Ledwaba Maphuti Betty, Glover Barbara Akorfa, Matle Itumeleng, Profiti Giuseppe, Martelli Pier Luigi, Casadio Rita, Zilli Katiuscia, Janowicz Anna, Marotta Francesca, Garofolo Giuliano, van Heerden Henriette
Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa.
Bacteriology Division, ARC-Onderstepoort Veterinary Research, Onderstepoort, Pretoria 0110, South Africa.
Microorganisms. 2021 Mar 11;9(3):570. doi: 10.3390/microorganisms9030570.
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 species and strains. In the present study, 13 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 virulent field strains. Moreover, it was shown that the South African strains grouped closely to strains from Mozambique and Zimbabwe, as well as other Eurasian countries, such as Portugal and India. WGS-SNP analysis of South African 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 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.
公共数据库中全基因组序列的可获取性使得对各种细菌物种进行全基因组比较研究成为可能。全基因组序列单核苷酸多态性（WGS-SNP）分析已在近期研究中得到应用，它能够区分各种物种和菌株。在本研究中，对来自南非各省不同地点牛的13种菌株进行了分型和鉴别。WGS-SNP分析表明，南非强毒田间菌株之间的最大成对距离为4至77个单核苷酸多态性（SNP）。此外，研究表明南非菌株与来自莫桑比克、津巴布韦以及其他欧亚国家（如葡萄牙和印度）的菌株密切聚类。对南非菌株的WGS-SNP分析表明，同一基因型在一个农场（农场1）中传播，而同一省份的另一个农场（农场2）有两种不同的基因型。这表明南非的布鲁氏菌病在一些农场的畜群中传播，而在其他农场，感染动物的引入是传播方式。从组织和流产材料中分离出的三株疫苗S19菌株是相同的，尽管它们来自南非不同的畜群和地区。这可能是由于对年龄超过推荐的4至8个月龄的动物进行了错误的疫苗接种，或者可能是与疫苗生产相关的问题。
