scholarly journals Lovastatin Has Significant Activity against Zygomycetes and Interacts Synergistically with Voriconazole

2006 ◽  
Vol 50 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Georgios Chamilos ◽  
Russell E. Lewis ◽  
Dimitrios P. Kontoyiannis
Keyword(s):  
Fungicidal Activity ◽  
Inhibitory Concentration ◽  
Effective Concentration ◽  
Significant Activity ◽  
In Vitro Activity ◽  
Testing Methods ◽  
Disk Diffusion Testing ◽  
Dye Staining

ABSTRACT Zygomycetes are emerging opportunistic molds resistant to most conventional antifungals. We evaluated the in vitro activity of lovastatin (LOV), a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, against seven clinical isolates of Zygomycetes by using standard microdilution methods in three different media, disk diffusion testing, and viability dye staining. To further study the in vivo efficacy of LOV against zygomycetes, we developed a Drosophila melanogaster model of zygomycosis. In different experiments, groups of Toll-deficient (Tl) flies fed LOV-containing food were subsequently injected with two representative Zygomycetes isolates (Mucor and Rhizopus spp.). Finally, we examined the effects of LOV on voriconazole (VRC) activity against zygomycetes in vitro by checkerboard dilution, Epsilometer test-based methods, and bis-(1,3-dibutylbarbituric acid) trimethine oxonol staining and in vivo in Tl flies fed food containing LOV plus VRC and infected with zygomycetes. LOV exhibited significant, medium, and strain-independent fungicidal activity against all Zygomycetes isolates in vitro by all testing methods (MIC50, 48.0 μg/ml; 50% minimal fungicidal concentration, 56.0 μg/ml; 50% effective concentration, 29.4 μg/ml [6.6 to 38.9 μg/ml]). Tl flies fed LOV-containing food and infected with Mucor had a significantly better 6-day survival rate than did infected Tl flies fed regular food (P = 0.0005). LOV displayed in vitro synergy with VRC against all Zygomycetes isolates (fractional inhibitory concentration index, 0.104 to 0.290) by all methods used. LOV also displayed synergy with VRC in the Drosophila model of zygomycosis (P < 0.01). LOV is significantly active against zygomycetes and synergizes with triazoles inherently resistant to them, such as VRC. The clinical significance of these findings needs to be further explored.

scholarly journals Synthesis, Fungicidal Activity and SAR of 2-Thiazolamide/Pyrazolamide-Cyclohexylsulfonamides against Botrytis cinerea

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2607
Author(s):  
Zhang ◽  
Meng ◽  
Xie ◽  
Yang ◽  
Zhang ◽  
...  
Keyword(s):  
Fungicidal Activity ◽  
Condensation Reaction ◽  
Effective Concentration ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Structure Activity ◽  
Median Effective Concentration ◽  
Germination Experiment

In order to explore more efficient sulfonamides against Botrytis cinereal, 36 novel cyclohexylsulfonamides were synthesized by N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide (EDCI) and 1-hydroxybenzotriazole (HOBt) condensation reaction using chesulfamide as a lead compound, introducing thiazole and pyrazole active groups. Their structures were characterized by 1H-NMR, 13C-NMR, mass spectrum (MS), and elemental analysis. Compound III -31 was further confirmed by X-ray single crystal diffraction. The in vitro and in vivo fungicidal activities against B. cinerea were evaluated by three bioassay methods. The results of mycelial growth demonstrated that median effective concentration (EC50) values of nine compounds were close to boscalid (EC50 = 1.72 µg/mL) and procymidone (EC50 = 1.79 µg/mL) against B. cinerea (KZ-9). In the spore germination experiment, it was found that compounds III-19 and III-31 inhibited germination 93.89 and 98.00%, respectively; at 10 µg/mL, they approached boscalid (95.97%). In the tomato pot experiment, the control effects of two compounds (III-21 and III-27) were 89.80 and 87.90%, respectively, at 200 µg/mL which were significantly higher than boscalid (81.99%). The structure–activity relationship (SAR) was also discussed, which provided a valuable idea for developing new fungicides.

