evolution of virulence and transmission. We review three inter-related 'approaches' that have dominated the study of the evolution of virulence and transmission for different host-parasite systems: (i) evolutionary trade-off theory, (ii) parasite local adaptation and (iii) parasite phylodynamics. These approaches consider the role of the environment in virulence and transmission evolution from different angles, which entail different advantages and potential biases. We suggest improvements to how to investigate virulence-transmission relationships, through conceptual and methodological developments and taking environmental context into consideration. By combining developments in life-history evolution, phylogenetics, adaptive dynamics and comparative genomics, we can improve our understanding of virulence-transmission relationships across a diversity of host-parasite systems that have eluded experimental study of parasite life history.
Collapse
Affiliation(s)
- Wendy C. Turner
- US Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Pauline L. Kamath
- School of Food and Agriculture, University of Maine, Orono, ME 04469, USA
| | - Henriette van Heerden
- Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | - Yen-Hua Huang
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Zoe R. Barandongo
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Spencer A. Bruce
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Kyrre Kausrud
- Section for Epidemiology, Norwegian Veterinary Institute, Ullevålsveien 68, 0454 Oslo, Norway
| |
Collapse
|
16
|
Madzingira O, Fasina FO, Kandiwa E, Musilika-Shilongo A, Chitate F, van Heerden H. A retrospective sero-epidemiological survey of bovine brucellosis on commercial and communal farming systems in Namibia from 2004 to 2018. Trop Anim Health Prod 2020; 52:3099-3107. [PMID: 32577935 DOI: 10.1007/s11250-020-02332-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 10/23/2019] [Accepted: 06/16/2020] [Indexed: 02/08/2023]
Abstract
Cattle production is the major livestock production activity and the mainstay of Namibia's economy. Sustained beef exports are contingent on a sound sanitary environment where diseases such as brucellosis are under control. In this retrospective study, 49,718 bovine brucellosis testing results from 2004 to 2018 were analyzed to determine the proportion of sero-positive cattle and herds, and the spatial distribution of positive reactors from commercial and communal areas. In total, 244 positive reactors were identified based on the Rose Bengal Test (RBT) and the Complement Fixation Test (CFT) in series, giving an overall proportion of infected animals of 0.49% (244/49,718; 95% CI, 0.43-0.56%) and an overall proportion of infected herds of 9.26% (78/842; 95% CI, 7.49-11.41%). There was a higher proportion of sero-positive communal herds (33.09%) and cattle (10.27%) than commercial herds (4.67%) and cattle (0.24%; p < 0.05). Annually, the proportion of positive reactors was 0-1.37% in the commercial area and 0-52.38% in the communal areas, with a clear decline in positive reactors in the communal areas. Within the commercial sector, the proportion of positive reactor dairy, beef, and export cattle was 0.19% (51/27,067; 95% CI, 0.14-0.25%), 0.30% (48/16,098; 95% CI, 0.22-0.40%), and 0.33% (16/4811; 95% CI, 0.20-0.54%), respectively. Abortions were found to be the major reason for Brucella testing in the communal areas. About 12.65% (96/759) of abortion-linked sera tested positive in the communal areas, but none were positive in beef or dairy cattle. Widespread vaccination of cattle and robust planned surveillance is recommended to reduce the incidence of the disease, its associated production losses and public health risk.
Collapse
Affiliation(s)
- Oscar Madzingira
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Windhoek, P. Bag 13301, Namibia.
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
| | - Folorunso Oludayo Fasina
- Emergency Centre for Transboundary Animal Diseases-Food and Agriculture Organisation of the United Nations (ECTAD-FAO), Dar es Salaam, Tanzania
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa
| | - Erick Kandiwa
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Windhoek, P. Bag 13301, Namibia
| | - Albertina Musilika-Shilongo
- Directorate of Veterinary Services, Ministry of Agriculture, Water and Forestry, P. Bag 12022, Government Office Park, Windhoek, Namibia
| | - Frank Chitate
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, Windhoek, P. Bag 13301, Namibia
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa
| |
Collapse
|
17
|
Mukarati NL, Ndumnego OC, Ochai SO, Jauro S, Loveridge A, van Heerden H, Matope G, Caron A, Hanyire TG, de Garine-Wichatitsky M, Pfukenyi DM. A serological survey of Bacillus anthracis reveals widespread exposure to the pathogen in free-range and captive lions in Zimbabwe. Transbound Emerg Dis 2020; 68:1676-1684. [PMID: 32964687 DOI: 10.1111/tbed.13842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 08/24/2020] [Accepted: 09/14/2020] [Indexed: 11/29/2022]
Abstract
Numerous unknown factors influence anthrax epidemiology in multi-host systems, especially at wildlife/livestock/human interfaces. Serology tests for anti-anthrax antibodies in carnivores are useful tools in identifying the presence or absence of Bacillus anthracis in a range. These were employed to ascertain whether the disease pattern followed the recognized high- and low-risk anthrax zonation in Zimbabwe and also to establish whether anthrax was absent from Hwange National Park in which there have been no reported outbreaks. African lions (Panthera leo) (n = 114) drawn from free-range protected areas and captive game parks located in recognized high- and low-risk zones across Zimbabwe were tested for antibodies to anthrax PA antigen using the ELISA immunoassay. A random selection of 27 lion sera samples comprising 17 seropositive and 10 seronegative sera was further tested in the species-independent toxin neutralization assay (TNA) in order to validate the former as a surveillance tool for anthrax in African lions. Using the ELISA-PA immunoassay, 21.9% (25/114) of the lions tested positive for antibodies to anthrax. Seropositivity was recorded in all study areas, and there was no significant difference (p = .852) in seropositivity between lions in high- and low-risk anthrax zones. Also, there was no significant difference (McNemar's chi-square test = 0.9, p = .343) in the proportion of lions testing positive to anti-PA anthrax antibodies on ELISA-PA immunoassay compared with the TNA, with fair agreement between the two tests [kappa (K) statistic = 0.30; 0.08 < K<0.613]. Results of this study indicate that anthrax could be more widespread than 42 currently realized in Zimbabwe, and present in recognized high- and low-risk zones, including 43 where it has not been reported in over 20 years such as Hwange National Park. This is also the 44 first report documenting the presence of anthrax lethal toxin-neutralizing antibodies in naturally 45 infected carnivores, further confirming exposure to B. anthracis. The research results point to a 46 need for revisiting the currently recognized anthrax risk zones in Zimbabwe. This should be based 47 on improved surveillance of the disease in both wild and domestic animals for better understanding and control of the disease.
