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)

Forty-nine cases of Legionnaires' disease were identified from May 1977 through July 1978 in patients and employees at Wadsworth Medical Center. Cases clustered in October and November 1977. Fifteen patients died. All Legionnaires' disease (LD) patients were in the hospital before onset of illness (median time from admission to onset, 17 days; range, 3 to 276 days). Twenty patients were immunosuppressed or compromised by malignancy. In 1977, six of 12 renal-homograft recipients acquired LD pneumonia in contrast to three of 22 during the preceding 3 years (P = 0.031, Fisher's exact test). In a prospective survey of 1658 consecutive hospital admissions, seven cases of Legionnaires' diseases occurred (0.4%), including six among 14 patients who seroconverted to the LD bacterium. Prevalence of a reciprocal titer of 128 or above in Wadsworth employees was significantly greater than in a nearby control population (P = 0.044, Fisher's exact test). Exposure to the external hospital environment may be an important factor, and soil may be a reservoir for the LD bacterium. Legionnaires' disease at Wadsworth may be a nosocomial pneumonia affecting a small group of patients with particular risk factors.
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PMID:Nosocomial Legionnaires' disease: a continuing common-source epidemic at Wadsworth Medical Center. 37 47

The results of serologic, cultural, and DNA relatedness studies have shown that the Legionnaires' disease (LD) bacterium and an unclassified agent isolated in 1947 are the same species. Both organisms grew on charcoal-yeast extract agar, enriched Mueller-Hinton agar, and F-G agar, but neither grew on blood agar, trypticase soy agar, or in thioglycollate broth. Both agents reacted with convalescent sera from patients with Legionnaires' disease and convalescent sera from guinea pigs infected experimentally with the LD bacterium. The percentage of guanine plus cytosine in DNA preparations from each organism was ascertained by thermal denaturation to be 39%. In DNA hybridization reactions the 1947 isolate showed the same degree of relatedness to Philadelphia 1 strain of the LD bacterium as did three recent isolates of the bacterium. The LD bacterium was also shown to be antigenically related to another unclassified organism isolated in 1959.
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PMID:Legionnaires' disease bacterium isolated in 1947. 37 48

We analyzed 24 environmental samples collected in or near the Indiana Memorial Union, where an epidemic of Legionnaires' disease occurred in early 1978. We conducted fluorescent antibody analyses and culture on F-G and charcoal yeast extract agars of each sample directly; splenic tissue of guinea pigs inoculated with the sample; and yolk sacs from embryonated eggs inoculated with splenic tissue of guinea pigs injected with the sample. Legionnaires' disease (LD) bacterium was isolated from seven of the 24 samples: one water sample from the air-conditioner cooling tower of the Union; three water samples from a stream near the Union; and three mud samples from the same stream. The LD bacterium strains were of three different serotypes. These findings indicate that LD bacteria may be widespread in nature.
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PMID:Isolation of the Legionnaires' disease bacterium from environmental samples. 37 49

Tissues from guinea pigs inoculated intraperitoneally with the Legionnaires' disease (LD) bacterium were studied with light, immunofluorescent, and electron microscopy. The principal gross lesion was diffuse peritonitis of varying severity. Microscopically, the peritonitis of covered by a mixed inflammatory infiltrate of macrophages, neutrophils, fibrin, and cellular debris. Foci of inflammation and necrosis were consistently observed in the splenic parenchyma, and similar lesions were often found in the lungs, liver, lymph nodes, pancreas, heart, and other organs. Numerous LD bacteria were seen in the peritoneal exudate; fewer were found in disseminated lesions. In electron micrographs, the highest concentrations were seen in macrophages, with fewer organisms present in neutrophils or extracellular spaces. Although the lung is the primary organ konwn to be affected by Legionnaires' disease in humans, our findings indicate that the LD bacterium is capable of dissemination.
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PMID:Pathologic findings in guinea pigs inoculated intraperitoneally with the Legionnaires' disease bacterium. 37 50

Immunologic factors affecting viability of the Legionnaires' disease (LD) bacterium were studied in vitro and in vivo in mice and guinea pigs. In bactericidal tests, fresh human serum quickly killed LD cells. Heating fresh serum to 56 degrees C for 30 min destroyed bactericidal activity; absorbing it with bentonite had little effect. Fresh normal human serum was more effective than guinea pig serum. Adding LD cells to fresh normal human serum caused a greater than 50% depletion in functional complement activity, apparently by activating the classic C-142 pathway, because human serum deficient in C4 was not bactericidal. Antibodies to the Knoxville 1 LD strain in guinea pigs showed enhanced complement-mediated bactericidal activity. Without complement, immune guinea pig or human sera prolonged in-vitro LD cell survival. Antibodies to Knoxville 1 in mice depressed in-vitro bactericidal activity of human complement against Knoxville 1. In-vitro bactericidal tests support in-vivo studies in subcutaneous chambers. Complement-deficient mice immunized with Knoxville 1 were (P less than 0.01) less resistant to homologous challenge than nonimmunized mice. Immunized guinea pigs had a greater than 80-fold increase in resistance to subcutaneous-chamber infection.
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PMID:Immunologic factors affecting the in-vivo and in-vitro survival of the Legionnaires' disease bacterium. 37 51

