Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Most strains of the Mycobacterium tuberculosis complex carry multiple copies of an IS3-like element, and these strains are highly polymorphic with regard to the site of integration in the chromosome. In contrast, Mycobacterium bovis BCG contains a single copy of the insertion element, and in all strains this copy is integrated at the same site in the chromosome. In this study, we determined the sequence of the single-copy insertion element from M. bovis BCG, IS987, and its flanking regions. The analysis of IS987 revealed that this element was virtually identical to the sequence of IS986 from M. tuberculosis. IS987 is located in a region containing direct repeats (DRs). The cloned flanking regions contained 20 virtually identical DRs of 36 bp, each separated by 35 to 41 bp of spacer DNA. Analysis of chromosomal DNA by the polymerase chain reaction revealed the presence of a cluster of 49 DRs, and IS987 is inserted in the 30th DR. Furthermore, the DR sequences were found to occur only in species of the M. tuberculosis complex and not in nine other mycobacterial species tested. Analysis of 14 M. tuberculosis strains revealed the presence of one insertion sequence element in the DR-containing region of eight strains, two insertion sequence elements were located in the DR region of five strains, and one strain did not contain an insertion sequence element in this region. Additionally, the DR-containing regions of these 14 M. tuberculosis strains were polymorphic in length and composition. We conclude that the DR cluster is a specific, hot-spot region for integration of insertion elements in the chromosome of M. tuberculosis complex strains.
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PMID:Insertion element IS987 from Mycobacterium bovis BCG is located in a hot-spot integration region for insertion elements in Mycobacterium tuberculosis complex strains. 164 98

IS986 of Mycobacterium tuberculosis belongs to the IS3-like family of insertion sequences, and it has previously been shown to be present in multiple copies in the chromosome of M. tuberculosis. In this study we investigated the value of a IS986-based DNA probe in the diagnosis and epidemiology of tuberculosis. IS986 was found only in species belonging to the M. tuberculosis complex. Independent isolates of M. tuberculosis complex strains showed a very high degree of polymorphism of restriction fragments which contained IS986 DNA. In contrast, Mycobacterium bovis BCG vaccine strains as well as clinical isolates of M. bovis BCG contained one copy of IS986, which was present at the same location in the chromosome. Different M. tuberculosis isolates from a recent M. tuberculosis outbreak showed an identical banding pattern. We concluded that IS986 is an extremely suitable tool for the diagnosis and epidemiology of tuberculosis.
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PMID:Insertion element IS986 from Mycobacterium tuberculosis: a useful tool for diagnosis and epidemiology of tuberculosis. 197 65

A repetitive element (IS986), previously isolated from Mycobacterium tuberculosis and shown to detect multiple restriction fragment-length polymorphisms (RFLPs), has been sequenced. It consists of a potential insertion sequence of 1358bp, with 30-bp inverted repeat ends. IS986 has four potentially significant open reading frames (ORFs): ORFa1, ORFa2 and ORFb on one strand and ORFc on the complementary strand. The sequences of the potential translated products identify IS986 as a member of the IS3 family, with an apparent frameshift between ORFa1 and ORFa2. IS986 has potential as a highly specific probe for detection and typing of M. tuberculosis, as well as for transposon mutagenesis of mycobacteria. The sequence of IS986 is virtually identical to that of another recently described element, IS6110 (Thierry et al., 1990).
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PMID:Characterization of a Mycobacterium tuberculosis insertion sequence belonging to the IS3 family. 198 Oct 88

An insertion sequence-like element, IS6110, was isolated from a Mycobacterium tuberculosis cosmid library as a repetitive sequence. IS6110 shows similarities with elements of the IS3 family. This insertion sequence was found to be specific to mycobacteria belonging to the M. tuberculosis complex. For detection and identification of M. tuberculosis bacilli in uncultured specimens, oligonucleotides derived from the IS6110 sequence were used as primers and probes in polymerase chain reaction studies. The results obtained were consistent with results of classical identification procedures, bacteriological data, and clinical criteria.
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PMID:Characterization of a Mycobacterium tuberculosis insertion sequence, IS6110, and its application in diagnosis. 217 47

A new insertion sequence (IS) has been isolated from Mycobacterium smegmatis. It is 1361 bp long and possesses characteristics of the IS3 family elements. It harbours 32 bp imperfect inverted repeats at its extremities and a 3 bp direct repeat flanks the element, possibly as the result of a transposition event. This IS, IS1137, contains three major ORFs. Two of them, ORF A and ORF B show homologies both at the amino acid sequence level and at the organization level with the ORFs encoding the transposase of the IS3 family elements. IS1137 has a narrow host range and was found only in M. smegmatis and M. chitae. The fact that IS1137 is not present in the M. tuberculosis complex strains makes this element a new candidate for transposon mutagenesis in mycobacteria.
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PMID:Insertion sequence IS1137, a new IS3 family element from Mycobacterium smegmatis. 800 May 45