Collapse
Affiliation(s)
- Norman L Mukarati
- Faculty of Veterinary Science, University of Zimbabwe, Harare, Zimbabwe
| | - Okechukwu C Ndumnego
- Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.,Moredun Scientific, Edinburgh, UK
| | - Sunday O Ochai
- Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Solomon Jauro
- Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | | | | | - Gift Matope
- Faculty of Veterinary Science, University of Zimbabwe, Harare, Zimbabwe
| | - Alexandre Caron
- ASTRE, Univ. de Montpellier, CIRAD, INRA, Montpellier, France.,CIRAD, UMR ASTRE, RP-PCP, Maputo, Mozambique.,Faculdade de Veterinária, Universidade Eduardo Mondlane, Maputo, Mozambique
| | | | - Michel de Garine-Wichatitsky
- ASTRE, Univ. de Montpellier, CIRAD, INRA, Montpellier, France.,CIRAD, UMR ASTRE, Bangkok, Thailand.,Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Davies M Pfukenyi
- Faculty of Veterinary Science, University of Zimbabwe, Harare, Zimbabwe
| |
Collapse
|
18
|
Ntivuguruzwa JB, Kolo FB, Gashururu RS, Umurerwa L, Byaruhanga C, van Heerden H. Seroprevalence and Associated Risk Factors of Bovine Brucellosis at the Wildlife-Livestock-Human Interface in Rwanda. Microorganisms 2020; 8:E1553. [PMID: 33050125 PMCID: PMC7600169 DOI: 10.3390/microorganisms8101553] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 11/16/2022] Open
Abstract
Bovine brucellosis is endemic in Rwanda; however, little information is available on seroprevalence and risk factors. Therefore, a cross-sectional study was conducted among cattle farmed at the wildlife-livestock-human interface (n = 1691) in five districts and one peri-urban district (n = 216). Cattle were screened using the Rose Bengal test, then the results were confirmed by indirect enzyme-linked immunesorbent assay. Potential risk factors were determined with a questionnaire and analyzed for their association with seropositivity. In all districts, the animal and herd-level seroprevalence was 7.4% (141/1907) and 28.9% (61/212), respectively, 8.3% (141/1691) and 30.9% (61/198) at the interface, and 0.0% (0/216) in peri-urban areas. Among the potential risk factors, old age (≥5 years), cattle farmed close to wildlife, herds of cattle and small ruminants, history of abortions, and replacement animals were significantly associated with brucellosis (p < 0.05). Low awareness of zoonotic brucellosis, assisting calving without biosafety protection, drinking raw milk, and manual milking were each observed in more than 21.7% of cattle keepers whose herds were seropositive. This study confirmed brucellosis endemicity in cattle farmed close to wildlife in Rwanda, suggesting the need to focus control efforts in these areas. Educated farmers with a high awareness of zoonotic brucellosis had low bovine brucellosis seropositivity, which emphasizes the importance of education.
Collapse
Affiliation(s)
- Jean Bosco Ntivuguruzwa
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa; (F.B.K.); (C.B.); (H.v.H.)
- Department of Veterinary Medicine, School of Veterinary Medicine, University of Rwanda, P.O.Box 57 Nyagatare, Rwanda;
| | - Francis Babaman Kolo
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa; (F.B.K.); (C.B.); (H.v.H.)
| | - Richard Simba Gashururu
- Department of Veterinary Medicine, School of Veterinary Medicine, University of Rwanda, P.O.Box 57 Nyagatare, Rwanda;
| | - Lydia Umurerwa
- Department of Animal Resources and Veterinary Services, Rwanda Agriculture and Animal Resources Board, P.O.Box 5016 Kigali, Rwanda;
| | - Charles Byaruhanga
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa; (F.B.K.); (C.B.); (H.v.H.)
- National Agricultural Research Organisation, P.O. Box 259 Entebbe, Uganda
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria 0110, South Africa; (F.B.K.); (C.B.); (H.v.H.)
| |
Collapse
|
19
|
Buys A, Crafford J, van Heerden H. Development and evaluation of indirect enzyme-linked immunosorbent assays for the determination of immune response to multiple clostridial antigens in vaccinated captive bred southern white rhinoceros (Ceratotherium simum simum). Acta Vet Scand 2020; 62:57. [PMID: 33028379 PMCID: PMC7541252 DOI: 10.1186/s13028-020-00555-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/18/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An overall increase in poaching of white rhinoceros results in captive breeding becoming a significant component of white rhinoceros conservation. However, this type of conservation comes with its own difficulties. When wildlife is captured, transported and/or confined to a boma environment, they are more predisposed to diseases caused by bacterial organisms such as spore forming Clostridium spp. A southern white rhinoceros (Ceratotherium simum simum) population on a captive bred farm was suspected to be affected by Clostridium infections. These endangered animals were apparently exposed to Clostridium spp., in the conservation area previously used for cattle farming. The rhinoceros population on the breeding operation property was vaccinated with a multi-component clostridial vaccine registered for use in cattle. Multiple indirect enzyme-linked immunosorbent assays (iELISAs) were developed in order to evaluate the serum antibody titres of these vaccinated animals. In evaluating vaccine efficacy, the gold standard mouse neutralization test (MNT) was not available and therefore iELISAs were developed for the detection of serum antibodies to C. perfringens type A (alpha toxin), C. chauvoei (whole cell), C. novyi (alpha toxin), C. septicum (alpha toxin) and C. sordellii (lethal toxin) in the white rhinoceros population using international reference sera of equine origin. Antibody titres against each clostridial antigen was evaluated in the vaccinated white rhinoceros population (n = 75). Analytical specificity showed slight cross-reactions for C. chauvoei and C. perfringens type A with the other antigens. Individual assay cut-off values were calculated with 95% confidence. Coefficient of variance (CV) values for both the international reference sera and in-house control sera across all the antigens were well below 16%, indicating good assay repeatability. This convenient and fast assay is suitable for monitoring humoral immune responses to clostridial antigens in vaccinated white rhinoceroses. RESULTS Checkerboard titrations indicated optimal antigen and antibody concentrations to be used for each respective iELISA developed. Each titration set of the respective international reference and in-house control sera showed good repeatability with low standard deviations and coefficient of variance values calculated between repeats for each antigen. Individual assays proved repeatable and showed good analytical sensitivity and specificity. CONCLUSIONS The developed iELISAs are able to evaluate antibody profiles of phospholipase C, C. chauvoei whole cells, TcnA, ATX, TcsL in white rhinoceros serum using international reference sera.
