Certain non-steroidal anti-inflammatory drugs can inhibit fungal growth, fungal prostaglandin E2 production, and enzyme activation. This study aims to investigate the antifungal effect of nimesulide against pathogenic filamentous fungi and yeast. The experiments detailed below were also designed to investigate whether the action is dependent on E2 fungal prostaglandins. Our data showed that nimesulide exhibited potent antifungal activity, mainly against Trichophyton mentagrophytes (ATCC 9533) and Cryptococcus neoformans with MIC values of 2 and 62 μg/mL, respectively. This drug was also able to inhibit the growth of clinic isolates of filamentous fungi, such as Aspergillus fumigatus, and dermatophytes, such as T. rubrum, T. mentagrophytes, Epidermophyton floccosum, Microsporum canis, and M. gypseum, with MIC values ranging from 112 to 770 μg/mL. Our data also showed that the inhibition of fungal growth by nimesulide was mediated by a mechanism dependent on PGE2, which led to the inhibition of essential fungal enzymes. Thus, we concluded that nimesulide exerts a fungicidal effect against pathogenic filamentous fungi and yeast, involving the inhibition of fungal prostaglandins and fungal enzymes important to the fungal growth and colonization.
- MeSH
- antifungální látky farmakologie MeSH
- Arthrodermataceae účinky léků růst a vývoj metabolismus MeSH
- Aspergillus fumigatus účinky léků růst a vývoj metabolismus MeSH
- Cryptococcus neoformans účinky léků růst a vývoj metabolismus MeSH
- dinoproston antagonisté a inhibitory biosyntéza MeSH
- mikrobiální testy citlivosti MeSH
- sulfonamidy farmakologie MeSH
- Trichophyton účinky léků růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Coniochaeta pulveracea is a dimorphic lignicolous fungus that has mostly been isolated from decaying wood. However, relatively little work was conducted on the conditions for the dimorphic switch or the biological interactions of the fungus in its yeast-like microcyclic growth phase. Therefore, in this study, the microcyclic conidiation of C. pulveracea strains and representatives of the closely related species, Coniochaeta boothii and Coniochaeta subcorticalis, was studied under different environmental conditions. The strains were found to exhibit hyphal growth on solid substrates and underwent a dimorphic switch to produce microcycle conidiation upon transfer to a liquid medium which differed in physico-chemical composition compared to the original solid medium. Factors that were found to contribute to this dimorphic switch were temperature, pH and the presence of complex nitrogen sources such as casamino acids and peptone in the medium. However, C. pulveracea showed intraspecific differences with regard to its response to changes in the physico-chemical environment. The interactions of microcyclic Coniochaeta strains with selected yeasts, such as representatives of Meyerozyma guilliermondii and Cryptococcus neoformans, were subsequently studied in complex liquid media and it was found that, depending on medium composition, the microcyclic Coniochaeta exerted different effects on the different yeasts strains. In some co-cultures, a positive effect on yeast growth was observed, whilst in other cases microcyclic Coniochaeta inhibited yeast growth.
- MeSH
- Ascomycota cytologie účinky léků růst a vývoj účinky záření MeSH
- Cryptococcus neoformans růst a vývoj MeSH
- hyfy cytologie účinky léků růst a vývoj účinky záření MeSH
- koncentrace vodíkových iontů MeSH
- kultivační média chemie MeSH
- mikrobiální interakce MeSH
- Saccharomycetales růst a vývoj MeSH
- sloučeniny dusíku metabolismus MeSH
- spory hub cytologie účinky léků růst a vývoj účinky záření MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
AIMS: Limited aeration has been demonstrated to cause slowdown in proliferation and delayed budding, resulting eventually in a unique unbudded G2-arrest in the obligate aerobic pathogenic yeast Cryptococcus neoformans. Also, the ability to adapt to decreased oxygen levels during pathogenesis has been identified as a virulence factor in C. neoformans. The aim of this study was to identify and characterize genes that are necessary for the proliferation slowdown and G2-arrest caused by limited aeration. METHODS: Random mutants were prepared and screened for lack of typical slowdown of proliferation under limited aeration. The CNAG_00156.2 gene coding for a zinc-finger transcription factor was identified in mutants showing most distinctive phenotype. Targeted deletion strain and reconstituted strain were prepared to characterize and confirm the gene functions. This gene was also identified in a parallel studies as homologous both to calcineurin responsive (Crz1) and PKC1-dependent (SP1-like) transcription factors. RESULTS: We have confirmed the role of the cryptococcal homologue of CRZ1/SP1-like transcription factor in cell integrity, and newly demonstrated its role in slowdown of proliferation and survival under reduced aeration, in biofilm formation and in susceptibility to fluconazole. CONCLUSIONS: Our data demonstrate a tight molecular link between slowdown of proliferation during hypoxic adaptation and maintenance of cell integrity in C. neoformans and present a new role for the CRZ1 family of transcription factors in fungi. The exact positioning of this protein in cryptococcal signalling cascades remains to be clarified.
- MeSH
- anaerobióza MeSH
- antifungální látky farmakologie MeSH
- biofilmy růst a vývoj MeSH
- Cryptococcus neoformans účinky léků genetika růst a vývoj MeSH
- delece genu MeSH
- flukonazol farmakologie MeSH
- kontrolní body buněčného cyklu genetika MeSH
- mikrobiální viabilita MeSH
- proteiny Caenorhabditis elegans genetika MeSH
- transkripční faktory genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cryptococcus neoformans was grown in 96-well microtiter plates sealed by foil which is less than 0.01 % permeable to oxygen. On day 14 of the cultivation, we observed peculiar clusters of small droplike daughter cells arranged around ?4 % of mother cells. The fact that most of the other cells had died indicates that few cells had been able to survive hypoxic conditions and escape the cell-cycle arrest. However, their daughters were unable to separate from them and to continue their proliferation under such conditions.
Growth patterns of Cryptococcus neoformans submerged culture in different culture volumes, intensity of agitation and types of sealing were evaluated to better understand the physiological role of hypoxia response in this yeast. When low intensity agitation was set at high culture volumes and air exchange between the cultivation vessel and external environment was not abolished completely, the cells proliferated slowly but steadily. On the other hand, when the intensity of agitation was high but the vessel was withheld from fresh air supply, the cells first proliferated rapidly, then arrested completely and finally died. Therefore, the central strategy of C. neoformans here seems to lie in its proliferation-rate adjustment to the available oxygen levels and not in its capacity to survive under anoxia. The data support the opinion that the cultures grown under limited aeration (even though not completely withheld from fresh air supply) are much closer to the real cryptococcal life in human tissues than conventional well-aerated exponential cultures.
- MeSH
- Cryptococcus neoformans izolace a purifikace metabolismus růst a vývoj MeSH
- dítě MeSH
- dospělí MeSH
- incidence MeSH
- kojenec MeSH
- kryptokokóza epidemiologie mikrobiologie MeSH
- kultivační média MeSH
- lidé středního věku MeSH
- lidé MeSH
- novorozenec MeSH
- oportunní infekce mikrobiologie MeSH
- prevalence MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- senioři MeSH
- ženské pohlaví MeSH
- MeSH
- Cryptococcus neoformans růst a vývoj účinky záření MeSH
- prasata MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
