Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts

ABSTARCT: Nonfermentative yeasts, such as Cryptococcus spp., have emerged as fungal pathogens during the last few years. However, standard methods to measure their antifungal susceptibility (antifungal susceptibility testing [AST]) are not completely reliable due to the impaired growth of these yeas...

Full description

Autores:
Zaragoza, Oscar
Mesa Arango, Ana Cecilia
Gomez Lopez, Alicia
Bernal Martinez, Leticia
Rodriguez Tudela, Juan Luis
Cuenca Estrella, Manuel
Tipo de recurso:
Article of investigation
Fecha de publicación:
2011
Institución:
Universidad de Antioquia
Repositorio:
Repositorio UdeA
Idioma:
eng
OAI Identifier:
oai:bibliotecadigital.udea.edu.co:10495/11717
Acceso en línea:
http://hdl.handle.net/10495/11717
Palabra clave:
Antifungal Agents
Cryptococcus
Cryptococcus neoformans
drug effects
Geotrichum
Microbial Sensitivity Tests
Rhodotorula
pharmacology
Trichosporon
Yarrowia
Antifúngicos
Farmacología
Pruebas de Sensibilidad Microbiana
Rights
openAccess
License
Atribución 2.5
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repository_id_str
dc.title.spa.fl_str_mv Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
title Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
spellingShingle Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
Antifungal Agents
Cryptococcus
Cryptococcus neoformans
drug effects
Geotrichum
Microbial Sensitivity Tests
Rhodotorula
pharmacology
Trichosporon
Yarrowia
Antifúngicos
Farmacología
Pruebas de Sensibilidad Microbiana
title_short Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
title_full Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
title_fullStr Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
title_full_unstemmed Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
title_sort Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts
dc.creator.fl_str_mv Zaragoza, Oscar
Mesa Arango, Ana Cecilia
Gomez Lopez, Alicia
Bernal Martinez, Leticia
Rodriguez Tudela, Juan Luis
Cuenca Estrella, Manuel
dc.contributor.author.none.fl_str_mv Zaragoza, Oscar
Mesa Arango, Ana Cecilia
Gomez Lopez, Alicia
Bernal Martinez, Leticia
Rodriguez Tudela, Juan Luis
Cuenca Estrella, Manuel
dc.subject.none.fl_str_mv Antifungal Agents
Cryptococcus
Cryptococcus neoformans
drug effects
Geotrichum
Microbial Sensitivity Tests
Rhodotorula
pharmacology
Trichosporon
Yarrowia
Antifúngicos
Farmacología
Pruebas de Sensibilidad Microbiana
topic Antifungal Agents
Cryptococcus
Cryptococcus neoformans
drug effects
Geotrichum
Microbial Sensitivity Tests
Rhodotorula
pharmacology
Trichosporon
Yarrowia
Antifúngicos
Farmacología
Pruebas de Sensibilidad Microbiana
description ABSTARCT: Nonfermentative yeasts, such as Cryptococcus spp., have emerged as fungal pathogens during the last few years. However, standard methods to measure their antifungal susceptibility (antifungal susceptibility testing [AST]) are not completely reliable due to the impaired growth of these yeasts in standard media. In this work, we have compared the growth kinetics and the antifungal susceptibilities of representative species of nonfermentative yeasts such as Cryptococcus neoformans, Cryptococcus gattii, Cryptococcus albidus, Rhodotorula spp., Yarrowia lipolytica, Geotrichum spp., and Trichosporon spp. The effect of the growth medium (RPMI medium versus yeast nitrogen base [YNB]), glucose concentration (0.2% versus 2%), nitrogen source (ammonium sulfate), temperature (30°C versus 35°C), shaking, and inoculum size (10(3), 10(4), and 10(5) cells) were analyzed. The growth rate, lag phase, and maximum optical density were obtained from each growth experiment, and after multivariate analysis, YNB-based media demonstrated a significant improvement in the growth of yeasts. Shaking, an inoculum size of 10(5) CFU/ml, and incubation at 30°C also improved the growth kinetics of organisms. Supplementation with ammonium sulfate and with 2% glucose did not have any effect on growth. We also tested the antifungal susceptibilities of all the isolates by the reference methods of the CLSI and EUCAST, the EUCAST method with shaking, YNB under static conditions, and YNB with shaking. MIC values obtained under different conditions showed high percentages of agreement and significant correlation coefficient values between them. MIC value determinations according to CLSI and EUCAST standards were rather complicated, since more than half of isolates tested showed a limited growth index, hampering endpoint determinations. We conclude that AST conditions including YNB as an assay medium, agitation of the plates, reading after 48 h of incubation, an inoculum size of 10(5) CFU/ml, and incubation at 30°C made MIC determinations easier without an overestimation of MIC values.
publishDate 2011
dc.date.issued.none.fl_str_mv 2011
dc.date.accessioned.none.fl_str_mv 2019-08-22T20:43:17Z
dc.date.available.none.fl_str_mv 2019-08-22T20:43:17Z
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dc.identifier.citation.spa.fl_str_mv Zaragoza O, Mesa-Arango AC, Gómez-López A, Bernal-Martínez L, Rodríguez-Tudela JL, Cuenca-Estrella M. Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts. Antimicrob Agents Chemother. 2011 Apr;55(4):1563-70
dc.identifier.issn.none.fl_str_mv 0066-4804
dc.identifier.uri.none.fl_str_mv http://hdl.handle.net/10495/11717
dc.identifier.doi.none.fl_str_mv 10.1128/AAC.01631-10
dc.identifier.eissn.none.fl_str_mv 1098-6596
