Abstract:In the fungal pathogen Aspergillus fumigatus, resistance to azole antifungals is often linked to mutations in CYP51A, a gene that encodes the azole antifungal drug target lanosterol 14α-demethylase. The aim of this study was to investigate whether similar changes could be associated with azole resistance in a Malaysian Fusarium solani species complex (FSSC) isolate collection. Most (11 of 15) clinical FSSC isolates were Neocosmospora keratoplastica and the majority (6 of 10) of environmental isolates were Neoc… Show more
“…F. keratoplasticum 2781, a clinical isolate that is resistant (MIC >32 mg/L) to itraconazole (ITC), posaconazole (PSC) and voriconazole (VRC) (James et al, 2020), was grown on potato dextrose agar (PDA; Oxoid Ltd., Hampshire, United Kingdom) plates incubated at 28 • C for 4-7 days. S. cerevisiae AD (Sagatova et al, 2015) was grown on yeast extract peptone dextrose [YPD; 1% w/v yeast extract (Formedium Ltd., Norfolk, United Kingdom), 2% w/v peptone (Formedium), and 2% w/v glucose (Formedium)] agar plates incubated at 30 • C for ∼3 days.…”
Section: Fungal Strains and Culture Conditionsmentioning
confidence: 99%
“…CYP51A and CYP51B are sterol 14-α demethylases, but the function of CYP51C remains unknown (Fan et al, 2013;Zheng et al, 2019). We have recently reported a 23 bp CYP51A promoter deletion that was associated with increased VRC resistance in both clinical and environmental FSSC isolates (James et al, 2020).…”
Section: Introductionmentioning
confidence: 99%
“…Species of the Fusarium solani species complex (FSSC) are ubiquitous moulds often detected in soil or on plants (Nalim et al, 2011;James et al, 2020) and in indoor plumbing drains (Short et al, 2014). They can infect plants (Coleman et al, 2009), animals (O'Donnell et al, 2016), and humans (Horn et al, 2014).…”
Section: Introductionmentioning
confidence: 99%
“…Fusarium keratoplasticum and Fusarium falciforme, two terrestrial FSSC species, have caused fusariosis of endangered sea turtle eggs (Sarmiento-Ramirez et al, 2014;Gleason et al, 2020). F. keratoplasticum and Fusarium petroliphilum are the two FSSC species most frequently isolated in the clinic (Herkert et al, 2019;James et al, 2020). FSSC infections are among the most common opportunistic nosocomial mould infections after infections caused by Aspergilli (Alastruey- Izquierdo et al, 2013;Lass-Florl and Cuenca-Estrella, 2017).…”
Section: Introductionmentioning
confidence: 99%
“…Aspergilli have two CYP51 orthologues (CYP51A and CYP51B) (Mellado et al, 2001) whereas Fusarium spp. have three CYP51 orthologues (CYP51A, CYP51B and CYP51C) (Becher et al, 2011;Zheng et al, 2019;James et al, 2020). The CYP51C orthologue is a unique characteristic of this fungal genus.…”
Fusarium keratoplasticum is arguably the most common Fusarium solani species complex (FSSC) species associated with human infections. Invasive fusariosis is a life-threatening fungal infection that is difficult to treat with conventional azole antifungals. Azole drug resistance is often caused by the increased expression of pleiotropic drug resistance (PDR) ATP-binding cassette (ABC) transporters of the ABCG sub-family. Most investigations of Fusarium ABC transporters associated with azole antifungal drug resistance are limited to plant pathogens. Through the manual curation of the entire ABCG protein family of four FSSC species including the fully annotated genome of the plant pathogen Nectria haematococca we identified PDR transporters ABC1 and ABC2 as the efflux pump candidates most likely to be associated with the innate azole resistance phenotype of Fusarium keratoplasticum. An initial investigation of the transcriptional response of logarithmic phase F. keratoplasticum cells to 16 mg/L voriconazole confirmed strong upregulation (372-fold) of ABC1 while ABC2 mRNA levels were unaffected by voriconazole exposure over a 4 h time-period. Overexpression of F. keratoplasticum ABC1 and ABC2 in the genetically modified Saccharomyces cerevisiae host ADΔΔ caused up to ∼1,024-fold increased resistance to a number of xenobiotics, including azole antifungals. Although ABC1 and ABC2 were only moderately (20% and 10%, respectively) expressed compared to the Candida albicans multidrug efflux pump CDR1, overexpression of F. keratoplasticum ABC1 caused even higher resistance levels to certain xenobiotics (e.g., rhodamine 6G and nigericin) than CDR1. Our investigations suggest an important role for ABC1 orthologues in the innate azole resistance phenotype of FSSC species.
