scholarly journals Associations between Cryptococcus Genotypes, Phenotypes, and Clinical Parameters of Human Disease: A Review

2021 ◽  
Vol 7 (4) ◽  
pp. 260
Author(s):  
Marhiah C. Montoya ◽  
Paul M. Magwene ◽  
John R. Perfect

The genus Cryptococcus contains two primary species complexes that are significant opportunistic human fungal pathogens: C. neoformans and C. gattii. In humans, cryptococcosis can manifest in many ways, but most often results in either pulmonary or central nervous system disease. Patients with cryptococcosis can display a variety of symptoms on a spectrum of severity because of the interaction between yeast and host. The bulk of our knowledge regarding Cryptococcus and the mechanisms of disease stem from in vitro experiments and in vivo animal models that make a fair attempt, but do not recapitulate the conditions inside the human host. To better understand the dynamics of initiation and progression in cryptococcal disease, it is important to study the genetic and phenotypic differences in the context of human infection to identify the human and fungal risk factors that contribute to pathogenesis and poor clinical outcomes. In this review, we summarize the current understanding of the different clinical presentations and health outcomes that are associated with pathogenicity and virulence of cryptococcal strains with respect to specific genotypes and phenotypes.

2005 ◽  
Vol 18 (1) ◽  
pp. 217-245 ◽  
Author(s):  
Leen De Bolle ◽  
Lieve Naesens ◽  
Erik De Clercq

SUMMARY Human herpesvirus 6 (HHV-6) is a betaherpesvirus that is closely related to human cytomegalovirus. It was discovered in 1986, and HHV-6 literature has expanded considerably in the past 10 years. We here present an up-to-date and complete overview of the recent developments concerning HHV-6 biological features, clinical associations, and therapeutic approaches. HHV-6 gene expression regulation and gene products have been systematically characterized, and the multiple interactions between HHV-6 and the host immune system have been explored. Moreover, the discovery of the cellular receptor for HHV-6, CD46, has shed a new light on HHV-6 cell tropism. Furthermore, the in vitro interactions between HHV-6 and other viruses, particularly human immunodeficiency virus, and their relevance for the in vivo situation are discussed, as well as the transactivating capacities of several HHV-6 proteins. The insight into the clinical spectrum of HHV-6 is still evolving and, apart from being recognized as a major pathogen in transplant recipients (as exemplified by the rising number of prospective clinical studies), its role in central nervous system disease has become increasingly apparent. Finally, we present an overview of therapeutic options for HHV-6 therapy (including modes of action and resistance mechanisms).


2008 ◽  
Vol 76 (6) ◽  
pp. 2273-2283 ◽  
Author(s):  
John H. Carlson ◽  
William M. Whitmire ◽  
Deborah D. Crane ◽  
Luke Wicke ◽  
Kimmo Virtaneva ◽  
...  

ABSTRACT Chlamydia trachomatis possesses a cryptic 7.5-kb plasmid of unknown function. Here, we describe a comprehensive molecular and biological characterization of the naturally occurring plasmidless human C. trachomatis strain L2(25667R). We found that despite minimal chromosomal polymorphisms, the LGV strain L2(25667R) was indistinguishable from plasmid-positive strain L2(434) with regard to its in vitro infectivity characteristics such as growth kinetics, plaquing efficiency, and plaque size. The only in vitro phenotypic differences between L2(434) and L2(25667R) were the accumulation of glycogen granules in the inclusion matrix and the lack of the typical intrainclusion Brownian-like movement characteristic of C. trachomatis strains. Conversely, we observed a marked difference between the two strains in their abilities to colonize and infect the female mouse genital tract. The 50% infective dose of plasmidless strain L2(25667R) was 400-fold greater (4 × 106 inclusion-forming units [IFU]) than that of plasmid-bearing strain L2(434) (1 × 104 IFU). Transcriptome analysis of the two strains demonstrated a decrease in the transcript levels of a subset of chromosomal genes for strain L2(25667R). Among those genes was glgA, encoding glycogen synthase, a finding consistent with the failure of L2(25667R) to accumulate glycogen granules. These findings support a primary role for the plasmid in in vivo infectivity and suggest that virulence is controlled, at least in part, by the plasmid's ability to regulate the expression of chromosomal genes. Our findings have important implications in understanding a role for the plasmid in the pathogenesis of human infection and disease.


2019 ◽  
Vol 58 (5) ◽  
pp. 579-592 ◽  
Author(s):  
M R Davis ◽  
M A Donnelley ◽  
G R Thompson

Abstract Ibrexafungerp is a novel glucan synthase inhibitor currently undergoing phase II and phase III clinical trials. This compound has demonstrated in vitro activity against clinically important fungal pathogens including Candida spp. and Aspergillus spp. It is able to retain activity against many echinocandin-resistant strains of Candida due to differential avidity for the target site compared to echinocandins. In vivo animal models have demonstrated efficacy in murine models of invasive candidiasis, aspergillosis, and pneumocystis. Due to high bioavailability, it can be administered both orally and intravenously. A favorable drug interaction and tolerability profile is observed with this compound. This review summarizes existing data that have either been published or presented at international symposia.


2021 ◽  
Vol 7 (6) ◽  
pp. 428
Author(s):  
Men Thi Ngo ◽  
Minh Van Nguyen ◽  
Jae Woo Han ◽  
Myung Soo Park ◽  
Hun Kim ◽  
...  

