Rifampicin-resistant Mycobacterium tuberculosis: susceptibility to isoniazid and other anti-tuberculosis drugs.
ABSTRACT Based on data from 14 Supranational Tuberculosis (TB) Reference Laboratories worldwide, the proportion of rifampicin (RMP) resistant isolates that were isoniazid (INH) susceptible by phenotypic drug susceptibility testing varied widely (0.5-11.6%). RMP-resistant isolates that were INH-susceptible had significantly lower rates of resistance to other first- and second-line anti-tuberculosis drugs (except rifabutin) compared to multidrug-resistant isolates. RMP resistance is not always a good proxy for a presumptive diagnosis of multidrug-resistant TB, which has implications for use of molecular assays that identify only RMP resistance-associated DNA mutations.
- SourceAvailable from: Akos Somoskövi[Show abstract] [Hide abstract]
ABSTRACT: Xpert-MTB/Rif is one of the most frequently used molecular screening test for multidrug-resistant tuberculosis worldwide. We report false negative results of the assay in the presence of rpoB Leu533Pro that is associated with low level of phenotypic rifampin resistance. Accurate and timely confirmation of rifampin results with Xpert-MTB/Rif is imperative.Journal of clinical microbiology 07/2013; · 4.16 Impact Factor
- Enfermedades Infecciosas y Microbiología Clínica 04/2013; · 1.48 Impact Factor
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ABSTRACT: Childhood multidrug-resistant (MDR) tuberculosis is an emerging disease with increasing numbers being recognized. This review presents recent developments in childhood MDR tuberculosis. New molecular-based diagnostic tests, although not optimal, have reduced the difficulty in confirming the diagnosis of MDR tuberculosis in children. However, the importance of making a diagnosis of probable MDR tuberculosis has been reaffirmed by contact tracing studies showing 80-90% of child contacts of MDR tuberculosis cases who develop disease have MDR tuberculosis themselves. Prevention of MDR tuberculosis in child contacts with appropriate preventive treatment regimens is supported by new observational data and deserves further study. When diagnosed and treated appropriately, outcomes for MDR tuberculosis and even extensively drug-resistant tuberculosis in children are good, despite limited pharmacokinetic data on second-line drugs. Novel anti-tuberculosis drugs and regimens are becoming available and should be studied in children for dose-finding and safety. Recording and reporting of MDR tuberculosis in children are frequently poor, leading to inaccurate estimates of disease burden and suboptimal resource planning. Rapid diagnosis and appropriate treatment results in good outcomes in the majority of children with MDR tuberculosis. Additional research on optimal diagnosis, prevention and treatment of MDR tuberculosis in children remains a high priority.Current Opinion in Infectious Diseases 04/2014; · 4.87 Impact Factor