scholarly journals In Vitro Activity and Interaction of Clindamycin Combined with Dihydroartemisinin against Plasmodium falciparum

2003 ◽  
Vol 47 (11) ◽  
pp. 3494-3499 ◽  
Author(s):  
M. Ramharter ◽  
H. Noedl ◽  
H. Winkler ◽  
W. Graninger ◽  
W. H. Wernsdorfer ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Interaction Analysis ◽  
Clinical Investigation ◽  
Effective Concentration ◽  
Significant Activity ◽  
Drug Resistant ◽  
In Vitro Activity ◽  
Promising Candidate ◽  
Combination Regimens

ABSTRACT Combination regimens are considered a valuable tool for the fight against drug-resistant falciparum malaria. This study was conducted to evaluate the antimalarial potential of clindamycin in combination with dihydroartemisinin in continuously cultured and in freshly isolated Plasmodium falciparum parasites, measuring the inhibition of Plasmodium falciparum histidine-rich protein II synthesis. Interaction analysis revealed a synergistic or additive mode of interaction at various concentration ratios in all continuously cultured parasites at the 50% effective concentration (EC50) level. Antagonism was not found for any of the culture-adapted parasites. In fresh P. falciparum isolates, a fixed clindamycin-dihydroartemisinin combination exhibited additive activity at the EC50 and EC90 levels. The drug mixture showed no significant activity correlation to other commonly used antimalarials. The clindamycin-dihydroartemisinin combination appears to be a promising candidate for clinical investigation.

scholarly journals Structure-In Vitro Activity Relationships of Pentamidine Analogues and Dication-Substituted Bis-Benzimidazoles as New Antifungal Agents

1998 ◽  
Vol 42 (10) ◽  
pp. 2495-2502 ◽  
Author(s):  
Maurizio Del Poeta ◽  
Wiley A. Schell ◽  
Christine C. Dykstra ◽  
Susan Jones ◽  
Richard R. Tidwell ◽  
...  
Keyword(s):  
Fungicidal Activity ◽  
Antifungal Agents ◽  
In Vitro Activity ◽  
Primary Metabolites ◽  
Structure Activity ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
Clinical Potential

ABSTRACT Twenty analogues of pentamidine, 7 primary metabolites of pentamidine, and 30 dicationic substituted bis-benzimidazoles were screened for their inhibitory and fungicidal activities againstCandida albicans and Cryptococcus neoformans. A majority of the compounds had MICs at which 80% of the strains were inhibited (MIC80s) comparable to those of amphotericin B and fluconazole. Unlike fluconazole, many of these compounds were found to have potent fungicidal activity. The most potent compound against C. albicans had an MIC80 of ≤0.09 μg/ml, and the most potent compound against C. neoformans had an MIC80 of 0.19 μg/ml. Selected compounds were also found to be active againstAspergillus fumigatus, Fusarium solani,Candida species other than C. albicans, and fluconazole-resistant strains of C. albicans and C. neoformans. It is clear from the data presented here that further studies on the structure-activity relationships, mechanisms of action and toxicities, and in vivo efficacies of these compounds are warranted to determine their clinical potential.

scholarly journals In vitro activity of fluvastatin, a cholesterol-lowering agent, and synergy with flucanazole and itraconazole against Candida species and Cryptococcus neoformans.

1997 ◽  
Vol 41 (4) ◽  
pp. 850-852 ◽  
Author(s):  
N X Chin ◽  
I Weitzman ◽  
P Della-Latta
Keyword(s):  
Cryptococcus Neoformans ◽  
Candida Species ◽  
Fungicidal Activity ◽  
Inhibitory Concentration ◽  
Additive Effects ◽  
In Vitro Activity ◽  
Cholesterol Lowering ◽  
Lowering Drug ◽  
Concentration Indices

Fluvastatin, a cholesterol-lowering drug, exhibited minimal activity (MICs of 64 to >128 microg/ml) against Candida species and Cryptococcus neoformans. When fluvastatin was combined with fluconazole or itraconazole, both synergistic and additive effects were noted (fractional inhibitory concentration indices of < or = 0.156 to 0.625; fractional lethal concentration indices of < or = 0.156 to 0.75). This combined fungicidal activity was confirmed by time-versus-killing studies.

scholarly journals In vitro susceptibilities of clinical yeast isolates to a new echinocandin derivative, LY303366, and other antifungal agents.