identifier_str_mv Zaragoza O, Mesa-Arango AC, Gómez-López A, Bernal-Martínez L, Rodríguez-Tudela JL, Cuenca-Estrella M. Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts. Antimicrob Agents Chemother. 2011 Apr;55(4):1563-70
0066-4804
10.1128/AAC.01631-10
1098-6596
url http://hdl.handle.net/10495/11717
dc.language.iso.spa.fl_str_mv eng
language eng
dc.relation.ispartofjournalabbrev.spa.fl_str_mv Antimicrob Agents Chemother
dc.rights.*.fl_str_mv Atribución 2.5
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dc.format.extent.spa.fl_str_mv 7
dc.format.mimetype.spa.fl_str_mv application/pdf
dc.publisher.spa.fl_str_mv American Society for Microbiology
dc.publisher.group.spa.fl_str_mv Grupo de Investigacion Dermatologica (GRID)
dc.publisher.place.spa.fl_str_mv Estados Unidos
institution Universidad de Antioquia
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spelling Zaragoza, OscarMesa Arango, Ana CeciliaGomez Lopez, AliciaBernal Martinez, LeticiaRodriguez Tudela, Juan LuisCuenca Estrella, Manuel2019-08-22T20:43:17Z2019-08-22T20:43:17Z2011Zaragoza O, Mesa-Arango AC, Gómez-López A, Bernal-Martínez L, Rodríguez-Tudela JL, Cuenca-Estrella M. Process analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeasts. Antimicrob Agents Chemother. 2011 Apr;55(4):1563-700066-4804http://hdl.handle.net/10495/1171710.1128/AAC.01631-101098-6596ABSTARCT: Nonfermentative yeasts, such as Cryptococcus spp., have emerged as fungal pathogens during the last few years. However, standard methods to measure their antifungal susceptibility (antifungal susceptibility testing [AST]) are not completely reliable due to the impaired growth of these yeasts in standard media. In this work, we have compared the growth kinetics and the antifungal susceptibilities of representative species of nonfermentative yeasts such as Cryptococcus neoformans, Cryptococcus gattii, Cryptococcus albidus, Rhodotorula spp., Yarrowia lipolytica, Geotrichum spp., and Trichosporon spp. The effect of the growth medium (RPMI medium versus yeast nitrogen base [YNB]), glucose concentration (0.2% versus 2%), nitrogen source (ammonium sulfate), temperature (30°C versus 35°C), shaking, and inoculum size (10(3), 10(4), and 10(5) cells) were analyzed. The growth rate, lag phase, and maximum optical density were obtained from each growth experiment, and after multivariate analysis, YNB-based media demonstrated a significant improvement in the growth of yeasts. Shaking, an inoculum size of 10(5) CFU/ml, and incubation at 30°C also improved the growth kinetics of organisms. Supplementation with ammonium sulfate and with 2% glucose did not have any effect on growth. We also tested the antifungal susceptibilities of all the isolates by the reference methods of the CLSI and EUCAST, the EUCAST method with shaking, YNB under static conditions, and YNB with shaking. MIC values obtained under different conditions showed high percentages of agreement and significant correlation coefficient values between them. MIC value determinations according to CLSI and EUCAST standards were rather complicated, since more than half of isolates tested showed a limited growth index, hampering endpoint determinations. We conclude that AST conditions including YNB as an assay medium, agitation of the plates, reading after 48 h of incubation, an inoculum size of 10(5) CFU/ml, and incubation at 30°C made MIC determinations easier without an overestimation of MIC values.7application/pdfengAmerican Society for MicrobiologyGrupo de Investigacion Dermatologica (GRID)Estados Unidosinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_2df8fbb1https://purl.org/redcol/resource_type/ARTArtículo de investigaciónhttp://purl.org/coar/version/c_970fb48d4fbd8a85Atribución 2.5info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/2.5/co/http://purl.org/coar/access_right/c_abf2https://creativecommons.org/licenses/by/4.0/Antifungal AgentsCryptococcusCryptococcus neoformansdrug effectsGeotrichumMicrobial Sensitivity TestsRhodotorulapharmacologyTrichosporonYarrowiaAntifúngicosFarmacologíaPruebas de Sensibilidad MicrobianaProcess analysis of variables for standardization of antifungal susceptibility testing of nonfermentative yeastsAntimicrob Agents ChemotherAntimicrobial Agents and Chemotherapy15631570554ORIGINALZaragozaOscar_2011_ProcessStandardizationAntifungal.pdfZaragozaOscar_2011_ProcessStandardizationAntifungal.pdfArtículo de Revistaapplication/pdf987981http://bibliotecadigital.udea.edu.co/bitstream/10495/11717/1/ZaragozaOscar_2011_ProcessStandardizationAntifungal.pdfa8688df95aab9460e95a8c8f6e6bc981MD51CC-LICENSElicense_urllicense_urltext/plain; charset=utf-849http://bibliotecadigital.udea.edu.co/bitstream/10495/11717/2/license_url4afdbb8c545fd630ea7db775da747b2fMD52license_textlicense_texttext/html; charset=utf-80http://bibliotecadigital.udea.edu.co/bitstream/10495/11717/3/license_textd41d8cd98f00b204e9800998ecf8427eMD53license_rdflicense_rdfLicenciaapplication/rdf+xml; charset=utf-80http://bibliotecadigital.udea.edu.co/bitstream/10495/11717/4/license_rdfd41d8cd98f00b204e9800998ecf8427eMD54LICENSElicense.txtlicense.txttext/plain; charset=utf-81748http://bibliotecadigital.udea.edu.co/bitstream/10495/11717/5/license.txt8a4605be74aa9ea9d79846c1fba20a33MD5510495/11717oai:bibliotecadigital.udea.edu.co:10495/117172021-04-01 13:42:11.696Repositorio Institucional Universidad de Antioquiaandres.perez@udea.edu.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