Four-hundred fifty-nine sera from 342 persons were examined at Ruchill Hospital, Glasgow, using an agar-grown heat-killed, ether-treated antigen derived from the Philadelphia 1 strain of the Legionnaires' disease bacterium. They were examined, in parallel, at the Center for Disease Control (CDC), Atlanta. Overall agreement (results agreeing +/- one twofold dilution) was reached with 90% of sera. Important differences were obtained with 10 (2.2%) sera. With three of these 10 sera the CDC alone obtained a significant titre (256) whereas with the other seven the Glasgow laboratory alone obtained a titre of 256. Altogether 28 persons (8.2%) with an agreed titre of 256 or higher were identified. However, some of these people had been ill 4 years before serum was obtained for examination. These persistent high titres make the serologic diagnosis of Legionnaires' disease difficult.
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PMID:Scottish experience with the serologic diagnosis of Legionnaires' disease. 37 52

The indirect fluorescent antibody (FA) technique for the diagnosis of Legionnaires' disease was used to investigate an outbreak of respiratory disease in a military population. The outbreak was later shown to be caused by an adenovirus. High titres were obtained using the ether-killed antigen supplied by the Center for Disease Control (CDC), Atlanta, but not with a formolised yolk-sac antigen prepared in out laboratory. The reactivity of these sera with the CDC antigen was removed by absorption with a partly identified gram-positive bacterium, whereas sera from persons with true Legionnaires' disease were unaffected by such treatment, suggesting that such reactivity is not specific for Legionnaires' disease. The lack of reactivity with negative control sera and strong reactivity from a small group of patients in whom seroconversion was demonstrated has led us to conclude that formolised yolk-sac antigen is a reliable antigen for the diagnosis of Legionnaires' disease by the FA method. Measurement of the sensitivity and specificity of the formolised yolk-sac antigen is still in progress.
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PMID:False positive reactions in the indirect fluorescent antibody test for Legionnaires' disease eliminated by use of formolised yolk-sac antigen. 37 53

The indirect fluorescent antibody test and a microhemagglutination technique detected antibodies in human sera to Legionnaires' disease antigen about equally. Since the hemagglutination technique was simpler, more rapid, and less expensive, we used it to ascertain the prevalence of antibody in 1200 sera from apparently healthy, nonhospitalized Michigan residents. Prevalence was analyzed by age, sex, geographic location (county or residence), and season of the year. There was a significant difference in prevalence between seasons: 91 of 600 sera (15.2%) from February to March 1978 had a titer equal to or greater than 1.16, contrasted with 179 of 600 sera (29.8%) from August to September 1978. This difference was independent of age and sex. There was no significant difference by geographic location, sex, or age except for decreased prevalence for persons 60 years or older.
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PMID:Prevalence of antibodies to Legionnaires' disease. A seroepidemiologic survey of Michigan residents using the hemagglutination test. 37 54

Since July 1976 when an outbreak of severe, acute respiratory disease of unknown origin occurred among attendees at the 58th Annual Convention of the American Legion in Philadelphia, great progress has been made, including identification of the causative organism, Legionella pneumophila. Clinical features include not only respiratory involvement but often abdominal complaints, encephalopathy, renal disease, and rhabdomyolysis. Erythromycin appears to be an effective antimicrobial agent. Epidemiologic studies have defined epidemics as well as sporadic cases. Legionella pneumophila has appeared as an opportunistic pathogen. Organisms have been isolated from air-handling equipment and evaporative condensers in four instances. At present diagnosis usually is based on the demonstration of a fourfold rise in antibody titer between serum specimens obtained 3 to 6 weeks apart. Recent data suggest that organisms may be shown in tracheal secretions using a direct flluorescent antibody procedure and that antigen may be shown in urine using the microenzyme-linked immunosorbent assay (ELISA) technique.
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PMID:Legionnaires' disease: one person's perspective. 37 55

We describe a sporadic case of Legionnaires' disease in which the diagnosis was made by direct immunofluorescence of material obtained by percutaneous aspiration of the involved lung via a needle. Employment of this technique among selected patients with suspected Legionnaires' disease would provide for more rapid diagnosis and more prompt initiation of definitive therapy for some patients.
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PMID:Rapid definitive diagnosis of Legionnaires' disease. 37 33


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