Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum
INTRODUCTION: Rhodococcus equi is an opportunistic pathogen, causing rhodococcosis, a condition that can be confused with tuberculosis. Often, without identifying M. tuberculosis, physicians initiate empiric treatment for tuberculosis. R. equi and M. tuberculosis have different susceptibility to dru...
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| Format: | Article |
| Language: | English |
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Elsevier
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| Series: | Brazilian Journal of Infectious Diseases |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000500001&lng=en&tlng=en |
| _version_ | 1819063865230491648 |
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| author | Paulo da Silva Adolfo Carlos Barreto Santos Daisy Nakamura Sato Jaqueline Otero Silva Marta Inês Cazentini Medeiros Ana Maria Machado Carneiro Sergio Roberto de Andrade Leite Clarice Queico Fujimura Leite |
| author_facet | Paulo da Silva Adolfo Carlos Barreto Santos Daisy Nakamura Sato Jaqueline Otero Silva Marta Inês Cazentini Medeiros Ana Maria Machado Carneiro Sergio Roberto de Andrade Leite Clarice Queico Fujimura Leite |
| author_sort | Paulo da Silva |
| collection | DOAJ |
| description | INTRODUCTION: Rhodococcus equi is an opportunistic pathogen, causing rhodococcosis, a condition that can be confused with tuberculosis. Often, without identifying M. tuberculosis, physicians initiate empiric treatment for tuberculosis. R. equi and M. tuberculosis have different susceptibility to drugs. Identification of R. equi is based on a variety of phenotypic, chromatographic, and genotypic characteristics. OBJECTIVE: This study aimed to characterize bacterial isolates from sputum samples suggestive of R. equi. METHODS: The phenotypic identification included biochemical assays; thin-layer chromatography (TLC) and polymerase chain reaction (PCR) were used for genotypic identification. RESULTS: Among 78 Gram-positive and partially acid-fast bacilli isolated from the sputum of tuberculosis-suspected patients, 51 were phenotypically and genotypically characterized as R. equi based on literature data. Mycolic acid analysis showed that all suspected R. equi had compounds with a retention factor (Rf) between 0.4-0.5. Genotypic characterization indicated the presence of the choE gene 959 bp fragments in 51 isolates CAMP test positive. Twenty-two CAMP test negative isolates were negative for the choE gene. Five isolates presumptively identified as R. equi, CAMP test positive, were choE gene negative, and probably belonged to other bacterial species. CONCLUSIONS: The phenotypic and molecular techniques used constitute a good methodological tool to identify R. equi. |
| first_indexed | 2024-12-21T15:21:28Z |
| format | Article |
| id | doaj.art-ddee3cf7c12841288cd6a53268422866 |
| institution | Directory Open Access Journal |
| issn | 1678-4391 |
| language | English |
| last_indexed | 2024-12-21T15:21:28Z |
| publisher | Elsevier |
| record_format | Article |
| series | Brazilian Journal of Infectious Diseases |
| spelling | doaj.art-ddee3cf7c12841288cd6a532684228662022-12-21T18:59:02ZengElsevierBrazilian Journal of Infectious Diseases1678-439116540941510.1016/j.bjid.2012.08.009S1413-86702012000500001Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputumPaulo da Silva0Adolfo Carlos Barreto Santos1Daisy Nakamura Sato2Jaqueline Otero Silva3Marta Inês Cazentini Medeiros4Ana Maria Machado Carneiro5Sergio Roberto de Andrade Leite6Clarice Queico Fujimura Leite7Instituto Adolfo LutzUniversidade Estadual PaulistaInstituto Adolfo LutzInstituto Adolfo LutzInstituto Adolfo LutzInstituto Adolfo LutzInstituto Adolfo LutzUniversidade Estadual PaulistaINTRODUCTION: Rhodococcus equi is an opportunistic pathogen, causing rhodococcosis, a condition that can be confused with tuberculosis. Often, without identifying M. tuberculosis, physicians initiate empiric treatment for tuberculosis. R. equi and M. tuberculosis have different susceptibility to drugs. Identification of R. equi is based on a variety of phenotypic, chromatographic, and genotypic characteristics. OBJECTIVE: This study aimed to characterize bacterial isolates from sputum samples suggestive of R. equi. METHODS: The phenotypic identification included biochemical assays; thin-layer chromatography (TLC) and polymerase chain reaction (PCR) were used for genotypic identification. RESULTS: Among 78 Gram-positive and partially acid-fast bacilli isolated from the sputum of tuberculosis-suspected patients, 51 were phenotypically and genotypically characterized as R. equi based on literature data. Mycolic acid analysis showed that all suspected R. equi had compounds with a retention factor (Rf) between 0.4-0.5. Genotypic characterization indicated the presence of the choE gene 959 bp fragments in 51 isolates CAMP test positive. Twenty-two CAMP test negative isolates were negative for the choE gene. Five isolates presumptively identified as R. equi, CAMP test positive, were choE gene negative, and probably belonged to other bacterial species. CONCLUSIONS: The phenotypic and molecular techniques used constitute a good methodological tool to identify R. equi.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000500001&lng=en&tlng=enPolymerase chain reactionRhodococcus equiMycolic acids |
| spellingShingle | Paulo da Silva Adolfo Carlos Barreto Santos Daisy Nakamura Sato Jaqueline Otero Silva Marta Inês Cazentini Medeiros Ana Maria Machado Carneiro Sergio Roberto de Andrade Leite Clarice Queico Fujimura Leite Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum Brazilian Journal of Infectious Diseases Polymerase chain reaction Rhodococcus equi Mycolic acids |
| title | Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum |
| title_full | Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum |
| title_fullStr | Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum |
| title_full_unstemmed | Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum |
| title_short | Phenotypic and genotypic characterization of Rhodococcus equi isolated from sputum |
| title_sort | phenotypic and genotypic characterization of rhodococcus equi isolated from sputum |
| topic | Polymerase chain reaction Rhodococcus equi Mycolic acids |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702012000500001&lng=en&tlng=en |
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