Please use this identifier to cite or link to this item:
Title: Detection of embB306 mutations in ethambutol-susceptible clinical isolates of Mycobacterium tuberculosis from Northwestern Russia: implications for genotypic resistance testing
Authors: Otten, Tatiana
Vyshnevskiy, Boris
Mokrousov, Igor V. 
Narvskaya, Olga V. 
Issue Date: Oct-2002
Publisher: American Society for Microbiology
Journal: Journal of Clinical Microbiology 
Abstract: A total of 183 epidemiologically unlinked Mycobacterium tuberculosis isolates collected in the St. Petersburg area of Russia from 1996 to 2001 were screened for alterations in codon 306 of the embB gene; mutations in this codon are reported to confer resistance to ethambutol (EMB). The embB306 mutations were detected in 14 (48.3%) of 29 EMB-resistant strains and, quite surprisingly, in 48 (31.2%) of 154 EMB-susceptible strains. A discrepancy between the results of phenotypic and genotypic EMB resistance tests was restricted to the strains already resistant to other antitubercular (anti-TB) drugs. In particular, 40 (60%) of the 69 EMB-susceptible strains resistant to rifampin, isoniazid, and streptomycin but none of the 43 pansusceptible strains harbored an embB306 mutation. We hypothesize that the phenomenon observed could reflect the presence of a target other than EmbB for the drug in tubercle bacilli; this unknown target could be sensitized and affected, sensu lato, by EMB during treatment with other first-line anti-TB drugs. Comparison with DNA fingerprinting data showed that, irrespectively of the phenotypic susceptibility profiles, 46 (50.6%) of 91 Beijing family strains and 16 (17.4%) of 92 strains of other genotypes had a mutation in embB306.
ISSN: 0095-1137
Appears in Collections:Journal articles

Show full item record


checked on Mar 17, 2019

Page view(s)

checked on Mar 23, 2019

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.