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.


mAbs ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 1954136
Author(s):  
Sujatha Kumar ◽  
Srimoyee Ghosh ◽  
Geeta Sharma ◽  
Zebin Wang ◽  
Marilyn R. Kehry ◽  
...  

BioControl ◽  
2021 ◽  
Author(s):  
Mudassir Iqbal ◽  
Maha Jamshaid ◽  
Muhammad Awais Zahid ◽  
Erik Andreasson ◽  
Ramesh R. Vetukuri ◽  
...  

AbstractUtilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.


2016 ◽  
Vol 68 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Hyun-Seuk Moon

Background: It has been generally accepted that being overweight or obese is a risk factor for several types of cancers, including breast, thyroid, colon, pancreatic and liver. In fact, people who are obese have more fat tissues that can produce hormones, such as insulin or estrogen, which may cause cancer cells to grow. Alpha lipoic acid (ALA) is anorganosulfur compound derived from octanoic acid, which is produced in animals normally, and is essential for aerobic metabolism. Summary: Studies in both in vitro cells and in vivo animal models have shown that ALA inhibits the initiation and promotion stages of carcinogenesis, suggesting that ALA has considerable attention as a chemopreventive agent. This brief review collects the scattered data available in the literature concerning ALA and highlights its anti-cancer properties, intermediary metabolism and exploratory implications. Key Messages: Based on scientific evidences so far, ALA might be useful agents in the management or chemoprevention of obesity-related cancers.


2020 ◽  
Vol 21 (15) ◽  
pp. 5499
Author(s):  
Hannah L. Smith ◽  
Stephen A. Beers ◽  
Juliet C. Gray ◽  
Janos M. Kanczler

Treatment for osteosarcoma (OS) has been largely unchanged for several decades, with typical therapies being a mixture of chemotherapy and surgery. Although therapeutic targets and products against cancer are being continually developed, only a limited number have proved therapeutically active in OS. Thus, the understanding of the OS microenvironment and its interactions are becoming more important in developing new therapies. Three-dimensional (3D) models are important tools in increasing our understanding of complex mechanisms and interactions, such as in OS. In this review, in vivo animal models, in vitro 3D models and in ovo chorioallantoic membrane (CAM) models, are evaluated and discussed as to their contribution in understanding the progressive nature of OS, and cancer research. We aim to provide insight and prospective future directions into the potential translation of 3D models in OS.


Author(s):  
Bhong Prabha N. ◽  
Naikawade Nilofar. S. ◽  
Mali Pratibha. R. ◽  
Bindu Madhavi. S.

Objectives: The present study designed to evaluate the Antiasthmatic activity of aqueous extract of bark of Eugenia Jambolana (AEEJ) on in vitro and in vivo animal models. Materials and methods: Different in vitro and in vivo animal models was used to study the anti asthmatic activity as isolated goat tracheal chain preparation, Acetylcholine and Histamine induced bronconstriction in guinea pigs, effect of drug extract on histamine release from mast cell was checked by clonidine-induced mast cell degranulation, and milk-induced eosinophilia and leukocytosis. Results: In-vitro study on goat tracheal chain preparation revealed that aqueous extract of Eugenia jambolana (AEEJ)bark exerted antagonistic effect on the histamine induced contraction. (P<0.05) The guinea pigs when exposed to 0.2% histamine aerosol showed signs of progressive dyspnoea leading to convulsions. AEEJ significantly prolonged the latent period of convulsions (PCT) as compared to control following the exposure of histamine (0.2%) aerosol (P<0.01). The observation of present study indicates aqueous extract of Eugenia jambolana shows significant inhibition of milk induced eosinophilia and leukocytosis. Group of animals pretreated with aqueous Eugenia jambolana bark extract showed significant reduction in degranulation of mast cells when challenged with clonidine. The prevention of degranulation process by the aqueous Eugenia jambolana bark extract (P<0.01) indicates a possible stabilizing effect on the mast cells, indicating mast cell stabilizing activity. Conclusions: Thus, AEEJ showed antihistaminic, mast cell stabilizing and protective in guinea pigs against histamine induced PCD, reduced eosinophilia and leukocytosis and hence possesses potential role in the treatment of asthma.


2018 ◽  
Vol 115 (31) ◽  
pp. 7973-7978 ◽  
Author(s):  
Xiaobai Patrinostro ◽  
Pallabi Roy ◽  
Angus Lindsay ◽  
Christopher M. Chamberlain ◽  
Lauren J. Sundby ◽  
...  

The highly similar cytoplasmic β- and γ-actins differ by only four functionally similar amino acids, yet previous in vitro and in vivo data suggest that they support unique functions due to striking phenotypic differences between Actb and Actg1 null mouse and cell models. To determine whether the four amino acid variances were responsible for the functional differences between cytoplasmic actins, we gene edited the endogenous mouse Actb locus to translate γ-actin protein. The resulting mice and primary embryonic fibroblasts completely lacked β-actin protein, but were viable and did not present with the most overt and severe cell and organismal phenotypes observed with gene knockout. Nonetheless, the edited mice exhibited progressive high-frequency hearing loss and degeneration of actin-based stereocilia as previously reported for hair cell-specific Actb knockout mice. Thus, β-actin protein is not required for general cellular functions, but is necessary to maintain auditory stereocilia.


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