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)

DNA of strains of Legionella pneumophila serogroups 1, 3, 4, and 6, isolated from patients and environmental sources, was examined by restriction endonuclease analysis (REA). Major differences in profiles enabled subtyping in many strains with the same serogroup antigen. However, a cluster of L. pneumophila strains, originating from all the examined serogroups, had similar restriction endonuclease profiles, sometimes with minor differences. This suggests that the genetic similarity between strains of L. pneumophila of different serogroups is sometimes closer than in strains with the same serogroup antigen. Seven environmental sources harbored two L. pneumophila strains with various serogroup antigens; six sources had similar restriction endonuclease profiles. The resolution of small differences in profiles is hampered in REA by the great magnitude of DNA fragments; even upon extensive analysis, these differences are not always readily visualized. Double digestions with the restriction enzymes HpaI and HpaII showed the best results and sometimes revealed differences not evident by digestions with a single endonuclease. REA has a great capacity for accurate epidemiological typing of L. pneumophila, in addition to classical serogrouping; it appeared that the results of the two techniques do not necessarily correlate. On the other hand, it should be stressed that small differences in profiles are not easily detected by REA.
 ...
PMID:Similar DNA restriction endonuclease profiles in strains of Legionella pneumophila from different serogroups. 284 49

In 1981, sixteen cases of nosocomial legionellosis occurred among 456 patients admitted to a new hematology-oncology unit (35 per 1000 admissions). Monoclonal antibody typing and restriction endonuclease plasmid analysis identified a unique strain (09,04) of Legionella pneumophila serogroup 1 isolated from both patients and water outlets. Continuous hyperchlorination of the hot and cold water began in January 1982, and chlorine levels of 3 to 5 mg/L have been maintained most recently. Water samples have been consistently negative for Legionella for more than five years. Four sporadic cases of nosocomial legionellosis have occurred in the hematology-oncology unit during the same period (one per 1000 admissions) associated with a different strain of L pneumophila serogroup 1 (09,00). The environmental reservoir(s) of L pneumophila serogroup 1 in these cases has not been identified. Levels of trihalomethanes (potential carcinogens) were high (greater than 100 micrograms/L) when chlorine levels of hot water exceeded 4 mg/L. Some corrosion damage to the water distribution system has occurred: the average number of leaks per month increased steadily from zero in 1982 to 5.2 in 1986. The chlorinator installation costs were +75,800, and annual operation expenses were +12,500. Continuous hyperchlorination is a promising but still experimental technique for control of nosocomial legionellosis. In our experience, epidemic disease has been controlled, but sporadic cases have continued to occur.
 ...
PMID:Legionnaires' disease associated with a hospital water system. A five-year progress report on continuous hyperchlorination. 335 31

Plasmid analysis and restriction-endonuclease digestion were used to study 54 clinical and environmental Legionella strains. Plasmids with approximate molecular masses of 40, 50, 70, and 90 megadaltons (Mdal) have been isolated from L. pneumophila serogroup 1 strains. One L. jordanis strain contained two plasmids of 25 and 70 Mdal. Restriction analysis of clinical and related hospital-environmental isolates resulted in identical patterns. Geographic diversity is shown for strains of different origin.
 ...
PMID:Plasmid profiles of Legionella spp. isolates, Italy. 365 54

