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)

The green fluorescent protein (GFP) from Aequorea victoria is a novel fluorescent marker that has potential use in the study of bacterial pathogenicity. To explore some of the potential applications of GFP to the study of host-parasite interactions, we constructed two GFP expression vectors suitable for different facultative intracellular bacterial pathogens. The first expression vector was tested in the enteric pathogens, Salmonella typhimurium and Yersinia pseudotuberculosis, and the second vector tested in Mycobacterium marinum (Mm). Both expression vectors were found to be stable and to direct high levels of GFP synthesis. Standard epifluorescence microscopy was used to detect all three bacterial pathogenic species during the early and late stages of infection of live mammalian cells. Mm expressing gfp was also visualized in infected animal tissues. gfp expression did not adversely affect bacterial survival, nor did it compromise entry into mammalian cells or their survival within macrophages. In addition, all three gfp-expressing bacterial pathogens could be detected and sorted in a flow cytometer, either alone or in association with epithelial cells or macrophages. Therefore, GFP not only provides a convenient tool to image pathogenic bacteria, but allows the quantitative measurement of bacterial association with mammalian cells.
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PMID:Applications for green fluorescent protein (GFP) in the study of host-pathogen interactions. 870 55

Bacteriological isolation of Yersinia pestis is the reference test for confirming plague infection, but recovery of the pathogen from human samples is usually very poor. When the etiology of the disease cannot be bacteriologically confirmed, it may be useful to possess alternative tests such as detection of specific circulating antibodies to help guide the diagnosis. In the present study, the immunoglobulin G (IgG) anti-F1 enzyme-linked immunosorbent assay (ELISA) has been applied to various human sera to evaluate its large-scale applicability in the high-endemicity plague foci of Madagascar. The sensitivity of the test was found to be 91.4%, and its specificity was 98.5%. The positive and negative predictive values were 96 and 96.6%, respectively. Seroconversion was observed on day 7 after onset of the disease. Patients with a positive ELISA result could be separated into high (82%) and low (18%) IgG anti-F1 responders. Cross-reactions with eight other infectious diseases prevalent in Madagascar were scarce and were found in 1 of 27 Mycobacterium tuberculosis-, 3 of 34 Schistosoma haematobium-, and 1 of 41 Salmonella-infected patients. Finally, the efficiency of the IgG anti-F1 ELISA was evaluated during the Mahajanga, Madagascar, plague outbreak of 1995. When the number of ELISA-positive patients was added to the number of bacteriologically confirmed and probable cases, the number of positive patients was increased by 35%. In conclusion, although it does not replace bacteriology, IgG anti-F1 ELISA is a useful and powerful tool for retrospective diagnosis and epidemiological surveillance of plague outbreaks.
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PMID:Field evaluation of an immunoglobulin G anti-F1 enzyme-linked immunosorbent assay for serodiagnosis of human plague in Madagascar. 930 10

An ambitious programme to eliminate pork as an important source of human salmonellosis was initiated in Denmark in 1993 by the Ministry of Food, Agriculture and Fisheries. The programme comprises control of feedmills, breeding and multiplying herds, slaughter herds and slaughter plants, as well as the final product, fresh pork. As a consequence, the level of occurrence of Salmonella spp. in fresh pork produced in Denmark is approximately 1%. Yersinia enterocolitica 0:3 infections are common in slaughter pig herds in Denmark, and pork is considered to be the only source of human infection in the country. The incidence of pork-related occurrences of human salmonellosis and yersiniosis in 1996 was approximately nine cases per 100,000 inhabitants for both diseases. All swine in Denmark are screened for Trichinella spp. infection, although no positive results have been obtained since 1930. Swine are not considered to be a source for Campylobacter jejuni or enterohaemorrhagic Escherichia coli in Denmark. Listeria monocytogenes can be detected in relatively high rates in pork: however, the incidence of human listeriosis is only 0.5 cases per 100,000 inhabitants. Toxoplasma gondii antibodies have been demonstrated in 3% of slaughter pigs, though the importance of pork as a source of infection is probably very low. Denmark is officially free from Brucella abortus, B. melitensis and Mycobacterium bovis.
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PMID:Public health and pork and pork products: regional perspectives of Denmark. 950 65

