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)

The DNA encoding the zinc metalloprotease of Legionella pneumophila Philadelphia 1 has been isolated and expressed in Escherichia coli. This protein, which is 38,000 Daltons in size, possesses immunological and biochemical properties identical to those previously described for the purified L. pneumophila protease. Periplasmic extracts of E. coli clones expressing the recombinant protease are also capable of causing the haemolysis of canine erythrocytes and the cytotoxic destruction of CHO cells. Using transposon mutagenesis, it was determined that a maximum of 1.2 kb of DNA encoded all three biological activities. Inactivation of proteolytic activity by transposon insertion occurred concomitantly with losses of the haemolytic and cytotoxic phenotypes. A putative regulatory sequence approximately 200-500 bp upstream of the gene's coding region was identified. A 4.0 kb fragment encoding these activities hybridized to the chromosomal DNA of the parent strain of L. pneumophila Philadelphia 1 as well as clinical isolates of L. pneumophila.
 ...
PMID:Analysis of a cloned sequence of Legionella pneumophila encoding a 38 kD metalloprotease possessing haemolytic and cytotoxic activities. 254 10

A total of 28 species of Legionella could be differentiated by rRNA gene restriction patterns generated after cleavage of total DNA with either EcoRV or HindIII restriction endonucleases, and hybridization of fragments with 32P-labelled Escherichia coli 16 + 23S rRNA. Different species gave different fragment patterns. When several isolates of a species were tested, the patterns obtained were often identical. However, more than one pattern was often observed when more than one serotype was considered. The method should be useful for the identification of all species of Legionella including those exhibiting immunological cross-reactions.
 ...
PMID:rRNA gene restriction patterns of Legionella species: a molecular identification system. 256 May 80

All Legionella species express a 60-kilodalton (kDa) protein which contains a genus-specific epitope recognized by murine monoclonal antibody GW2X4B8B2H6. A genomic cosmid library of Legionella pneumophila chromosomal DNA was constructed in pHC79 and screened for 60-kDa antigen-expressing clones with the monoclonal antibody. A 3.2-kilobase EcoRI fragment from cosmid 14B11 expressing a 60-kDa protein was subcloned into pUC19 (pSH16), and deletion of a 1.2-kilobase HindIII fragment (pSH16A) generated a 33-kDa truncated polypeptide no longer reactive with the monoclonal antibody. Southern blot analysis of chromosomal DNA from selected Legionella species restricted with EcoRI and probed with the 1.2-kilobase fragment coding for the carboxyl region of the protein revealed DNA homology which was not observed with DNA from Escherichia coli. Maxicell analysis of pSH16 identified a second polypeptide of approximately 15 kDa expressed from a gene (htpA) upstream of the gene coding the 60-kDa protein (htpB). Both proteins were preferentially synthesized by L. pneumophila following heat shock (temperature shift from 25 to 42 degrees C), and under steady-state growth conditions the relative level of 60-kDa protein was unaffected by temperature. In E. coli, expression of a 60-kDa protein from pSH16 also increased following heat shock (25 to 42 degrees C), but under steady-state conditions expression was temperature dependent. Temperature-dependent expression from pSH16 was not observed in an rpoH (htpR) mutant strain of E. coli. The Legionella 60-kDa protein appears to be a heat shock protein which shares cross-reactive epitopes with the GroEL homolog of E. coli. In addition, a region of htpB encoding the 27-kDa carboxyl portion of the protein containing the monoclonal antibody-reactive epitope also contains DNA sequences unique to and conserved within the genus.
 ...
PMID:Cloning and temperature-dependent expression in Escherichia coli of a Legionella pneumophila gene coding for a genus-common 60-kilodalton antigen. 256 81

We applied monoclonal antibody typing and restriction endonuclease analysis of plasmid DNA to study 28 clinical and 35 environmental (potable water) isolates of Legionella pneumophila serogroup 1 from three hospitals in Iowa between 1981 and 1986. Monoclonal antibody typing employed a panel of seven antibodies and delineated eight different subtypes. Plasmids were present in 57% of the isolates including 12 of 28 (43%) clinical and 25 of 35 (69%) potable water isolates. The plasmids ranged in size from 28 to 98 kilobase pairs and comprised eight distinct subtypes by restriction endonuclease analysis with Eco RI. Combination of monoclonal antibody and restriction endonuclease subtyping (composite subtyping) revealed 19 different composite subtypes of Legionella pneumophila serogroup 1. The most common composite subtype, 09:04, comprised 29% (18 of 63) of the isolates and was only found in clinical and potable water samples from a single pavilion in hospital A during an outbreak of Legionella pneumophila serogroup 1 pneumonia. Aside from this cluster the diversity of composite subtypes of Legionella pneumophila serogroup 1 observed in clinical and potable water sources over the 5-year period was striking. The combination of monoclonal antibody and restriction endonuclease typing resulted in improved strain delineation and a more useful use of epidemiologic markers for Legionella pneumophila serogroup 1.
 ...
PMID:The application of molecular and immunologic techniques to study the epidemiology of Legionella pneumophila serogroup 1. 259 Nov 66

