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)

Upper respiratory tract infections are the most common types of infectious diseases among adults. It is estimated that each adult in the United States experiences two to four respiratory infections annually. The morbidity of these infections is measured by an estimated 75 million physician visits per year, almost 150 million days lost from work, and more than $10 billion in costs for medical care. Serotypes of the rhinoviruses account for 20 to 30 percent of episodes of the common cold. However, the specific causes of most upper respiratory infections are undefined. Pneumonia remains an important cause of morbidity and mortality for nonhospitalized adults despite the widespread use of effective antimicrobial agents. There are no accurate figures on the number of episodes of pneumonia that occur each year in ambulatory patients. In younger adults, the atypical pneumonia syndrome is the most common clinical presentation; Mycoplasma pneumoniae is the most frequently identified causative agent. Other less common agents include Legionella pneumophila, influenza viruses, adenoviruses, and Chlamydia. More than half a million adults are hospitalized each year with pneumonia. Persons older than 65 years of age have the highest rate of pneumonia admissions, 11.5 per 1,000 population. Pneumonia ranks as the sixth leading cause of death in the United States. The pathogens responsible for community-acquired pneumonias are changing. Forty years ago, Streptococcus pneumoniae accounted for the majority of infections. Today, a broad array of community-acquired pathogens have been implicated as etiologic agents including Legionella species, gram-negative bacilli, Hemophilus influenzae, Staphylococcus aureus and nonbacterial pathogens. Given the diversity of pathogenic agents, it has become imperative for clinicians to establish a specific etiologic diagnosis before initiating therapy or to consider the diagnostic possibilities and treat with antimicrobial agents that are effective against the most likely pathogens.
 ...
PMID:Epidemiology of community-acquired respiratory tract infections in adults. Incidence, etiology, and impact. 401 85

The objective of this study was to evaluate by relatively simple metabolic tests the usefulness of buffers and energy sources commonly used in Legionella growth media. Legionella pneumophila serogroups 1 to 6, Legionella micdadei, and Legionella bozemanii were grown in an enriched charcoal-yeast extract diphasic medium. The cells were washed thrice, suspended in various buffers (pH 6.9) with 1 or 5 mM MgSO4, and used immediately or after controlled-rate cryopreservation. CO2 produced and C incorporated into the cold trichloracetic acid-insoluble fractions from 14C-labeled substrates were determine. Potassium phosphate buffer (0.02 M) was as satisfactory as organic buffers for glutamate metabolism, but the addition of KCl or NaCl reduced activity. Metabolic activity for glutamate was not lost upon cryopreservation, and cryopreserved cells were used to test the utilization of other single or paired substrates. Rates of activity for serine, glutamate, threonine, and pyruvate, in this descending order, were high, and those for alpha-ketoglutarate, succinate, and gamma-aminobutyrate were low. Although glutamine was not used as rapidly as glutamate, when added to glutamate it was preferentially metabolized, possibly because of more rapid transport. When glutamate and serine were combined, glutamate furnished more C for CO2 and less for incorporation, whereas the reverse was true of serine. In conclusion, glutamate as an energy source may in some cases spare other amino acids for synthesis. alpha-Ketoglutarate, a common constituent of Legionella media, may reduce oxygen toxicity but is probably not a chief energy source.
 ...
PMID:Substrate utilization by Legionella cells after cryopreservation in phosphate buffer. 614 14

A qualitative and quantitative survey of environmental Legionella in the Paris area was undertaken because of its epidemiological implications. Over a 2-year period, 322 water samples from the Paris area (unrelated to a legionnaires' disease outbreak) were examined for the presence of Legionella. No Legionella strain was isolated from the main water supplies of the municipality or from the distribution entry points of 36 buildings. Inside buildings, however, 84/190 (44.2%) tap water samples yielded one or several strains of Legionella (10(2) to 10(6) CFU/l). Contamination was significantly more frequent in hot tap water than in cold tap water. Legionella was isolated from 11 out of 14 air-conditioning systems investigated. Sixty-four of the 132 strains isolated were L. pneumophila serogroup 1. Other strains were L. pneumophila serogroups 2 to 6 (including a serogroup 4-5 variant), L. longbeachae serogroup 2 and 6 atypical Legionella.
 ...
PMID:[Survey of Legionella in the Parisian environment. Practical implications]. 623 26

Lipopolysaccharide was extracted with cold phenol water from Legionella pneumophila and used as antigen for ELISA. IgG and IgM antibodies were measured with the ELISA and the immunofluorescence assay (IFA). Agglutinating antibodies were measured by the microagglutination (MA) test. In tests on sera from 27 patients with confirmed Legionella infections predominantly due to L. pneumophila serogroup 1 the results with the ELISA, the IFA and the MA were compared to each other. Antibody titers obtained by the ELISA were in general much higher than those obtained by both other tests. The ELISA proved to be the most sensitive method (IgG: 91.3%, IgM: 52.2%) whereas the sensitivities of IFA and MA were IgG: 69.6%, IgM: 30.4% and 60.9%, respectively. There was low correlation of the IgG antibody titers but good correlation of the IgM titers. Further 49 sera from patients without Legionella infection were screened to calculate the specificities of the three tests which were equally good with all methods (98%).
 ...
PMID:Indirect immunofluorescence assay (IFA), microagglutination test (MA) and enzyme-linked-immunosorbent assay (ELISA) in diagnosis of legionellosis. 635 6