“…F. keratoplasticum 2781, a clinical isolate that is resistant (MIC >32 mg/L) to itraconazole (ITC), posaconazole (PSC) and voriconazole (VRC) (James et al, 2020), was grown on potato dextrose agar (PDA; Oxoid Ltd., Hampshire, United Kingdom) plates incubated at 28 • C for 4-7 days. S. cerevisiae AD (Sagatova et al, 2015) was grown on yeast extract peptone dextrose [YPD; 1% w/v yeast extract (Formedium Ltd., Norfolk, United Kingdom), 2% w/v peptone (Formedium), and 2% w/v glucose (Formedium)] agar plates incubated at 30 • C for ∼3 days.…”
Section: Fungal Strains and Culture Conditionsmentioning
confidence: 99%
“…CYP51A and CYP51B are sterol 14-α demethylases, but the function of CYP51C remains unknown (Fan et al, 2013;Zheng et al, 2019). We have recently reported a 23 bp CYP51A promoter deletion that was associated with increased VRC resistance in both clinical and environmental FSSC isolates (James et al, 2020).…”
Section: Introductionmentioning
confidence: 99%
“…Species of the Fusarium solani species complex (FSSC) are ubiquitous moulds often detected in soil or on plants (Nalim et al, 2011;James et al, 2020) and in indoor plumbing drains (Short et al, 2014). They can infect plants (Coleman et al, 2009), animals (O'Donnell et al, 2016), and humans (Horn et al, 2014).…”
Section: Introductionmentioning
confidence: 99%
“…Fusarium keratoplasticum and Fusarium falciforme, two terrestrial FSSC species, have caused fusariosis of endangered sea turtle eggs (Sarmiento-Ramirez et al, 2014;Gleason et al, 2020). F. keratoplasticum and Fusarium petroliphilum are the two FSSC species most frequently isolated in the clinic (Herkert et al, 2019;James et al, 2020). FSSC infections are among the most common opportunistic nosocomial mould infections after infections caused by Aspergilli (Alastruey- Izquierdo et al, 2013;Lass-Florl and Cuenca-Estrella, 2017).…”
Section: Introductionmentioning
confidence: 99%
“…Aspergilli have two CYP51 orthologues (CYP51A and CYP51B) (Mellado et al, 2001) whereas Fusarium spp. have three CYP51 orthologues (CYP51A, CYP51B and CYP51C) (Becher et al, 2011;Zheng et al, 2019;James et al, 2020). The CYP51C orthologue is a unique characteristic of this fungal genus.…”
Fusarium keratoplasticum is arguably the most common Fusarium solani species complex (FSSC) species associated with human infections. Invasive fusariosis is a life-threatening fungal infection that is difficult to treat with conventional azole antifungals. Azole drug resistance is often caused by the increased expression of pleiotropic drug resistance (PDR) ATP-binding cassette (ABC) transporters of the ABCG sub-family. Most investigations of Fusarium ABC transporters associated with azole antifungal drug resistance are limited to plant pathogens. Through the manual curation of the entire ABCG protein family of four FSSC species including the fully annotated genome of the plant pathogen Nectria haematococca we identified PDR transporters ABC1 and ABC2 as the efflux pump candidates most likely to be associated with the innate azole resistance phenotype of Fusarium keratoplasticum. An initial investigation of the transcriptional response of logarithmic phase F. keratoplasticum cells to 16 mg/L voriconazole confirmed strong upregulation (372-fold) of ABC1 while ABC2 mRNA levels were unaffected by voriconazole exposure over a 4 h time-period. Overexpression of F. keratoplasticum ABC1 and ABC2 in the genetically modified Saccharomyces cerevisiae host ADΔΔ caused up to ∼1,024-fold increased resistance to a number of xenobiotics, including azole antifungals. Although ABC1 and ABC2 were only moderately (20% and 10%, respectively) expressed compared to the Candida albicans multidrug efflux pump CDR1, overexpression of F. keratoplasticum ABC1 caused even higher resistance levels to certain xenobiotics (e.g., rhodamine 6G and nigericin) than CDR1. Our investigations suggest an important role for ABC1 orthologues in the innate azole resistance phenotype of FSSC species.