In Japan, a fatal case due to Legionella micdadei was first recognized in our laboratory in 1986. On the epidemiological study just after the case, no Legionella was detected from the environmental samples of the patient's residence, such as shower water, tank water and so on. In the course of prospective investigations, no Legionella was isolated, but many organisms were grown on BCYE alpha and MWY agar plates. In the retrospective study, one of these organisms was found to support satellite growth of Legionella on BCYEagar without L-cysteine. This was the isolate from the shower hose and identified as Pseudomonas vesicularis with the biochemical and DNA-DNA hybridization test. And P. vesicularis type strain ATCC11426 also supported satellite growth of Legionella. Especially in the water supply system, the existence of P. vesicularis seemed to be effective on the growth of Legionella. It must be taken into consideration that efforts made to isolate the nutrient produced organisms as well as Legionella are needed.
 ...
PMID:[A strain of Pseudomonas vesicularis isolated from shower hose which supports the multiplication of Legionella]. 261 89

To study individual Legionella antigens, a Legionella micdadei genomic library in Escherichia coli SC181 was established. Partially Sau3A digested L. micdadei DNA fragments (15-25 kilobase pairs (kb] were cloned into the tetracycline resistance gene of the cosmid vector pHC79. Four thousand ampicillin resistant recombinants were obtained; seven hundred were screened for expression of Legionella antigens in Western blot analysis with a polyspecific E. coli-absorbed anti-L. micdadei rabbit antibody. One of the positive clones expressed a 60 kilodalton (K) antigen, which reacted strongly with a monospecific rabbit antiserum raised against L. micdadei "common antigen" (CA), and an additional 13 K L. micdadei protein. The region encoding these two proteins from the 17 kb recombinant plasmid (pBA 2) was subcloned in pBGS18+. The DNA sequence of the CA encoding region in the 2.7 kb subcloned fragment will provide important information with respect to genetic vs. antigenic relatedness among Legionellae and other Gram-negative species, as well as to CA structure and possible function.
 ...
PMID:Cloning and expression of the Legionella micdadei "common antigen" in Escherichia coli. 264 77

Legionellae are ubiquitous aquatic organisms. They are unique among the agents commonly responsible for bacterial pneumonia in humans in that they are not part of the normal human flora but are acquired from environmental sources. Prospective studies have shown that legionellae consistently rank among the top three bacteria as etiologic agents of community-acquired pneumonia. The clinical presentation of Legionnaires' disease is not distinguishable from that of other bacterial pneumonias. Culture of respiratory secretions using selective media, combined with one or more rapid diagnostic methods (direct fluorescent antibody staining, radiolabelled DNA probe, or urinary antigen detection) provides a specific diagnosis in the vast majority of cases. Sporadic cases have been linked to legionella colonization of water systems in homes and the work setting. Antibiotics commonly used in the therapy of community-acquired pneumonias, such as beta-lactam agents, are ineffective. Specific therapy with erythromycin reduces mortality to less than 10%.
 ...
PMID:Community-acquired Legionnaires' disease. 265 33

Legionella longbeachae serogroup 1 was isolated from the respiratory secretions of two patients with community-acquired pneumonia. One patient had a mild infection without evidence of the involvement of other organs and recovered, in spite of inappropriate antibiotic therapy. The other patient was severely-ill on presentation with multisystem failure and died soon after admission to hospital. The organisms were identified by the immunofluorescence technique and by quantitative DNA-hybridization studies. The sources of the infection in these patients are unknown as the organism has never been isolated from the SA environment.
 ...
PMID:Legionella longbeachae pneumonia: report of two cases. 265 79

Several strains of Legionella pneumophila and other species of Legionella with proteolytic activities were compared by assays, including Southern hybridizations and Western immunoblots, to determine their proteolytic, hemolytic, and cytotoxic activities. Only proteases from strains of L. pneumophila were both hemolytic and cytotoxic, and proteolytic activities extracted from other species of Legionella possessed only hemolytic activity. A 4.0-kilobase DNA sequence encoding the 38-kilodalton metalloprotease from L. pneumophila Philadelphia 1 that we showed previously was responsible for the observed hemolytic and cytotoxic phenotypes (F. D. Quinn and L. S. Tompkins, Mol. Microbiol., 3:797-805, 1989) was used in Southern hybridizations to probe chromosomal DNA from several strains of L. pneumophila and other Legionella species. The probe hybridized to the chromosomal DNA of all serogroups of L. pneumophila but not to any strains of L. dumoffii, L. micdadei, L. feeleii, or L. jordanis that we examined. Additionally, Western immunoblots done with rabbit antisera made to the cloned L. pneumophila protease demonstrated cross-reactions among 38-kilodalton proteins from strains of L. pneumophila, but no reactions were observed with proteins from other species of Legionella. Similarly, the cloned protease from L. pneumophila reacted with convalescent-phase sera from patients infected with L. pneumophila, but not with antisera isolated from patients infected with other Legionella species. Thus, despite some similarities among the proteolytic activities of members of the genus Legionella, including proteolytic and hemolytic phenotypes, metal requirements for zinc or iron, sensitivity to EDTA, and temperature and pH optima, we documented distinct genetic, immunological, and cytotoxicity differences among the proteolytic activities produced by Legionella species.
 ...
PMID:Genetic, immunological, and cytotoxic comparisons of Legionella proteolytic activities. 266 84

A Legionella-like organism (strain 1087-AZ-H) was isolated from a pleural-fluid specimen from a renal transplant patient undergoing immunosuppressive therapy. Growth characteristics and gas-liquid chromatography profiles of the isolate were consistent with those for Legionella spp. The isolate fluoresced blue-white under long-wave UV light. Strain 1087-AZ-H was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization studies placed it in a new Legionella species, Legionella tucsonensis (ATCC 49180).
 ...
PMID:Legionella tucsonensis sp. nov. isolated from a renal transplant recipient. 229 76


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