Acanthamoeba castellanii Neff supports the intracellular growth of Legionella pneumophila. When acanthamoebae were exposed to L. pneumophila for 1 h and then washed free of unassociated bacteria and placed in liquid culture, levels of viable amoeba-associated legionellae and legionellae free in the culture medium increased by three to four orders of magnitude in 48 to 72 h. However, most of the legionellae remained amoeba-associated and could be cultured only after disruption of the amoebae. Furthermore, legionella viability declined rapidly in amoeba culture medium alone or when bacteria and amoebae were separated by a microporous membrane. Therefore, direct amoeba-legionella contact is required for this growth. Infected acanthamoebae treated with cold acetone to permeabilize them to fluorescent-labeled anti-L. pneumophila antibody appeared to contain far more legionellae than amoebae fixed with glutaraldehyde so as to prevent antibody penetration. Electron micrographs of infected A. castellanii showed numerous bacteria, including some dividing forms, within vacuoles in the cytoplasm. These results together show that A. castellanii is able to provide an intracellular niche for the growth of L. pneumophila.
 ...
PMID:Intracellular growth of Legionella pneumophila within Acanthamoeba castellanii Neff. 637 54

The distribution of Legionella pneumophila in water inside buildings was examined by means of culture methods. Cooling tower sumps and condenser valves harboured the organism at the highest frequency and in the highest concentrations. The bacterium was also frequently isolated from potable water systems, including hot and cold mixed taps, drinking water fountains and showers. When water quality parameters were examined, only elevated pH, total particulate nitrogen and alkalinity were correlated with the occurrence of L. pneumophila. Survival of the organism in water was increased at slightly basic pH and lower temperatures. The proliferation of the organism in water within buildings is probably due to a number of interrelated environmental factors that influence its survival and growth.
 ...
PMID:Incidence of Legionella organisms in selected Ontario (Canada) cities. 652 27

A survey of water symptoms in 12 Victorian hospitals was undertaken to establish the prevalence of Legionella pneumophila in buildings not known to be associated with cases of Legionnaires' disease. Samples of hot, cold and shower water were taken, together with water from cooling towers, and isolation was attempted by guinea-pig inoculation. Legionella pneumophila was not isolated from any of the hot, cold or shower samples, but six strains were isolated from five of the cooling towers sampled.
 ...
PMID:Isolation of Legionella pneumophila from hospital water systems in Victoria. 713 74

We present a case of Legionnaires' disease complicated by cold agglutinin disease. Therapy with erythromycin gluceptate was associated with resolution of both the pneumonia and the hemolysis. Complement-fixing antibody levels to Mycoplasma pneumoniae, influenza A, and adenoviruses were measured repeatedly throughout the clinical illness and were persistently nondiagnostic. The cold agglutinin present in the patient's serum was characterized as an IgM that demonstrated anti-I specificity. Thus, Legionella pneumophila should be considered a potential causative agent in patients with pneumonia and cold agglutinin disease.
 ...
PMID:Cold agglutinin disease in a patient with Legionnaires' disease. 743 51

During the autumn and winter of 1993-94 four cases of legionellosis were diagnosed in a Department of Nephrology. Three of the patients were kidney transplanted patients. Two of the patients died. The diagnosis was based on positive culture in two patients and by positive urinary antigen test in the other two patients. Serology was negative for all four patients. Legionella pneumophila was initially found in the cold and hot shower water, in ice-water from the ice machine, from the hot water tank and in the cold water inlet to the building. The isolate from patient no. one and isolates of serogroup 5 from the ice machine and the shower water had identical REA profiles, different from the profiles of the isolate from patient no. four. We concluded that at least one of the four patients was likely to have been infected from the water in the department, either by inhalation of contaminated aerosols from the shower or by aspiration of contaminated ice-water. Precautions were taken to reduce the number of Legionella in the shower- and ice-water. In addition, restrictions in the use of showers and ice-water from the ice machine were introduced.
 ...
PMID:[Nosocomial Legionella pneumophila infection in a nephrology department]. 763 15

The occurrence of legionellae in the hot water distribution systems of 67 buildings located in different parts of Finland was studied. Most of the buildings were apartment buildings. They had different hot water temperatures, and some received their cold potable water from surface water plants and some from ground water plants. Hot water samples were taken from taps, showers, and water mains just before and after the heat exchanger. Legionella pneumophila was isolated from 30% of the distribution systems. In the legionella-positive samples the legionella concentration varied from < 50 to 3.2 x 10(5) colony-forming units (cfu)/L (mean 2.7 x 10(3) cfu/L). The highest concentration of legionellae was found in the shower water. Legionellae appeared more often and with higher concentrations in hot water systems using cold water processed in surface water plants than in hot water systems associated with ground water plants. A high organic matter content in surface waters might favor the occurrence of legionellae and also the growth of other heterotrophic microbes. Mean water temperature just after heating was slightly higher in the legionella-negative systems than in the legionella-positive systems (53.5 vs. 51.5 degrees C).
 ...
PMID:Occurrence of legionellae in hot water distribution systems of Finnish apartment buildings. 770 35


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