Resolving lineage assignation on Mycobacterium tuberculosis clinical isolates classified by spoligotyping with a new high-throughput 3R SNPs based method.

We developed a new multiplexed-PCR assay to accurately classify Mycobacterium tuberculosis complex (MTC) isolates at the sublineage level by single nucleotide polymorphisms (SNPs). This method relies on 7 SNPs located in different genes of the MTC strains (recC, rec0, recR, ligB, ligC, alkA, and mgtC). Most of these genes are involved in replication, repair and recombination (3R) functions of M.

Comparison of the pharmacokinetics of two dosage regimens of linezolid in multidrug-resistant and extensively drug-resistant tuberculosis patients.

Background And Objectives: For the treatment of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB), potent new drugs are urgently needed. Linezolid is a promising drug, but its use is limited by adverse effects with prolonged administration of 600 mg twice daily. In order to reduce its adverse effects and maintain efficacy, we investigated whether linezolid in a reduced dosage resulted in drug serum concentrations exceeding a ratio of the in vitro minimum inhibitory concentration (MIC) to the area under the serum concentration-time curve (AUC) over 24 hours (AUC(24)) [AUC(24)/MIC] of >100.

High-resolution typing by integration of genome sequencing data in a large tuberculosis cluster.

To investigate whether genome sequencing yields more useful markers than those currently used to study the epidemiology of tuberculosis, it was applied to three Mycobacterium tuberculosis isolates of the Harlingen outbreak. Our findings suggest that single nucleotide polymorphisms can be used to identify transmission chains in restriction fragment length polymorphism clusters.

Comparative study on genotypic and phenotypic second-line drug resistance testing of Mycobacterium tuberculosis complex isolates.

The mycobacterium growth indicator tube (MGIT960) automated liquid medium testing method is becoming the international gold standard for second-line drug susceptibility testing of multidrug- and extensively drug-resistant Mycobacterium tuberculosis complex isolates. We performed a comparative study of the current gold standard in the Netherlands, the Middlebrook 7H10 agar dilution method, the MGIT960 system, and the GenoType MTBDRsl genotypic method for rapid screening of aminoglycoside and fluoroquinolone resistance. We selected 28 clinical multidrug- and extensively drug-resistant M.

Validation of the GenoType MTBDRplus assay for diagnosis of multidrug resistant tuberculosis in South Vietnam.

Background: To control multidrug resistant tuberculosis (MDR-TB), the drug susceptibility profile is needed to guide therapy. Classical drug susceptibility testing (DST) may take up to 2 to 4 months. The GenoType MTBDRplus test is a commercially available line-probe assay that rapidly detects Mycobacterium tuberculosis (MTB) complex, as well as the most common mutations associated with rifampin and isoniazid resistance.

Multidrug-resistant and extensively drug-resistant tuberculosis: a threat to global control of tuberculosis.

Although progress has been made to reduce global incidence of drug-susceptible tuberculosis, the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis during the past decade threatens to undermine these advances. However, countries are responding far too slowly. Of the estimated 440,000 cases of MDR tuberculosis that occurred in 2008, only 7% were identified and reported to WHO.

[Nontuberculous mycobacteria: clinically relevant].

The nontuberculous or atypical mycobacteria (NTM) are a group of largely opportunistic pathogens, which are increasingly being detected in patients and being associated with clinical disease. Various host factors are responsible for this, such as the ageing population with the accompanying increase in the number of patients with chronic diseases, but NTM are also detected more often as a result of improvements in diagnostic laboratory techniques. The clinical relevance, i.

Surveillance of extensively drug-resistant tuberculosis in Europe, 2003-2007.

This paper describes the results of second-line drug (SLD) susceptibility tests among multidrug-resistant tuberculosis (MDR TB) cases reported in 20 European countries aiming to identify extensively drug-resistant tuberculosis (XDR TB) cases. A project on molecular surveillance of MDR TB cases was conducted by EuroTB and the National Institute for Public Health and the Environment (RIVM) from 2005 to 2007. Information on drug susceptibility testing (DST) was provided to this project and case-based data on MDR TB cases were reported on a quarterly basis by 20 countries of the World Health Organization s European Region, including 15 European Union Member States.

Mycobacterium bovis, but also M. africanum present in raw milk of pastoral cattle in north-central Nigeria.

Using deletion typing technique, five mycobacteria isolated from unpasteurised milk samples from cows in north-central Nigeria were characterized as Mycobacterium bovis (n = 4) and M. africanum (n = 1). This report emphasizes that transmission between the animal and human reservoir is a serious threat in Nigeria.

Thioridazine cures extensively drug-resistant tuberculosis (XDR-TB) and the need for global trials is now!

Thioridazine (TDZ) has been shown to have in vitro activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis, to promote the killing of intracellular MDR and XDR strains and to cure the mouse of antibiotic-susceptible and -resistant pulmonary tuberculosis (TB) infections. Recently, TDZ was used to cure 10 of 12 XDR-TB patients in Buenos Aires, Argentina. At the time of writing, it is being used for the therapy of non-antibiotic-responsive terminal XDR-TB patients in Mumbai, India, on the basis of compassionate therapy and although it is too early to determine a cure, the patients have improved appetite, weight gain, are afebrile and free of night sweats, and their radiological picture shows great improvement.

