The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol （EMB） resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization （RDBH...The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol （EMB） resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization （RDBH） in addition to evaluating the clinical value with application of PCR-RDBH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates （65.9%） showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation （38/91, 41.8% ） and the ATA mutation （16/91, 17.6% ） were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing fcr one wide-type probe and 5 probes for specific mutations was 100%. It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.展开更多
Hepatitis associated anti-tuberculous treatment（HATT） has been a main obstacle in managing patients co-infected with Mycobacterium tuberculosis and hepatitis B virus（HBV）. Therefore, we evaluated the factors relat...Hepatitis associated anti-tuberculous treatment（HATT） has been a main obstacle in managing patients co-infected with Mycobacterium tuberculosis and hepatitis B virus（HBV）. Therefore, we evaluated the factors related to the severity of adverse effects during HATT, especially those associated with liver failure. A retrospective study was carried out at Tongji Hospital from 2007 to 2012. Increases in serum transaminase levels of 〉3, 5, and 10 times the upper limit of normal（ULN） were used to define liver damage as mild, moderate, and severe, respectively. Patients with elevated total bilirubin（TBil） levels that were more than 10 times the ULN（〉171 μmol/L） with or without decreased（〈40%） prothrombin activity（PTA） were diagnosed with liver failure. A cohort of 87 patients was analyzed. The incidence of liver damage and liver failure was 59.8%（n=52） and 25.3%（n=22）, respectively. The following variables were correlated with the severity of hepatotoxicity： albumin（ALB） levels, PTA, platelet counts（PLT）, and the use of antiretroviral therapies（P〈0.05）. Hypo-proteinemia and antiretroviral therapy were significantly associated with liver failure, and high viral loads were a significant risk factor with an odds ratio（OR） of 2.066. Judicious follow-up of clinical conditions, liver function tests, and coagulation function, especially in patients with high HBV loads and hypoalbuminemia is recommended. It may be advisable to reconsider the use of antiviral drugs failure during the course of anti-tuberculous treatment of HBV infection patients to avoid the occurrence of furious liver failure.展开更多
文摘The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol （EMB） resistance of the clinical isolates of tuberculous patients in China was investigated by reversedot blot hybridization （RDBH） in addition to evaluating the clinical value with application of PCR-RDBH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates （65.9%） showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation （38/91, 41.8% ） and the ATA mutation （16/91, 17.6% ） were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing fcr one wide-type probe and 5 probes for specific mutations was 100%. It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.
基金supported in part by the Organization Department of the Central Committee of the Communist Party of China 2015“sunshine of the west”visiting scholar program(No.2903)
文摘Hepatitis associated anti-tuberculous treatment（HATT） has been a main obstacle in managing patients co-infected with Mycobacterium tuberculosis and hepatitis B virus（HBV）. Therefore, we evaluated the factors related to the severity of adverse effects during HATT, especially those associated with liver failure. A retrospective study was carried out at Tongji Hospital from 2007 to 2012. Increases in serum transaminase levels of 〉3, 5, and 10 times the upper limit of normal（ULN） were used to define liver damage as mild, moderate, and severe, respectively. Patients with elevated total bilirubin（TBil） levels that were more than 10 times the ULN（〉171 μmol/L） with or without decreased（〈40%） prothrombin activity（PTA） were diagnosed with liver failure. A cohort of 87 patients was analyzed. The incidence of liver damage and liver failure was 59.8%（n=52） and 25.3%（n=22）, respectively. The following variables were correlated with the severity of hepatotoxicity： albumin（ALB） levels, PTA, platelet counts（PLT）, and the use of antiretroviral therapies（P〈0.05）. Hypo-proteinemia and antiretroviral therapy were significantly associated with liver failure, and high viral loads were a significant risk factor with an odds ratio（OR） of 2.066. Judicious follow-up of clinical conditions, liver function tests, and coagulation function, especially in patients with high HBV loads and hypoalbuminemia is recommended. It may be advisable to reconsider the use of antiviral drugs failure during the course of anti-tuberculous treatment of HBV infection patients to avoid the occurrence of furious liver failure.
