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

Many bacterial responses to environmental stimuli are mediated by response regulators which coordinately regulate genes involved in particular adaptive responses. Degenerate oligonucleotide primers were used to amplify by the polymerase chain reaction (PCR), fragments from genes encoding eleven novel response regulators. Sequence and phylogenetic analysis revealed that phoB, phoP and creB gene fragments had been amplified from Yersinia enterocolitica and Yersinia pseudotuberculosis, and that a creB sequence had been amplified from Campylobacter jejuni. Four amplified fragments from C. jejuni, Listeria monocytogenes, Mycobacterium tuberculosis and Escherichia coli clearly came from response regulator genes, but were not closely related to any of the known genes. Mutagenesis of the newly identified genes should allow us to determine their function and the genes under their control.
 ...
PMID:Degenerate PCR primers for the amplification of fragments from genes encoding response regulators from a range of pathogenic bacteria. 149 Jun 12

Culture studies have suggested that Mycobacterium paratuberculosis may play a role in the aetiology of Crohn's disease. However, evidence of sensitization to mycobacterial antigens amongst patients with Crohn's disease has not yet been adequately demonstrated. Previous studies of cell-mediated immunity (CMI) in Crohn's disease were restricted to responses of peripheral blood mononuclear cells (PBMC) to mycobacterial antigens. In this study we have investigated the proliferative responses of both PBMC and mesenteric lymph node mononuclear cells (MLNMC) to a range of mycobacterial and non-mycobacterial antigens. There was no evidence of specific sensitization in the responses of MLNMC and PBMC from patients with inflammatory bowel disease (IBD) to the mycobacterial antigens. However, anergy to M. paratuberculosis could not be excluded. IBD MLNMC responses to most antigens were generally greater than those of PBMC, which were often undetectable. When compared with controls, there was evidence of increased CMI to a range of non-mycobacterial antigens, especially Yersinia enterocolitica, amongst both MLNMC and PBMC from patients with Crohn's disease and ulcerative colitis (UC). These results do not provide support to the proposed role of mycobacteria in the pathogenesis of Crohn's disease, but indicate that further investigation may determine a role for bacterial-specific T cell-mediated responses in the pathogenesis of IBD.
 ...
PMID:Mucosal cell-mediated immunity to mycobacterial, enterobacterial and other microbial antigens in inflammatory bowel disease. 173 86

The analysis of literary and own data testifies that the dissociants may appear in bacteria population from spontaneous mutations and transfer of genetic material (conjugation, transformation, transduction). The phage conversion and different DNA reorganizations within a cell where prophage plays an active role, probably introduce the largest contribution into the dissociative transitions of variants which occur with high frequency (about 10(-2)-10(-4). The dissociation of various bacteria has been studied with different degree. The role of temperate phage has been shown in splitting of bacteria into variants in the genera Mycobacterium, Corynebacterium, some Bacillus, Clostridium, Staphylococcus, some enterobacteria, Yersinia, Vibrio Pseudomonas, Rhizobium, Nostoc; the participation of prophage in dissociation of bacteria of the genera Xanthomonas, Erwinia, Bacteroides is proposed. A method for obtaining the nondissociating S-variants for stability of biologically active substances synthesized by cells has been suggested.
 ...
PMID:[Role of temperate phage in bacterial dissociation]. 301 Nov 28

Several microorganisms, including Yersinia sp., Salmonella sp., Brucella sp., Mycobacterium sp. and Leishmania sp., have successfully adapted to grow within macrophage phagolysosomes. Infections caused by these intracellular pathogens are among the most difficult to treat. As part of an antimicrobial strategy directed at modifying the phagolysosomal environment to the disadvantage of these important pathogens, we are defining the ambient conditions within the organism-containing phagolysosome. To probe this environment, we have used Yersinia pestis, whose expression of several virulence attributes is highly dependent on the Ca2+ concentration in its growth environment. We first genetically engineered a strain of Y. pestis which responds to a low-calcium environment by transcription of inserted structural genes of the Escherichia coli lac operon. Using this mutant organism as a relevant biological probe, we demonstrate here that the calcium concentration in Y. pestis-containing phagolysosomes is sufficiently low to permit virulence gene expression; this resolves the question of where Y. pestis might express its Ca2+-regulated genes in vivo.
 ...
PMID:Probing the phagolysosomal environment of human macrophages with a Ca2+-responsive operon fusion in Yersinia pestis. 374 70