This article presents an update of several emerging or reemerging pathogens: Yersinia, Cryptosporidia, Cyclospora, Brucella, and Mycobacterium. All of these zoonotic pathogens show evidence of food borne transmission. Yersiniosis is presented as an emerging pathogen that has as its major route of transmission preparation and consumption of pork products. New evidence is presented that supports the transmission of brucellosis via the food chain, especially through contaminated raw milk and cheese. While TB has limited transmission via raw milk, it is highlighted as a reemerging infection due to the development of multiple drug resistance. Public health veterinarians stand in an excellent position to recognize these emerging diseases and apply intervention strategies to prevent and control these infections in the future. This article is intended to raise their consciousness as to the management and medical practices that can diminish food borne transmission.
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PMID:Other food borne infections. 953 68

The data base (DB) "Primers of microorganisms" for the accumulation and systematization of information on oligonucleotide sequences, used as primers in polymerase chain reaction, has been created. This DB includes data on primers for the laboratory diagnostics of 20 bacterial genera (Aerococcus, Aeromonas, Bartonella, Borrelia, Burkholderia, Chlamydia, Clostridium, Corynebacterium, Escherichia, Francisella, Helicobacter, Legionella, Listeria, Mycobacterium, Mycoplasma, Salmonella, Shigella, Staphylococcus, Vibrio, Yersinia) and 6 viral families (Arenaviridae, Flaviviridae, Hepadnaviridae, Herpesviridae, Picornaviridae, Retroviridae). DB contains data on 145 pairs of primers and 530 bibliographic sources. The retrospective depth of DB is 10 years (1987-1996), and it is replenished as new Russian and foreign documented sources of information arrive.
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PMID:[Database on nucleotide sequences used as primers of microorganisms]. 982 98

Molecular analysis of Mycobacterium ulcerans has revealed two new insertion sequences (ISs), IS2404 and IS2606. IS2404 was identified by complete sequencing of a previously described repetitive DNA segment from M. ulcerans. This element is 1,274 bp long, contains 12-bp inverted repeats and a single open reading frame (ORF) potentially encoding a protein of 327 amino acids (aa), and apparently generates 7-bp direct repeats upon transposition. Amino acid similarity was found between the putative transposase and those encoded by ISs in other bacterial sequences from Aeromonas salmonicida (AsIs1), Escherichia coli (H repeat element), Vibrio cholerae (VcIS1), and Porphyromonas gingivalis (PGIS2). The second IS, IS2606, was discovered by sequence analysis of a HaeIII fragment of M. ulcerans genomic DNA containing a repetitive sequence. This element is 1,404 bp long, with 12-bp inverted repeats and a single ORF potentially encoding a protein of 445 aa. Database searches revealed a high degree of amino acid identity (70%) with the putative transposase of IS1554 from M. tuberculosis. Significant amino acid identity (40%) was also observed with transposases from several other microorganisms, including Rhizobium meliloti (ISRm3), Burkholderia cepacia (IS1356), Corynebacterium diphtheriae, and Yersinia pestis. PCR screening of DNA from 45 other species of mycobacteria with primers for IS2404 confirm that this element is found only in M. ulcerans. However, by PCR, IS2606 was also found in Mycobacterium lentiflavum, another slow-growing member of the genus Mycobacterium that is apparently genetically distinct from M. ulcerans. Testing the sensitivity of PCR based on IS2404 and IS2606 primers demonstrated the ability to detect 0.1 and 1 M. ulcerans genome equivalents, respectively. The ability to detect small numbers of cells by using two gene targets will be particularly useful for analyzing environmental samples, where there may be low concentrations of M. ulcerans among large numbers of other environmental mycobacteria.
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PMID:Identification and characterization of IS2404 and IS2606: two distinct repeated sequences for detection of Mycobacterium ulcerans by PCR. 1007 20