Collapse
|
20
|
Glover B, Macfarlane M, Bengis R, O’Dell J, Steyl J, van Heerden H, Abernethy D. Investigation of Brucella melitensis in Sable Antelope ( Hippotragus niger) in South Africa. Microorganisms 2020; 8:E1494. [PMID: 33003292 PMCID: PMC7600299 DOI: 10.3390/microorganisms8101494] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/09/2020] [Accepted: 09/16/2020] [Indexed: 11/17/2022] Open
Abstract
In this study, Brucella melitensis infection in sable antelope (Hippotragus niger) was investigated on two wildlife ranches in South Africa over a 12-year period in order to determine the origin of the outbreaks and the role of livestock in maintaining the disease. Retrospective data were obtained from farm records and interviews as well as samples tested from different disease scenarios and clinical settings. On one ranch, 10 of 74 sable tested seropositive for B. melitensis in 2004 but were certified clear of infection after no further brucellosis cases were detected following repeated serological tests and culling over a five-year period. Recrudescence occurred in 2013 (7 of 187 brucellosis positives) and in 2014 (one positive), with persistent, latent infection being the most reasonable explanation. In a second case study, linked to the first one through a common vendor, 15 of 80 sable tested positive in 2016, some five years after the acquisition of the animals from a putative source. Brucella melitensis biovar 1 and/or 3 were isolated from each outbreak on both ranches. Both outbreaks resulted in substantial losses for the owners, arising from testing and culling and significant resource expenditure by the state. The study identified the diagnostic challenges for identifying and resolving disease outbreaks in wildlife, the persistence of B. melitensis in sable, the risks associated with animal movements, and the need for a wildlife-sensitive disease control scheme. Although the actual source of infection could not be identified, the investigation points away from local livestock as a source of ongoing infection while the persistent infection is consistent with the disease circulating within small, ranched populations and being spread through the keeping and trading of high-value animals. The implications of the study findings to disease control in wildlife are discussed.
Collapse
Affiliation(s)
- Barbara Glover
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa;
| | - Malcolm Macfarlane
- Former Chief State Veterinarian of the Graaff Reinet State Vet Area, Eastern Cape 6280, South Africa;
| | - Roy Bengis
- Former Chief State Veterinarian, Kruger National Park 1350, South Africa;
| | - Jacques O’Dell
- Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa; (J.O.); (J.S.); (D.A.)
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0028, South Africa
| | - Johan Steyl
- Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa; (J.O.); (J.S.); (D.A.)
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0028, South Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa;
| | - Darrell Abernethy
- Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa; (J.O.); (J.S.); (D.A.)
- Aberystwyth School of Veterinary Science, Aberystwyth University, Aberystwyth, Wales SY23 3FL, UK
| |
Collapse
|
21
|
Jauro S, C. Ndumnego O, Ellis C, Buys A, Beyer W, van Heerden H. Immunogenicity of Non-Living Anthrax Vaccine Candidates in Cattle and Protective Efficacy of Immune Sera in A/J Mouse Model Compared to the Sterne Live Spore Vaccine. Pathogens 2020; 9:pathogens9070557. [PMID: 32664259 PMCID: PMC7400155 DOI: 10.3390/pathogens9070557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 11/16/2022] Open
Abstract
The Sterne live spore vaccine (SLSV, Bacillus anthracis strain 34F2) is the veterinary vaccine of choice against anthrax though contra-indicated for use with antimicrobials. However, the use of non-living anthrax vaccine (NLAV) candidates can overcome the SLSV limitation. In this study, cattle were vaccinated with either of the NLAV (purified recombinant PA (PrPA) or crude rPA (CrPA) and formaldehyde-inactivated spores (FIS of B. anthracis strain 34F2) and emulsigen-D®/alhydrogel® adjuvants) or SLSV. The immunogenicity of the NLAV and SLSV was assessed and the protective efficacies evaluated using a passive immunization mouse model. Polyclonal IgG (including the IgG1 subset) and IgM responses increased significantly across all vaccination groups after the first vaccination. Individual IgG subsets titres peaked significantly with all vaccines used after the second vaccination at week 5 and remained significant at week 12 when compared to week 0. The toxin neutralization (TNA) titres of the NLAV vaccinated cattle groups showed similar trends to those observed with the ELISA titres, except that the former were lower, but still significant, when compared to week 0. The opsonophagocytic assay indicated good antibody opsonizing responses with 75% (PrPA+FIS), 66% (CrPA+FIS) and 80% (SLSV) phagocytosis following spores opsonization. In the passive protection test, A/J mice transfused with purified IgG from cattle vaccinated with PrPA+FIS+Emulsigen-D®/Alhydrogel® and SLSV had 73% and 75% protection from challenge with B. anthracis strain 34F2 spores, respectively, whereas IgG from cattle vaccinated with CrPA+FIS+Emulsigen-D®/Alhydrogel® offered insignificant protection of 20%. There was no difference in protective immune response in cattle vaccinated twice with either the PrPA+FIS or SLSV. Moreover, PrPA+FIS did not show any residual side effects in vaccinated cattle. These results suggest that the immunogenicity and protective efficacy induced by the NLAV (PrPA+FIS) in the cattle and passive mouse protection test, respectively, are comparable to that induced by the standard SLSV.
Collapse
Affiliation(s)
- Solomon Jauro
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa;
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Maiduguri, Maiduguri 600230, Nigeria
- Correspondence:
| | | | - Charlotte Ellis
- Design Biologix, Building 43b CSIR, Meiring Naude Road, Brummeria 0184, South Africa; (C.E.); (A.B.)
| | - Angela Buys
- Design Biologix, Building 43b CSIR, Meiring Naude Road, Brummeria 0184, South Africa; (C.E.); (A.B.)
| | - Wolfgang Beyer
- Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Science, University of Hohenheim, Stuttgart 70599, Germany;
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa;
| |
Collapse
|
22
|
Hassim A, Lekota KE, van Dyk DS, Dekker EH, van Heerden H. A Unique Isolation of a Lytic Bacteriophage Infected Bacillus anthracis Isolate from Pafuri, South Africa. Microorganisms 2020; 8:microorganisms8060932. [PMID: 32575780 PMCID: PMC7356010 DOI: 10.3390/microorganisms8060932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 04/30/2020] [Revised: 06/04/2020] [Accepted: 06/11/2020] [Indexed: 11/24/2022] Open
Abstract
Bacillus anthracis is a soil-borne, Gram-positive endospore-forming bacterium and the causative agent of anthrax. It is enzootic in Pafuri, Kruger National Park in South Africa. The bacterium is amplified in a wild ungulate host, which then becomes a source of infection to the next host upon its death. The exact mechanisms involving the onset (index case) and termination of an outbreak are poorly understood, in part due to a paucity of information about the soil-based component of the bacterium’s lifecycle. In this study, we present the unique isolation of a dsDNA bacteriophage from a wildebeest carcass site suspected of having succumbed to anthrax. The aggressively lytic bacteriophage hampered the initial isolation of B. anthracis from samples collected at the carcass site. Classic bacteriologic methods were used to test the isolated phage on B. anthracis under different conditions to simulate deteriorating carcass conditions. Whole genome sequencing was employed to determine the relationship between the bacterium isolated on site and the bacteriophage-dubbed Bacillus phage Crookii. The 154,012 bp phage belongs to Myoviridae and groups closely with another African anthrax carcass-associated Bacillus phage WPh. Bacillus phage Crookii was lytic against B. cereus sensu lato group members but demonstrated a greater affinity for encapsulated B. anthracis at lower concentrations (<1 × 108 pfu) of bacteriophage. The unusual isolation of this bacteriophage demonstrates the phage’s role in decreasing the inoculum in the environment and impact on the life cycle of B. anthracis at a carcass site.
Collapse
Affiliation(s)
- Ayesha Hassim
- Department of Veterinary Tropical diseases, University of Pretoria, Faculty of Veterinary Science, Pretoria 0110, South Africa; (K.E.L); (H.v.H.)
