119 research outputs found
A Neuromedin U Receptor Acts with the Sensory System to Modulate Food Type-Dependent Effects on C. elegans Lifespan
Different food types modulate worm lifespan and involve the neuropeptide receptor NMUR-1, which acts with the sensory neurons in a bacterial lipopolysaccaharide structure-dependent manner
Unsuspected and extensive transmission of a drug-susceptible Mycobacterium tuberculosis strain
<p>Abstract</p> <p>Background</p> <p>A large and unsuspected tuberculosis outbreak involving 18.7% of the total of the tuberculosis cases studied, was detected in a population-based molecular epidemiological study performed in Zaragoza (Spain) from 2001 to 2004.</p> <p>Methods</p> <p>The <it>Mycobacterium tuberculosis </it>drug-susceptible strain, named <it>MTZ </it>strain, was genetically characterized by IS<it>6110</it>-RFLP, Spoligotyping and by MIRU-VNTR typing and the genetic patterns obtained were compared with those included in international databases. The characteristics of the affected patients, in an attempt to understand why the <it>MTZ </it>strain was so highly transmitted among the population were also analyzed.</p> <p>Results</p> <p>The genetic profile of the <it>MTZ </it>strain was rare and not widely distributed in our area or elsewhere. The patients affected did not show any notable risk factor for TB.</p> <p>Conclusion</p> <p>The <it>M. tuberculosis </it>strain <it>MTZ</it>, might have particular transmissibility or virulence properties, and we believe that greater focus should be placed on stopping its widespread dissemination.</p
High-Resolution Melting Analysis for the Rapid Detection of Fluoroquinolone and Streptomycin Resistance in Mycobacterium tuberculosis
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IL10 Haplotype Associated with Tuberculin Skin Test Response but Not with Pulmonary TB
Evidence from genetic association and twin studies indicates that susceptibility to tuberculosis (TB) is under genetic control. One gene implicated in susceptibility to TB is that encoding interleukin-10 (IL10). In a group of 2010 Ghanaian patients with pulmonary TB and 2346 healthy controls exposed to Mycobacterium tuberculosis, among them 129 individuals lacking a tuberculin skin test (PPD) response, we genotyped four IL10 promoter variants at positions β2849 , β1082 , β819 , and β592 and reconstructed the haplotypes. The IL10 low-producer haplotype β2849A/β1082A/β819C/β592C, compared to the high-producer haplotype β2849G/β1082G/β819C/β592C, occurred less frequent among PPD-negative controls than among cases (OR 2.15, CI 1.3β3.6) and PPD-positive controls (OR 2.09, CI 1.2β3.5). Lower IL-10 plasma levels in homozygous β2849A/β1082A/β819C/β592C carriers, compared to homozygous β2849G/β1082G/β819C/β592C carriers, were confirmed by a IL-10 ELISA (pβ=β0.016). Although we did not observe differences between the TB patients and all controls, our results provide evidence that a group of individuals exposed to M. tuberculosis transmission is genetically distinct from healthy PPD positives and TB cases. In these PPD-negative individuals, higher IL-10 production appears to reflect IL-10-dependent suppression of adaptive immune responses and sustained long-term specific anergy
Locating essential Escherichia coli genes by using mini-Tn10 transposons: the pdxJ operon.
operon.using mini-Tn10 transposons: the pdxJ Locating essential Escherichia coli genes b
Organization of the origins of replication of the chromosomes of Mycobacterium smegmatis, Mycobacterium leprae and Mycobacterium tuberculosis and isolation of a functional origin from M. smegmatis
The genus Mycobacterium is composed of species with widely differing growth rates ranging from approximately three hours in Mycobacterium smegmatis to two weeks in Mycobacterium leprae. As DNA replication is coupled to cell duplication, it may be regulated by common mechanisms. The chromosomal regions surrounding the origins of DNA replication from M. smegmatis, M. tuberculosis, and M. leprae have been sequenced, and show very few differences. The gene order, rnpA-rpmH-dnaA-dnaN-recF-orf-gyrB-gyrA, is the same as in other Gram-positive organisms. Although the general organization in M. smegmatis is very similar to that of Streptomyces spp., a closely related genus, M. tuberculosis and M. leprae differ as they lack an open reading frame, between dnaN and recF, which is similar to the gnd gene of Escherichia coli. Within the three mycobacterial species, there is extensive sequence conservation in the intergenic regions flanking dnaA, but more variation from the consensus DnaA box sequence was seen than in other bacteria. By means of subcloning experiments, the putative chromosomal origin of replication of M. smegmatis, containing the dnaA-dnaN region, was shown to promote autonomous replication in M. smegmatis, unlike the corresponding regions from M. tuberculosis or M. leprae
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