1997 ◽  
Vol 41 (4) ◽  
pp. 763-766 ◽  
Author(s):  
M A Pfaller ◽  
S A Messer ◽  
S Coffman
Keyword(s):  
Amphotericin B ◽  
Fungicidal Activity ◽  
Antifungal Agents ◽  
Candida Parapsilosis ◽  
Clinical Laboratory ◽  
National Committee ◽  
In Vitro Activity ◽  
Medical Centers

LY303366 is a new semisynthetic echinocandin derivative with potent, broad-spectrum fungicidal activity. We investigated the in vitro activity of LY303366, amphotericin B, flucytosine (5FC), fluconazole, and itraconazole against 435 clinical yeast isolates (413 Candida and 22 Saccharomyces cerevisiae isolates) obtained from over 30 different medical centers. MICs for all five antifungal agents were determined by the National Committee for Clinical Laboratory Standards method with RPMI 1640 test medium. LY303366 was also tested in antibiotic medium 3 as specified by the manufacturer. Overall, LY303366 was quite active against all of the yeast isolates when tested in RPMI 1640 (MIC at which 90% of the isolates are inhibited [MIC90], 1.0 microg/ml) but appeared to be considerably more potent when tested in antibiotic medium 3 (MIC90, 0.03 microg/ml). When tested in antibiotic medium 3, LY303366 was 16- to >2,000-fold more active than itraconazole, fluconazole, amphotericin B, or 5FC against all species except Candida parapsilosis. When tested in RPMI 1640, LY303366 was comparable to amphotericin B and itraconazole and more active than fluconazole and 5FC. All of the isolates for which fluconazole and itraconazole had elevated MICs (> or = 128 and > or = 2.0 microg/ml, respectively) were inhibited by < or = 0.007 microg of LY303366/ml when tested in antibiotic medium 3 and < or = 0.5 microg/ml when tested in RPMI 1640. Based on these studies, LY303366 has promising antifungal activity and warrants further in vitro and in vivo investigation.

scholarly journals In Vitro Susceptibility Testing Methods for Caspofungin against Aspergillus andFusarium Isolates

2001 ◽  
Vol 45 (1) ◽  
pp. 327-330 ◽  
Author(s):  
Sevtap Arikan ◽  
Mario Lozano-Chiu ◽  
Victor Paetznick ◽  
John H. Rex
Keyword(s):  
Incubation Time ◽  
Susceptibility Testing ◽  
Effective Concentration ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Testing Methods ◽  
In Vitro Susceptibility ◽  
Minimum Effective Concentration ◽  
In Vitro Susceptibility Testing

ABSTRACT We investigated the relevance of prominent reduction in turbidity macroscopically (MIC) and formation of aberrant hyphal tips microscopically (minimum effective concentration; MEC) in measuring the in vitro activity of caspofungin against Aspergillus andFusarium. Caspofungin generated low MICs and MECs againstAspergillus, but not for Fusarium. While MICs increased inconsistently when the incubation time was prolonged, MEC appeared as a stable and potentially relevant endpoint in testing in vitro caspofungin activity.

scholarly journals A Peptide Found in Human Serum, Derived from the C-Terminus of Albumin, Shows Antifungal Activity In Vitro and In Vivo

2020 ◽  
Vol 8 (10) ◽  
pp. 1627
Author(s):  
Tecla Ciociola ◽  
Pier Paolo Zanello ◽  
Tiziana D’Adda ◽  
Serena Galati ◽  
Stefania Conti ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Human Serum ◽  
Fungicidal Activity ◽  
Galleria Mellonella ◽  
Serum Proteins ◽  
Morphological Alterations ◽  
C Terminus ◽  
Different Sources