- Correspondence: ; Tel.: +27-125-298-339
| | - Kgaugelo Edward Lekota
- Department of Veterinary Tropical diseases, University of Pretoria, Faculty of Veterinary Science, Pretoria 0110, South Africa; (K.E.L); (H.v.H.)
- Unit for Environmental Sciences and Management: Microbiology, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa
| | - David Schalk van Dyk
- Department of Agriculture Fisheries and Forestry, Office of the State Veterinarian, Skukuza 1350, South Africa; (D.S.v.D.); (E.H.D.)
| | - Edgar Henry Dekker
- Department of Agriculture Fisheries and Forestry, Office of the State Veterinarian, Skukuza 1350, South Africa; (D.S.v.D.); (E.H.D.)
| | - Henriette van Heerden
- Department of Veterinary Tropical diseases, University of Pretoria, Faculty of Veterinary Science, Pretoria 0110, South Africa; (K.E.L); (H.v.H.)
| |
Collapse
|
23
|
Lekota KE, Hassim A, van Heerden H. Genomic sequence data and single nucleotide polymorphism genotyping of Bacillus anthracis strains isolated from animal anthrax outbreaks in Northern Cape Province, South Africa. Data Brief 2019; 28:105040. [PMID: 31970271 PMCID: PMC6965700 DOI: 10.1016/j.dib.2019.105040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 10/26/2022] Open
Abstract
This report presents genomic data on sequence reads and draft genomes of Bacillus anthracis isolates from anthrax outbreaks in animals in an endemic region of South Africa as well as genotyping of the strains using canonical single nucleotide polymorphisms (canSNPs). It is derived from an article entitle "Phylogenomic structure of B. anthracis strains in the Northern Cape Province, South Africa revealed novel single nucleotide polymorphisms". Whole genome sequencing (WGS) of twenty-three B. anthracis strains isolated during 1998 and 2009 anthrax outbreaks in the Northern Cape Province (NCP), as well as a strain from Botswana (6102_6B) and one from Namibia-South Africa transfrontier conservation area (Sendlingsdrift, 6461_SP2) were obtained using both the HiSeq 2500 and MiSeq Illumina platforms. Mismatch amplification mutation assay (melt-MAMA) qPCR were used to identify the canSNP genotypes within the global population of B. anthracis. DNA sequencing data is available at NCBI Sequence Read Archive and GenBank database under accession N0. PRJNA580142 and PRJNA510736 respectively. A phylogenetic tree and CanSNP typing profiles of the isolates are presented within this article.
Collapse
Affiliation(s)
- Kgaugelo Edward Lekota
- University of Pretoria, Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, Onderstepoort, 0110, South Africa.,College of Agriculture and Environmental Sciences, University of South Africa, Florida Campus, Florida, 1710, South Africa
| | - Ayesha Hassim
- University of Pretoria, Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, Onderstepoort, 0110, South Africa
| | - Henriette van Heerden
- University of Pretoria, Faculty of Veterinary Science, Department of Veterinary Tropical Diseases, Onderstepoort, 0110, South Africa
| |
Collapse
|
24
|
Kolo FB, Adesiyun AA, Fasina FO, Katsande CT, Dogonyaro BB, Potts A, Matle I, Gelaw AK, van Heerden H. Seroprevalence and characterization of Brucella species in cattle slaughtered at Gauteng abattoirs, South Africa. Vet Med Sci 2019; 5:545-555. [PMID: 31414558 PMCID: PMC6868451 DOI: 10.1002/vms3.190] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Brucellosis is an infectious and contagious zoonotic bacterial disease of both humans and animals. In developing countries where brucellosis is endemic, baseline data on the prevalence of brucellosis, using abattoir facilities, is important. OBJECTIVES The aim of this study was to determine the seroprevalence of antibodies against Brucella in slaughter cattle at Gauteng province, South Africa and to characterize isolates of Brucella spp. METHODS In this cross-sectional study, un-clotted blood samples with corresponding organ tissue samples were collected from slaughtered cattle. Serological [Rose Bengal test (RBT), complement fixation test (CFT) and indirect ELISA (iELISA)], molecular (PCR) and bacteriological methods were used to detect Brucella antibodies and Brucella spp. from 200 slaughtered cattle in 14 abattoirs. RESULTS The RBT revealed a seroprevalence of brucellosis as 11.0% (22 of 200) and iELISA confirmed 5.5% (11 of 200). The estimated seroprevalence from RBT and iELISA was 5.5% while RBT and CFT was 2.0% (4 of 200). Brucella melitensis (n = 6) and B. abortus (n = 5) were isolated from 11 cattle tissues (5.5%) as confirmed to species level with AMOS PCR and differentiated from vaccine strains with Bruce-ladder PCR. Seven of the 11 isolates originated from seropositive cattle of which five were biotyped as B. abortus bv 1 (n = 2) and B. melitensis bv 2 (n = 1) and B. melitensis bv 3 (n = 2). CONCLUSIONS This is the first documentation of B. melitensis in cattle in South Africa. The zoonotic risk of brucellosis posed by Brucella-infected slaughter cattle to abattoir workers and consumers of improperly cooked beef cannot be ignored.
Collapse
Affiliation(s)
- Francis B. Kolo
- Department of Veterinary Tropical DiseasesUniversity of PretoriaPretoriaSouth Africa
| | - Abiodun A. Adesiyun
- Department of Production Animal StudiesUniversity of PretoriaPretoriaSouth Africa
- Department of Basic Veterinary SciencesFaculty of Medical SciencesUniversity of the West IndiesSt. AugustineTrinidad and Tobago
| | - Folorunso O. Fasina
- Department of Veterinary Tropical DiseasesUniversity of PretoriaPretoriaSouth Africa
| | - Charles T. Katsande
- Gauteng Department of Agriculture and Rural DevelopmentJohannesburgSouth Africa
| | - Banenat B. Dogonyaro
- Department of Veterinary Tropical DiseasesUniversity of PretoriaPretoriaSouth Africa
| | - Andrew Potts
- Agricultural Research Council - Onderstepoort Veterinary ResearchPretoriaSouth Africa
| | - Itumeleng Matle
- Agricultural Research Council - Onderstepoort Veterinary ResearchPretoriaSouth Africa
| | - Awoke K. Gelaw
- Agricultural Research Council - Onderstepoort Veterinary ResearchPretoriaSouth Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical DiseasesUniversity of PretoriaPretoriaSouth Africa
| |
Collapse
|
25
|
Oloso NO, Adeyemo IA, van Heerden H, Fasanmi OG, Fasina FO. Antimicrobial Drug Administration and Antimicrobial Resistance of Salmonella Isolates Originating from the Broiler Production Value Chain in Nigeria. Antibiotics (Basel) 2019; 8:antibiotics8020075. [PMID: 31174274 PMCID: PMC6627717 DOI: 10.3390/antibiotics8020075] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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: 03/25/2019] [Revised: 05/19/2019] [Accepted: 05/21/2019] [Indexed: 02/05/2023] Open
Abstract
Salmonella is among the pathogens on the high global priority lists for monitoring for studies on the discovery of new antimicrobials and understanding of how antimicrobial resistance (AMR) develops. AMR in connection with antibiotic usage patterns has been considered as a strong factor and contributor to the AMR pool. The purposes of use, pattern of antimicrobial drug administration, as well as the prevalence of AMR in Salmonella originating from the Nigeria broiler production value chain (NBPVC) was explored. A well-structured questionnaire on antimicrobial usage (n = 181) was used for sampling that focused on 21 antimicrobials from 151 locations. Simultaneously, AMR testing for 18 commonly used antimicrobials on Salmonella in humans was also carried out. Antimicrobial resistance Salmonella spp. were isolated in 23% of the samples (261 of 1135 samples from the broiler input, products, and the environment) using modified ISO 6579 and invA PCR protocols. Over 80% of the antimicrobials used in the NBPVC were administered without a veterinarian prescription. Prevalence of antimicrobial administration without prescription were as follows: live-bird-market (100%), hatchery (86.7%), grow-out-farm (75%), and breeder (66.7%). Widespread prophylactic and metaphylactic use of antimicrobials were recorded with the highest use seen for enrofloxacin (63% and 24%), tetracycline (58% and 33%), and erythromycin (50% and 17%). Antimicrobial resistance was highest for flumequine (100%), penicillin (95%), and perfloxacin (89%). High levels of use without laboratory support of a newer generation of a class of antibiotics suspected to confer high resistance on older generations of the same class (quinolones) was observed.
