College of Veterinary Medicine and Biomedical Sciences, Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania.
Département de Santé et Productions Animales, Faculté d'Agronomie et de Bio-Ingénierie, Université du Burundi, Bujumbura, Burundi.
Vet Med Sci. 2020 Nov;6(4):711-719. doi: 10.1002/vms3.298. Epub 2020 Jun 21.
Brucellosis is a zoonotic disease of importance to both public health and the livestock industry. The disease is likely to be endemic in Tanzania and little is reported on molecular characterization of Brucella species in pastoral settings. This study aimed at characterizing Brucella species (targeting genus Brucella) infecting humans, cattle and goat in Kagera region (Ngara and Karagwe districts) using real-time PCR, PCR amplification of 16S rRNA genes and Sanger sequencing. Brucella spp. were detected in 47 samples (19 sera and 28 milk) out of 125 samples (77 sera, 35 milk and 13 aborted materials) using real-time PCR. All aborted materials (13 samples) were negative to real-time PCR. Out of the 47 real-time PCR positive samples (28 milk and 19 sera), 20 samples (10 milk and 10 sera) showed an expected 16S rRNA gene PCR product. Sequence analysis and blasting confirmed the presence of Brucella spp. in pastoral areas of Kagera region. The Brucella spp. from Kagera were phylogenetically grouped in two clades and three branches all closer to B. melitensis, B. abortus and B. suis from USA, Sudan and Iran. However, they were distinct from other species isolated also in USA, New Zealand, Germany and Egypt. This was expected based on the distance between the geographical regions from which the data (nucleotides sequences from 16S gene sequencing) for the phylogeny reconstruction were obtained. This is the first study to report Brucella species identified using 16S rRNA gene sequencing in East and Central Africa. A livestock vaccination program re-inforced with a high index of Brucella diagnosis is needed to eradicate brucellosis in animals and minimize suffering from Brucella infections in humans in Tanzania.
布鲁氏菌病是一种对公共卫生和畜牧业都很重要的人畜共患病。坦桑尼亚可能存在地方性布鲁氏菌病，但关于畜牧业中布鲁氏菌种的分子特征的报道很少。本研究旨在利用实时 PCR、16S rRNA 基因 PCR 扩增和 Sanger 测序，对卡盖拉地区（恩加拉和卡雷古区）感染人类、牛和山羊的布鲁氏菌种（针对布鲁氏菌属）进行特征描述。使用实时 PCR 从 125 个样本（77 个血清、35 个牛奶和 13 个流产材料）中检测到 47 个样本（19 个血清和 28 个牛奶）中存在布鲁氏菌属。所有流产材料（13 个样本）均为实时 PCR 阴性。在 47 个实时 PCR 阳性样本（28 个牛奶和 19 个血清）中，20 个样本（10 个牛奶和 10 个血清）显示出预期的 16S rRNA 基因 PCR 产物。序列分析和 Blast 证实了布鲁氏菌属在卡盖拉地区的畜牧业中存在。来自卡盖拉的布鲁氏菌属在两个分支群中分为三个分支，均与来自美国、苏丹和伊朗的 B. melitensis、B. abortus 和 B. suis 更为接近。然而，它们与在美国、新西兰、德国和埃及等地分离的其他物种也有所不同。这是基于用于系统发育重建的地理区域之间的距离来预测的。这是东非和中非首次使用 16S rRNA 基因测序报告鉴定布鲁氏菌属的研究。坦桑尼亚需要加强牲畜疫苗接种计划，并辅以高布鲁氏菌诊断指数，以根除动物中的布鲁氏菌病，并最大限度地减少人类感染布鲁氏菌的痛苦。
