Kang Y.-J.,Chinese National Institute for Communicable Disease Control and Prevention |
Kang Y.-J.,Center for Diagnosis and Treatment of Infectious Diseases |
Diao X.-N.,Veterinary Station |
Zhao G.-Y.,Chinese National Institute for Communicable Disease Control and Prevention |
And 16 more authors.
BMC Evolutionary Biology | Year: 2014
Background: Bacteria of the order Rickettsiales (Alphaproteobacteria) are obligate intracellular parasites that infect species from virtually every major eukaryotic lineage. Several rickettsial genera harbor species that are significant emerging and re-emerging pathogens of humans. As species of Rickettsiales are associated with an extremely diverse host range, a better understanding of the historical associations between these bacteria and their hosts will provide important information on their evolutionary trajectories and, particularly, their potential emergence as pathogens. Results: Nine species of Rickettsiales (two in the genus Rickettsia, three in the genus Anaplasma, and four in the genus Ehrlichia) were identified in two species of hard ticks (Dermacentor nuttalli and Hyalomma asiaticum) from two geographic regions in Xinjiang through genetic analyses of 16S rRNA, gltA, and groEL gene sequences. Notably, two lineages of Ehrlichia and one lineage of Anaplasma were distinct from any known Rickettsiales, suggesting the presence of potentially novel species in ticks in Xinjiang. Our phylogenetic analyses revealed some topological differences between the phylogenies of the bacteria and their vectors, which led us to marginally reject a model of exclusive bacteria-vector co-divergence. Conclusions: Ticks are an important natural reservoir of many diverse species of Rickettsiales. In this work, we identified a single tick species that harbors multiple species of Rickettsiales, and uncovered extensive genetic diversity of these bacteria in two tick species from Xinjiang. Both bacteria-vector co-divergence and cross-species transmission appear to have played important roles in Rickettsiales evolution. © 2014 Kang et al.; licensee BioMed Central Ltd.
Mehlhorn H.,Heinrich Heine University Düsseldorf |
Schumacher B.,Veterinary Station |
Jatzlau A.,Veterinary Station |
Abdel-Ghaffar F.,Cairo University |
And 3 more authors.
Parasitology Research | Year: 2011
Ticks are known to be able to transmit a broad spectrum of agents of diseases in cattle or sheep. Therefore, measurements are needed to keep ticks away from the body of any ruminant belonging to the agricultural life stock. The present study dealt with investigations to measure the efficacy of the insecticide deltamethrin (Butox® 7.5 pour on) against specimens of two important species (Ixodes ricinus and Rhipicephalus sanguineus). Four sheep and four young cattle were treated lege arte along the vertebral column with 10 ml Butox® (deltamethrin) per sheep or 30 ml Butox® per cattle. Day 7, 14, 21, and 28 after the treatment, hair was shaved off from the head, ears, the back, belly, and the feet being collected in separate, suitable plastic bags, and transported to the institute, where these hair were brought into close contact with either adult and/or nymph stages of I. ricinus and R. sanguineus. As results, strong, acaricidal effects were seen, which varied according to the parasite species, the origin of the hair (e.g., head, leg, etc.) and according to the period after the treatment. In sheep, the acaricidal effect was noted for the whole period of 28 days along the whole body with respect to adults and nymphs of I. ricinus, while the acaricidal effects of deltamethrin were reduced for R. sanguineus stages beginning at day 21 after treatment. In cattle, the full acaricidal effect was seen for 21 days in I. ricinus stages and for 14 days in R. sanguineus, while the acaricidal efficacy became reduced after these periods of full action - beginning at the hair taken from the legs. Only R. sanguineus adults did not show any reaction on day 28 after treatment. Besides these acaricidal effects, repellent effects were also noted. Full repellency for both species was seen during the first 14 days in sheep and cattle against Ixodes and Rhipicephalus, while the repellency was later reduced, especially in contact with hair from the legs. As conclusion, deltamethrin, besides its very good effects against biting insects, brings acaricidal as well as repellent effects against ticks, thus protecting the sheep and cattle from transmission of agents of diseases. © Springer-Verlag 2010.
PubMed | Guangxi Mangrove Research Center, U.S. Center for Disease Control and Prevention, University of Texas Medical Branch, Chinese National Institute for Communicable Disease Control and Prevention and Veterinary Station
Type: Journal Article | Journal: Journal of virology | Year: 2015
Viruses of the family Flaviviridae are important pathogens of humans and other animals and are currently classified into four genera. To better understand their diversity, evolutionary history, and genomic flexibility, we used transcriptome sequencing (RNA-seq) to search for the viruses related to the Flaviviridae in a range of potential invertebrate and vertebrate hosts. Accordingly, we recovered the full genomes of five segmented jingmenviruses and 12 distant relatives of the known Flaviviridae (flavi-like viruses) from a range of arthropod species. Although these viruses are highly divergent, they share a similar genomic plan and common ancestry with the Flaviviridae in the NS3 and NS5 regions. Remarkably, although these viruses fill in major gaps in the phylogenetic diversity of the Flaviviridae, genomic comparisons reveal important changes in genome structure, genome size, and replication/gene regulation strategy during evolutionary history. In addition, the wide diversity of flavi-like viruses found in invertebrates, as well as their deep phylogenetic positions, suggests that they may represent the ancestral forms from which the vertebrate-infecting viruses evolved. For the vertebrate viruses, we expanded the previously mammal-only pegivirus-hepacivirus group to include a virus from the graceful catshark (Proscyllium habereri), which in turn implies that these viruses possess a larger host range than is currently known. In sum, our data show that the Flaviviridae infect a far wider range of hosts and exhibit greater diversity in genome structure than previously anticipated.The family Flaviviridae of RNA viruses contains several notorious human pathogens, including dengue virus, West Nile virus, and hepatitis C virus. To date, however, our understanding of the biodiversity and evolution of the Flaviviridae has largely been directed toward vertebrate hosts and their blood-feeding arthropod vectors. Therefore, we investigated an expanded group of potential arthropod and vertebrate host species that have generally been ignored by surveillance programs. Remarkably, these species contained diverse flaviviruses and related viruses that are characterized by major changes in genome size and genome structure, such that these traits are more flexible than previously thought. More generally, these data suggest that arthropods may be the ultimate reservoir of the Flaviviridae and related viruses, harboring considerable genetic and phenotypic diversity. In sum, this study revises the traditional view on the evolutionary history, host range, and genomic structures of a major group of RNA viruses.