| Resum: |
Mycobacterium bovis (M. bovis) is the main causative agent for bovine tuberculosis (BTB) and can also be the cause of zoonotic tuberculosis in humans. In view of its zoonotic nature, slaughterhouse surveillance, potentially resulting in total or partial condemnation of the carcasses and organs, is conducted routinely. Spoligotyping, VNTR profiling, and whole genome sequencing (WGS) of M. bovis isolated from tissues with tuberculosis-like lesions collected from 14 cattle at Eritrea's largest slaughterhouse in the capital Asmara, were conducted. The 14 M. bovis isolates were classified into three different spoligotype patterns (SB0120, SB0134 and SB0948) and six VNTR profiles. WGS results matched those of the conventional genotyping methods and further discriminated the six VNTR profiles into 14 strains. Furthermore, phylogenetic analysis of the M. bovis isolates suggests two independent introductions of BTB into Eritrea possibly evolving from a common ancestral strain in Europe. This molecular study revealed the most important strains of M. bovis in Eritrea and their (dis)similarities with the strains generally present in East Africa and Europe, as well as potential routes of introduction of M. bovis. Though the sample size is small, the current study provides important information as well as platform for future in-depth molecular studies on isolates from both the dairy and the traditional livestock sectors in Eritrea and the region. This study provides information onthe origin of some of the M. bovis strains in Eritrea, its genetic diversity, evolution and patterns of spread between dairy herds. Such information is essential in the development and implementation of future BTB control strategy for Eritrea. The livestock sector plays a major role in poverty and hunger reduction in the vast majority of Africa, as a source of food, cash income, manure, draught power, transportation, savings, insurance and social status. However, for livestock to play this vital role, the impact of diseases of economic and zoonotic importance need to be reduced. Bovine tuberculosis, mainly caused by Mycobacterium bovis, is such an infectious disease. Slaughterhouse (gross pathology) surveillance, followed by bacterial culture and genotyping, are options to identify the disease-causing agents, their distribution, and enabling trace back of the sources of infections, in order to prevent their re-introduction and spread. Unfortunately, genotyping is by far not generally introduced in the continent. In the present study, tissues with tuberculosis-like lesions were collected from the Asmara municipal slaughterhouse, the largest slaughterhouse in Eritrea, and bacterial culture, classical Mycobacterium tuberculosis complex typing (Spoligotyping and VNTR profiling), as well as whole genome sequencing (WGS) were used to gain insight into the spatial and temporal distribution, genetic diversity and evolution of M. bovis strains circulating in Eritrean dairy cattle. The results revealed (dis)similarities of the Eritrean M. bovis strains with the strains generally present in Africa and Europe, potential routes of introduction to Eritrea and genetic diversity of the M. bovis strains. Future in-depth molecular studies including more samples from dairy cattle as well as cattle and goats from the traditional livestock sector are recommended. |
visitant ::
identificació
(Hamelmalo Agricultural College. Department of Veterinary Sciences)
