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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A numerical taxonomic classification study was carried out on 177 strains representing the "rhodochrous" complex and the genera Gordona, Mycobacterium and Nocardia. The strains were examined for 92 unit characters and the data were analysed by computer. Three clusters were defined at the 75 to 80% similarity level. The first was a heterogeneous cluster corresponding to the "rhodochrous" taxon whereas the other two contained Mycobacterium and Nocardia strains respectively. The good correlation between the numerical analysis and chemo-taxonomic, serological and genetical data collected from previous studies provides sufficient evidence for raising the "rhodochrous" taxon to generic status. We consider the generic name Rhodococcus Aopf to have priority over Proactinomyces (Jensen) Bradley & Bond, Jensenia Bisset & Moore and Gordona Tsukamura. In addition to the type species, Rhodococcus rhodochrous, nine species are recognized: R. bronchialis, R. coprophilus, R. corallinus, R. erythropolis, R. equi, R. rhodnii, R. rubrus, R. rubropertinctus and R. terrae.
J Gen Microbiol 1977 May
PMID:The actinomycete-genus Rhodococcus: a home for the "rhodochrous" complex. 87 50

A pseudolysogenic Mycobacterium chelonei and its phage phi630 are described. Phage phi630 is the first mycobacteriophate reported to be resistant to the nonpolar solvents chloroform, dioxan and diethyl ether. The phage had a latent period of 75 min, a rise period of 90 min and a burst size of 5I. Evidence is presented for host modification and restriction. Phage phi630A, grown on host strain M. chelonei F-630 Rg, plated on the alternative host M. smegmatis ATCC607 with an efficiency of plating (e.o.p.) of 10(-5). Phage phi630B, grown on host M. smegmatis, plated with an e.o.p. of 10(-5) on the alternative host F-630 Rg. Phages phi630A and phi630B absorbed equally well on their alternative hosts and on their indicator host strains. The progeny of plaques from initial platings on the alternative host, when grown in the alternative host, exhibited a marked reduction in e.o.p. on their original host.
J Gen Microbiol 1977 Apr
PMID:Host modification and restriction with a mycobacteriophage isolated from a pseudolysogenic Mycobacterium chelonei. 87 54

Menaquinones were the only isoprenoid quinones found in 48 corynebacteria and actinomycete strains examined. Dihydromenaquinones having nine isoprene units were the main components isolated from Gordona, Mycobacterium, Corynebacterium bovis, Corynebacterium glutamicum and a strain labelled Nocardia farcinica, but dihydromenaquinones having eight isoprene units were characteristic of other Corynebacterium species and representatives of the 'rhodochrous' complex. Tetrahydromenaquinones having six and eight isoprene units were found in Nocardia strains and in a single strain of Micropolyspora brevicatena, which also contained mycolic acids similar in chain length to those of Nocardia. Menaquinones having nine isoprene units with from one to five double bonds hydrogenated were the main components in Actinomadura madurae, Actinomadura pelletieri, Micropolyspora faeni, Oerskovia turbata and Streptomyces strains. Actinomadura dassonvillei strains had a characteristic pattern of di-, tetra- and hexahydromenaquinones with 10 isoprene units which was slightly different from the pattern in mixtures of similar quinones from Actinomyces israelii and Actinomyces viscosus.
J Gen Microbiol 1977 Jun
PMID:Distribution of menaquinones in actinomycetes and corynebacteria. 89 61

The methyl esters of free mycolic acids from representative strains of Nocardia asteroides, N. brasiliensis, N. caviae and the 'rhodochrous' complex were subjected to detailed mass spectral analysis. The anhydromycolic esters of the Nocardia strains consisted of homologous series containing from zero to three double bonds, with the main components of the parent mycolic acids centred on C52 to C54 (range C46 to C58). The anhydromycolates from one rhodochrous strain, Nocardia opaca, had a molecular weight range similar to the nocardiae (C46 to C57) but the remaining rhodochrous strains gave an homologous series of anhydromycolates containing from zero to two double bonds, with the main components of the parent mycolic acids centred on C38, C42, C44 or C46 (total range from C34 to C50). The mycolic acids from the rhodochrous strains with chain lengths centred around C40 form a group intermediate in size between corynomycolic acids (centred around C32) and nocardomycolic acids (centred around C50). These data weaken the case for retaining the 'rhodochrous' complex in the genus Mycobacterium, and also show that many rhodochrous strains can be distinguished from true nocardiae and corynebacteria. These results confirm the value of lipid characters in the classification of these organisms.
J Gen Microbiol 1976 Jan
PMID:Free mycolic acids as criteria in the classification of Nocardia and the 'rhodochrous' complex. 110 81

The methyl esters of free mycolic acids from representative strains of Gordona bronchialis, G. rubra, G. terrae and Nocardia kirovani each gave, on mass spectroscopy, homologous series of anhydromycolic esters containing from one to four double bonds with the main components of the parent mycolic acids centered on 56, 58, 62 or 64 carbon atoms (total range from C52 to C66). The mycolic acids from the Gordona strains, with chain lengths centered around C60, form a group intermediate in size between nocardomycolic acids (centered around C50) and mycolie different from those of the 'rhodochrous' complex which have anhydromycolates ranging from C34 to C50. Gordonae are thus more closely related in their mycolic acid composition to Nocardia than to Mycobacterium but can be distinguished from each of these genera.
J Gen Microbiol 1976 Jan
PMID:Free mycolic acids as criteria in the classification of Gordona and the 'rhodochrous' complex. 124 38

