Ledwaba, Maphuti BettyGlover, BarbaraMatle, ItumelengProfiti, GiuseppeMartelli, Pier LuigiCasadio, RitaZilli, KatiusciaJanowicz, AnnaMarotta, FrancescaGarofolo, GiulianoVan Heerden, Henriette2022-05-242022-05-242021-03-11Ledwaba, M.B.; Glover, B.A.; Matle, I.; Profiti, G.; Martelli, P.L.; Casadio, R.; Zilli, K.; Janowicz, A.; Marotta, F.; Garofolo, G.; et al. Whole Genome Sequence Analysis of Brucella abortus Isolates from Various Regions of South Africa. Microorganisms 2021, 9, 570. https://DOI.org/ 10.3390/microorganisms9030570.2072-666X (online)10.3390/microorganisms9030570https://repository.up.ac.za/handle/2263/85639SUPPLEMENTARY TABLES: Table S1: Sample order used in Bruce-ladder (A) and AMOS (B) multiplex PCR assays and the descriptive information of the gel images, Table S2: Clean unique variants of the South African strains (refer to Table 2 for the sample names (in column 1) and sample ID (in column 2)).The availability of whole genome sequences in public databases permits genome-wide comparative studies of various bacterial species. Whole genome sequence-single nucleotide polymorphisms (WGS-SNP) analysis has been used in recent studies and allows the discrimination of various Brucella species and strains. In the present study, 13 Brucella spp. strains from cattle of various locations in provinces of South Africa were typed and discriminated. WGS-SNP analysis indicated a maximum pairwise distance ranging from 4 to 77 single nucleotide polymorphisms (SNPs) between the South African Brucella abortus virulent field strains. Moreover, it was shown that the South African B. abortus strains grouped closely to B. abortus strains from Mozambique and Zimbabwe, as well as other Eurasian countries, such as Portugal and India. WGS-SNP analysis of South African B. abortus strains demonstrated that the same genotype circulated in one farm (Farm 1), whereas another farm (Farm 2) in the same province had two different genotypes. This indicated that brucellosis in South Africa spreads within the herd on some farms, whereas the introduction of infected animals is the mode of transmission on other farms. Three B. abortus vaccine S19 strains isolated from tissue and aborted material were identical, even though they originated from different herds and regions of South Africa. This might be due to the incorrect vaccination of animals older than the recommended age of 4–8 months or might be a problem associated with vaccine production.en© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Bovine brucellosisBrucella abortusWhole genome sequencing (WGS)Single nucleotide polymorphismsComparative analysisArticle