Case 37

2020 ◽  
pp. 255-260
Author(s):  
Andrew Woodhouse
Keyword(s):  
Geographic Distribution ◽  
Parasitic Infection ◽  
Systemic Infection ◽  
Host Factors ◽  
Skin Ulceration ◽  
Phlebotomine Sandflies

Leishmaniasis is an intracellular protozoan parasitic infection caused by organisms of the genus Leishmania. The parasite is usually transmitted to humans by the bite of Phlebotomine sandflies. A spectrum of illness is seen ranging from localized skin ulceration (which can be self-limiting) to disseminated systemic infection which can be fatal. Different species of Leishmania cause different forms of disease and the species are restricted in their geographic distribution. Host factors also seem to be important in determining how the infection will manifest itself.

scholarly journals Unique Tropism and Entry Mechanism of Mumps Virus

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1746
Author(s):  
Marie Kubota ◽  
Takao Hashiguchi
Keyword(s):  
Systemic Infection ◽  
Mumps Virus ◽  
Host Factors ◽  
Core Motif ◽  
Viral Attachment ◽  
Host Interactions ◽  
The Central Nervous System ◽  
Glycan Receptors ◽  
Attachment Proteins ◽  
Underlying Mechanisms

Mumps virus (MuV) is an important human pathogen that causes parotitis, orchitis, oophoritis, meningitis, encephalitis, and sensorineural hearing loss. Although mumps is a vaccine-preventable disease, sporadic outbreaks have occurred worldwide, even in highly vaccinated populations. MuV not only causes systemic infection but also has a unique tropism to glandular tissues and the central nervous system. In general, tropism can be defined by multiple factors in the viral life cycle, including its entry, interaction with host factors, and host-cell immune responses. Although the underlying mechanisms of MuV tropism remain to be fully understood, recent studies on virus–host interactions have provided insights into viral pathogenesis. This review was aimed at summarizing the entry process of MuV by focusing on the glycan receptors, particularly the recently identified receptors with a trisaccharide core motif, and their interactions with the viral attachment proteins. Here, we describe the receptor structures, their distribution in the human body, and the recently identified host factors for MuV and analyze their relationship with MuV tropism.

scholarly journals Molecular Co-Chaperone SGT1 Is Critical for Cell-to-Cell Movement and Systemic Infection of Tomato Spotted Wilt Virus in Nicotiana benthamiana

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 647 ◽  
Author(s):  
Xin Qian ◽  
Qing Xiang ◽  
Tongqing Yang ◽  
Hongyu Ma ◽  
Xin Ding ◽  
...  
Keyword(s):  
Virus Infection ◽  
Nicotiana Benthamiana ◽  
Tomato Spotted Wilt Virus ◽  
Rna Virus ◽  
Cell Movement ◽  
Systemic Infection ◽  
Plant Viruses ◽  
Host Factors ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Tospovirus is a tripartite negative stranded RNA virus and is considered as one of the most devastating plant viruses. Successful virus infection in plant requires many host factors. To date, very few host factors have been identified as important in Tospovirus infection in plants. We reported earlier that NSm protein encoded by Tomato spotted wilt virus (TSWV), a type species of the genus Orthotospovirus, plays critical roles in viral cell-to-cell and long-distance movement. In this study, we determined that molecular co-chaperone NbSGT1 interacted with TSWV NSm in Nicotiana benthamiana. TSWV infection significantly upregulated the expression of NbSGT1 gene and transient overexpression of NbSGT1 in N. benthamiana leaves accelerated TSWV infection. In contrast, silencing the NbSGT1 gene expression using a virus-induced gene silencing (VIGS) approach strongly inhibited TSWV NSm cell-to-cell movement, as well as TSWV local and systemic infection in N. benthamiana plants. Furthermore, NbSGT1 was found to regulate the infection of both American and Euro/Asia type tospoviruses in N. benthamiana plant. Collectively, our findings presented in this paper and the results published previously indicated that molecular co-chaperone NbSGT1 plays important roles in modulating both positive stranded and tripartite negative stranded RNA virus infection in plants.

scholarly journals Isolation of an Arabidopsis thalianaMutant in Which the Multiplication of both Cucumber Mosaic Virus and Turnip Crinkle Virus Is Affected

1998 ◽  
Vol 72 (11) ◽  
pp. 8731-8737 ◽  
Author(s):  
Motoyasu Yoshii ◽  
Norimichi Yoshioka ◽  
Masayuki Ishikawa ◽  
Satoshi Naito
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Cell Movement ◽  
Systemic Infection ◽  
Virus Multiplication ◽  
Host Factors ◽  
Recessive Mutation ◽  
Turnip Crinkle Virus ◽  
Wild Type ◽  
Chromosome Iii

ABSTRACT During the systemic infection of plants by viruses, host factors play an important role in supporting virus multiplication. To identify and characterize the host factors involved in this process, we isolated an Arabidopsis thaliana mutant named RB663, in which accumulation of the coat protein (CP) of cucumber mosaic virus (CMV) in upper uninoculated leaves was delayed. Genetic analyses suggested that the phenotype of delayed accumulation of CMV CP in RB663 plants was controlled by a monogenic, recessive mutation designatedcum2-1, which is located on chromosome III and is distinct from the previously characterized cum1 mutation. Multiplication of CMV was delayed in inoculated leaves of RB663 plants, whereas the multiplication in RB663 protoplasts was similar to that in wild-type protoplasts. This suggests that the cum2-1mutation affects the cell-to-cell movement of CMV rather than CMV replication within a single cell. In RB663 plants, the multiplication of turnip crinkle virus (TCV) was also delayed but that of tobacco mosaic virus was not affected. As observed with CMV, the multiplication of TCV was normal in protoplasts and delayed in inoculated leaves of RB663 plants compared to that in wild-type plants. Furthermore, the phenotype of delayed TCV multiplication cosegregated with thecum2-1 mutation as far as we examined. Therefore, thecum2-1 mutation is likely to affect the cell-to-cell movement of both CMV and TCV, implying a common aspect to the mechanisms of cell-to-cell movement in these two distinct viruses.

Host factors in bacteremic CAP

Pneumologie ◽  
2004 ◽  
Vol 58 (S 1) ◽  
Author(s):  
R Erzen ◽  
E Music ◽  
V Tomic
Keyword(s):  
Host Factors

A new species of Contomastix (Squamata, Teiidae) supported by total evidence, with remarks on diagnostic characters defining the genus

2019 ◽  
pp. 23-36
Author(s):  
Mario. R. Cabrera
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Phylogenetic Reconstruction ◽  
Total Evidence ◽  
Molecular Evidence ◽  
Proximal Margin ◽  
Diagnostic Characters ◽  
Morphological Differences ◽  
A New Species ◽  
Molecular Characters

Formerly Cnemidophorus was thought to be the most speciose genus of Teiidae. This genus comprised four morphological groups that were later defined as four different genera, Ameivula, Aurivela, Cnemidophorus and Contomastix. The last appears as paraphyletic in a recent phylogenetic reconstruction based on morphology, but monophyletic in a reconstruction using molecular characters. Six species are allocated to Contomastix. One of them, C. lacertoides, having an extensive and disjunct geographic distribution in Argentina, Uruguay and Brazil. Preliminary analyses revealed morphological differences among its populations, suggesting that it is actually a complex of species. Here, we describe a new species corresponding to the Argentinian populations hitherto regarded as C. lacertoides, by integrating morphological and molecular evidence. Furthermore, we demonstrate that the presence of notched proximal margin of the tongue is a character that defines the genus Contomastix.

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