Collapse
Affiliation(s)
- Nurudeen Olalekan Oloso
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
| | - Ismail Adewuyi Adeyemo
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Ibadan, Ibadan 200284, Nigeria.
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
| | - Olubunmi Gabriel Fasanmi
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
- Federal Colleges of Animal Health and Production Technology, Ibadan 200262, Nigeria.
| | - Folorunso Oludayo Fasina
- Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
- Emergency Centre for Transboundary Animal Diseases-Food and Agriculture Organisation (ECTAD-FAO), Dar es Salaam 14111, United Republic of Tanzania.
| |
Collapse
|
26
|
Ledwaba MB, Gomo C, Lekota KE, Le Flèche P, Hassim A, Vergnaud G, van Heerden H. Molecular characterization of Brucella species from Zimbabwe. PLoS Negl Trop Dis 2019; 13:e0007311. [PMID: 31107864 PMCID: PMC6544324 DOI: 10.1371/journal.pntd.0007311] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 05/31/2019] [Accepted: 03/18/2019] [Indexed: 12/30/2022] Open
Abstract
Brucella abortus and B. melitensis have been reported in several studies in animals in Zimbabwe but the extent of the disease remains poorly known. Thus, characterizing the circulating strains is a critical first step in understanding brucellosis in the country. In this study we used an array of molecular assays including AMOS-PCR, Bruce-ladder, multiple locus variable number tandem repeats analysis (MLVA) and single nucleotide polymorphisms from whole genome sequencing (WGS-SNP) to characterize Brucella isolates to the species, biovar, and individual strain level. Sixteen Brucella strains isolated in Zimbabwe at the Central Veterinary laboratory from various hosts were characterized using all or some of these assays. The strains were identified as B. ovis, B. abortus, B. canis and B. suis, with B. canis being the first report of this species in Zimbabwe. Zimbabwean strains identified as B. suis and B. abortus were further characterized with whole genome sequencing and were closely related to reference strains 1330 and 86/8/59, respectively. We demonstrate the range of different tests that can be performed from simple assays that can be run in laboratories lacking sophisticated instrumentation to whole genome analyses that currently require substantial expertise and infrastructure often not available in the developing world.
Collapse
Affiliation(s)
- Maphuti Betty Ledwaba
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Calvin Gomo
- Central Veterinary Laboratory (CVL), Harare, Zimbabwe
- Chinhoyi University of Technology, Department of Animal Production and Technology, Harare, Zimbabwe
| | - Kgaugelo Edward Lekota
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Philippe Le Flèche
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Gilles Vergnaud
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
- * E-mail:
| |
Collapse
|
27
|
Ndumnego OC, Koehler SM, Crafford JE, Beyer W, van Heerden H. Immunogenicity of anthrax recombinant peptides and killed spores in goats and protective efficacy of immune sera in A/J mouse model. Sci Rep 2018; 8:16937. [PMID: 30446695 PMCID: PMC6240085 DOI: 10.1038/s41598-018-35382-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 06/12/2018] [Accepted: 11/02/2018] [Indexed: 11/09/2022] Open
Abstract
Anthrax is primarily recognized as an affliction of herbivores with incubation period ranging from three to five days post-infection. Currently, the Sterne live-spore vaccine is the only vaccine approved for control of the disease in susceptible animals. While largely effective, the Sterne vaccine has several problems including adverse reactions in sensitive species, ineffectiveness in active outbreaks and incompatibility with antibiotics. These can be surmounted with the advent of recombinant peptides (non-living) next generation vaccines. The candidate vaccine antigens comprised of recombinant protective antigen (PA), spore-specific antigen (bacillus collagen-like protein of anthracis, BclA) and formaldehyde inactivated spores (FIS). Presently, little information exists on the protectivity of these novel vaccine candidates in susceptible ruminants. Thus, this study sought to assess the immunogenicity of these vaccine candidates in goats and evaluate their protectivity using an in vivo mouse model. Goats receiving a combination of PA, BclA and FIS yielded the highest antibody and toxin neutralizing titres compared to recombinant peptides alone. This was also reflected in the passive immunization experiment whereby mice receiving immune sera from goats vaccinated with the antigen combination had higher survival post-challenge. In conclusion, the current data indicate promising potential for further development of non-living anthrax vaccines in ruminants.
Collapse
Affiliation(s)
- Okechukwu C Ndumnego
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa. .,Africa Health Research Institute, Durban, South Africa.
| | - Susanne M Koehler
- Institute of Animal Science, Department of Livestock Infectiology and Environmental Hygiene, University of Hohenheim, Stuttgart, Germany.,Robert Koch Institute, Berlin, Germany
| | - Jannie E Crafford
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa
| | - Wolfgang Beyer
- Institute of Animal Science, Department of Livestock Infectiology and Environmental Hygiene, University of Hohenheim, Stuttgart, Germany
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, South Africa.
