Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence

ABSTRACT Candida glabrata causes persistent infections in patients treated with fluconazole and often acquires resistance following exposure to the drug. Here we found that clinical strains of C. glabrata exhibit cell-to-cell variation in drug response (heteroresistance). We used population analysis...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Ronen Ben-Ami, Offer Zimmerman, Talya Finn, Sharon Amit, Anna Novikov, Noa Wertheimer, Mor Lurie-Weinberger, Judith Berman
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2016
Materias:	Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/d11681c6648a4cfe94be9a524d353a87
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:d11681c6648a4cfe94be9a524d353a87
record_format	dspace
spelling	oai:doaj.org-article:d11681c6648a4cfe94be9a524d353a872021-11-15T15:50:19ZHeteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence10.1128/mBio.00655-162150-7511https://doaj.org/article/d11681c6648a4cfe94be9a524d353a872016-09-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.00655-16https://doaj.org/toc/2150-7511ABSTRACT Candida glabrata causes persistent infections in patients treated with fluconazole and often acquires resistance following exposure to the drug. Here we found that clinical strains of C. glabrata exhibit cell-to-cell variation in drug response (heteroresistance). We used population analysis profiling (PAP) to assess fluconazole heteroresistance (FLCHR) and to ask if it is a binary trait or a continuous phenotype. Thirty (57.6%) of 52 fluconazole-sensitive clinical C. glabrata isolates met accepted dichotomous criteria for FLCHR. However, quantitative grading of FLCHR by using the area under the PAP curve (AUC) revealed a continuous distribution across a wide range of values, suggesting that all isolates exhibit some degree of heteroresistance. The AUC correlated with rhodamine 6G efflux and was associated with upregulation of the CDR1 and PDH1 genes, encoding ATP-binding cassette (ABC) transmembrane transporters, implying that HetR populations exhibit higher levels of drug efflux. Highly FLCHR C. glabrata was recovered more frequently than nonheteroresistant C. glabrata from hematogenously infected immunocompetent mice following treatment with high-dose fluconazole (45.8% versus 15%, P = 0.029). Phylogenetic analysis revealed some phenotypic clustering but also variations in FLCHR within clonal groups, suggesting both genetic and epigenetic determinants of heteroresistance. Collectively, these results establish heteroresistance to fluconazole as a graded phenotype associated with ABC transporter upregulation and fluconazole efflux. Heteroresistance may explain the propensity of C. glabrata for persistent infection and the emergence of breakthrough resistance to fluconazole. IMPORTANCE Heteroresistance refers to variability in the response to a drug within a clonal cell population. This phenomenon may have crucial importance for the way we look at antimicrobial resistance, as heteroresistant strains are not detected by standard laboratory susceptibility testing and may be associated with failure of antimicrobial therapy. We describe for the first time heteroresistance to fluconazole in C. glabrata, a finding that may explain the propensity of this pathogen to acquire resistance following exposure to fluconazole and to persist despite treatment. We found that, rather than being a binary all-or-none trait, heteroresistance was a continuously distributed phenotype associated with increased expression of genes that encode energy-dependent drug efflux transporters. Moreover, we show that heteroresistance is associated with failure of fluconazole to clear infection with C. glabrata. Together, these findings provide an empirical framework for determining and quantifying heteroresistance in C. glabrata.Ronen Ben-AmiOffer ZimmermanTalya FinnSharon AmitAnna NovikovNoa WertheimerMor Lurie-WeinbergerJudith BermanAmerican Society for MicrobiologyarticleMicrobiologyQR1-502ENmBio, Vol 7, Iss 4 (2016)
institution	DOAJ
collection	DOAJ
language	EN
topic	Microbiology QR1-502
spellingShingle	Microbiology QR1-502 Ronen Ben-Ami Offer Zimmerman Talya Finn Sharon Amit Anna Novikov Noa Wertheimer Mor Lurie-Weinberger Judith Berman Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence
