Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 1986, an unusual syndrome of acute febrile cerebrovasculitis in the Piedmont Region of Virginia was reported. All patients had encephalopathy and prior exposure to both a sylvan environment and flea-infested animals. The initial serological studies suggested a rickettsial origin, corroborating clinical, epidemiological, and histopathological findings. Sera from four of five patients were subsequently studied by immunoblotting. Unabsorbed and absorbed sera were tested with electrophoresed and electroblotted Rickettsia typhi, Legionella bozemanii, and Proteus vulgaris OX19 antigens. The unabsorbed sera reacted with all three antigens. The P. vulgaris- and L. bozemanii-absorbed sera reacted with R. typhi only and without significantly less intensity. In contrast, the reactivity of R. typhi-absorbed sera was significantly lower with all three antigens. These results indicate that these patients had specific antibodies to a typhus group antigen. Although our findings suggest that a rickettsia of the typhus group may have caused this syndrome, no definitive diagnosis could be achieved because a rickettsial organism was not isolated.
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PMID:Immunoblot studies to analyze antibody to the Rickettsia typhi group antigen in sera from patients with acute febrile cerebrovasculitis. 172 73

Antibodies to Rickettsia rickettsii erythrocyte-sensitizing substance (ESS) were raised in rabbits by using a derivatized ESS. The resulting antibodies reacted with R. rickettsii and cross-reacted with Rickettsia conorii, a member of the spotted fever group rickettsiae, but did not react with Rickettsia typhi, a member of the typhus group rickettsiae, Legionella bozemanii, or Proteus vulgaris OX19 or OX2. Immunoblot analysis indicated that ESS was present in more than one fraction and that the major haptenic fraction was proteinase resistant. Immunoelectron microscopy indicated that the antibodies to R. rickettsii were specific to components located on the cell surface and intracellularly to components between the cell wall and cytoplasmic membrane.
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PMID:Production of antibody to and cellular localization of erythrocyte-sensitizing substance from Rickettsia rickettsii. 249 37

A procedure is described for assaying antibodies based on the application of antigen to nitrocellulose as a line with an ink pen point. The method requires no expensive apparatus, is easy to perform, and requires less than 0.25 micrograms of antigen per assay. More than 45 antigens can be assayed simultaneously with a single antibody. Antigens can be applied as purified proteins, extracts, or sodium dodecyl sulfate solubilized extracts. The application of the line blot assay for the detection of monoclonal antibodies which recognize heat-sensitive and insensitive epitopes on the typhus rickettsia surface protein antigen is described. A new serotyping assay for Gram-negative bacteria is also described in which sodium dodecyl sulfate solubilized antigens are applied as lines with and without prior proteinase K digestion. The value of the line blot serotyping assay is demonstrated with Proteus. Rickettsia, Rochalimaea, and Legionella antigens. The line blot immunoassay is a simple, but powerful and flexible, alternative to dot and cross-dot immunoassays.
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PMID:The line blot: an immunoassay for monoclonal and other antibodies. Its application to the serotyping of gram-negative bacteria. 260 66

Sera from patients suffering from Mediterranean spotted fever (i.e. an infection due to Rickettsia conorii) were studied by immunoblot to investigate cross-reactivity. A prevalence of IgM antibodies to Proteus OX 19, Proteus OX 2, to the Rickettsia typhus group, to Legionella pneumophila serovars 4 and 5, to L. bozemanii Wiga and to L. micdadei Tatlock was found. Western blot confirmed that the antibodies were directed against the lipopolysaccharide as demonstrated by proteinase K digestion of the antigens. Cross-adsorptions showed that there is a common cross-reacting epitope among L. bozemanii Wiga, R. typhi and Proteus OX 19 but cross-reacting antibodies to L. micdadei and OX 2 were distinct and independent. This IgM cross-reaction could lead to a misdiagnosis.
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PMID:Immunoblot cross-reactions among Rickettsia, Proteus spp. and Legionella spp. in patients with Mediterranean spotted fever. 754 Dec 70

Rickettsia prowazekii, the etiologic agent for epidemic typhus, and Borrelia recurrentis, the etiologic agent of relapsing fever, both utilize the same vector, the human body louse (Pediculus humanus), to transmit human disease. We have developed an assay to detect both bacterial pathogens in a single tube utilizing real-time PCR. Assays for both agents are specific. The R. prowazekii and B. recurrentis assays do not detect nucleic acid from R. typhi, R. canada, or any of eight spotted fever rickettsiae. In addition they did not react with Neorickettsia risticii, N. sennetsu, Franciscella persica, Bartonella quintana, Legionella pneumophila, Proteus mirabilis, Salmonella enterica, Escherichia coli, and Staphylococcus aureus. Moreover, the B. recurrentis assay did not detect B. duttonii, B. coriaceae, B. afzelii, B. garinii, B. hermsii, or B. burgdorferi nucleic acid. Both assays detected repeatedly only R. prowazekii or B. recurrentis either when tested alone or together in one test tube.
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PMID:Real-time PCR duplex assay for Rickettsia prowazekii and Borrelia recurrentis. 1286 Jun 43