| |
Collapse
|
28
|
Lekota KE, Bezuidt OKI, Mafofo J, Rees J, Muchadeyi FC, Madoroba E, van Heerden H. Whole genome sequencing and identification of Bacillus endophyticus and B. anthracis isolated from anthrax outbreaks in South Africa. BMC Microbiol 2018; 18:67. [PMID: 29986655 PMCID: PMC6038202 DOI: 10.1186/s12866-018-1205-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 11/30/2017] [Accepted: 06/20/2018] [Indexed: 11/25/2022] Open
Abstract
Background Bacillus endophyticus is a soil plant-endophytic bacterium, while B. anthracis is the causative agent of anthrax. The virulence factors of B. anthracis are the plasmid encoded tripartite toxins (pXO1) and poly-γ-glutamic acid (PGA) capsule (pXO2). B. endophyticus isolated alongside B. anthracis from animals that died of anthrax in Northern Cape Province (NCP), South Africa, harbored polyglutamate genes. The study compared the characteristics of B. anthracis and B. endophyticus with other Bacillus species with a focus on the presence of the PGA capsule or/and unbound PGA. The morphology and whole genome sequence analysis of B. endophyticus strains and B. anthracis were compared. Results In conventional microbiology, B. endophyticus showed gram-positive round-shaped rods in single/short chains, which were endospore-forming, non-motile, non-haemolytic with white and dry colonies, and γ-phage resistant. B. anthracis was differentiated from B. endophyticus based on the latter’s box-shaped rods in pairs/long chains, white-grey and slimy colonies, encapsulated and γ-phage susceptible. The study identified a PGA polyglutamate synthase operon that consisted of pgsBCA, γ-glutamyltranspeptidase (ggt) and pgsE in B. endophyticus genomes. Conclusions PGA regions of B. anthracis contain capBCADE genes located in the pXO2 required for capsulation formation, while B. endophyticus contain the pgsBCAE genes in the chromosome. Whole genome and microbiology analysis identified B. endophyticus, as a non-capsuled endospore-forming bacterium that consists of PGA required for biosynthesis. B. endophyticus strains do not synthesize surface associated PGA, therefore capsule visualization of B. anthracis is a key diagnostic characteristic. The study highlights the significance of using whole genome shotgun sequencing to identify virulence and other important genes that might be present amongst unknown samples from natural outbreaks. None of the B. anthracis related plasmids or virulence genes were found in the B. endophyticus genomes. Electronic supplementary material The online version of this article (10.1186/s12866-018-1205-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kgaugelo Edward Lekota
- The Biotechnology Platform, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110, South Africa.,Department of Veterinary Tropical Diseases, University of Pretoria, Private bag X4, Onderstepoort, 0110, South Africa.,Bacteriology section, Agricultural Research Council-Onderstepoort Veterinary Institute, Private Bag X5, Onderstepoort, 0110, South Africa.,College of Agriculture and Environmental Sciences, University of South Africa, Florida Campus, Christiaan De Wet/ Pioneer Dr, P.O. Box X6, Florida, 1710, South Africa
| | | | - Joseph Mafofo
- The Biotechnology Platform, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110, South Africa
| | - Jasper Rees
- The Biotechnology Platform, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110, South Africa
| | - Farai Catherine Muchadeyi
- The Biotechnology Platform, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110, South Africa
| | - Evelyn Madoroba
- Bacteriology section, Agricultural Research Council-Onderstepoort Veterinary Institute, Private Bag X5, Onderstepoort, 0110, South Africa.,College of Agriculture and Environmental Sciences, University of South Africa, Florida Campus, Christiaan De Wet/ Pioneer Dr, P.O. Box X6, Florida, 1710, South Africa.,Department of Biochemistry and Microbiology, University of Zululand, Private Bag X1001, KwaDlangezwa, 3886, South Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Private bag X4, Onderstepoort, 0110, South Africa.
| |
Collapse
|
29
|
Kolo FB, Fasina FO, Ledwaba B, Glover B, Dogonyaro BB, van Heerden H, Adesiyun AA, Katsande TC, Matle I, Gelaw AK. Isolation of Brucella melitensis from cattle in South Africa. Vet Rec 2018; 182:668-669. [PMID: 29884641 DOI: 10.1136/vr.k2450] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | | | | | | | | | | | - Abiodun A Adesiyun
- Department of Production Animal Studies, University of Pretoria, South Africa
| | - Tendai C Katsande
- Gauteng Department of Agriculture and Rural Development, South Africa
| | | | | |
Collapse
|
30
|
Koehler SM, Buyuk F, Celebi O, Demiraslan H, Doganay M, Sahin M, Moehring J, Ndumnego OC, Otlu S, van Heerden H, Beyer W. Protection of farm goats by combinations of recombinant peptides and formalin inactivated spores from a lethal Bacillus anthracis challenge under field conditions. BMC Vet Res 2017; 13:220. [PMID: 28701192 PMCID: PMC5508662 DOI: 10.1186/s12917-017-1140-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 12/13/2016] [Accepted: 07/04/2017] [Indexed: 11/30/2022] Open
Abstract
Background Bacillus (B.) anthracis, the causal agent of anthrax, is effectively controlled by the Sterne live spore vaccine (34F2) in animals. However, live spore vaccines are not suitable for simultaneous vaccination and antibiotic treatment of animals being at risk of infection in an outbreak situation. Non-living vaccines could close this gap. Results In this study a combination of recombinant protective antigen and recombinant Bacillus collagen-like antigen (rBclA) with or without formalin inactivated spores (FIS), targeted at raising an immune response against both the toxins and the spore of B. anthracis, was tested for immunogenicity and protectiveness in goats. Two groups of goats received from local farmers of the Kars region of Turkey were immunized thrice in three weeks intervals and challenged together with non-vaccinated controls with virulent B. anthracis, four weeks after last immunization. In spite of low or none measurable toxin neutralizing antibodies and a surprisingly low immune response to the rBclA, 80% of the goats receiving the complete vaccine were protected against a lethal challenge. Moreover, the course of antibody responses indicates that a two-step vaccination schedule could be sufficient for protection. Conclusion The combination of recombinant protein antigens and FIS induces a protective immune response in goats. The non-living nature of this vaccine would allow for a concomitant antibiotic treatment and vaccination procedure. Further studies should clarify how this vaccine candidate performs in a post infection scenario controlled by antibiotics. Electronic supplementary material The online version of this article (doi:10.1186/s12917-017-1140-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Susanne M Koehler
- Department of Infectiology and Animal Hygiene, University of Hohenheim, Institute of Animal Science, 70593, Stuttgart, Germany.,Robert-Koch-Institut, 13353, Berlin, Germany
| | - Fatih Buyuk
- Faculty of Veterinary Medicine, Department of Microbiology, Kafkas University, 36300, Kars, Turkey
| | - Ozgur Celebi
- Faculty of Veterinary Medicine, Department of Microbiology, Kafkas University, 36300, Kars, Turkey
| | - Hayati Demiraslan
- Faculty of Medicine, Department of Infectious Diseases, Erciyes University, 38039, Kayseri, Turkey
| | - Mehmet Doganay
- Faculty of Medicine, Department of Infectious Diseases, Erciyes University, 38039, Kayseri, Turkey
| | - Mitat Sahin
- Faculty of Veterinary Medicine, Department of Microbiology, Kafkas University, 36300, Kars, Turkey
| | - Jens Moehring
- Institute for Crop Science, University of Hohenheim, Biostatistical Unit, 70593, Stuttgart, Germany
| | - Okechukwu C Ndumnego
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa.,Africa Health Research Institute, Durban, 4013, South Africa
| | - Salih Otlu
- Faculty of Veterinary Medicine, Department of Microbiology, Kafkas University, 36300, Kars, Turkey
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Wolfgang Beyer
- Department of Infectiology and Animal Hygiene, University of Hohenheim, Institute of Animal Science, 70593, Stuttgart, Germany.
