| 1. |
- Norte, Ana Cláudia, et al.
(författare)
-
Host dispersal shapes the population structure of a tick-borne bacterial pathogen
- 2020
-
Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 29:3, s. 485-501
-
Tidskriftsartikel (refereegranskat)abstract
- Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies “Candidatus Borrelia aligera” was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.
|
|
| 2. |
- Schaufler, Katharina, et al.
(författare)
-
Genomic and Functional Analysis of Emerging Virulent and Multidrug-Resistant Escherichia coli Lineage Sequence Type 648
- 2019
-
Ingår i: Antimicrobial Agents and Chemotherapy. - : AMER SOC MICROBIOLOGY. - 0066-4804 .- 1098-6596. ; 63:6
-
Tidskriftsartikel (refereegranskat)abstract
- The pathogenic extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli lineage ST648 is increasingly reported from multiple origins. Our study of a large and global ST648 collection from various hosts (87 whole-genome sequences) combining core and accessory genomics with functional analyses and in vivo experiments suggests that ST648 is a nascent and generalist lineage, lacking clear phylogeographic and host association signals. By including large numbers of ST131 (n = 107) and ST10 (n = 96) strains for comparative genomics and phenotypic analysis, we demonstrate that the combination of multidrug resistance and high-level virulence are the hallmarks of ST648, similar to international high-risk clonal lineage ST131. Specifically, our in silico, in vitro, and in vivo results demonstrate that ST648 is well equipped with biofilm-associated features, while ST131 shows sophisticated signatures indicative of adaption to urinary tract infection, potentially conveying individual ecological niche adaptation. In addition, we used a recently developed NFDS (negative frequency-dependent selection) population model suggesting that ST648 will increase significantly in frequency as a cause of bacteremia within the next few years. Also, ESBL plasmids impacting biofilm formation aided in shaping and maintaining ST648 strains to successfully emerge worldwide across different ecologies. Our study contributes to understanding what factors drive the evolution and spread of emerging international high-risk clonal lineages.
|
|
| 3. |
- Valan, Miroslav, 1987-, et al.
(författare)
-
Redescriptions and new host records of chewing lice of the genus Ricinus (Phthiraptera Ricinidae) from the Neotropical Region.
- 2016
-
Ingår i: Zootaxa. - 1175-5326 .- 1175-5334. ; 4154:2, s. 179-189
-
Tidskriftsartikel (refereegranskat)abstract
- Two species of the chewing louse genus Ricinus are redescribed and illustrated: Ricinus dalgleishi Nelson, 1972 from Helmitheros vermivorum (Gmelin, 1789), a new host-louse association, and Ricinus tanagraephilus Eichler, 1956 from Euphonia laniirostris d'Orbigny & Lafresnaye, 1837. Also, new host-louse associations are recorded for Ricinus vireoensis Nelson, 1972 from Vireo pallens Salvin, 1863, and for females of an unidentified species of Ricinus sp. from Corythopis delalandi (Lesson, 1831), which are described and illustrated.
|
|