The novel mycobacterial insertion sequence IS900 was analysed by coupled transcription-translation, of both strands independently, in a cell-free E. coli extract using an exogenous promoter. This revealed only one protein product, p43, as predicted from the nucleotide sequence. The protein was readily translated in recombinant E. coli, using the tac promoter, though it did not appear as a major product by SDS-PAGE analysis. A synthetic peptide was used to generate and affinity-purify a specific anti-p43 antibody, which clearly identified the protein in recombinant E. coli. p43 was relatively stable in exponential phase and stationery phase bacteria, though a 28 kDa processed form was seen to accumulate over a period of hours. Both forms appeared in the soluble fraction of the bacterial lysate. The anti-p43 antibody also identified p43, as a 28 kDa processed product, in Western blots of protein extracts from Mycobacterium paratuberculosis, indicating a level of expression which would be unusually high for a classical transposase. These data have important implications for the relationship between IS900 and its host.
J Gen Microbiol 1992 Aug
PMID:p43, the protein product of the atypical insertion sequence IS900, is expressed in Mycobacterium paratuberculosis. 132 96

The activation of catalase genes in response to oxidative stress may contribute to the intracellular survival of mycobacteria. In this report, the nucleotide sequence of a mycobacterial catalase gene is described. The deduced protein sequence of this Mycobacterium intracellulare gene (MI85) was 60% identical to the Escherichia coli hydroperoxidase I (HPI) protein, 59% identical to the Salmonella typhimurium (HPI) catalase, and 47% identical to a Bacillus stearothermophilus peroxidase. The MI85 protein, expressed in E. coli, has also been shown to have peroxidase and catalase activities. Furthermore, Southern blot hybridizations, which demonstrated that a MI85 gene probe hybridizes with chromosomal DNA from thirteen different strains of mycobacteria, suggest that this catalase-peroxidase gene is prevalent in the mycobacterial genus. The availability of catalase gene probes should permit an evaluation, at the molecular level, of the role of catalase in mycobacterial pathogenesis.
J Gen Microbiol 1992 Nov
PMID:The catalase-peroxidase of Mycobacterium intracellulare: nucleotide sequence analysis and expression in Escherichia coli. 133 34

An insertion sequence element of Mycobacterium avium subsp. silvaticum was isolated and its complete nucleotide sequence determined. IS902 is 1470 bp in size and is repeated 10-12 times per genome. An open reading frame of 1200 bp was identified, encoding a protein product of Mr 43932. This protein is highly similar to the predicted proteins of IS900 of Mycobacterium paratuberculosis, IS116 of Streptomyces clavuligerus and IS110 of Streptomyces coelicolor. IS902 lacks terminal inverted repeats and flanking direct repeats but displays insertion site specificity.
J Gen Microbiol 1992 Jan
PMID:IS902, an insertion element of the chronic-enteritis-causing Mycobacterium avium subsp. silvaticum. 134 67

We present a computerized pattern recognition model used to speciate mycobacteria based on their restriction fragment length polymorphism (RFLP) banding patterns. DNA fragment migration distances were normalized to minimize lane-to-lane variability of band location both within and among gels through the inclusion of two internal size standards in each sample. The computer model used a library of normalized RFLP patterns derived from samples of known origin to create a probability matrix which was then used to classify the RFLP patterns from samples of unknown origin. The probability matrix contained the proportion of bands that fell within defined migration distance windows for each species in the library of reference samples. These proportions were then used to compute the likelihood that the banding pattern of an unknown sample corresponded to that of each species represented in the probability matrix. As a test of this process, we developed an automated, computer-assisted model for the identification of Mycobacterium species based on their normalized RFLP banding patterns. The probability matrix contained values for the M. tuberculosis complex, M. avium, M. intracellulare, M. kansasii and M. gordonae species. Thirty-nine independent strains of known origin, not included in the probability matrix, were used to test the accuracy of the method in classifying unknowns: 37 of 39 (94.9%) were classified correctly. An additional set of 16 strains of known origin representing species not included in the model were tested to gauge the robustness of the probability matrix. Every sample was correctly identified as an outlier, i.e. a member of a species not included in the original matrix.(ABSTRACT TRUNCATED AT 250 WORDS)
J Gen Microbiol 1992 Nov
PMID:Computer-assisted pattern recognition model for the identification of slowly growing mycobacteria including Mycobacterium tuberculosis. 136 11

Mycobacterium tuberculosis H37Rv has a single rrn (ribosomal RNA) operon. The operon was cloned and a region of 1536 nucleotides was sequenced, starting 621 bp upstream from the 5'-end of the 16S rRNA coding region and continuing to the start of the 23S rRNA coding region. The 16S rRNA sequence inferred from the gene sequence was found to differ in one position from Mycobacterium bovis (nucleotide 1443) and from Mycobacterium microti (nucleotide 427). A single putative promoter was identified on the basis of similarities with the sequence of rrn operons of Bacillus subtilis and Escherichia coli. The regions of similarity include a -35 box, a -10 box, a stringent response element, antitermination signals, potential RNAase III processing sites and features of precursor rRNA secondary structure. Sequences upstream from the 5'-end of Mycobacterium leprae 16S rRNA were also investigated. Homologous schemes of secondary structure were deduced for precursor rRNA of both M. tuberculosis and M. leprae; although the principal features are common to both species there are notable differences.
J Gen Microbiol 1992 Aug
PMID:The nucleotide sequence of the promoter, 16S rRNA and spacer region of the ribosomal RNA operon of Mycobacterium tuberculosis and comparison with Mycobacterium leprae precursor rRNA. 138 14


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