Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

When infected with Leishmania species, patients develop specific antibodies that constitute the basis of serodiagnosis. using Western blot analysis we studied the specificity of anti-leishmania donovani antibodies in patients with visceral leishmaniasis, healthy subjects living in an endemic and non-endemic areas, and patients of other infectious diseases like malaria, leprosy, tuberculosis and tropical splenomegaly. Sera from patients with kala-azar recognised numerous antigens that had a molecular weight of 150 KD, 145 KD, 120 KD, 92 KD, 87 KD, 72 KD, 65 KD, 56 KD, 50 KD, 40 KD, 26 KD, 21 KD, 14 KD, AND 12 KD. The 150, 145, 120, 92, 87, 81, 65, 25, 21, 14, and 12 KD antigens had the greatest specificity for kala-azar sera while the bands of molecular weights 72, 56, 50, and 40 KD were found to be cross reactive with sera of patients of other diseases.
Biochem Mol Biol Int 1995 Nov
PMID:Evaluation of antibody responses in Indian kala-azar by immunoblot. 862 3

The katG gene and the inhA gene of 30 INH-resistant (INH-R) and 28 INH-sensitive (INH-S) isolates of M. tuberculosis from Haiti and Maryland were analysed by PCR to establish the presence and frequency of two postulated mechanisms of INH-resistance, total katG gene deletion and inhA Ser94 to Ala94 amino acid substitution. Only two of 30 INH-R isolates (3%) appear to have total katG gene deletions. All 28 INH-S isolates (100%) produced a PCR product at both the 5' and the 3' ends of the katG gene. Gene deletion of katG is a rare mechanism of INH resistance. Allele specific oligonucleotide hybridisation analysis of the inhA PCR products from the same 58 isolates revealed no mutation at amino acid 94 or directly surrounding it. Other inhA gene mutations may be responsible for INH resistance in M. tuberculosis. Diagnostic strategies using katG gene deletion or inhA Ser94 mutations would fail to detect almost all INH-R isolates.
Mol Cell Probes 1996 Feb
PMID:Evaluation of inhA gene and catalase-peroxidase gene among isoniazid-sensitive and resistant Mycobacterium tuberculosis isolates. 868 71

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.
Mol Microbiol 1996 Apr
PMID: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. 873 28

The polymerase chain reaction with a single universal primer (UP-PCR) was applied to bacterial strains and mycobacteria isolates alongside conventional methods. A universal protocol of preparation of PCR samples from cultures representing Escherichia coli, Enterobacter aerogenes, Serratia marcescens, Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Mycobacterium tuberculosis, Mycobacterium bovis, and several non-tuberculous mycobacteria was found to be reproducible and efficient with these organisms. The bands of UP-PCR products observed in an agarose gel after electrophoresis were species-specific and provided an efficient means of distinguishing bacterial species. The applicability of this approach to mycobacteria identification was assessed by comparing the DNA bands obtained for different strains. Three reference strains and 22 clinical isolates of M. tuberculosis and M. bovis produced very similar DNA banding patterns. They comprised a triplet of prominent and several minor fragments within the 200-500 base pair (bp) size range and were the easiest to interpret. The DNA profiles of unrelated mycobacteria clearly differed from each other when subjected to electrophoretic analysis and correlated well with results of culture method. The method provides a real promise of its application in clinical studies as a simple assay for distinguishing between tubercle bacilli.
Mol Cell Probes 1996 Apr
PMID:Polymerase chain reaction of bacterial genomes with single universal primer: application to distinguishing mycobacteria species. 873 95

Strand displacement amplification (SDA) is an isothermal, in vitro method of amplifying a target DNA sequence. We performed SDA in the presence of a 5'-32P-oligodeoxynucleotide detector probe that contains a target binding sequence at its 3'-end and a recognition site for the restriction enzyme HincII at its 5'-end which is not homologous to the target sequence. The single-stranded probe hybridizes to the rising concentration of amplified product during SDA and is converted to a fully double-stranded form that is cleaved by HincII, releasing a 32P-labelled 5-mer fragment. Uncleaved probe (42-mer) and cleaved probe (5-mer) were separated by either gel electrophoresis or size exclusion filtration using a commercially available microcentrifuge device. The combined SDA/filtration protocol is simple and provides detection of as few as 10 molecules of target DNA. We applied the technique to detection of M. tuberculosis DNA.
Mol Cell Probes 1995 Dec
PMID:A DNA probe assay using strand displacement amplification (SDA) and filtration to separate reacted and unreacted detector probes. 880 10

One of the mechanisms of isoniazid resistance to Mycobacterium tuberculosis has been proved to be the chromosomal deletion of katG. Based on this finding, 22 isoniazid-resistant isolates of M. tuberculosis obtained in Japan and Yemen were analysed for katG by polymerase chain reaction and catalase activity. Only six (27%) of the 22 isolates were compatible with the mechanism (lack of amplification of katG and loss of catalase activity). In contrast, eight isolates (36%) were katG positive but catalase activity-negative and eight (36%) were positive for both factors, indicating that isoniazid resistance is multifactorial and the deletion of katG was not the major cause of resistance in the isolates examined in this study.
Mol Cell Probes 1995 Dec
PMID:KatG sequence deletion is not the major cause of isoniazid resistance in Japanese and Yemeni Mycobacterium tuberculosis isolates. 880 14

