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Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples

In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoc...

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Autores principales: Alvarez, Christian, Barbosa, Glaucia Gonçalves, de Oliveira, Raquel de Vasconcellos Carvalhaes, Morales, Bernardina Penarrieta, Wanke, Bodo, Lazéra, Márcia dos Santos
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Instituto Oswaldo Cruz, Ministério da Saúde 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3974326/
https://www.ncbi.nlm.nih.gov/pubmed/23440129
http://dx.doi.org/10.1590/S0074-02762013000100023
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author Alvarez, Christian
Barbosa, Glaucia Gonçalves
de Oliveira, Raquel de Vasconcellos Carvalhaes
Morales, Bernardina Penarrieta
Wanke, Bodo
Lazéra, Márcia dos Santos
author_facet Alvarez, Christian
Barbosa, Glaucia Gonçalves
de Oliveira, Raquel de Vasconcellos Carvalhaes
Morales, Bernardina Penarrieta
Wanke, Bodo
Lazéra, Márcia dos Santos
author_sort Alvarez, Christian
collection PubMed
description In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoculated on 10 Niger seed agar (NSA) plates. The conventional technique (CT) yielded a greater number of positive samples and indicated a higher fungal density [in colony forming units per gram of wood (CFU.g(-1)) ] compared to the humid swab technique (ST). However, the difference in positive and false negative results between the CT-ST was not significant. The threshold of detection for the CT was 0.05.10(3) CFU.g(-1), while the threshold for the ST was greater than 0.1.10(3) CFU(-1). No colonies were recovered using the dry swab technique. We also determined the viability of Cryptococcus in wood samples stored for 45 days at 25ºC using the CT and ST and found that samples not only continued to yield a positive response, but also exhibited an increase in CFU.g(-1), suggesting that Cryptococcus is able to grow in stored environmental samples. The ST.1, in which samples collected with swabs were immediately plated on NSA medium, was more efficient and less laborious than either the CT or ST and required approximately 10 min to perform; however, additional studies are needed to validate this technique.
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spelling pubmed-39743262014-05-21 Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples Alvarez, Christian Barbosa, Glaucia Gonçalves de Oliveira, Raquel de Vasconcellos Carvalhaes Morales, Bernardina Penarrieta Wanke, Bodo Lazéra, Márcia dos Santos Mem Inst Oswaldo Cruz Technical Notes In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoculated on 10 Niger seed agar (NSA) plates. The conventional technique (CT) yielded a greater number of positive samples and indicated a higher fungal density [in colony forming units per gram of wood (CFU.g(-1)) ] compared to the humid swab technique (ST). However, the difference in positive and false negative results between the CT-ST was not significant. The threshold of detection for the CT was 0.05.10(3) CFU.g(-1), while the threshold for the ST was greater than 0.1.10(3) CFU(-1). No colonies were recovered using the dry swab technique. We also determined the viability of Cryptococcus in wood samples stored for 45 days at 25ºC using the CT and ST and found that samples not only continued to yield a positive response, but also exhibited an increase in CFU.g(-1), suggesting that Cryptococcus is able to grow in stored environmental samples. The ST.1, in which samples collected with swabs were immediately plated on NSA medium, was more efficient and less laborious than either the CT or ST and required approximately 10 min to perform; however, additional studies are needed to validate this technique. Instituto Oswaldo Cruz, Ministério da Saúde 2013-02 /pmc/articles/PMC3974326/ /pubmed/23440129 http://dx.doi.org/10.1590/S0074-02762013000100023 Text en http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Technical Notes
Alvarez, Christian
Barbosa, Glaucia Gonçalves
de Oliveira, Raquel de Vasconcellos Carvalhaes
Morales, Bernardina Penarrieta
Wanke, Bodo
Lazéra, Márcia dos Santos
Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
title Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
title_full Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
title_fullStr Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
title_full_unstemmed Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
title_short Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
title_sort techniques for the detection of pathogenic cryptococcus species in wood decay substrata and the evaluation of viability in stored samples
topic Technical Notes
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3974326/
https://www.ncbi.nlm.nih.gov/pubmed/23440129
http://dx.doi.org/10.1590/S0074-02762013000100023
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