Comparative Study of Highly Pathogenic Avian Infl uenza Strains Isolated in Ukraine in 2005 and 2008

2014 ◽  
Vol 1 (1) ◽  
pp. 68-71
Author(s):  
A. Gerilovych ◽  
B. Stegniy ◽  
A. Stegniy ◽  
M. Stegniy ◽  
K. Smietanka ◽  
...  

Objective. To research the molecular characteristics of two HPAI strains – A/Ch/Syvash/02/05/H5N1 and A/Ch/Krasnogvardeysk/58/08/H5N1, which were identifi ed as representatives of the highly pathogenic H5N1 viruses. Methods. RNA extraction, real-time polymerase chain reaction (PCR). Results. The phylogenetic studies revealed that the above mentioned strains belong to two various genetic lineages originated from the Eastern European strains isolated in 2005, but differ from the viruses introduced to the Central and Western Europe in 2005/2006, and also the lineages consisting of H5N1 viruses isolated in the Europe and Middle East in late 2007. Conclusions. Relying on experimental studies, it can be concluded that the strains of A/Ch/Syvash/02/05/H5N1 and A/Ch/Krasnogvardeysk/58/08/H5N1 are highly pathogenic.

Tick-borne encephalitis virus (TBEV) exists in natural foci, which are areas where TBEV is circulating among its vectors (ticks of different species and genera) and reservoir hosts (usually rodents and small mammals). Based on phylogenetic studies, four TBEV subtypes (Far-Eastern, Siberian, European, Baikalian) and two putative subtypes (Himalayan and “178-79” group) are known. Within each subtype, some genetic lineages are described. The European subtype (TBEV-EU) (formerly known also as the “Western subtype”) of TBEV is prevalent in Europe, but it was also isolated in Western and Eastern Siberia in Russia and South Korea. The Far-Eastern subtype (TBEV-FE) was preferably found in the territory of the far-eastern part of Eurasia, but some strains were isolated in other regions of Eurasia. The Siberian (TBEV-SIB) subtype is the most common and has been found in almost all TBEV habitat areas. The Baikalian subtype is prevalent around Lake Baikal and was isolated several times from ticks and rodents. In addition to the four TBEV subtypes, one single isolate of TBEV (178-79) and two genetic sequences (Himalayan) supposed to be new TBEV subtypes were described in Eastern Siberia and China. The data on TBEV seroprevalence in humans and animals can serve as an indication for the presence or absence of TBEV in studied area.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 352
Author(s):  
Wei Wei ◽  
Valeria Trivellone ◽  
Christopher H. Dietrich ◽  
Yan Zhao ◽  
Kristi D. Bottner-Parker ◽  
...  

Phytoplasmas are obligate transkingdom bacterial parasites that infect a variety of plant species and replicate in phloem-feeding insects in the order Hemiptera, mainly leafhoppers (Cicadellidae). The insect capacity in acquisition, transmission, survival, and host range directly determines the epidemiology of phytoplasmas. However, due to the difficulty of insect sampling and the lack of follow-up transmission trials, the confirmed phytoplasma insect hosts are still limited compared with the identified plant hosts. Recently, quantitative polymerase chain reaction (qPCR)-based quick screening of 227 leafhoppers collected in natural habitats unveiled the presence of previously unknown phytoplasmas in six samples. In the present study, 76 leafhoppers, including the six prescreened positive samples, were further examined to identify and characterize the phytoplasma strains by semi-nested PCR. A total of ten phytoplasma strains were identified in leafhoppers from four countries including South Africa, Kyrgyzstan, Australia, and China. Based on virtual restriction fragment length polymorphism (RFLP) analysis, these ten phytoplasma strains were classified into four distinct ribosomal (16Sr) groups (16SrI, 16SrIII, 16SrXIV, and 16SrXV), representing five new subgroups (16SrI-AO, 16SrXIV-D, 16SrXIV-E, 16SrXIV-F, and 16SrXV-C). The results strongly suggest that the newly identified phytoplasma strains not only represent new genetic subgroup lineages, but also extend previously undiscovered geographical distributions. In addition, ten phytoplasma-harboring leafhoppers belonged to seven known leafhopper species, none of which were previously reported insect vectors of phytoplasmas. The findings from this study provide fresh insight into genetic diversity, geographical distribution, and insect host range of phytoplasmas. Further transmission trials and screening of new potential host plants and weed reservoirs in areas adjacent to collection sites of phytoplasma harboring leafhoppers will contribute to a better understanding of phytoplasma transmission and epidemiology.


