Bacterial factors may contribute to the global emergence and spread of drug-resistant tuberculosis (TB). Only a few studies have reported on the interactions between different bacterial factors. We studied drug-resistant Mycobacterium tuberculosis isolates from a nationwide study conducted from 2000 to 2008 in Switzerland. We determined quantitative drug resistance levels of first-line drugs by...

OBJECTIVES Ontario bears the greatest burden of tuberculosis in Canada, with 40% of all cases and 60% of multidrug-resistant cases. The purpose of this study was to genotypically characterize isoniazid- and rifampicin-resistant isolates and compare these results with phenotypic drug susceptibility testing data. This is the first Canadian study to examine gene mutations that contribute to multid...

A case-control study in Rio de Janeiro in 1994 included 552 patients with a positive culture for Mycobacterium tuberculosis and reported a 1.8% resistance rate to rifampicin and isoniazid. Prior treatment for tuberculosis (the exposure factor) was associated with resistance. The binomial proportion was used to test the hypothesis of no dependence between the observed associations based on prior...

Fourteen of 22 (68%) Mycobacterium bovis strains isolated from cattle in Sardinia were found to be resistant to rifampin and isoniazid. Analysis of the rpoB and the katG, oxyR-ahpC, and inhA gene regions of these strains was performed in order to investigate the molecular basis of rifampin and isoniazid resistance, respectively. The most frequent mutation, encountered in 6 of 10 strains (60%), ...

BACKGROUND There is limited evidence that the DOTS (directly observed therapy, short course) strategy for tuberculosis (TB) control can contain the emergence and spread of drug resistance in the absence of second-line treatment. We compared drug-resistance levels between 1996 and 2001 in the south of Vietnam, an area with a well-functioning DOTS program. METHODS Sputum specimens were collecte...

INTRODUCTION Systematic surveillance of antituberculosis drug resistance allows identification of multidrug-resistant and extensively drug-resistant isolates of Mycobacterium tuberculosis. Surveillance studies of antituberculosis drug resistance systematically conducted in Cuba for over 15 years have revealed low circulation of multidrug-resistant tuberculosis, under 1% in new cases. OBJECTIVE ...

Abstract Background Previous studies have shown significant differences and lack clarity on whether resistance to either isoniazid or rifampicin can predict multidrug tuberculosis (MDR-TB). Some consider be a surrogate for MDR-TB. We, therefore, conducted this study determine Results A total of 315 Mycobacteria isolates were tested against isoniazid, rifampicin, ethambutol streptomycin using th...

Background: One third of the world’s population is infected with TB, and the disease is known as the second deadly global infection, even more severe than measles. The disease kills about 2 million people a year. Approximately 8 million people in the world are affected by advanced tuberculosis (TB). Objective: The current study aimed to determine the freq...

INTRODUCTION Resistance of Mycobacterium tuberculosis (MTB) to anti-tuberculosis (TB) drugs presents a serious challenge to TB control worldwide. We investigated the status of drug resistance, including multidrug-resistant (MDR) TB, and possible risk factors among newly diagnosed TB patients in Hanoi, the capital of Viet Nam. METHODS Clinical and epidemiological information was collected from...

The present study investigated the prevalence and diagnostic potential of the most commonly reported mutations associated with isoniazid resistance, katG 315Thr, katG 315Asn, inhA -15T, inhA -8A, and the oxyR-ahpC intergenic region, in a population sample of 202 isoniazid-resistant Mycobacterium tuberculosis isolates and 176 randomly selected fully sensitive isolates from England and Wales iden...