A variety of bacterial pathogens including Campylobacter, Yersinia, Listeria, Brucella, and Mycobacteria have been suggested as potential etiologic agents for Crohn's disease. To assess the role of these organisms we studied responses to eight antigens in sera from patients with active Crohn's disease and healthy age- and sex-matched controls. In complement-fixation assays, the sera from the Crohn's disease patients had enhanced reactivity compared with the control sera to all seven orally ingested pathogens studied; however, only the difference in distribution of titers to Yersinia pseudotuberculosis was statistically significant (p less than 0.0025). There was no difference between the two groups in reactivity to arabinomannan, a common mycobacterial antigen. Seroreactivity to enteric pathogens not resident in the bowel flora probably represents a nonspecific sensitization to cross-reacting antigens. Lack of response to the mycobacterial antigen suggests that widespread mycobacterial disease with high bacillary load is not present in Crohn's disease.
 ...
PMID:Patients with active Crohn's disease have elevated serum antibodies to antigens of seven enteric bacterial pathogens. 646 76

To investigate the role of heat shock proteins (HSP) of Yersinia enterocolitica for the host immune response against this pathogen, we cloned and expressed a 60-kDa HSP of Y. enterocolitica serotype O8. A fragment of Y. enterocolitica O8 HSP60 encoded by amino acids 90 to 286 was sequenced and showed more than 90% homology with HSP60 of Y. enterocolitica O3 and GroEL of Escherichia coli and 59% homology with HSP65 of Mycobacterium bovis. The arthritogenic T-cell epitope of mycobacterial HSP65 (amino acid residues 180 to 188) was not found on Yersinia HSP60. To determine whether Yersinia HSP60 is an immunodominant antigen, the immune responses of Yersinia-infected C57BL/6 mice were analyzed. Yersinia-infected mice evolved a significant serum antibody and splenic T-cell response against Yersinia HSP60. CD4+ alpha beta T-cell clones which were generated from splenic T cells isolated from either Yersinia-infected or Yersinia HSP60-immunized mice, recognized both heat-killed Yersinia serotypes O3 and O8 as well as recombinant Yersinia HSP60 but not heat-killed Yersinia pseudotuberculosis, Salmonella typhimurium, or recombinant HSP65 of Mycobacterium bovis. The adoptive transfer of HSP60-reactive T-cell clones mediated significant protection against a lethal infection with Y. enterocolitica O8. These results indicate that HSP60 of Y. enterocolitica is an immunodominant antigen which is recognized by both antibodies and CD4+ alpha beta T cells. Moreover, this is the first report providing direct evidence that microbial HSP may elicit a protective immune response which is not associated with autoimmunity.
 ...
PMID:Protective role for heat shock protein-reactive alpha beta T cells in murine yersiniosis. 791 84