Possible underlying mechanisms for successful emergence of the Mycobacterium tuberculosis Beijing genotype strains.

The wide geographic distribution of one clade of Mycobacterium tuberculosis, the Beijing genotype family, and its genetic homogeneity, suggests that strains belonging to this grouping might have a selective advantage over other M tuberculosis strains. This hypothesis was addressed by reviewing molecular-epidemiological, experimental, and clinical studies. Beijing strains represent about 50% of strains in east Asia and at least 13% of strains worldwide.

Isolation of mycobacteria other than Mycobacterium avium from porcine lymph nodes.

Mycobacterium avium causes lymphadenitis in pigs. This presents an economical burden, as these pigs meat is considered inappropriate for consumption. In humans, lymphadenitis due to nontuberculous mycobacteria (NTM) primarily affects children and is caused by a variety of NTM, though M.

Mycobacterium tuberculosis Beijing genotype is an independent risk factor for tuberculosis treatment failure in Indonesia.

Animal studies have shown that the globally emerging Beijing genotype strains of Mycobacterium tuberculosis are more virulent than other strains. We examined whether Beijing strains increase treatment failure in a prospective cohort study in Indonesia. Among 818 tuberculosis cases, positive sputum culture results after 6 months of treatment were more common among patients infected with Beijing strains (33.

In vitro drug susceptibility of 2275 clinical non-tuberculous Mycobacterium isolates of 49 species in The Netherlands.

In this study, 2275 clinical isolates of 49 species of non-tuberculous mycobacteria isolated in The Netherlands were subjected to standardised drug susceptibility testing using the Middlebrook 7H10 agar dilution method. Clarithromycin and rifabutin were most active, with 87% and 83% of all isolates, respectively, being susceptible. Susceptibility to ciprofloxacin (44%) and amikacin (32%) was limited and was mostly restricted to Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium fortuitum and phylogenetically related species.

Serodiagnosis of Mycobacterium avium infections in pigs.

The aim of this study is the development and evaluation of a serodiagnostic assay for Mycobacterium avium (MA). After screening MA lipid fractions in an ELISA format, a polar lipid fraction was selected as antigen because of its superior recognition by serum antibodies in experimentally infected pigs. The resulting MA-ELISA was evaluated as an alternative for detection of MA infection by traditional pathological examination of pig lymph nodes for granulomatous lesions by meat inspectors.

Surgical treatment of non-tuberculous mycobacterial lung disease: strike in time.

Setting: The Netherlands.

Objective: To describe our experiences with the adjunctive role and benefits of surgery for lung disease due to non-tuberculous mycobacteria (NTM), specifically addressing its indications and timing.

Design: Retrospective medical file review of eight patients who underwent surgical treatment for NTM lung disease in the period January 2000 to January 2009, and review of the available literature.

Progress towards tuberculosis elimination: secular trend, immigration and transmission.

This study aimed to determine to what extent tuberculosis trends in the Netherlands depend on secular trend, immigration and recent transmission. Data on patients in the Netherlands Tuberculosis Register in the period 1993-2007 were matched with restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis isolates. Index patients were defined as patients with pulmonary tuberculosis whose isolates had RFLP patterns not observed in another patient in the previous 2 yrs.

Re-analysis of 178 previously unidentifiable Mycobacterium isolates in the Netherlands in 1999-2007.

Nontuberculous mycobacteria (NTM) that cannot be identified to the species level by reverse line blot hybridization assays and sequencing of the 16S rRNA gene comprise a challenge for reference laboratories. However, the number of 16S rRNA gene sequences added to online public databases is growing rapidly, as is the number of Mycobacterium species. Therefore, we re-analysed 178 Mycobacterium isolates with 53 previously unmatched 16S rRNA gene sequences, submitted to our national reference laboratory in 1999–2007.

Mycobacterium tuberculosis genotype and case notification rates, rural Vietnam, 2003-2006.

Tuberculosis case notification rates (CNRs) for young adults in Vietnam are increasing. To determine whether this finding could reflect emergence of Mycobacterium tuberculosis Beijing genotype, we studied all new sputum smear-positive pulmonary tuberculosis patients registered for treatment in 3 rural districts in Vietnam during 2003-2006. Beijing strain infections were more frequent in younger patients (15-24 years of age, 53%) than in older patients (31%; p<0.

Environmental sources of rapid growing nontuberculous mycobacteria causing disease in humans.

Nontuberculous mycobacteria are environmental, opportunistic pathogens whose role in human disease is increasingly recognized, especially regarding the rapid growing mycobacteria (RGM). RGM are recovered from various environmental sources, both natural and man-made. In water systems, RGM can survive by forming biofilms and by interactions with protozoa.

The tempo and mode of molecular evolution of Mycobacterium tuberculosis at patient-to-patient scale.

A total of six polymorphisms were identified by comparing the genomes of the first and the last isolate of a well-characterized transmission chain of Mycobacterium tuberculosis involving five patients over a 12 and a half year period. The six polymorphisms consisted of four single nucleotide changes (SNPs), a tandem repeat polymorphism (TRP) and a previously identified IS6110 transposition event. These polymorphic sites were surveyed in each of the isolates from the five patients in the transmission chain.