Although the polymerase chain reaction (PCR) has been used increasingly for rapid diagnosis of tuberculosis (TB) in clinical specimens, no consensus exists regarding DNA extraction protocols. We compared a simple boiling method to a conventional, labor-intensive chemical method using lysozyme and silica particles. The boiling method was performed in less than 30 min; the chemical method required at least 6 h. A total of 82 clinical specimens (mostly respiratory) from 77 patients were obtained after routine processing from the microbiology laboratory. After DNA extraction by each method, PCR was performed to detect the 123-bp segment of IS6110, and results were compared to culture. Of 20 culture-positive specimens, 17 (85%) and 12 (60%) were positive by boiling and chemical methods, respectively. Of 62 culture-negative specimens, 61 (98%) and 57 (92%) were negative by boiling and chemical methods, respectively. The sensitivity was 100 and 92% for the boiling and chemical methods, respectively, for smears containing more than rare AFB. Our results suggest that boiling method of DNA extraction is more sensitive and no less specific than a conventional chemical method. Larger studies including a variety of clinical specimens are necessary to standardize the optimal conditions of PCR for diagnosis of M. tuberculosis.
Biochem Mol Med 1996 Feb
PMID:Polymerase chain reaction for diagnosis of M. tuberculosis: comparison of simple boiling and a conventional method for DNA extraction. 881 20

Disseminated Mycobacterium avium-Mycobacterium intracellulare disease is a prevalent opportunistic infection in patients with acquired immune deficiency syndrome (AIDS). These pathogens are generally resistant to isoniazid (INH), a powerful antituberculosis drug. It is now generally accepted that the INH susceptibility of Mycobacterium tuberculosis results from the transformation of the drug into a toxic derivative, as a result of the action of the enzyme catalase-peroxidase (HPI), encoded by the katG gene. It has been speculated that the presence of a second catalase (HPII) in some mycobacterial species, but lacking in M. tuberculosis, may impair the action of INH. In this report, the nucleotide sequence of the M. avium katE gene, encoding catalase HPII, is described. This enzyme shows strong similarity to Escherichia coli catalase HPII and eukaryotic catalases. All amino acids previously postulated as participating directly in catalysis by liver catalase and most of the amino acids binding the prosthetic group are conserved in M. avium catalase HPII. The enzyme is expressed in E. coli and is inhibited by 3-amino-1,2,4-triazole (AT). Furthermore, Southern blot hybridizations and polymerase chain reaction experiments demonstrate the distribution of katE gene in several mycobacterial species. To evaluate the potentially antagonistic effect of HPII catalase on INH susceptibility, the katE gene was transformed into M. tuberculosis H37Rv and the minimum inhibitory concentration (MIC) for INH was determined. Despite strong expression of the katE gene, no change in MIC was observed, thus ruling out a possible contribution of this enzyme to the natural resistance of M. avium to the drug. The availability of the gene probe, encoding the second mycobacterial catalase HPII, should open the way for the development of new drugs and diagnostic tests to combat drug-resistant pathogen strains.
Mol Microbiol 1996 Jan
PMID:The katE gene, which encodes the catalase HPII of Mycobacterium avium. 882 41

A gene conferring low-level isoniazid (INH) resistance on Mycobacterium smegmatis was isolated from a cosmid library of the genome of an INH-resistant Mycobacterium bovis strain. The gene had good homology with ahpC, the product of which is a subunit of alkyl hydroperoxide reductase, and also with a family of thiol-specific antioxidant enzymes. A mutation was found in the promoter upon comparison with the equivalent DNA sequence from the INH-sensitive parent strain. Promoter sequences from other INH-sensitive and INH-resistant M. bovis and Mycobacterium tuberculosis strains were sequenced and the mutation was found only in the INH-resistant strains. An INH-resistant M. tuberculosis strain also had an additional mutation in the promoter region. The wild-type promoter and promoters with one and two mutations were ligated into a reporter plasmid containing the lacZ gene. The presence of the first mutation resulted in a sixfold induction of beta-galactosidase activity, and the presence of both mutations caused a 10-fold induction. Increased expression of AhpC may account for some of the INH resistance of strains of the M. tuberculosis complex.
Mol Microbiol 1996 Mar
PMID:ahpC, a gene involved in isoniazid resistance of the Mycobacterium tuberculosis complex. 883 Feb 60

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB) is thought to infect a quarter of the world's population and accounts for 3 million deaths each year. Leprosy, caused by Mycobacterium leprae continues to afflict millions. In many countries, the incidence of TB is increasing due to its association with acquired immune deficiency syndrome (AIDS) and the emergence of multidrug resistance strains of tubercle bacilli. Genes that encode major antigens, enzymes, potential virulence determinants and drug resistance in mycobacteria have been isolated and characterized; however, further genetic analysis of pathogenic mycobacteria has been severely hampered by the difficulty in precisely defining the phenotype of both wild-type and mutant genes by utilizing homologous recombination to perform allele exchange. Recombination mechanisms have been intensely studied in Escherichia coli but it is unclear how far mechanistic pathways elucidated in this species are applicable to other organisms, such as mycobacteria. The aim of this review is to examine what is currently known about homologous recombination in mycobacteria. A model is proposed to account for both low levels of homologous recombination and high levels of illegitimate recombination found in the tubercle bacillus.
Mol Microbiol 1996 Jul
PMID:Recombination in mycobacteria. 885 76


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