Smooth Brucella spp. share certain lipopolysaccharide antigens with other bacteria, resulting in serological cross-reactions which can prevent the definitive diagnosis of brucellosis. To identify other antigens with serodiagnostic potential, immunoblot studies following sodium dodecyl sulphate-polyacrylamide gel electrophoresis were carried out. Sera from pigs experimentally infected with Brucella suis and naturally infected feral pigs, sera from pigs from a farm with a known history of Yersinia enterocolitica 0:9 infection, Brucella Complement Fixation Test (CFT) reactor pigs (aetiology unknown) and pigs from consistently Brucella CFT negative farms were examined. Although B. suis infected pigs recognized a total of nine B. melitensis antigens, individual pigs rarely recognized more than three antigens in the range. A 62 kDa antigen was recognized by the majority (73%) of the Brucella infected pigs, but only by 10 to 23% of pigs from the other groups. This antigen was shown to be the Brucella homologue of the ubiquitous 65 kDa heat shock protein (HSP-65) family by immunoblot studies with 14 monoclonal antibodies to the Mycobacterium leprae HSP-65. Only four of these monoclones (Y1.2, ML-30, D7C and IIIC8) identified the B. melitensis 62 kDa protein suggesting that unshared, potentially Brucella specific, regions exist. Sera from Y. enterocolitica 0:9 infected pigs, CFT reactor pigs (aetiology unknown), CFT negative pigs and hyperimmune pig serum raised to Y. enterocolitica 0:9 also recognized B. melitensis antigens, most notably a 17 kDa protein. This antigen appears to be a common cross-reactive protein.
 ...
PMID:Immunoblot studies in the differential diagnosis of porcine brucellosis: an immunodominant 62 kDa protein is related to the mycobacterial 65 kDa heat shock protein (HSP-65). 820 27

This review compares the clinical usefulness of immunological methods for the detection of structural components and metabolites of bacteria and fungi. Bacterial antigens (especially those of Mycobacterium, Neisseria, Staphylococcus aureus, Yersinia enterocolitica, Escherichia coli, Salmonella, Chlamydia, and Brucella) are best detected by enzyme-linked immunosorbent assay. Methods involving antibodies are more expensive and are effective only when performed in series. The detection of antibodies that recognize S aureus teichoic acid merely confirms the presence of a metastatic complication. Tissue invasion by Candida albicans is not yet reliably detectable by the presence of a specific antigen. Simple, but not completely reliable methods are available such as the latex test for mannans detection and/or agglutination with liposomes for detecting 48-kDa cytoplasmic protein antigen and an assay for detecting enolase antigen. A latex agglutination test has also been developed for the mannans antigen of Aspergillus and for Cryptococcus neoformans capsular polysaccharide; the latter test is more cost effective. The sensitivity of both tests is improved by serial assays. A negative finding with hemagglutination-based antibody tests rules out C albicans infection, and titers of 1/640 or higher have been associated with disseminated infection by Aspergillus. Concentrations of C albicans blastopore antigen antibodies higher than 400 IU/ml can be seen in disseminated candidiasis. High concentrations of endotoxin are indicative of imminent septic shock. Some biological indicators (C reactive protein, angiotensin converting enzyme, fibronectin, elastase-alpha 1-antitrypsin complex, tumor necrosis factor and interleukin-6) have been used to rule out a bacterial cause of fever.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Immunological methods for the detection of structural components and metabolites of bacteria and fungi in blood. 821 14

A 15-year-old boy who developed acute arthritis following an episode of urethritis, was found to have agglutinating antibodies (titre 1:320) against Yersinia enterocolitica 0:3. Synovial fluid mononuclear cell (SFMC) proliferative responses to this agent and other antigens were examined on four occasions over the subsequent 40 months. Responses to Yersinia were predominant during the first year, but after 29 months responses to purified protein derivative of Mycobacterium tuberculosis and Salmonella were greater than to Yersinia. Moderate responses to a mycobacterial heat shock protein (HSP65) were present throughout the illness. These results suggest that maximal mononuclear cell proliferative responses may change over time, and raise the possibility that responses which are initially specific for the inciting arthritogenic agent may eventually become more generalized.
 ...
PMID:Evolution of synovial fluid mononuclear cell responses in a HLA B27-positive patient with Yersinia-associated juvenile arthritis. 836 2

Analysis of the nucleotide sequence of a gene cloned from a Mycobacterium tuberculosis H37Rv genomic library predicted a 339-amino-acid protein with an M(r) of 37,656. The protein exhibited significant homology with the Cfad, FapR and Rns proteins from different enterotoxigenic strains of Escherichia coli, VirF protein of Shigella and VirFy protein of Yersinia, all of which regulate virulence-associated genes.
 ...
PMID:Sequence of a newly identified Mycobacterium tuberculosis gene encoding a protein with sequence homology to virulence-regulating proteins. 847 58


1 2 3 4 5 6 7 8 9 10 Next >>