Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa.
Unit for Environmental Sciences and Management, North-West University, Potchefstroom, 2531, South Africa.
J Microbiol. 2024 Sep;62(9):759-773. doi: 10.1007/s12275-024-00155-8. Epub 2024 Jul 22.
Brucellosis is an economically important zoonotic disease affecting humans, livestock, and wildlife health globally and especially in Africa. Brucella abortus and B. melitensis have been isolated from human, livestock (cattle and goat), and wildlife (sable) in South Africa (SA) but with little knowledge of the population genomic structure of this pathogen in SA. As whole genome sequencing can assist to differentiate and trace the origin of outbreaks of Brucella spp. strains, the whole genomes of retrospective isolates (n = 19) from previous studies were sequenced. Sequences were analysed using average nucleotide identity (ANI), pangenomics, and whole genome single nucleotide polymorphism (wgSNP) to trace the geographical origin of cases of brucellosis circulating in human, cattle, goats, and sable from different provinces in SA. Pangenomics analysis of B. melitensis (n = 69) and B. abortus (n = 56) was conducted with 19 strains that included B. abortus from cattle (n = 3) and B. melitensis from a human (n = 1), cattle (n = 1), goat (n = 1), Rev1 vaccine strain (n = 1), and sable (n = 12). Pangenomics analysis of B. melitensis genomes, highlighted shared genes, that include 10 hypothetical proteins and genes that encodes for acetyl-coenzyme A synthetase (acs), and acylamidase (aam) amongst the sable genomes. The wgSNP analysis confirmed the B. melitensis isolated from human was more closely related to the goat from the Western Cape Province from the same outbreak than the B. melitensis cattle sample from different cases in the Gauteng Province. The B. melitensis sable strains could be distinguished from the African lineage, constituting their own African sub-clade. The sequenced B. abortus strains clustered in the C2 lineage that is closely related to the isolates from Mozambique and Zimbabwe. This study identified genetically diverse Brucella spp. among various hosts in SA. This study expands the limited known knowledge regarding the presence of B. melitensis in livestock and humans in SA, further building a foundation for future research on the distribution of the Brucella spp. worldwide and its evolutionary background.
布鲁氏菌病是一种具有经济重要性的人畜共患病，影响着全球人类、牲畜和野生动物的健康，尤其是在非洲。在南非（SA），已经从人类、牲畜（牛和山羊）和野生动物（黑貂）中分离出了布鲁氏菌 abortus 和 B. melitensis，但对该病原体在 SA 的群体基因组结构知之甚少。由于全基因组测序可以帮助区分和追踪布鲁氏菌属菌株的暴发起源，因此对之前研究中回顾性分离株（n=19）的全基因组进行了测序。使用平均核苷酸同一性（ANI）、泛基因组学和全基因组单核苷酸多态性（wgSNP）分析来追踪在南非不同省份循环的人类、牛、山羊和黑貂中布鲁氏菌病的地理起源。对 69 株 B. melitensis（n=69）和 56 株 B. abortus（n=56）进行了泛基因组学分析，其中包括来自牛的 3 株 B. abortus 和来自人类的 1 株 B. melitensis、1 株来自牛、1 株来自山羊、Rev1 疫苗株和 12 株来自黑貂。对 B. melitensis 基因组的泛基因组学分析突出了共享基因，包括 10 个假设蛋白和编码乙酰辅酶 A 合成酶（acs）和酰基酰胺酶（aam）的基因，这些基因存在于黑貂基因组中。wgSNP 分析证实，与来自不同暴发事件的 Gauteng 省的牛 B. melitensis 样本相比，从同一暴发事件的人类中分离出的 B. melitensis 与西开普省的山羊更为密切相关。可以将 B. melitensis 黑貂菌株与非洲谱系区分开来，构成它们自己的非洲亚谱系。测序的 B. abortus 菌株聚类在 C2 谱系中，与来自莫桑比克和津巴布韦的分离株密切相关。本研究在 SA 的各种宿主中发现了遗传上多样化的布鲁氏菌属。本研究扩大了对 SA 中牲畜和人类中存在 B. melitensis 的有限知识，为未来研究布鲁氏菌属在全球的分布及其进化背景奠定了基础。