Cancers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 87
Author(s):  
Linda Silina ◽  
Fatlinda Maksut ◽  
Isabelle Bernard-Pierrot ◽  
François Radvanyi ◽  
Gilles Créhange ◽  
...  

Bladder cancer is among the top ten most common cancer types in the world. Around 25% of all cases are muscle-invasive bladder cancer, for which the gold standard treatment in the absence of metastasis is the cystectomy. In recent years, trimodality treatment associating maximal transurethral resection and radiotherapy combined with concurrent chemotherapy is increasingly used as an organ-preserving alternative. However, the use of this treatment is still limited by the lack of biomarkers predicting tumour response and by a lack of targeted radiosensitising drugs that can improve the therapeutic index, especially by limiting side effects such as bladder fibrosis. In order to improve the bladder-preserving treatment, experimental studies addressing these main issues ought to be considered (both in vitro and in vivo studies). Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, we conducted a literature search in PubMed on experimental studies investigating how to improve bladder cancer radiotherapy with different radiosensitising agents using a comprehensive search string. We made comments on experimental model selection, experimental design and results, formulating the gaps of knowledge still existing: such as the lack of reliable predictive biomarkers of tumour response to chemoradiation according to the molecular tumour subtype and lack of efficient radiosensitising agents specifically targeting bladder tumour cells. We provided guidance to improve forthcoming studies, such as taking into account molecular characteristics of the preclinical models and highlighted the value of using patient-derived xenografts as well as syngeneic models. Finally, this review could be a useful tool to set up new radiation-based combined treatments with an improved therapeutic index that is needed for bladder preservation.


2007 ◽  
Vol 79 (6) ◽  
pp. 811-819 ◽  
Author(s):  
Takeshi Ichinohe ◽  
Noriyo Nagata ◽  
Peter Strong ◽  
Shin-ichi Tamura ◽  
Hidehiro Takahashi ◽  
...  

2016 ◽  
Vol 283 (1845) ◽  
pp. 20162159 ◽  
Author(s):  
Sarah C. Hill ◽  
Ruth J. Manvell ◽  
Bodo Schulenburg ◽  
Wendy Shell ◽  
Paul S. Wikramaratna ◽  
...  

For viruses such as avian influenza, immunity within a host population can drive the emergence of new strains by selecting for viruses with novel antigens that avoid immune recognition. The accumulation of acquired immunity with age is hypothesized to affect how influenza viruses emerge and spread in species of different lifespans. Despite its importance for understanding the behaviour of avian influenza viruses, little is known about age-related accumulation of immunity in the virus's primary reservoir, wild birds. To address this, we studied the age structure of immune responses to avian influenza virus in a wild swan population ( Cygnus olor ), before and after the population experienced an outbreak of highly pathogenic H5N1 avian influenza in 2008. We performed haemagglutination inhibition assays on sampled sera for five avian influenza strains and show that breadth of response accumulates with age. The observed age-related distribution of antibody responses to avian influenza strains may explain the age-dependent mortality observed during the highly pathogenic H5N1 outbreak. Age structures and species lifespan are probably important determinants of viral epidemiology and virulence in birds.


2011 ◽  
Vol 31 (4) ◽  
pp. 393-400 ◽  
Author(s):  
Adam J. Karpala ◽  
John Bingham ◽  
Karel A. Schat ◽  
Li-Mei Chen ◽  
Ruben O. Donis ◽  
...  

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