| 1. |
- Brynildsrud, Ola B., et al.
(författare)
-
Global expansion of Mycobacterium tuberculosis lineage 4 shaped by colonial migration and local adaptation
- 2018
-
Ingår i: Science Advances. - : AMER ASSOC ADVANCEMENT SCIENCE. - 2375-2548. ; 4:10
-
Tidskriftsartikel (refereegranskat)abstract
- On the basis of population genomic and phylogeographic analyses of 1669 Mycobacterium tuberculosis lineage 4 (L4) genomes, we find that dispersal of L4 has been completely dominated by historical migrations out of Europe. We demonstrate an intimate temporal relationship between European colonial expansion into Africa and the Americas and the spread of L4 tuberculosis (TB). Markedly, in the age of antibiotics, mutations conferring antimicrobial resistance overwhelmingly emerged locally (at the level of nations), with minimal cross-border transmission of resistance. The latter finding was found to reflect the relatively recent emergence of these mutations, as a similar degree of local restriction was observed for susceptible variants emerging on comparable time scales. The restricted international transmission of drug-resistant TB suggests that containment efforts at the level of individual countries could be successful.
|
|
| 2. |
- Pettersson, John, 1981-, et al.
(författare)
-
Characterizing the virome of Ixodes ricinus ticks from northern Europe
- 2017
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- RNA viruses are abundant infectious agents and present in all domains of life. Arthropods, including ticks, are well known as vectors of many viruses of concern for human and animal health. Despite their obvious importance, the extent and structure of viral diversity in ticks is still poorly understood, particularly in Europe. Using a bulk RNA-sequencing approach that captures the complete transcriptome, we analysed the virome of the most common tick in Europe - Ixodes ricinus. In total, RNA sequencing was performed on six libraries consisting of 33 I. ricinus nymphs and adults sampled in Norway. Despite the small number of animals surveyed, our virus identification pipeline revealed nine diverse and novel viral species, phylogenetically positioned within four different viral groups bunyaviruses, luteoviruses, mononegavirales and partitiviruses - and sometimes characterized by extensive genetic diversity including a potentially novel genus of bunyaviruses. This work sheds new light on the virus diversity in I. ricinus, expands our knowledge of potential host/vector-associations and tick-transmitted viruses within several viral groups, and pushes the latitudinal limit where it is likely to find tick-associated viruses. Notably, our phylogenetic analysis revealed the presence of tick-specific virus clades that span multiple continents, highlighting the role of ticks as important virus reservoirs.
|
|
| 3. |
- Pettersson, John H.-O. 1981-, et al.
(författare)
-
Re-visiting the evolution, dispersal and epidemiology of Zika virus in Asia
- 2018
-
Ingår i: Emerging Microbes & Infections. - : Nature Publishing Group. - 2222-1751. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Based on serological evidence and viral isolation, Zika virus (ZIKV) has circulated for many years relatively benignly in a sylvatic cycle in Africa and an urban cycle in South East Asia (SEA). With the recent availability of limited but novel Indian ZIKV sequences to add to the plethora of SEA sequences, we traced the phylogenetic history and spatio-temporal dispersal pattern of ZIKV in Asia prior to its explosive emergence in the Pacific region and the Americas. These analyses demonstrated that the introduction and dispersal of ZIKV on the Pacific islands were preceded by an extended period of relatively silent transmission in SEA, enabling the virus to expand geographically and evolve adaptively before its unanticipated introduction to immunologically naive populations on the Pacific islands and in the Americas. Our findings reveal new features of the evolution and dispersal of this intriguing virus and may benefit future disease control strategies.
|
|
