scholarly journals In Vitro Rearing of Perkinsiella saccharicida and the Use of Leaf Segments to Assay Fiji disease virus Transmission

2008 ◽  
Vol 98 (7) ◽  
pp. 810-814 ◽  
Author(s):  
G. L. Hughes ◽  
P. G. Allsopp ◽  
S. M. Brumbley ◽  
K. N. Johnson ◽  
S. L. O'Neill
Keyword(s):  
Disease Virus ◽  
Vector Competence ◽  
Virus Transmission ◽  
Subsequent Development ◽  
Leaf Segment ◽  
Rt Pcr ◽  
Additional Measure ◽  
Fiji Disease Virus ◽  
Leaf Segments

Fiji leaf gall (FLG) is caused by the Reovirus, Fiji disease virus (FDV), which is transmitted to sugarcane by planthoppers of the genus Perkinsiella. Low vector transmission rates and slow disease symptom development make experimentation within the FDV-Perkinsiella-sugarcane system inherently difficult. A laboratory-based technique was devised to rear the vector using sugarcane leaves as a food source. Planthoppers were reared on sugarcane leaf segments embedded in agarose enclosed within plastic containers. To provide a nondestructive assay for determination of the inoculation potential of planthoppers, FDV was detected by reverse transcription-polymerase chain reaction (RT-PCR) in newly infected sugarcane leaf segments following exposure to viruliferous planthoppers. Leaf segment inoculation correlated with development of FLG symptoms in whole plants that were fed on by the same planthoppers. Analysis of FDV RNAs within the planthopper, measured by quantitative RT-PCR (qRT-PCR), indicated that FDV RNA concentration was associated with successful inoculation of the leaf segment, transmission of FDV to sugarcane and subsequent development of FLG in plants. Quantification of FDV RNA within planthoppers provided an additional measure to assess vector competence in individuals.

scholarly journals Transstadial Transmission and Replication Kinetics of West Nile Virus Lineage 1 in Laboratory Reared Ixodes ricinus Ticks

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 780
Author(s):  
Cristian Răileanu ◽  
Oliver Tauchmann ◽  
Ana Vasić ◽  
Ulrike Neumann ◽  
Birke Andrea Tews ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Ixodes Ricinus ◽  
Tick Species ◽  
Vector Competence ◽  
Virus Transmission ◽  
Viral Agent ◽  
West Nile ◽  
Transstadial Transmission ◽  
Kinetics Of

West Nile virus (WNV) is a mosquito-borne agent that has also been isolated from several tick species. Vector competence of Ixodes ricinus, one of the most common tick species in Europe, has been poorly investigated for WNV to date. As such, to evaluate the vector competence, laboratory reared Ixodes ricinus nymphs were in vitro fed with WNV lineage 1 infectious blood, allowed to molt, and the resulting females artificially fed to study the virus transmission. Furthermore, we studied the kinetics of WNV replication in ticks after infecting nymphs using an automatic injector. Active replication of WNV was detected in injected nymphs from day 7 post-infection until 28 dpi. In the nymphs infected by artificial feeding, the transstadial transmission of WNV was confirmed molecularly in 46.7% of males, while virus transmission during in vitro feeding of I. ricinus females originating from infected nymphs was not registered. The long persistence of WNV in I. ricinus ticks did not correlate with the transmission of the virus and it is unlikely that I. ricinus represents a competent vector. However, there is a potential reservoir role that this tick species can play, with hosts potentially acquiring the viral agent after ingesting the infected ticks.