The growing problem of antimicrobial resistance highlights the need for alternative strategies to combat infections. From this perspective, there is a considerable interest in natural molecules obtained from different sources, which are shown to be active against microorganisms, either alone or in association with conventional drugs. In this paper, peptides with the same sequence of fragments, found in human serum, derived from physiological proteins, were evaluated for their antifungal activity. A 13-residue peptide, representing the 597–609 fragment within the albumin C-terminus, was proved to exert a fungicidal activity in vitro against pathogenic yeasts and a therapeutic effect in vivo in the experimental model of candidal infection in Galleria mellonella. Studies by confocal microscopy and transmission and scanning electron microscopy demonstrated that the peptide penetrates and accumulates in Candida albicans cells, causing gross morphological alterations in cellular structure. These findings add albumin to the group of proteins, which already includes hemoglobin and antibodies, that could give rise to cryptic antimicrobial fragments, and could suggest their role in anti-infective homeostasis. The study of bioactive fragments from serum proteins could open interesting perspectives for the development of new antimicrobial molecules derived by natural sources.

scholarly journals In Silico Predicted Antifungal Peptides: In Vitro and In Vivo Anti-Candida Activity

2021 ◽  
Vol 7 (6) ◽  
pp. 439
Author(s):  
Tecla Ciociola ◽  
Walter Magliani ◽  
Tiziano De Simone ◽  
Thelma A. Pertinhez ◽  
Stefania Conti ◽  
...  
Keyword(s):  
In Silico ◽  
Mammalian Cells ◽  
Galleria Mellonella ◽  
Ex Vivo ◽  
Consensus Sequence ◽  
In Silico Analysis ◽  
Significant Activity ◽  
Synthetic Antibody

It has been previously demonstrated that synthetic antibody-derived peptides could exert a significant activity in vitro, ex vivo, and/or in vivo against microorganisms and viruses, as well as immunomodulatory effects through the activation of immune cells. Based on the sequence of previously described antibody-derived peptides with recognized antifungal activity, an in silico analysis was conducted to identify novel antifungal candidates. The present study analyzed the candidacidal and structural properties of in silico designed peptides (ISDPs) derived by amino acid substitutions of the parent peptide KKVTMTCSAS. ISDPs proved to be more active in vitro than the parent peptide and all proved to be therapeutic in Galleria mellonella candidal infection, without showing toxic effects on mammalian cells. ISDPs were studied by circular dichroism spectroscopy, demonstrating different structural organization. These results allowed to validate a consensus sequence for the parent peptide KKVTMTCSAS that may be useful in the development of novel antimicrobial molecules.

scholarly journals Intracellular localisation of Mycobacterium tuberculosis affects efficacy of the antibiotic pyrazinamide

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pierre Santucci ◽  
Daniel J. Greenwood ◽  
Antony Fearns ◽  
Kai Chen ◽  
Haibo Jiang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Host Cell ◽  
Combination Chemotherapy ◽  
In Vitro Activity ◽  
In Vivo Efficacy ◽  
Human Macrophages ◽  
Ion Microscopy ◽  
Intracellular Localisation

AbstractTo be effective, chemotherapy against tuberculosis (TB) must kill the intracellular population of the pathogen, Mycobacterium tuberculosis. However, how host cell microenvironments affect antibiotic accumulation and efficacy remains unclear. Here, we use correlative light, electron, and ion microscopy to investigate how various microenvironments within human macrophages affect the activity of pyrazinamide (PZA), a key antibiotic against TB. We show that PZA accumulates heterogeneously among individual bacteria in multiple host cell environments. Crucially, PZA accumulation and efficacy is maximal within acidified phagosomes. Bedaquiline, another antibiotic commonly used in combined TB therapy, enhances PZA accumulation via a host cell-mediated mechanism. Thus, intracellular localisation and specific microenvironments affect PZA accumulation and efficacy. Our results may explain the potent in vivo efficacy of PZA, compared to its modest in vitro activity, and its critical contribution to TB combination chemotherapy.

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