| |
Collapse
|
31
|
Ndumnego OC, Köhler SM, Crafford J, van Heerden H, Beyer W. Comparative analysis of the immunologic response induced by the Sterne 34F2 live spore Bacillus anthracis vaccine in a ruminant model. Vet Immunol Immunopathol 2016; 178:14-21. [PMID: 27496738 DOI: 10.1016/j.vetimm.2016.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/18/2016] [Accepted: 06/15/2016] [Indexed: 01/26/2023]
Abstract
The Sterne 34F2 live spore vaccine (SLSV) developed in 1937 is the most widely used veterinary vaccine against anthrax. However, literature on the immunogenicity of this vaccine in a target ruminant host is scarce. In this study, we evaluated the humoral response to the Bacillus anthracis protective antigen (rPA), a recombinant bacillus collagen-like protein of anthracis (rBclA), formaldehyde inactivated spores (FIS) prepared from strain 34F2 and a vegetative antigen formulation prepared from a capsule and toxin deficient strain (CDC 1014) in Boer goats. The toxin neutralizing ability of induced antibodies was evaluated using an in vitro toxin neutralization assay. The protection afforded by the vaccine was also assessed in vaccinates. Anti-rPA, anti-FIS and lethal toxin neutralizing titres were superior after booster vaccinations, compared to single vaccinations. Qualitative analysis of humoral responses to rPA, rBclA and FIS antigens revealed a preponderance of anti-FIS IgG titres following either single or double vaccinations with the SLSV. Antibodies against FIS and rPA both increased by 350 and 300-fold following revaccinations respectively. There was no response to rBclA following vaccinations with the SLSV. Toxin neutralizing titres increased by 80-fold after single vaccination and 700-fold following a double vaccination. Lethal challenge studies in naïve goats indicated a minimum infective dose of 36 B. anthracis spores. Single and double vaccination with the SLSV protected 4/5 and 3/3 of goats challenged with>800 spores respectively. An early booster vaccination following the first immunization is suggested in order to achieve a robust immunity. Results from this study indicate that this crucial second vaccination can be administered as early as 3 months after the initial vaccination.
Collapse
Affiliation(s)
- Okechukwu C Ndumnego
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa.
| | - Susanne M Köhler
- Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Sciences, University of Hohenheim, Stuttgart, Germany
| | - Jannie Crafford
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, Pretoria, South Africa
| | - Wolfgang Beyer
- Department of Livestock Infectiology and Environmental Hygiene, Institute of Animal Sciences, University of Hohenheim, Stuttgart, Germany
| |
Collapse
|
32
|
Goolab S, Roth RL, van Heerden H, Crampton MC. Analyzing the molecular mechanism of lipoprotein localization in Brucella. Front Microbiol 2015; 6:1189. [PMID: 26579096 PMCID: PMC4623201 DOI: 10.3389/fmicb.2015.01189] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 07/02/2015] [Accepted: 10/12/2015] [Indexed: 01/18/2023] Open
Abstract
Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria are well characterized and may be useful to infer a solution to better understand the translocation process in Brucella.
Collapse
Affiliation(s)
- Shivani Goolab
- Protein Technologies, Biosciences, Council for Scientific and Industrial ResearchPretoria, South Africa
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of PretoriaPretoria, South Africa
| | - Robyn L. Roth
- Protein Technologies, Biosciences, Council for Scientific and Industrial ResearchPretoria, South Africa
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of PretoriaPretoria, South Africa
| | - Michael C. Crampton
- Protein Technologies, Biosciences, Council for Scientific and Industrial ResearchPretoria, South Africa
| |
Collapse
|
33
|
Ndumnego OC, Crafford J, Beyer W, van Heerden H. Quantitative anti-PA IgG ELISA; assessment and comparability with the anthrax toxin neutralization assay in goats. BMC Vet Res 2013; 9:265. [PMID: 24373579 PMCID: PMC3892015 DOI: 10.1186/1746-6148-9-265] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 12/20/2013] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Presently, few data exist on the level and duration of anti-protective antigen (PA) IgG in vaccinated livestock. Various adaptation of enzyme-linked immunosorbent assays (ELISAs) have been developed in studies to assess immune response following vaccination, albeit mostly in laboratory rodent models. The quantitative anti-anthrax IgG ELISA in this study describes a method of enumerating the concentration of anti-PA specific IgG present in sera of immunized goats, with the aid of an affinity-purified caprine polyclonal anti-anthrax PA-83 IgG standard. This was compared with the anthrax toxin neutralization assay (TNA) which measures a functional subset of toxin neutralizing anti-PA IgG. RESULTS The measured concentrations obtained in the standard curve correlated with the known concentration at each dilution. Percentage recovery of the standard concentrations ranged from 89 to 98% (lower and upper asymptote respectively). Mean correlation coefficient (r2) of the standard curve was 0.998. Evaluation of the intra-assay coefficient of variation showed ranges of 0.23-16.90% and 0.40-12.46% for days 28 and 140 sera samples respectively, following vaccination. The mean inter-assay coefficient of variation for triplicate samples repeated on 5 different days was 18.53 and 12.17% for days 28 and 140 sera samples respectively. Spearman's rank correlation of log-transformed IgG concentrations and TNA titres showed strong positive correlation (rs = 0.942; p = 0.01). CONCLUSION This study provides evidence that an indirect ELISA can be used for the quantification of anti-anthrax PA IgG in goats with the added advantage of using single dilutions to save time and resources. The use of such related immunoassays can serve as potential adjuncts to potency tests for Sterne and other vaccine types under development in ruminant species. This is the first report on the correlation of polyclonal anti-anthrax PA83 antibody with the TNA in goats.