Improving Fiji disease resistance screening trials in sugarcane by considering virus transmission class and possible origin of Fiji disease virus

2004 ◽  
Vol 55 (6) ◽  
pp. 665 ◽  
Author(s):  
Grant R. Smith ◽  
Judith M. Candy
Keyword(s):  
Disease Virus ◽  
Disease Incidence ◽  
Virus Transmission ◽  
Rating System ◽  
Plant Host ◽  
Plant Infection ◽  
Disease Resistance Screening ◽  
Disease Rating ◽  
Fiji Disease Virus ◽  
Persistently Transmitted Viruses

Fiji disease virus is a propagative, persistently transmitted virus that multiplies in species of the delphacid planthopper genus Perkinsiella, and in sugarcane, the feeding host of the insect. Efforts to improve and modify the disease rating system for Fiji disease have largely focussed on the planthopper as individual vectors of the virus, rather than as a population of the principal, or at least an alternative, host of the virus. This perspective has resulted in key parameters of disease incidence resulting from plant infection by propagative, persistently transmitted viruses being largely overlooked or misunderstood during efforts to improve the rating system. These parameters include the relatively long acquisition, latency, and transmission times, the percentage of the population containing virus, or viruliferous, in the above periods, and the effects of population density and number of plants visited on disease incidence. Suggestions to modify trial design to improve virus transmission to the plant, based on the disease incidence parameters of the propagative, persistent transmission class, are presented and the practical difficulties of implementing these proposals are discussed. In the context of fully understanding the underlying biology of this virus–insect–plant system, the hypothesis that Fiji disease virus, as a plant-infecting member of the Reoviridae, is primarily an insect virus with a secondary plant host, and may have diverged from an insect-infecting virus relatively recently is proposed and compared with other members of the family Reoviridae.

scholarly journals Vector competence experiments with Rocio virus and three mosquito species from the epidemic zone in Brazil

1986 ◽  
Vol 20 (3) ◽  
pp. 171-177 ◽  
Author(s):  
Carl J. Mitchell ◽  
Oswaldo Paulo Forattini ◽  
Barry R. Miller
Keyword(s):  
First Generation ◽  
Vector Competence ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Infection Rates ◽  
Feeding Technique ◽  
Generation Progeny ◽  
In Vitro Feeding ◽  
Vector Competency

First-generation progeny of field-collected Psorophora ferox, Aedes scapularis, and Aedes serratus from the Rocio encephalitis epidemic zone in S.Paulo State, Brazil, were tested for vector competency in the laboratory. Psorophora ferox and Ae. scapularis are susceptible to per os infection with Rocio virus and can transmit the virus by bite following a suitable incubation period. Oral ID50S for the two species (10(4.1) and 10(4.3) Vero cell plaque forming units, respectively) did not differ significantly. Infection rates in Ae. serratus never exceeded 36%, and, consequently, an ID50 could not be calculated for this species. It is unlikely that Ae. serratus is an epidemiologically important vector of Rocio virus. The utility of an in vitro feeding technique for demonstrating virus transmission by infected mosquitoes and difficulties encountered in working with uncolonized progeny of field-collected mosquitoes are discussed.

Foot and mouth disease virus replication in bovine skin Langerhans cells under in vitro conditions detected by RT-PCR

Virus Genes ◽  
1995 ◽  
Vol 10 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Dan David ◽  
Yehuda Stram ◽  
Hagai Yadin ◽  
Zeev Trainin ◽  
Yechiel Becker
Keyword(s):  
Disease Virus ◽  
Virus Replication ◽  
Langerhans Cells ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Rt Pcr ◽  
Mouth Disease Virus ◽  
Foot And Mouth

scholarly journals Vector Competence of Eucampsipoda africana (Diptera: Nycteribiidae) for Marburg Virus Transmission in Rousettus aegyptiacus (Chiroptera: Pteropodidae)

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2226
Author(s):  
Janusz T. Pawęska ◽  
Petrus Jansen van Vuren ◽  
Nadia Storm ◽  
Wanda Markotter ◽  
Alan Kemp
Keyword(s):  
Vector Competence ◽  
Virus Transmission ◽  
Marburg Virus ◽  
Mechanical Transmission ◽  
Virus Concentration ◽  
Post Inoculation ◽  
Rt Pcr ◽  
Bat Flies ◽  
Filial Generation ◽  
Contaminated Blood