A procedure for preparing a DNA probe to be used in the specific detection of Legionella pneumophila by dot or colony hybridization has been devised. When total DNA from L. pneumophila was used as a radioactive probe, cross-hybridization occurred with DNA from many other species belonging to various families (including Legionellaceae, Enterobacteriaceae, Pseudomonadaceae, and Vibrionaceae). Cross-hybridizing restriction fragments in L. pneumophila ATCC 33152 DNA were identified on Southern blots. When unlabeled DNA from strain ATCC 33152 was cleaved by endonuclease BamHI, the DNA fragments cross-hybridizing with the labeled DNA from all of the other species and genera tested (or with Escherichia coli 16 + 23 S RNA) had a size of 21.4 and 16.2 kilobase pairs (major bands) and 28.0, 12.8, and 10.1 kilobase pairs (minor bands). BamHI restriction fragments of L. pneumophila DNA deprived of the cross-hybridizing fragments were pooled and used as a probe for the detection of L. pneumophila. This probe proved to be specific for L. pneumophila in colony and dot hybridization. It can potentially be used for the detection of L. pneumophila in clinical and water samples. The procedure described can be readily applied to the preparation of probes specific for phylogenetically isolated bacterial species other than L. pneumophila.
 ...
PMID:DNA probe specific for Legionella pneumophila. 398 Jun 93

The DNA of patient and environmental isolates of Legionella pneumophila serogroup 1 was analyzed by restriction endonuclease cleavage. The electrophoretic patterns of the DNA digests of isolates from a group of patients with Legionnaires disease acquired in a hospital were indistinguishable from one another and were identical to the DNA pattern of a strain isolated from the hot water supply of the hospital. On the other hand, they were easily differentiated from strains isolated from patients and hot water supplies in other hospitals in the same city. The homogeneity of populations of L. pneumophila serogroup 1 colonizing plumbing systems was also investigated by DNA restriction endonuclease analysis in three hospitals. We distinguished two subtypes in one hospital; the two other hospitals had homogeneous populations. Restriction endonuclease digest analysis of L. pneumophila serogroup 1 DNA enables subtyping and appears to be a useful method for examining the epidemiology of outbreaks of Legionnaires disease.
 ...
PMID:Molecular epidemiology of Legionella pneumophila serogroup 1. 609 23

To isolate and characterize Legionella pneumophila antigens, we constructed a genomic library of L. pneumophila serogroup 1 (strain 130b). L, pneumophila DNA fragments (2.5 to 7.5 megadaltons) obtained by partial digestion with Sau 3A endonuclease and size fractionation on a sucrose density gradient were inserted into the dephosphorylated BamHI site of vector pBR322; CaCl2-treated Escherichia coli cells of strain HB101 were transformed with hybrid plasmids. To detect expression of antigens, 2,559 ampicillin-resistant transformants were transferred to nitrocellulose paper, lysed in situ, and screened by enzyme immunoassay (EIA) with E. coli-absorbed rabbit anti-L. pneumophila sera. A total of 77 (3%) of the colonies were reactive by EIA; 31 (1.2%) were strongly reactive, and 6 were strongly reactive by EIA without colony lysis. Analysis of 29 stable, strongly reactive clones by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electroblotting showed antigenic bands in 18 clones by EIA with E. coli-absorbed antisera. Absorption of antisera with heat- and Formalin-killed L. pneumophila antigen eliminated or diminished the reactivity of the antigenic bands in representative clones. These studies confirm that several L. pneumophila antigens can be cloned and expressed in E. coli.
 ...
PMID:Cloning and expression of Legionella pneumophila antigens in Escherichia coli. 632 47

Plasmid analysis was used in the investigation of an outbreak of nosocomial Legionnaires' disease in four patients. Serogroup 1 strains were isolated from two patients, the air-conditioning cooling tower, and two hot-water tanks. All serogroup 1 strains contained two plasmids with approximate molecular masses of 21 and 48 megadaltons (Mdal). The serogroup 1 strain found in the cooling-tower isolate also contained an additional 1.9 Mdal-plasmid. Restriction-endonuclease analysis of the 21-Mdal plasmid that was present in patient and hot water-tank isolates revealed identical EcoRI and HaeIII fragment patterns. Digestion of the similarly sized plasmid in the cooling-tower isolate resulted in a unique fragment pattern. The data provide direct bacteriologic evidence implicating the hot-water tanks rather than the cooling tower as the source of the infecting strain.
 ...
PMID:Plasmids as epidemiological markers in nosocomial Legionnaires' disease. 669 35

