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

From April 1977 through March 1978, 28 presumptive cases of Legionnaires' disease were identified among 432 consecutive candidates having paired sera or tissue samples submitted to the Massachusetts Public Health Laboratories. Among the subgroup of 209 candidates with documented diffuse pneumonia and temperature of 39 degrees C or above, 24 (11.5%) had Legionnaires' disease whereas the diagnostic yield was only four of 223 (1.8%) among the remainder. The case-fatality rate was two of 28 (7%). Patients with Legionnaires' disease when compared to the entire group of candidates were similar in mean age (49 versus 48 years) and frequency of immunosuppressant therapy (15% versus 12%) but were more often male (64% versus 47%) with underlying chronic illness (46% versus 22%). Complement fixation tests against Mycoplasma pneumoniae (whole organisms) showed seroreactivity in 81% of Legionnaires' disease (LD) cases (22 to 27) compared to 13% of non-LD cases; conversely, 29% of all cases seropositive for M. pneumoniae (22 of 75) were seropositive for the LD bacterium compared to only 1% (five of 357) of the remainder. The coincidence of seroreactivity for M. pneumoniae and the LD bacterium is unexplained but suggests that M. pneumoniae seropositive cases should be evaluated for the possibility of Legionnaires' disease.
 ...
PMID:Relation of Mycoplasma pneumoniae seroreactivity, immunosuppression, and chronic disease to Legionnaires' disease. A twelve-month prospective study of sporadic cases in Massachusetts. 43 45

The occurrence, clinical, and epidemiologic characteristics of fatal nosocomial Legionnaires' disease were ascertained by examining a sample of autopsy specimens submitted by hospitals participating in the National Nosocomial Infections Study. Sections of lung tissue from 263 patients were submitted by 40 hospitals in 24 states. Legionnaires' disease was identified in 10 patients (3.8%) from six hospitals in five states. The clinical and epidemiologic characteristics of sporadic fatal nosocomial Legionnaires' disease were similar to those from cases that occurred during epidemics of Legionnaires' diseases. A case-control study showed that cases of Legionnaires' disease were associated with an increased occurrence of Legionnaires' disease during the period June through November, temperatures greater than 39.2 degrees C, and administration of corticosteroids before onset of pneumonia. Legionnaires' disease can occur as a fatal nosocomial pneumonia and has clinical and epidemiologic features that may be helpful in differentiating it from nosocomial pneumonia of other causes.
 ...
PMID:Fatal nosocomial Legionnaires' disease: clinical and epidemiologic characteristics. 43 46

The Legionnaires' disease (LD) bacterium is a gram-negative organism whose "endotoxicity" appears to differ in several respects from the classic endotoxicity generally associated with gram-negative bacteria. Discrepancies were noted between the high activity of LD bacteria in gelating limulus lysate in vitro and their low pyrogenicity in rabbits. Further in-vivo biologic tests indicated that LD bacteria were relatively weak in "endotoxicity". Analysis of LD bacterial cells and in their cellular fractions by gas-liquid chromatography indicated that LD bacteria did not contain hydroxy fatty acids commonly associated with lipid A of endotoxin. The branched-chain fatty acids that were characteristic of LD bacteria were associated with the cell envelope, and were readily extracted into organic solvents without prior saponification. The presence of 2-keto-3-deoxyoctonate in LD bacteria and cell extracts was detected by a microassay method but remains to be confirmed with gas-liquid chromatography and mass spectrometry. The active principle "endotoxicity" in LD bacteria may be a new type of bacterial lipopolysaccharide.
 ...
PMID:"Endotoxicity" of the Legionnaires' disease bacterium. 43 47

We studied the cell-envelope structure of the Legionnaires' disease (LD) bacterium by electron microscopy and biochemical assays. There were apparent differences in cell structure by electron microscopy using two different prefixation methods. Organisms prefixed with gluteraldehyde had a single surrounding membrane. The typical two-membrane structure of gram-negative bacteria, however, was observed after prefixation with a combination of gluteraldehyde, formalin, and creosol. The cell wall (peptidoglycan) was seen in electron micrographs of plasmolyzed bacteria and in papain-digested cells. Both cytoplasmic and outer membranes were separated by differential centrifugation of spheroplast sonicates followed by sucrose density gradient ultracentrifugation. We identified each membrane by characteristic enzyme activity (cytoplasmic membrane) and 2-keto-3-deoxyoctonate content (outer membrane).
 ...
PMID:The cell envelope of the Legionnaires' disease bacterium. Morphologic and biochemical characteristics. 43 48

We qualitatively and quantitatively analyzed the simple and complex lipids of 10 Legionnaires' disease bacteria. The phospholipids in decreasing order of concentration were phosphatidylcholine, phosphatidylethanolamine, cardiolipin, phosphatidylmonomethylethanolamine, phosphatidylglycerol, and phosphatidyldimethylethanolamine. The total phospholipids averaged 96 micromoles per gram dry cell weight. Phospholipid fatty acids were solely branched-chain fatty acids and were, in decreasing order of concentration, iso-C16:0, anteiso-C15:0, anteiso-C17:0, iso-C14:0, iso-C16:1, and an unidentified fatty acid. Neutral lipids identified were free fatty acid, ubiquinone, triglyceride, diglyceride, monoglyceride, and wax ester. Neutral lipid fatty acids consisted predominately of branched-chain fatty acids, normal fatty acids, and a minor unidentified fatty acid. Analysis of the cellular lipids of 10 Legionnaires' disease bacteria revealed an unusual and novel microorganism.
 ...
PMID:Cellular lipids of the Legionnaires' disease bacterium. 43 49

