Antimicrobial susceptibility determined by the E test, Lõwenstein-Jensen proportion, and DNA sequencing methods among Mycobacterium tuberculosis isolates discrepancies, preliminary results
Mem. Inst. Oswaldo Cruz
;
99(1): 107-110, Feb. 2004. tab
Artigo
em Inglês
| LILACS
| ID: lil-356453
RESUMO
Mycobacterium tuberculosis strains resistant to streptomycin (SM), isoniazid (INH), and/or rifampin (RIF) as determined by the conventional Lõwenstein-Jensen proportion method (LJPM) were compared with the E test, a minimum inhibitory concentration susceptibility method. Discrepant isolates were further evaluated by BACTEC and by DNA sequence analyses for mutations in genes most often associated with resistance to these drugs (rpsL, katG, inhA, and rpoB). Preliminary discordant E test results were seen in 75 percent of isolates resistant to SM and in 11 percent to INH. Discordance improved for these two drugs (63 percent) for SM and none for INH when isolates were re-tested but worsened for RIF (30 percent). Despite good agreement between phenotypic results and sequencing analyses, wild type profiles were detected on resistant strains mainly for SM and INH. It should be aware that susceptible isolates according to molecular methods might contain other mechanisms of resistance. Although reproducibility of the LJPM susceptibility method has been established, variable E test results for some M. tuberculosis isolates poses questions regarding its reproducibility particularly the impact of E test performance which may vary among laboratories despite adherence to recommended protocols. Further studies must be done to enlarge the evaluated samples and looked possible mutations outside of the hot spot sequenced gene among discrepant strains.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Mycobacterium tuberculosis
/
Antituberculosos
Limite:
Humanos
Idioma:
Inglês
Revista:
Mem. Inst. Oswaldo Cruz
Assunto da revista:
Medicina Tropical
/
Parasitologia
Ano de publicação:
2004
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Brasil
/
Egito
Instituição/País de afiliação:
Fundação Oswaldo Cruz/BR
/
Ministério da Saúde/BR
/
Suez Canal University School of Medicine/EG
/
Universidade Federal do Rio de Janeiro/BR
/
Universidade do Estado do Rio de Janeiro/BR
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