Collapse
Affiliation(s)
- Okechukwu C Ndumnego
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort 0110, South Africa
| | - Jannie Crafford
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort 0110, South Africa
| | - Wolfgang Beyer
- Institute of Environmental and Animal Hygiene, University of Hohenheim, Stuttgart, Germany
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort 0110, South Africa
| |
Collapse
|
34
|
Phillips SM, Dubery IA, van Heerden H. Molecular characterisation of two homoeologous elicitor-responsive lipin genes in cotton. Mol Genet Genomics 2013; 288:519-33. [PMID: 23897433 DOI: 10.1007/s00438-013-0770-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/04/2013] [Indexed: 11/24/2022]
Abstract
The identification and molecular characterisation of two lipin-like gene copies (GhLIPN) in cotton, Gossypium hirsutum, an allotetraploid derived from two progenitor diploid Gossypium species, is described. Sequence analyses of the GhLIPN copies, designated GhLIPN-1 and -2, revealed that they contain 11 exons, separated by ten introns. They each have a 2,643 bp open reading frame that encodes 880 aa proteins, and share a 97.7 and 95.5 % sequence similarity at the translated nucleotide and amino acid level, respectively. The GhLIPN genes have a distinct domain architecture consisting of an archetypical N-terminal lipin domain, followed by a haloacid dehalogenase (HAD) domain towards the C-terminus. A Southern blot did not distinguish between the two gene copies, which suggests that they may be homoeologs rather than paralogs. GhLIPN-2 is more similar to a homoeologous sequence from G. raimondii, representing the ancestral D-genome, compared to GhLIPN-1 that matches G. herbaceum and that represents the A-genome. Our data indicate that GhLIPN-1 and GhLIPN-2 are homoeologs that derive from the A- and the D-diploid genomes, respectively. The promoter sequences of GhLIPN-1 and -2 differ by 56 %, as a result of multiple indels. In silico analysis of the promoter regions revealed that both genes contain numerous putative defence-related and elicitor-responsive cis-elements that support a role for GhLIPN in defence responses. Relative quantification real-time PCR confirmed the up-regulation in response to a cell-wall-derived V. dahliae elicitor, which supported the association of GhLIPN with defence signalling. The results add a new dimension to the proposed roles of lipins in plants by suggesting that lipins may have a role in defence signalling.
Collapse
Affiliation(s)
- Sonia M Phillips
- Department of Biochemistry, University of Johannesburg, Kingsway Campus, P.O. Box 524, Auckland Park, 2006, South Africa
| | | | | |
Collapse
|
35
|
Phillips SM, Dubery IA, van Heerden H. Molecular characterization of an elicitor-responsive Armadillo repeat gene (GhARM) from cotton (Gossypium hirsutum). Mol Biol Rep 2012; 39:8513-23. [PMID: 22714909 DOI: 10.1007/s11033-012-1706-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 06/06/2012] [Indexed: 11/28/2022]
Abstract
Only a few Armadillo (ARM) repeat proteins have been characterized in plants where they appear to have diverse functions, including the regulation of defence responses. In this study, the identification, cloning and characterization of a gene, encoding an ARM repeat protein (GhARM), is described. GhARM exists as multiple copies in cotton, with an 1713 bp ORF encoding 570 amino acids. The predicted protein contains three consecutive ARM repeats within an Armadillo-type fold, with no other distinguishing domains. Sequence alignments and phylogenetic analysis revealed that GhARM has a high homology with other ARM proteins in plants. The predicted three dimensional model of GhARM displayed a characteristic right-handed superhelical twist. In silico analysis of the promoter sequence revealed that it contains several defence- and hormone-responsive cis-regulatory elements. Expression of GhARM was significantly down-regulated in response to treatment with a V. dahliae elicitor suggesting that GhARM may function as a negative-regulator of cotton defence signalling against V. dahliae. To date, GhARM is the only ARM repeat gene that has been completely sequenced and characterized in cotton.
Collapse
Affiliation(s)
- Sonia M Phillips
- Department of Biochemistry, University of Johannesburg, Kingsway Campus, Auckland Park, 2006, P.O. Box 524, Johannesburg, South Africa.
| | | | | |
Collapse
|
36
|
Collins NE, Liebenberg J, de Villiers EP, Brayton KA, Louw E, Pretorius A, Faber FE, van Heerden H, Josemans A, van Kleef M, Steyn HC, van Strijp MF, Zweygarth E, Jongejan F, Maillard JC, Berthier D, Botha M, Joubert F, Corton CH, Thomson NR, Allsopp MT, Allsopp BA. The genome of the heartwater agent Ehrlichia ruminantium contains multiple tandem repeats of actively variable copy number. Proc Natl Acad Sci U S A 2005; 102:838-43. [PMID: 15637156 PMCID: PMC545511 DOI: 10.1073/pnas.0406633102] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heartwater, a tick-borne disease of domestic and wild ruminants, is caused by the intracellular rickettsia Ehrlichia ruminantium (previously known as Cowdria ruminantium). It is a major constraint to livestock production throughout subSaharan Africa, and it threatens to invade the Americas, yet there is no immediate prospect of an effective vaccine. A shotgun genome sequencing project was undertaken in the expectation that access to the complete protein coding repertoire of the organism will facilitate the search for vaccine candidate genes. We report here the complete 1,516,355-bp sequence of the type strain, the stock derived from the South African Welgevonden isolate. Only 62% of the genome is predicted to be coding sequence, encoding 888 proteins and 41 stable RNA species. The most striking feature is the large number of tandemly repeated and duplicated sequences, some of continuously variable copy number, which contributes to the low proportion of coding sequence. These repeats have mediated numerous translocation and inversion events that have resulted in the duplication and truncation of some genes and have also given rise to new genes. There are 32 predicted pseudogenes, most of which are truncated fragments of genes associated with repeats. Rather then being the result of the reductive evolution seen in other intracellular bacteria, these pseudogenes appear to be the product of ongoing sequence duplication events.
Collapse
Affiliation(s)
- Nicola E Collins
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
van Heerden H, Collins NE, Brayton KA, Rademeyer C, Allsopp BA. Characterization of a major outer membrane protein multigene family in Ehrlichia ruminantium. Gene 2004; 330:159-68. [PMID: 15087135 DOI: 10.1016/j.gene.2004.01.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2003] [Revised: 11/26/2003] [Accepted: 01/26/2004] [Indexed: 11/27/2022]
Abstract
Ehrlichia ruminantium is a tick-transmitted rickettsial pathogen, which causes heartwater or cowdriosis in wild and domestic ruminants. A dominant antibody response of animals infected with E. ruminantium is directed against the outer membrane protein MAP1 (major antigenic protein 1). Part of the locus containing map1 has been characterized and consists of four map1 paralogs, designated map1-2, map1-1, map1 and map1+1, indicating that map1 is encoded by a multigene family. The purpose of this study was to determine the total number of map1 paralogs and their transcriptional activities. Using genome walking and data from an ongoing E. ruminantium genome sequencing project at the Onderstepoort Veterinary Institute, we found 16 paralogs of the map1 gene tandemly arranged in a 25 kb region of the E. ruminantium genome. The map1 multigene family is downstream of a hypothetical transcriptional regulator gene and upstream of the secA gene. Thirteen paralogs at the 5' end of the 25-kb locus were connected by short intergenic spaces (ranging from 0 to 42 bp) and the remaining three paralogs at the 3' end were connected by longer intergenic spaces (ranging from 375 to 1612 bp). All 16 map1 paralogs were transcriptionally active in E. ruminantium grown in endothelial cells and paralogs with short intergenic spaces were co-transcribed with their adjacent genes.
Collapse
Affiliation(s)
- Henriette van Heerden
- Department of Chemistry and Biochemistry, Rand Afrikaans University, P.O. Box 524, Auckland Park 2006, South Africa
| | | | | | | | | |
Collapse
|