Azole drugs target fungal sterol biosynthesis and are used to treat millions of human fungal infections each year. Resistance to azole drugs has emerged in multiple fungal pathogens including Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum, and Aspergillus fumigatus. The most well-studied resistance mechanism in A. fumigatus arises from missense mutations in the coding sequence combined with a tandem repeat in the promoter of cyp51A, which encodes a cytochrome P450 enzyme in the fungal sterol biosynthesis pathway. Filamentous members of Ascomycota such as A. fumigatus have either one or two of three Cyp51 paralogs (Cyp51A, Cyp51B, and Cyp51C). Most previous research in A. fumigatus has focused on Cyp51A due to its role in azole resistance. We used the A. fumigatus Cyp51A protein sequence as the query in database searches to identify Cyp51 proteins across Fungi. We found 435 Cyp51 proteins in 295 species spanning from early-diverging fungi (Blastocladiomycota, Chytridiomycota, Zoopagomycota and Mucormycota) to late-diverging fungi (Ascomycota and Basidiomycota). We found these sequences formed 4 major Cyp51 groups: Cyp51, Cyp51A, Cyp51B, and Cyp51C. Surprisingly, we found all filamentous Ascomycota had a Cyp51B paralog, while only 50% had a Cyp51A paralog. We created maximum likelihood trees to investigate the evolution of Cyp51 in Fungi. Our results suggest Cyp51 is present in all fungi with three paralogs emerging in Pezizomycotina, including Cyp51C which appears to have diverged from the progenitor of the Cyp51A and Cyp51B groups.
Azole drugs target fungal sterol biosynthesis and are used to treat millions of human fungal infections each year. Resistance to azole drugs has emerged in multiple fungal pathogens including Candida albicans, Cryptococcus neoformans, Histoplasma capsulatum, and Aspergillus fumigatus. The most well-studied resistance mechanism in A. fumigatus arises from missense mutations in the coding sequence combined with a tandem repeat in the promoter of cyp51A, which encodes a cytochrome P450 enzyme in the fungal sterol biosynthesis pathway. Filamentous members of Ascomycota such as A. fumigatus have either one or two of three Cyp51 paralogs (Cyp51A, Cyp51B, and Cyp51C). Most previous research in A. fumigatus has focused on Cyp51A due to its role in azole resistance. We used the A. fumigatus Cyp51A protein sequence as the query in database searches to identify Cyp51 proteins across Fungi. We found 435 Cyp51 proteins in 301 species spanning from early-diverging fungi (Blastocladiomycota, Chytridiomycota, Zoopagomycota and Mucormycota) to late-diverging fungi (Ascomycota and Basidiomycota). We found these sequences formed 4 major Cyp51 groups: Cyp51, Cyp51A, Cyp51B, and Cyp51C. Surprisingly, we found all filamentous Ascomycota had a Cyp51B paralog, while only 50% had a Cyp51A paralog. We created maximum likelihood trees to investigate the evolution of Cyp51 in Fungi. Our results suggest Cyp51 is present in all fungi with three paralogs emerging in Pezizomycotina, including Cyp51C which appears to have diverged from the progenitor of the Cyp51A and Cyp51B groups.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.