scholarly journals Comparative whitefly transmission ofTomato chlorosis virusandTomato infectious chlorosis virusfrom single or mixed infections

2009 ◽  
Vol 58 (2) ◽  
pp. 221-227 ◽  
Author(s):  
A. Dalmon ◽  
F. Fabre ◽  
L. Guilbaud ◽  
H. Lecoq ◽  
M. Jacquemond
2020 ◽  
Vol 110 (1) ◽  
pp. 49-57 ◽  
Author(s):  
C. Alcaide ◽  
M. P. Rabadán ◽  
M. Juárez ◽  
P. Gómez

Mixed viral infections are common in plants, and the evolutionary dynamics of viral populations may differ depending on whether the infection is caused by single or multiple viral strains. However, comparative studies of single and mixed infections using viral populations in comparable agricultural and geographical locations are lacking. Here, we monitored the occurrence of pepino mosaic virus (PepMV) in tomato crops in two major tomato-producing areas in Murcia (southeastern Spain), supporting evidence showing that PepMV disease-affected plants had single infections of the Chilean 2 (CH2) strain in one area and the other area exhibited long-term (13 years) coexistence of the CH2 and European (EU) strains. We hypothesized that circulating strains of PepMV might be modulating the differentiation between them and shaping the evolutionary dynamics of PepMV populations. Our phylogenetic analysis of 106 CH2 isolates randomly selected from both areas showed a remarkable divergence between the CH2 isolates, with increased nucleotide variability in the geographical area where both strains cocirculate. Furthermore, the potential virus–virus interaction was studied further by constructing six full-length infectious CH2 clones from both areas, and assessing their viral fitness in the presence and absence of an EU-type isolate. All CH2 clones showed decreased fitness in mixed infections and although complete genome sequencing indicated a nucleotide divergence of those CH2 clones by area, the magnitude of the fitness response was irrespective of the CH2 origin. Overall, these results suggest that although agroecological cropping practices may be particularly important for explaining the evolutionary dynamics of PepMV in tomato crops, the cocirculation of both strains may have implications on the genetic variability of PepMV populations.


1990 ◽  
Vol 11 (03) ◽  
pp. 271-280
Author(s):  
J. H. P. Nyeko ◽  
O. K. Ole-Moiyoi ◽  
P. A. O. Majiwa ◽  
L. H. Otieno ◽  
P. M. Ociba

2021 ◽  
Vol 27 (1) ◽  
pp. 11-27
Author(s):  
Aminallah Tahmasebi ◽  
Bahman Khahani ◽  
Elahe Tavakol ◽  
Alireza Afsharifar ◽  
Muhammad Shafiq Shahid

1954 ◽  
Vol 87 (3) ◽  
pp. 500-507 ◽  
Author(s):  
L. A. Mika ◽  
R. J. Goodlow ◽  
J. Victor ◽  
W. Braun
Keyword(s):  
Q Fever ◽  

2003 ◽  
Vol 93 (12) ◽  
pp. 1478-1484 ◽  
Author(s):  
C. Desbiez ◽  
A. Gal-On ◽  
M. Girard ◽  
C. Wipf-Scheibel ◽  
H. Lecoq

Zucchini yellow mosaic virus (ZYMV, Potyvirus) is a very damaging cucurbit virus worldwide. Interspecific crosses with resistant Cucurbita moschata have led to the release of “resistant” zucchini squash (C. pepo) F1 hybrids. However, although the resistance is almost complete in C. moschata, the commercial C. pepo hybrids are only tolerant. ZYMV evolution toward increased aggressiveness on tolerant hybrids was observed in the field and was obtained experimentally. Sequence comparisons and recombination experiments revealed that a point mutation in the P3 protein of ZYMV was enough to induce tolerance breaking. Competition experiments were performed between quasi-isogenic wild-type, and aggressive variants of ZYMV distinguished by monoclonal antibodies. The aggressive mutants were more fit than wild-type strains in mixed infections of tolerant zucchini, but they presented a drastic fitness loss in mixed infections of susceptible zucchini or melon. Thus, the ability to induce severe symptoms in tolerant zucchini is related to a genetic load in susceptible zucchini, but also on other susceptible hosts. This represents the first quantitative study of the fitness cost associated with tolerance breaking for a plant virus. Thus, although easily broken, the tolerance might prove durable in some conditions if the aggressive variants are counterselected in susceptible crops.


1927 ◽  
Vol 23 (12) ◽  
pp. 1296-1296
Author(s):  
O. Vasilieva
Keyword(s):  

Having treated 144 cases of purulent inflammations of the middle ear according to Bezredek's method, the author concluded that coke infections are successfully cured exclusively with filtrate-bullion-vaccine, while mixed infections require the addition of weak disinfectant solutions to the latter.


2021 ◽  
Vol 70 (7) ◽  
Author(s):  
Rosemonde Isabella Power ◽  
Nichola Elisa Davies Calvani ◽  
Yaarit Nachum-Biala ◽  
Harold Salant ◽  
Shimon Harrus ◽  
...  

Introduction. Bartonellosis is an emerging zoonotic disease caused by bacteria of the genus Bartonella . Mixed Bartonella infections are a well-documented phenomenon in mammals and their ectoparasites. The accurate identification of Bartonella species in single and mixed infections is valuable, as different Bartonella species have varying impacts on infected hosts. Gap Statement. Current diagnostic methods are inadequate at identifying the Bartonella species present in mixed infections. Aim. The aim of this study was to adopt a Next Generation Sequencing (NGS) approach using Illumina sequencing technology to identify Bartonella species and demonstrate that this approach can resolve mixed Bartonella infections. Methodology. We used Illumina PCR amplicon NGS to target the ssrA and gltA genes of Bartonella in fleas collected from cats, dogs and a hedgehog in Israel. We included artificially mixed Bartonella samples to demonstrate the ability for NGS to resolve mixed infections and we compared NGS to traditional Sanger sequencing. Results. In total, we identified 74 Ctenocephalides felis, two Ctenocephalides canis, two Pulex irritans and three Archaeopsylla e. erinacei fleas. Real-time PCR of a subset of 48 fleas revealed that twelve were positive for Bartonella , all of which were cat fleas. Sanger sequencing of the ssrA and gltA genes confirmed the presence of Bartonella henselae , Bartonella clarridgeiae and Bartonella koehlerae . Illumina NGS of ssrA and gltA amplicons further confirmed the Bartonella species identity in all 12 flea samples and unambiguously resolved the artificially mixed Bartonella samples. Conclusion. The adaptation and multiplexing of existing PCR assays for diversity profiling via NGS is a feasible approach that is superior to traditional Sanger sequencing for Bartonella speciation and resolving mixed Bartonella infections. The adaptation of other PCR primers for Illumina NGS will be useful in future studies where mixed bacterial infections may be present.


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