title: Phenotypic and genotypic characterization of Brucella strains isolated from autochthonous livestock reveals the dominance of B. abortus biovar 3a in Nigeria.
abstract: Brucellosis is a worldwide widespread zoonosis caused by bacteria of the genus Brucella. Control of this disease in a given area requires an understanding of the Brucella species circulating in livestock and humans. However, because of the difficulties intrinsic to Brucella isolation and typing, such data are scarce for resource-poor areas. The paucity of bacteriological data and the consequent imperfect epidemiological picture are particularly critical for Sahelian and Sub-Sahara African countries. Here, we report on the characterization of 34 isolates collected between 1976 and 2012 from cattle, sheep and horses in Nigeria. All isolates were identified as Brucella abortus by Bruce-ladder PCR and assigned to biovar 3 by conventional typing. Further analysis by enhanced AMOS-ERY PCR showed that all of them belonged to the 3a sub-biovar, and MLVA analysis grouped them in a cluster clearly distinct from that formed by European B. abortus biovar 3b strains. Nevertheless, MLVA detected heterogeneity within the Nigerian biovar 3a strains. The close genetic profiles of the isolates from cattle, sheep and horses, suggest that, at least in some parts of Nigeria, biovar 3a circulates among animal species that are not the preferential hosts of B. abortus. Consistent with previous genetic analyses of 7 strains from Ivory Cost, Gambia and Togo, the analysis of these 34 Nigerian strains supports the hypothesis that the B. abortus biovar 3a lineage is dominant in West African countries.
authors: Brucellosis Research Unit, National Veterinary Research Institute, Vom 930001, Plateau State, Nigeria.
authors: Wilson J
authors: WJ
authors: Bertu
authors: Division of Infection and Pathway, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors: Marie J
authors: MJ
authors: Ducrotoy
authors: Unidad de Producción y Sanidad Animal, Centro de Investigación y Tecnología Agroalimentaria (CITA), del Gobierno de Aragón, Av. Montañana 930, 50059 Zaragoza, Spain.
authors: Pilar M
authors: PM
authors: Muñoz
authors: Paris-Est University/Anses, EU/OIE/FAO & National Reference Laboratory for Brucellosis, Animal Health Laboratory, 14 rue Pierre et Marie Curie, 94701 Maisons-Alfort Cedex, France.
authors: Virginie
authors: V
authors: Mick
authors: IDISNA-Instituto de Salud Tropical y Depto., Microbiología y Parasitología, Universidad de Navarra, Edificio de Investigación, c/Irunlarrea 1, 31008 Pamplona, Spain.
authors: Amaia
authors: A
authors: Zúñiga-Ripa
authors: Avia-GIS, Risschotlei 33, BE-2980 Zoersel, Belgium.
authors: Ward
authors: W
authors: Bryssinckx
authors: Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, PMB 1096, Ahmadu Bello University, Zaria, Nigeria.
authors: Jacob K P
authors: JK
authors: Kwaga
authors: Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, PMB 1096, Ahmadu Bello University, Zaria, Nigeria.
authors: Junaid
authors: J
authors: Kabir
authors: Division of Infection and Pathway, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
authors: Susan C
authors: SC
authors: Welburn
authors: IDISNA-Instituto de Salud Tropical y Depto., Microbiología y Parasitología, Universidad de Navarra, Edificio de Investigación, c/Irunlarrea 1, 31008 Pamplona, Spain. Electronic address: imoriyon@unav.es.
authors: Ignacio
authors: I
authors: Moriyón
authors: Division of Infection and Pathway, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, The University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK. Electronic address: rbocholi@yahoo.com.
authors: Reuben A
authors: RA
authors: Ocholi
mesh_terms: D000818:Animals; D002003:Brucella abortus / Q000235:genetics*; D002006:Brucellosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005838:Genotype; D006801:Humans; D058751:Livestock; D009549:Nigeria / Q000453:epidemiology
keywords: AMOS-ERY PCR; B. abortus biovar 3; Brucellosis; MLVA; Nigeria; Phenotyping