We isolated a high molecular weight antigen of the Legionnaires' disease (LD) bacterium by column chromatography. The antigen was composed of 35% carbohydrate, 2.6% protein, 1.8% phospholipid, and 1% 2-keto-3-deoxyoctonate and was important in the host's antibody response because it inhibited the indirect immunofluorescent and microagglutination titers of convalescent sera from patients with Legionnaires' disease. The antigen also formed precipitin bands with seven of 10 convalescent sera from patients with Legionnaires' disease. We found chemical and biological evidence of endotoxinlike activity associated with the antigen. Cell sonicates and acid extracts of the LD bacterium gave multiple bands in immunodiffusion with human convalescent serum and rabbit antisera prepared against heat-killed LD bacteria. The antigenic structure of the LD bacterium therefore appears complex.
 ...
PMID:A high molecular weight antigen in Legionnaires' disease bacterium: isolation and partial characterization. 43 50

Six clinical isolates of the Legionnaires' disease bacterium have been isolated from patients in two Michigan hospitals. These organisms were recovered and cultivated in vitro and the strains named by city of recovery and order of isolation Detroit 1 to 4 and Flint 1 and 2. All strains, studied by scanning and transmission electron microscopy preparations from 7-day growth on agar, showed similar characteristics. By scanning electron microscopy the cells appeared bacillary, straight, and slightly curved, and spindle shapes and forms with rounded ends were observed. Detroit 2 and 3 and Flint 1 strains showed cells with ends having reduced diameters, the cells resembling an old-fashioned rolling pin. Cell widths ranged from 0.29 to 0.39 micron, and average lengths varied from 1.60 to 2.34 microns. Filamentous forms as long as 9.8 microns were observed. Surfaces appeared quite wrinkled compared to that of an Escherichia coli control organism. As seen by transmission electron microscopy, fine structure included a multilayered cell wall characteristic of gram-negative bacteria that was irregular, reflecting wrinkling; plasma membrane; and periplasmic space. Distinct nucleoid, intracytoplasmic ribosomes and rare vacuoles were also seen. No evidence of a spore or an adversity-resistant body was observed.
 ...
PMID:Surface topography and fine structure of the Legionnaires' disease bacterium. A study of six isolates from hospitalized patients. 43 51

Deoxyribonucleic acid (DNA) relatedness was used to classify strains of the Legionnaires' disease (LD) bacterium. These DNA comparisons showed that all strains of the LD bacterium were members of the same species. Included were strains isolated from the environment and strains with three different O-antigens. The DNA from the LD bacterium was not significantly related to DNA from any other group of bacteria that was tested. Biochemical data, growth characteristics, and guanine-plus-cytosine ratios were used to rule out the possibility that the LD bacterium was significantly related to members of genera whose DNA was not tested. In view of these data we propose that the LD bacterium be named Legionella pneumophila species nova, the type species of Legionella, genus novum. The type strain of L. pneumophila is Philadelphia 1.
 ...
PMID:Classification of the Legionnaires' disease bacterium: Legionella pneumophila, genus novum, species nova, of the family Legionellaceae, familia nova. 43 52

By 31 October 1978 there had been four confirmed instances where the Legionnaires' disease bacterium had been isolated from water samples taken from cooling towers or evaporative condensers located near the site of an epidemic of Legionnaires' disease. These devices are widely used to reject unwanted heat into the atmosphere and vary greatly in size and configuration. However, the operation of all towers and condensers depends on intimate contact between the circulating water and ambient air. Airborne contaminants in the vicinity of these devices are likely to be absorbed to some degree by the circulating water. The airstream leaving a cooling tower is saturated with water vapor and may also contain a relatively minute portion of the circulating water in the form of fine droplets known as drift. It is common practice to bleed a small portion of the circulating water, including all contaminants, from the tower into a storm sewer, sanitary sewer, or even a nearby body of water.
 ...
PMID:Cooling towers and evaporative condensers. 43 54

Female AKR/J mice were challenged with the Washington strain of Legionnaires' disease (LD) bacteria. Nonimmunized mice inoculate intraperitoneally with 2 x 10(8) colony forming units became ill within 4 h and died within 24 h. Progressive histopathologic changes initiated as early as 2 h after inoculation involved the lymphoid organs, the crypts of the small intestine, and the liver. Necrosis with minimal inflammatory cell reaction was the primary lesion. Immunization with a soluble LD bacterial antigen failed to prevent illness but protected against death and development of abnormal histologic changes.
 ...
PMID:Immunologic protection against the Legionnaires' disease bacterium in the AKR/J mouse. 43 55


<< Previous 1 2 3 4 5 6 7 8 9 10