Abstract:
The anthrax-causing bacterium Bacillus anthracis comprises the genetic clades A, B, and C. In the northernmost part (Pafuri) of Kruger National Park (KNP), South Africa, both the common A and rare B strains clades occur. The B clade strains were reported to be dominant in Pafuri before 1991, while A clade strains occurred towards the central parts of KNP. The prevalence of B clade strains is currently much lower as only A clade strains have been isolated from 1992 onwards in KNP. In this study 319 B. anthracis strains were characterized with 31-loci multiple-locus variable-number tandem repeat analysis (MLVA-31). B clade strains from soil (n = 9) and a Tragelaphus strepsiceros carcass (n = 1) were further characterised by whole genome sequencing and compared to publicly available genomes. The KNP strains clustered in the B clade before 1991 into two dominant genotypes. South African strains cluster into a dominant genotype A.Br.005/006 consisting of KNP as well as the other anthrax endemic region, Northern Cape Province (NCP), South Africa. A few A.Br.001/002 strains from both endemic areas were also identified. Subclade A.Br.101 belonging to the A.Br.Aust94 lineage was reported in the NCP. The B-clade strains seems to be vanishing, while outbreaks in South Africa are caused mainly by the A.Br.005/006 genotypes as well as a few minor clades such as A.Br.001/002 and A.Br.101 present in NCP. This work confirmed the existence of the rare and vanishing B-clade strains that group in B.Br.001 branch with KrugerB and A0991 KNP strains.
摘要:
导致炭疽的细菌炭疽芽孢杆菌包括遗传进化枝A,B,和C.在克鲁格国家公园(KNP)的最北端(Paffuri),南非,常见的A株和罕见的B株进化枝都出现。据报道,在1991年之前,B进化枝菌株在Pafuri中占主导地位,而A进化枝菌株则出现在KNP的中部。B进化枝菌株的流行率目前低得多,因为从1992年起在KNP中仅分离出A进化枝菌株。在这项研究中,用31个基因座多基因座可变数串联重复分析(MLVA-31)对319个炭疽杆菌菌株进行了表征。通过全基因组测序进一步表征了来自土壤(n=9)和Tragelaphusstrepsiceroscar体(n=1)的B进化枝菌株,并与公开可用的基因组进行了比较。1991年之前,KNP菌株在B进化枝中聚集为两个显性基因型。南非菌株聚集为由KNP以及其他炭疽流行区组成的显性基因型A.Br.005/006,北开普省(NCP),南非。还鉴定了来自两个流行区的一些A.Br.001/002菌株。属于A.Br.的SubcladeA.Br.101在NCP中报道了Aust94谱系。B进化枝菌株似乎正在消失,而南非的疫情主要是由A.Br.005/006基因型以及一些小分支引起的,例如NCP中存在的A.Br.001/002和A.Br.101。这项工作证实了在B.Br.001分支中与KrugerB和A0991KNP菌株组成的稀有和消失的B进化枝菌株的存在。