This study aimed to determine the vector competence of bat-associated nycteribiid flies (Eucamsipoda africana) for Marburg virus (MARV) in the Egyptian Rousette Bat (ERB), Rousettus aegyptiacus. In flies fed on subcutaneously infected ERBs and tested from 3 to 43 days post infection (dpi), MARV was detected only in those that took blood during the peak of viremia, 5–7 dpi. Seroconversion did not occur in control bats in contact with MARV-infected bats infested with bat flies up to 43 days post exposure. In flies inoculated intra-coelomically with MARV and tested on days 0–29 post inoculation, only those assayed on day 0 and day 7 after inoculation were positive by q-RT-PCR, but the virus concentration was consistent with that of the inoculum. Bats remained MARV-seronegative up to 38 days after infestation and exposure to inoculated flies. The first filial generation pupae and flies collected at different times during the experiments were all negative by q-RT-PCR. Of 1693 nycteribiid flies collected from a wild ERB colony in Mahune Cave, South Africa where the enzootic transmission of MARV occurs, only one (0.06%) tested positive for the presence of MARV RNA. Our findings seem to demonstrate that bat flies do not play a significant role in the transmission and enzootic maintenance of MARV. However, ERBs eat nycteribiid flies; thus, the mechanical transmission of the virus through the exposure of damaged mucous membranes and/or skin to flies engorged with contaminated blood cannot be ruled out.

Leaf Color of Plants Regenerated through In Vitro Culture from Variegated Leaf Segments of Caladium.

1993 ◽  
Vol 62 (3) ◽  
pp. 619-624 ◽  
Author(s):  
Yu Zhu ◽  
Tetsuyuki Takemoto ◽  
Susumu Yazawa
Keyword(s):  
In Vitro Culture ◽  
Leaf Color ◽  
Leaf Segments ◽  
Variegated Leaf

Anti-Mycobacterial Peroxides: A New Class of Agents for Development Against Tuberculosis

2020 ◽  
Vol 16 (3) ◽  
pp. 392-402
Author(s):  
Christiaan W. van der Westhuyzen ◽  
Richard K. Haynes ◽  
Jenny-Lee Panayides ◽  
Ian Wiid ◽  
Christopher J. Parkinson
Keyword(s):  
Subsequent Development ◽  
Antitubercular Activity ◽  
Organic Peroxide ◽  
New Drugs ◽  
Skeletal Myoblast ◽  
Artemisinin Derivatives ◽  
Malaria Therapy ◽  
New Class ◽  
Alternative Approach

Background: With few exceptions, existing tuberculosis drugs were developed many years ago and resistance profiles have emerged. This has created a need for new drugs with discrete modes of action. There is evidence that tuberculosis (like other bacteria) is susceptible to oxidative pressure and this has yet to be properly utilised as a therapeutic approach in a manner similar to that which has proven highly successful in malaria therapy. Objective: To develop an alternative approach to the incorporation of bacterial siderophores that results in the creation of antitubercular peroxidic leads for subsequent development as novel agents against tuberculosis. Methods: Eight novel peroxides were prepared and the antitubercular activity (H37Rv) was compared to existing artemisinin derivatives in vitro. The potential for toxicity was evaluated against the L6 rat skeletal myoblast and HeLa cervical cancer lines in vitro. Results: The addition of a pyrimidinyl residue to an artemisinin or, preferably, a tetraoxane peroxidic structure results in antitubercular activity in vitro. The same effect is not observed in the absence of the pyrimidine or with other heteroaromatic substituents. Conclusion: The incorporation of a pyrimidinyl residue adjacent to the peroxidic function in an organic peroxide results in anti-tubercular activity in an otherwise inactive peroxidic compound. This will be a useful approach for creating oxidative drugs to target tuberculosis.

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