Before twentieth centuries and during early twentieth centuries, communicable diseases were the major cause of morbidity and mortality in Korea. But reliable data are not available. After 1975, the overall morbidity and mortality from communicable diseases, rapidly declined. Recently many new pathogenic microbes were recognized: L. monocytogenes, Hantaan virus, Y. pseudotuberculosis, P. multocida, L. pneumophilia, Human immunodeficiency virus (HIV), G. seoi, H. capsulatum, C. burnetii, V. cholerae 0139, C. parvum, F. tularensis, E. coli 0157:H7, B. burgdorferi, S. Typhimurium DT104, Rotavirus, hepatitis C virus and so on. Since the first HIV infection recognized in 1985, the reported cases of infection and deaths from HIV/AIDS have been steady increased each year. Legionnaire's disease, E. coli 0157:H7 colitis, listeriosis and crytosporidiasis have been occurring just sporadically among immunocompromized cases. Many re-emerging communicable diseases were occurred in Korea: leptospirosis, malaria, endemic typhus, cholera, tsutsugamushi disease, salmonellosis, hepatitis A, shigellosis, mumps, measles, acute hemorrhagic conjunctivitis, brucellosis and so on. Leptospirosis and tsutsugamushi diseases have been noticed as major public health problems since 1980s. The malaria that had been virtually disappeared for a decade has reappeared from 1993 with striking increase of patients in recent 3-4 years. The distributions of salmonella and shigella serotypes have been changed a lot in recent few decades. Furthermore rapid emergence of antibiotic-resistant bacterial strains induces more difficult and complex problems in control of communicable diseases. We must recognize on the importance of environment and ecosystem conservation and careful prescription of anti-microbial agent in order to prevent communicable diseases.
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PMID:[Changing patterns of communicable diseases in Korea]. 1631 47

An immunofluorescent assay (IFAT) using whole cell antigen derived from Burkholderia thailandensis used for detection of total antibodies to Burkholderia pseudomallei, was found to compare favorably with a previous published report on a B. pseudomallei IFAT assay. At a 1:20 cut-off titer, the assay had high sensitivity (98.9%) and satisfactory specificity (92.3%), when tested against sera from 94 patients suspected of melioidosis. Sera from 12 patients with culture proven melioidosis gave absolute concordance with the 2 test antigens. No sera from 50 blood donors had a titer of > or =20. Cross-reactivity with patients' sera positive for Chlamydia, Mycoplasma, Legionella and typhoid was not observed, except for 3 sera from typhus patients and one from a patient with leptospirosis. The major advantage of this assay is that the cultivation and preparation of B. thailandensis as antigen can be carried out in any laboratory with basic microbiological set-up. The serodiagnosis of melioidosis can be made safe for medical laboratory personnel, particularly in B. pseudomallei endemic regions.
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PMID:Burkholderia thailandensis whole cell antigen cross-reacts with B. pseudomallei antibodies from patients with melioidosis in an immunofluorescent assay. 2057 23

Bacterial Sec7-domain-containing proteins (RalF) are known only from species of Legionella and Rickettsia, which have facultative and obligate intracellular lifestyles, respectively. L. pneumophila RalF, a type IV secretion system (T4SS) effector, is a guanine nucleotide exchange factor (GEF) of ADP-ribosylation factors (Arfs), activating and recruiting host Arf1 to the Legionella-containing vacuole. In contrast, previous in vitro studies showed R. prowazekii (Typhus Group) RalF is a functional Arf-GEF that localizes to the host plasma membrane and interacts with the actin cytoskeleton via a unique C-terminal domain. As RalF is differentially encoded across Rickettsia species (e.g., pseudogenized in all Spotted Fever Group species), it may function in lineage-specific biology and pathogenicity. Herein, we demonstrate RalF of R. typhi (Typhus Group) interacts with the Rickettsia T4SS coupling protein (RvhD4) via its proximal C-terminal sequence. RalF is expressed early during infection, with its inactivation via antibody blocking significantly reducing R. typhi host cell invasion. For R. typhi and R. felis (Transitional Group), RalF ectopic expression revealed subcellular localization with the host plasma membrane and actin cytoskeleton. Remarkably, R. bellii (Ancestral Group) RalF showed perinuclear localization reminiscent of ectopically expressed Legionella RalF, for which it shares several structural features. For R. typhi, RalF co-localization with Arf6 and PI(4,5)P2 at entry foci on the host plasma membrane was determined to be critical for invasion. Thus, we propose recruitment of PI(4,5)P2 at entry foci, mediated by RalF activation of Arf6, initiates actin remodeling and ultimately facilitates bacterial invasion. Collectively, our characterization of RalF as an invasin suggests that, despite carrying a similar Arf-GEF unknown from other bacteria, different intracellular lifestyles across Rickettsia and Legionella species have driven divergent roles for RalF during infection. Furthermore, our identification of lineage-specific Arf-GEF utilization across some rickettsial species illustrates different pathogenicity factors that define diverse agents of rickettsial diseases.
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PMID:Which Way In? The RalF Arf-GEF Orchestrates Rickettsia Host Cell Invasion. 2629 22