Growth of infective forms of Trypanosoma rhodesiense in vitro, the causative agent of African trypanosomiasis

Science ◽  
1978 ◽  
Vol 202 (4369) ◽  
pp. 763-765 ◽  
Author(s):  
G. Hill ◽  
S. Shimer ◽  
B Caughey ◽  
L. Sauer
Keyword(s):  
Causative Agent ◽  
African Trypanosomiasis

scholarly journals PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR

1929 ◽  
Vol 50 (3) ◽  
pp. 315-326 ◽  
Author(s):  
F. Duran-Reynals ◽  
James B. Murphy
Keyword(s):  
Muscle Tissue ◽  
Causative Agent ◽  
Chicken Muscle

Ground muscle from susceptible chickens fixes in vitro in a proportion of instances the agent of the filterable Chicken Tumor I, and in a lesser degree inactivates it, whereas the muscle from resistant animals such as rabbit and pigeon, is without effect. It is shown that the power of fixation of the chicken muscle is far greater than its inactivating properties. Brain and liver from chicken, rabbit and pigeon seem devoid of any action on the agent. The desiccated chicken muscle tissue shares the properties of the fresh organ; and the process of desiccation does not release the agent from the inactive or slightly active mixture of fresh muscle and filtrate.

scholarly journals Cross-Resistance to Nitro Drugs and Implications for Treatment of Human African Trypanosomiasis

2010 ◽  
Vol 54 (7) ◽  
pp. 2893-2900 ◽  
Author(s):  
Antoaneta Y. Sokolova ◽  
Susan Wyllie ◽  
Stephen Patterson ◽  
Sandra L. Oza ◽  
Kevin D. Read ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Human African Trypanosomiasis ◽  
Parent Drug ◽  
Cross Resistance ◽  
Pharmacokinetic Studies ◽  
African Trypanosomiasis ◽  
Trypanosoma Brucei Brucei ◽  
Resistant Lines

ABSTRACT The success of nifurtimox-eflornithine combination therapy (NECT) for the treatment of human African trypanosomiasis (HAT) has renewed interest in the potential of nitro drugs as chemotherapeutics. In order to study the implications of the more widespread use of nitro drugs against these parasites, we examined the in vivo and in vitro resistance potentials of nifurtimox and fexinidazole and its metabolites. Following selection in vitro by exposure to increasing concentrations of nifurtimox, Trypanosoma brucei brucei nifurtimox-resistant clones designated NfxR1 and NfxR2 were generated. Both cell lines were found to be 8-fold less sensitive to nifurtimox than parental cells and demonstrated cross-resistance to a number of other nitro drugs, most notably the clinical trial candidate fexinidazole (∼27-fold more resistant than parental cells). Studies of mice confirmed that the generation of nifurtimox resistance in these parasites did not compromise virulence, and NfxR1 remained resistant to both nifurtimox and fexinidazole in vivo. In the case of fexinidazole, drug metabolism and pharmacokinetic studies indicate that the parent drug is rapidly metabolized to the sulfoxide and sulfone form of this compound. These metabolites retained trypanocidal activity but were less effective in nifurtimox-resistant lines. Significantly, trypanosomes selected for resistance to fexinidazole were 10-fold more resistant to nifurtimox than parental cells. This reciprocal cross-resistance has important implications for the therapeutic use of nifurtimox in a clinical setting and highlights a potential danger in the use of fexinidazole as a monotherapy.

scholarly journals Chemical Derivatization and Characterization of Novel Antitrypanosomals for African Trypanosomiasis

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4488
Author(s):  
Aboagye Kwarteng Dofuor ◽  
Temitayo Samson Ademolue ◽  
Cynthia Mmalebna Amisigo ◽  
Kwaku Kyeremeh ◽  
Theresa Manful Gwira
Keyword(s):  
Structural Modification ◽  
Spectroscopic Analysis ◽  
Microscopic Analysis ◽  
The Novel ◽  
Chemical Derivatization ◽  
African Trypanosomiasis ◽  
Chemical Structures ◽  
Normal Ratio

The search for novel antitrypanosomals and the investigation into their mode of action remain crucial due to the toxicity and resistance of commercially available antitrypanosomal drugs. In this study, two novel antitrypanosomals, tortodofuordioxamide (compound 2) and tortodofuorpyramide (compound 3), were chemically derived from the natural N-alkylamide tortozanthoxylamide (compound 1) through structural modification. The chemical structures of these compounds were confirmed through spectrometric and spectroscopic analysis, and their in vitro efficacy and possible mechanisms of action were, subsequently, investigated in Trypanosoma brucei (T. brucei), one of the causative species of African trypanosomiasis (AT). The novel compounds 2 and 3 displayed significant antitrypanosomal potencies in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (compound 1, EC50 = 7.3 μM, SI = 29.5; compound 2, EC50 = 3.2 μM, SI = 91.3; compound 3, EC50 = 4.5 μM, SI = 69.9). Microscopic analysis indicated that at the EC50 values, the compounds resulted in the coiling and clumping of parasite subpopulations without significantly affecting the normal ratio of nuclei to kinetoplasts. In contrast to the animal antitrypanosomal drug diminazene, compounds 1, 2 and 3 exhibited antioxidant absorbance properties comparable to the standard antioxidant Trolox (Trolox, 0.11 A; diminazene, 0.50 A; compound 1, 0.10 A; compound 2, 0.09 A; compound 3, 0.11 A). The analysis of growth kinetics suggested that the compounds exhibited a relatively gradual but consistent growth inhibition of T. brucei at different concentrations. The results suggest that further pharmacological optimization of compounds 2 and 3 may facilitate their development into novel AT chemotherapy.