IS6100 is an insertion sequence of the IS3 family and it is present in multiple copies in the chromosome of Mycobacterium tuberculosis. Four to 15 copies are present in various strains of M. tuberculosis. In this study, the value of IS6110 as an epidemiological marker of tuberculosis was examined. Unrelated clinical strains from Greek patients presented, in restriction fragment length polymorphism analysis, a high degree of polymorphism, whereas patterns of related clinical strains from familial outbreaks were identical. Since RFLP analysis with acetylaminofluorene labeled IS6110 as the probe gave satisfactory results, it is suggested that this non-radioactive probe can be used in hospitals and health centres for the epidemiological survey of M. tuberculosis infections.
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PMID:Use of the insertion element IS6110 for DNA fingerprinting of Mycobacterium tuberculosis isolates presenting various profiles of drug susceptibility. 809 74

The structure and distribution of 1S990, a new Mycobacterium tuberculosis DNA sequence with homology to characterized insertion sequences (ISs), were investigated. IS990 was related to IS elements of the IS3 family and was present as a single copy in all 21 investigated M. tuberculosis strains, two Mycobacterium bovis strains and two M. bovis BCG strains. The sequence appears to be specific for the M. tuberculosis complex. The element carries two frameshift mutations and appears to be defective.
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PMID:IS990, a new species-specific insertion-sequence-related element of the Mycobacterium tuberculosis complex. 988 33

The genome sequence of Mycobacterium tuberculosis H37Rv was found to contain 56 loci with homology to insertion sequences (ISs). As well as the previously described IS6110, IS1081, IS1547 and IS-like elements, new ISs belonging to the IS3, IS5, IS21, IS30, IS110, IS256 and ISL3 families were identified. In addition, six ISs created a grouping of their own to form a new family (the IS1535 family). Elements with similarity to ISs in other actinomycetes were identified, suggesting the movement of ISs between related genera. The location of ISs on the chromosome revealed that an approximately 600 kb region close to the origin of replication lacks ISs, pointing to the possible detrimental effect of insertions in this area. Analysis of the distribution of ISs through the tubercle strains Mycobacterium africanum, M. microti, M. bovis, M. bovis BCG Pasteur, M. tuberculosis H37Ra, M. tuberculosis CSU#93 and 29 clinical isolates revealed that only IS1532, IS1533, 1S1534, and IS1561' were absent from some of the strains tested. A novel repeated sequence, the REP13E12 family, is described that is present in seven copies on the M. tuberculosis H37Rv chromosome and which contains a probable phage attachment site. This study therefore offers an insight into the possible role of ISs and repetitive elements in the evolution of the M. tuberculosis genome, as well as identifying genetic markers that may be useful for phylogenetic and epidemiological analysis of the tubercle complex.
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PMID:New insertion sequences and a novel repeated sequence in the genome of Mycobacterium tuberculosis H37Rv. 1022 Jan 67

The Mycobacterium tuberculosis-specific insertion sequence IS6110/986 has been widely used as a probe because of the multiple polymorphism observed among different strains. To investigate transposition of IS6110, a series of artificially constructed composite transposons containing IS6110 and a kanamycin resistance marker were constructed. The composite transposons were inserted into a conditionally replicating, thermosensitive, Escherichia coli-mycobacterial shuttle vector and introduced into M. smegmatis mc2155. Lawns of transformants were grown at the permissive temperature on kanamycin-supplemented agar and subsequently prevented from further growth by shifting to the non-permissive temperature. Under normal atmospheric conditions, kanamycin-resistant papillae appeared after only about 5-6 weeks of incubation. However, these events were not associated with transposon mobilization. In contrast, lawns that were exposed to a 48 h microaerobic shock generated kanamycin-resistant papillae after only 6-14 days. These events were generated by conservative transposition of the IS6110 composite transposon into the M. smegmatis chromosome, with loss of the shuttle vector. In common with other IS3 family elements, transposition of IS6110 is thought to be controlled by translational frameshifting. However, we were unable to detect any significant frameshifting within the putative frameshifting site of IS6110, and the level of frameshifting was not affected by microaerobic incubation. The finding that transposition of IS6110 is stimulated by incubation at reduced oxygen tensions may be relevant to transposition of IS6110 in M. tuberculosis harboured within TB lesions.
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PMID:Stimulation of transposition of the Mycobacterium tuberculosis insertion sequence IS6110 by exposure to a microaerobic environment. 1047 32

Renibacterium salmoninarum, a slowly growing, Gram-positive bacterium, is responsible for bacterial kidney disease in salmonid fishes world-wide. To date, no mobile genetic elements have been reported for this pathogen. Here, we describe the first insertion sequence (IS) identified from R. salmoninarum. This element, IS994, has a significant predicted amino acid sequence homology (64.8 and 71.9%) to the two open reading frames encoding the transposase of IS6110 of Mycobacterium tuberculosis. Protein parsimony and protein distance matrix analyses show that IS994 is a member of group IS51 of the IS3 family. From a conservative estimate, there are at least 17 chromosomal insertions of IS994 or closely related elements. Sequence analysis of seven of these loci reveals single nucleotide polymorphisms throughout the element (including the terminal inverted repeats), a 15bp insertion in three of the seven loci, and an absence of flanking direct repeats or conserved insertion site. Restriction fragment length polymorphism analysis of XbaI-digested chromosomal DNA shows variations among European and North American isolates, indicating that IS994 may be a useful molecular marker for epizootiological studies.
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PMID:Description and characterization of IS994, a putative IS3 family insertion sequence from the salmon pathogen, Renibacterium salmoninarum. 1068 92


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