description	ABSTRACT Candida glabrata causes persistent infections in patients treated with fluconazole and often acquires resistance following exposure to the drug. Here we found that clinical strains of C. glabrata exhibit cell-to-cell variation in drug response (heteroresistance). We used population analysis profiling (PAP) to assess fluconazole heteroresistance (FLCHR) and to ask if it is a binary trait or a continuous phenotype. Thirty (57.6%) of 52 fluconazole-sensitive clinical C. glabrata isolates met accepted dichotomous criteria for FLCHR. However, quantitative grading of FLCHR by using the area under the PAP curve (AUC) revealed a continuous distribution across a wide range of values, suggesting that all isolates exhibit some degree of heteroresistance. The AUC correlated with rhodamine 6G efflux and was associated with upregulation of the CDR1 and PDH1 genes, encoding ATP-binding cassette (ABC) transmembrane transporters, implying that HetR populations exhibit higher levels of drug efflux. Highly FLCHR C. glabrata was recovered more frequently than nonheteroresistant C. glabrata from hematogenously infected immunocompetent mice following treatment with high-dose fluconazole (45.8% versus 15%, P = 0.029). Phylogenetic analysis revealed some phenotypic clustering but also variations in FLCHR within clonal groups, suggesting both genetic and epigenetic determinants of heteroresistance. Collectively, these results establish heteroresistance to fluconazole as a graded phenotype associated with ABC transporter upregulation and fluconazole efflux. Heteroresistance may explain the propensity of C. glabrata for persistent infection and the emergence of breakthrough resistance to fluconazole. IMPORTANCE Heteroresistance refers to variability in the response to a drug within a clonal cell population. This phenomenon may have crucial importance for the way we look at antimicrobial resistance, as heteroresistant strains are not detected by standard laboratory susceptibility testing and may be associated with failure of antimicrobial therapy. We describe for the first time heteroresistance to fluconazole in C. glabrata, a finding that may explain the propensity of this pathogen to acquire resistance following exposure to fluconazole and to persist despite treatment. We found that, rather than being a binary all-or-none trait, heteroresistance was a continuously distributed phenotype associated with increased expression of genes that encode energy-dependent drug efflux transporters. Moreover, we show that heteroresistance is associated with failure of fluconazole to clear infection with C. glabrata. Together, these findings provide an empirical framework for determining and quantifying heteroresistance in C. glabrata.
format	article
author	Ronen Ben-Ami Offer Zimmerman Talya Finn Sharon Amit Anna Novikov Noa Wertheimer Mor Lurie-Weinberger Judith Berman
author_facet	Ronen Ben-Ami Offer Zimmerman Talya Finn Sharon Amit Anna Novikov Noa Wertheimer Mor Lurie-Weinberger Judith Berman
author_sort	Ronen Ben-Ami
title	Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence
title_short	Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence
title_full	Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence
title_fullStr	Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence
title_full_unstemmed	Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence
title_sort	heteroresistance to fluconazole is a continuously distributed phenotype among <named-content content-type="genus-species">candida glabrata</named-content> clinical strains associated with <italic toggle="yes">in vivo</italic> persistence
publisher	American Society for Microbiology
publishDate	2016
url	https://doaj.org/article/d11681c6648a4cfe94be9a524d353a87
work_keys_str_mv	AT ronenbenami heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT offerzimmerman heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT talyafinn heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT sharonamit heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT annanovikov heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT noawertheimer heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT morlurieweinberger heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence AT judithberman heteroresistancetofluconazoleisacontinuouslydistributedphenotypeamongnamedcontentcontenttypegenusspeciescandidaglabratanamedcontentclinicalstrainsassociatedwithitalictoggleyesinvivoitalicpersistence
_version_	1718427426868953088

Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among <named-content content-type="genus-species">Candida glabrata</named-content> Clinical Strains Associated with <italic toggle="yes">In Vivo</italic> Persistence

Ejemplares similares