scholarly journals ANTIFUNGAL POTENTIAL OF ETHANOL EXTRACTS OF ALLIUM SATIVUM AND ALLIUM AMPELOPRASUM

2017 ◽  
Vol 10 (4) ◽  
pp. 207
Author(s):  
Shahid Khan ◽  
Neeta Raj Sharma
Keyword(s):  
Growth Inhibition ◽  
Causative Agent ◽  
Magnaporthe Oryzae ◽  
Allium Sativum ◽  
Microtiter Plate ◽  
Blast Disease ◽  
Allium Ampeloprasum ◽  
Antifungal Potential ◽  
Ethanol Extracts

Objective: In vitro analysis of Allium sativum and Allium ampeloprasum was performed to evaluate their antifungal potential against Alternaria triticina (ITCC 5496), causative agent of leaf blight in wheat and Magnaporthe oryzae (ITCC 6808), causative agent of blast disease in rice.Methods: Ethanol extracts of A. ampeloprasum and A. sativum were prepared by crushing their bulb in liquid nitrogen and then immersing them in 90% ethanol and 100% ethanol separately. The antifungal activity test was determined by quantitative assay using 96-well microtiter plate and results were statistically analyzed using GraphPad Prism v. 5.03.Results: A. triticina and M. oryzae showed above 90% and 95% growth inhibition, respectively against the ethanol extracts of A. ampeloprasum. Conversely, growth inhibition of either fungus remained mostly below 35% against ethanol extracts of A. sativum at all tested concentrations.Conclusion: Ethanol extracts of A. ampeloprasum have relatively higher antifungal potential than ethanol extracts of A. sativum and could be considered as a natural alternative to chemical fungicides.Keywords: Allium sativum, Allium ampeloprasum, Alternaria triticina, Magnaporthe oryzae.

scholarly journals The avian haemophili.

1989 ◽  
Vol 2 (3) ◽  
pp. 270-277 ◽  
Author(s):  
P J Blackall
Keyword(s):  
Causative Agent ◽  
Protective Immunity ◽  
In Vitro Growth ◽  
Phenotypic Properties ◽  
Infectious Coryza ◽  
The Common ◽  
Recent Attention

There are four currently recognized taxa to accommodate the avian haemophili: Haemophilus paragallinarum, Pasteurella avium, Pasteurella volantium, and Pasteurella species A (the last three being formerly united as Haemophilus avium). A range of other taxa has also been recognized, but they have been neither named nor assigned to a genus. All of these various taxa, legitimate and otherwise, have the common characteristic of requiring V factor, but not X factor, for in vitro growth. Several recent studies have established the phenotypic properties that allow the differentiation of the recognized taxa, both named and unnamed. The serological properties of H. paragallinarum, the causative agent of infectious coryza of chickens, has received considerable recent attention. In contrast, many questions on the pathogenicity and virulence mechanisms of H. paragallinarum remain unanswered. Another area requiring further work is the identification of those antigens responsible for inducing protective immunity in vaccinated or naturally infected chickens.

scholarly journals In Vitro Inhibition of Fungal Antagonists on Fusarium sp., the Disease Causative Agent on Dragon Fruit Plant (Hylocereus undatus (Haw.) Britton & Rose)

2018 ◽  
Vol 5 (2) ◽  
pp. 224
Author(s):  
Dewa Ayu Andriastini ◽  
Yan Ramona ◽  
Meitini Wahyuni Proborini
Keyword(s):  
Causative Agent ◽  
Biocontrol Agent ◽  
Antagonistic Activity ◽  
Assay Method ◽  
In Vitro Growth ◽  
Dragon Fruit ◽  
Fusarium Sp ◽  
In Vitro Inhibition ◽  
Hylocereus Undatus

A research on in vitro inhibition of fungal antagonists, isolated from dragon fruit plantation in Sembung village, Bali, on Fusarium sp. (the disease causative agent of dragon fruit plant) was conducted with the main objective to investigate the effectiveness of these fungal antagonists to inhibit the in vitro growth of the pathogen. Dual assay method was applied in this experiment. The results showed that three potential fungal antagonists were successfully isolated in this research and they were identified as Trichoderma harzianum, Aspergillus niger, dan Paecilomyces lilacinus. All these fungal antagonists showed antagonistic activity against Fusarium sp. which was statistically significant (p<0.05) when compared to control. This indicated that all antagonist isolates were potential to be developed as biocontrol agent candidates.

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