RESUMO
AIMS: This study aimed to isolate actinomycetes from marine environments and examine their antifungal activity against Talaromyces marneffei both in vitro and in vivo. METHODS AND RESULTS: Nineteen out of 101 actinomycete extracts were active and further determined for their minimum inhibitory concentrations (MIC). Three extracts of AMA50 that isolated from sediment showed strong antifungal activity against T. marneffei yeast (MICs ≤0·03-0·25 µg ml-1 ) and mould (MICs 0·5-16 µg ml-1 ) forms. The hexane extract from the cells of AMA50 (AMA50CH) exhibited the best activity against both the forms (MIC ≤ 1 µg ml-1 ). Three extracts from AMA50 killed the melanized yeast cells at 0·5 µg ml-1 . The AMA50CH was further tested for protective effects in Caenorhabditis elegans model. At concentrations of 1-8 µg ml-1 , the AMA50CH prolonged survival of T. marneffei-infected C. elegans with a 60-70% survival rate. The composition of AMA50CH was determined by gas chromatography-mass spectrometry. The major components were n-hexadecanoic acid, tetradecanoic acid and pentadecanoic acid. Sequencing analysis revealed that isolate AMA50 belonged to the genus Streptomyces. CONCLUSIONS: The AMA50CH from Streptomyces sp. AMA50 was the most effective extract against T. marneffei. SIGNIFICANCE AND IMPACT OF THE STUDY: Talaromyces marneffei is one of the most important thermally dimorphic pathogenic fungi. These results indicated the potency of marine-derived actinomycete extracts against T. marneffei both in vitro and in vivo.
Assuntos
Actinobacteria/fisiologia , Antibiose , Antifúngicos/farmacologia , Talaromyces/efeitos dos fármacos , Talaromyces/fisiologia , Actinobacteria/química , Actinobacteria/isolamento & purificação , Animais , Antifúngicos/isolamento & purificação , Antifúngicos/toxicidade , Organismos Aquáticos/microbiologia , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/microbiologia , Sedimentos Geológicos/microbiologia , Testes de Sensibilidade Microbiana , Talaromyces/ultraestruturaRESUMO
The CH2Cl2 extract from the pericarp of Garcinia hombroniana yielded three 17,14-friedolanostanes [(24E)-3alpha-hydroxy-17,14-friedolanostan-8, 14,24-trien-26-oic acid, methyl (24E)-3alpha,23-dihydroxy-17,14-friedolanostan-8,14,24 -trien-26-oate and methyl (24E)-3alpha,9,23-trihydroxy-17,14-friedolanostan-14,2 4-dien-26-oate] and two lanostanes [3beta- and 3alpha-hydroxy-23-oxo-9,16-lanostadien-26-oic acid]. The structure of (14E)-3alpha-hydroxy-17,14-friedolanostan-8,14,24-trie n-26-oic acid was determined using spectroscopic and X-ray analyses, while the structures of the other compounds were elucidated solely from analysis of spectroscopic data.
