Membrane Proteins of Legionellaceae I. Membrane Proteins of Different Strains and Serogroups of Legionella pneumophila

Ehret, W.; Ruckdeschel, G.

doi:10.1016/s0176-6724(85)80075-4

Cited by 13 publications

(11 citation statements)

References 38 publications

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“…In this report we present an additional biochemical characterization of the 24-kDa antigen, including confirmation of its separate identity from the previously recognized major outer membrane protein (MOMP) with which it comigrates (5,11,16,23,35). We also present the DNA sequence of mip and the inferred amino acid sequence of the 24-kDa antigen.…”

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confidence: 66%

DNA sequence of mip, a Legionella pneumophila gene associated with macrophage infectivity

et al. 1989

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In a previous study, a 24-kilodalton (kDa) protein surface antigen of Legionella pneumophila was cloned into Escherichia coli and found to be expressed on the host cell surface. Subsequently, a site-directed mutation in this gene (designated mip) in L. pneumophila was found to impair the capacity of this bacterium to initiate intracellular infection in human macrophages. The work presented here indicates that the antigenic gene product is distinct from the 24to 29-kDa major outer membrane protein of L. pneumophila. In addition,.the antigen was identified as a highly basic protein on two-dimensional nonequilibrium polyacrylamide gels and on two-dimensional monoclonal antibody immunoblots. When the DNA fragment encoding this protein was sequenced, a long open reading frame of 699 base pairs was identified within a region to which antigen expression was previously mapped. mip mRNA isolated from both L. pneumophila and transformed E. coli had the same 5' end, as determined by primer extension analysis, indicating that the same promoter sequences are used in both species. A likely factor-independent transcriptional terminator was found 20 residues downstream of the stop codon, suggesting that mip is encoded on a moniocistronic message. The inferred polypeptide began with a possible 20to 24-residue signal sequence, and, as predicted by two-dimensional electrophoresis, had a molecular weight of 24,868 and was a potent polycation with an estimated pl of 9.8. In previous reports we have described the identification and molecular cloning of a major, 24,000-dalton (Da) surface antigen of Legionella pneumophila (14, 35). This protein is expressed from a cloned fragment on a multicopy plasmid in Escherichia coli and is localized to the surface of the host E. coli strain (15). Recently, we exchanged a mutated copy of this gene for the wild-type gene in L. pneumophila to yield a mutant strain that produced no detectable 24-kDa antigen (8). Although this mutant replicated as well as its isogenic parent within macrophages, it was approximately 80-fold * Corresponding author.

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DNA sequence of mip, a Legionella pneumophila gene associated with macrophage infectivity

et al. 1989

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“…Various methods have been described for subtyping Legionella pneumophila. These methods include monoclonal antibody subtyping (1)(2)(3), analysis of outer membrane proteins (4), peptide profile analysis (5), multilocus enzyme electrophoresis (6,7), plasmid profile analysis (8,9), analysis of restriction fragment length polymorphisms by means of probes (10)(11)(12), and restriction endonuclease digest analysis of whole cell DNA i13, 14). Most of these methods have proved to be useful in special cases but some of them are not suitable for general use in a clinical laboratory because of problems concerning the discriminatory ability, reproducibility, ease of use, availability of reagents, or duration of the procedure.…”

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Subtyping ofLegionella pneumophila serogroup 1 isolates by small-fragment restriction endonuclease analysis

Haertl¹,

Bandlow²

1991

Eur. J. Clin. Microbiol. Infect. Dis.

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Whole cell DNA of Legionella pneumophila isolates was examined by small-fragment restriction endonuclease analysis (SF-REA). Fourteen serogroup 1 isolates from tap water in one hospital collected before and after eradication measures had been taken were compared with control strains of serogroup 1 and other serogroups that were not epidemiologically linked. DNA was digested with EcoRI and electrophoresed on polyacrylamide gels. The gel patterns were made visible by silver staining and analysed by direct visual comparison. All 15 epidemiologically unrelated strains of Legionella pneumophila serogroup 1 and of other serogroups exhibited different restriction fragment patterns. The isolates from the hospital could be clearly subdivided into two groups by SF-REA, suggesting that the hot water supply of the hospital was contaminated with two different strains. SF-REA performed on Legionella pneumophila serogroup 1 DNA enabled further subtyping of these organisms and thus appears to be a useful technique for investigating their epidemiology.

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“…Several methods have been described for subtyping of Legionella pneumophila. These include monoclonal antibody typing schemes, plasmid analysis, DNA digest analysis, polyacrylamide gel electrophoresis of outer membrane proteins, and electromorph (alloenzyme) analysis of enzymes (2,3,8,10,13,14,17,21,22). Some of these methods have already been shown to be useful in epidemiologic analysis, but extensive comparative studies of several different methods are lacking (1, 4, 9, 11, 14-16, 21, 22).…”

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confidence: 99%

Paleoepidemiologic investigation of Legionnaires disease at Wadsworth Veterans Administration Hospital by using three typing methods for comparison of legionellae from clinical and environmental sources

Edelstein¹,

Nakahama²,

Tobin³

et al. 1986

J Clin Microbiol

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Multilocus enzyme electrophoresis, monoclonal antibody typing for Legionella pneumophila serogroup 1, and plasmid analysis were used to type 89 L. pneumophill strains isolated from nosocomial cases of Legionnaires disease at the Veterans Administration Wadsworth Medical Center (VAWMC) and from the hospital environment. Twelve L. pneumophila clinical isolates, obtained from patients at non-VAWMC hospitals, were also typed by the same methods to determine typing specificity. Seventy-nine percent of 33 VAWMC L. pneumophila serogroup 1 clinical isolates and 70% of 23 environmental isolates were found in only one of the five monoclonal subgroups. Similar clustering was found for the other two typing methods, with excellent correlation between all methods. Enzyme electrophoretic typing divided the isolates into the greatest number of distinct groups, resulting in the identification of 10 different L. pneumophila types and 5 types not belonging to L. pneumophila, which probably constitute an undescribed Legionella species; 7 clinical and 34 environmental VAWMC isolates and 2 non-VAWMC clinical isolates were found to be members of the new species. Twelve different plasmid patterns were found; 95% of VAWMC clinical isolates contained plasmids. Major VAWMC epidemic-bacterial types were common in the hospital potable-water distribution system and cooling towers. Strains of L. pneumophila which persisted after disinfection of contaminated environmental sites were of a different type from the prechlorination strains. All three typing methods were useful in the epidemiologic analysis of the VAWMC outbreak.

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Membrane Proteins of Legionellaceae I. Membrane Proteins of Different Strains and Serogroups of Legionella pneumophila

Cited by 13 publications

References 38 publications

DNA sequence of mip, a Legionella pneumophila gene associated with macrophage infectivity

DNA sequence of mip, a Legionella pneumophila gene associated with macrophage infectivity

Subtyping ofLegionella pneumophila serogroup 1 isolates by small-fragment restriction endonuclease analysis

Paleoepidemiologic investigation of Legionnaires disease at Wadsworth Veterans Administration Hospital by using three typing methods for comparison of legionellae from clinical and environmental sources

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