Legionella pneumophila serogroup 1 strains isolated from a cooling tower during the investigation of an outbreak of Legionnaires' disease were shown previously to be related closely or indistinguishable by hybridisation-based restriction fragment length polymorphism analysis. However, these strains could be differentiated into five different MAb subgroups by comparison of their reactivity patterns with a recognised panel of monoclonal antibodies (MAbs). Pulsed-field gel electrophoresis (PFGE) of genomic fragments obtained after cleavage with rare-cutting restriction endonucleases also differentiated these strains. Four different restriction patterns were obtained with SfiI, EagI and SmaI, three restriction patterns with NotI, ApaI and SacII, and two patterns with NaeI. Generally, the restriction patterns were related closely, differing in only one or two bands. The combined results of the restriction endonuclease digestions allowed the strains to be differentiated into groups that correlated to the MAb subgroups. Both PFGE patterns and MAb subgroups were found to be stable markers. The findings demonstrated that the MAb variability seen amongst the L. pneumophilia serogroup 1 strains from this cooling tower was not solely phenotypic.
 ...
PMID:Correlation of MAb subgroups with genotype in closely related Legionella pneumophila serogroup 1 strains from a cooling tower. 760 56

Ten patients from a rehabilitation center were admitted to hospital with serious respiratory infections within ten weeks. An outbreak of Legionnaire's disease was suspected based on the epidemic and atypical manifestation of pneumonia and could be proven microbiologically. Pulmonary and extrapulmonary complications included respiratory failure, lung abscess, transitory renal impairment in five patients and acute renal failure requiring dialysis in one, tetraparesis caused by peripheral neuropathy and acute psychosis. Three patients died despite immediate institution of therapy with erythromycin. Legionella pneumophila serogroup 1 subtype Pontiac was isolated from a bronchial lavage sample of one patient and from the water supply of the rehabilitation center. Monoclonal antibody subtyping and restriction endonuclease analysis were performed on both environmental and patient isolates. Potable water was identified as the source of the outbreak based on identical patterns on restriction endonuclease analysis. Despite thermic and chemical disinfection with chlorination (up to 15 ppm) in the rehabilitation clinic, an eleventh case of Legionnaire's disease was detected 11 months later.
 ...
PMID:Nosocomial outbreak of legionellosis in a rehabilitation center. Demonstration of potable water as a source. 822 27

A genomic library derived from a virulent isolate of Legionella pneumophila was constructed in Escherichia coli JM 83 using the cloning vector pUC19. The clones were screened by filter immunoassay using L. pneumophila rabbit polyclonal antisera and in the absence of in situ bacterial lysis one such clone, LP 116, expressed L. pneumophila-specific antigens on the surface of E. coli. Restriction endonuclease digest analysis and agarose gel electrophoresis revealed a fragment measuring approximately 750 bp. Southern hybridization confirmed that the fragment was L. pneumophila DNA. Sequencing data showed that the fragment was 810 bp in length with an open reading frame (ORF) of 678 bp. The outer-membrane profiles of the E. coli parent, the L. pneumophila DNA-contributing strain and clone LP 116 were compared by SDS-PAGE. A protein of 25 kDa was found in outer-membrane preparations of both the clone LP 116 and L. pneumophila but not in E. coli JM 83. This was in agreement with the molecular mass of the deduced peptide of the mature protein. Immunoblots using L. pneumophila-specific polyclonal antiserum confirmed that this 25 kDa outer-membrane protein (OMP) was a L. pneumophila polypeptide. Both direct immunofluorescence assay and immunoblots using the commercially produced monoclonal antibody specific for the common antigen of the major outer-membrane protein (MOMP) confirmed that the 25 kDa protein produced by LP 116 was involved with the MOMP complex. The gene encoding this protein has been designated ompM.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Cloning, nucleotide sequence and expression in Escherichia coli of a gene (ompM) encoding a 25 kDa major outer-membrane protein (MOMP) of legionella pneumophila. 840 14


<< Previous 1 2 3 Next >>