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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| Format: | Article |
| Language: | English |
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Fundação Oswaldo Cruz (FIOCRUZ)
2013-02-01
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| Series: | Memorias do Instituto Oswaldo Cruz |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762013000100023 |
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| author | Christian Alvarez Glaucia Gonçalves Barbosa Raquel de Vasconcellos Carvalhaes de Oliveira Bernardina Penarrieta Morales Bodo Wanke Márcia dos Santos Lazéra |
| author_facet | Christian Alvarez Glaucia Gonçalves Barbosa Raquel de Vasconcellos Carvalhaes de Oliveira Bernardina Penarrieta Morales Bodo Wanke Márcia dos Santos Lazéra |
| author_sort | Christian Alvarez |
| collection | DOAJ |
| 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 0.05.10³ CFU.g-1, while the threshold for the ST was greater than 0.1.10³ 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. |
| first_indexed | 2024-03-12T07:37:54Z |
| format | Article |
| id | doaj.art-f8fa2b8a04754b39a1dbc13cd870fde7 |
| institution | Directory Open Access Journal |
| issn | 0074-0276 1678-8060 |
| language | English |
| last_indexed | 2024-03-12T07:37:54Z |
| publishDate | 2013-02-01 |
| publisher | Fundação Oswaldo Cruz (FIOCRUZ) |
| record_format | Article |
| series | Memorias do Instituto Oswaldo Cruz |
| spelling | doaj.art-f8fa2b8a04754b39a1dbc13cd870fde72023-09-02T21:28:48ZengFundação Oswaldo Cruz (FIOCRUZ)Memorias do Instituto Oswaldo Cruz0074-02761678-80602013-02-011081126129Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samplesChristian AlvarezGlaucia Gonçalves BarbosaRaquel de Vasconcellos Carvalhaes de OliveiraBernardina Penarrieta MoralesBodo WankeMárcia dos Santos LazéraIn 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 0.05.10³ CFU.g-1, while the threshold for the ST was greater than 0.1.10³ 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.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762013000100023isolation techniquesCryptococcus neoformansCryptococcus gattiiwood decay substrata |
| spellingShingle | Christian Alvarez Glaucia Gonçalves Barbosa Raquel de Vasconcellos Carvalhaes de Oliveira Bernardina Penarrieta Morales Bodo Wanke Márcia dos Santos Lazéra Techniques for the detection of pathogenic Cryptococcus species in wood decay substrata and the evaluation of viability in stored samples Memorias do Instituto Oswaldo Cruz isolation techniques Cryptococcus neoformans Cryptococcus gattii wood decay substrata |
| 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 | isolation techniques Cryptococcus neoformans Cryptococcus gattii wood decay substrata |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762013000100023 |
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