We have previously reported the identification of a gene from Mycobacterium tuberculosis, H37Rv, which on the basis of its nucleotide sequence encoded a protein product of 38 kDa. This 38-Kda mycobacterial protein designated as VirS exhibits homology with the VirF protein of Shigella, the VirFy protein of Yersinia and the Cfad, Rns and FapR proteins from various enterotoxigenic Escherichia coli strains. In this communication, we show the close sequence and structural similarities of the VirS protein with VirF, VirFy, Cfad, Rns and FapR and describe the results of our studies on the characterization of the virS gene promoter and its expression in E. coli and mycobacteria. virS was present exclusively in the species belonging to the M. tuberculosis complex as revealed by Southern blot and PCR analysis. Our findings suggest the involvement of virS in the regulation of pathogenesis of M. tuberculosis.
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PMID:Analysis, expression and prevalence of the Mycobacterium tuberculosis homolog of bacterial virulence regulating proteins. 1018 41

Yersinia pseudotuberculosis survived and multiplied in the phagosomes of B10.A mouse peritoneal macrophages. As one of the possible mechanisms for the bacteria's survival in the phagosomes, we demonstrated that live Y. pseudotuberculosis inhibited the phagosomal acidification; pH within phagosomes containing the live Y. pseudotuberculosis remained at about 6.0, whereas pH within phagosomes containing the dead Y. pseudotuberculosis fell to about 4. 5. This ability to inhibit intraphagosomal acidification was also shared by mutants lacking the 42 Md virulence plasmid, indicating that it is chromosomally encoded. The phagosomes containing dead bacteria raised the pH to 6.2 after the treatment of their macrophages with an inhibitor (bafilomycin A1) specific for V-ATPase. Although the amount of V-ATPase in the A and B subunits on the phagosomes was not significantly different between the live and dead bacteria infection, the phagosomes containing live bacteria had a 10-fold smaller V-ATPase activity than those containing the dead bacteria. These results indicated that the inhibition of phagosomal acidification by Y. pseudotuberculosis infection was due to the attenuation of V-ATPase activity, and not due to the exclusion of V-ATPase subunits from the phagosome membrane as found in Mycobacterium avium.
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PMID:Yersinia pseudotuberculosis blocks the phagosomal acidification of B10.A mouse macrophages through the inhibition of vacuolar H(+)-ATPase activity. 1050 66

Specialized epithelia known as M cells overlying the lymphoid follicles of Peyer's patches are important in the mucosal immune system, but also provide a portal of entry for pathogens such as Salmonella typhimurium, Mycobacterium bovis, Shigella flexneri, Yersinia enterocolitica and reoviruses. Penetration of intestinal M cells and epithelial cells by Salmonella typhimurium requires the invasion genes of Salmonella Pathogenicity Island 1 (SPI1). SPI1-deficient S. typhimurium strains gain access to the spleen following oral administration and cause lethal infection in mice without invading M cells or localizing in Peyer's patches, which indicates that Salmonella uses an alternative strategy to disseminate from the gastrointestinal tract. Here we report that Salmonella is transported from the gastrointestinal tract to the bloodstream by CD18-expressing phagocytes, and that CD18-deficient mice are resistant to dissemination of Salmonella to the liver and spleen after oral administration. This CD18-dependent pathway of extraintestinal dissemination may be important for the development of systemic immunity to gastrointestinal pathogens, because oral challenge with SPI1-deficient S. typhimurium elicits a specific systemic IgG humoral immune response, despite an inability to stimulate production of specific mucosal IgA.
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PMID:Extraintestinal dissemination of Salmonella by CD18-expressing phagocytes. 1054 7

Among etiological factors suspected of causing Crohn's disease a number of bacteria was listed (Yersinia, Mycobacterium kansasi, Mycobacterium pseudotuberculosis) as well as viruses (measles). None of them however can be considered as the only agent. As to external influences, we know the adverse effect of smoking, the toxic effect Al and oral contraceptives. The listed causes may enhance the development of mesenteric thromboses or immunocomplex vasculitis with ischaemization of a certain portion of the small or large intestine with subsequent inflammation. So far we do not know what starts the immunological reaction, but subsequently the process takes place via cytokines, prostaglandin PGE2, leukotriene LTB4 and liberation of free oxygen radicals (this knowledge is applied in therapy). The authors discuss the problem whether Crohn's disease is one clinical entity with a different course or whether a single diagnosis comprises two or more pathological units.
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PMID:[Current views on the development and course of Crohn's disease]. 1056 24


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