Jürgen H. Helbig

TU Dresden

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Paul Christian Lück

TU Dresden

Enno Jacobs

University of Freiburg

Timothy G. Harrison

University of Bristol

Ulrich Zähringer

Research Center Borstel - Leibniz Lung Center

Paul Christian Lück

Institut für Medizinische Informatik, Biometrie und Epidemiologie

Christian Lück

TU Dresden

Søren A. Uldum

Statens Serum Institut

Esteban Fernández-Moreira

Universidad de Especialidades Espíritu Santo

Fumiaki Kura

National Institute of Infectious Diseases

Yuriy A. Knirel

N.D. Zelinsky Institute of Organic Chemistry

Cooperative Institutions

TU Dresden

Institute of Medical Microbiology and Hygiene

University Hospital Carl Gustav Carus

Carl Gustav Carus-Institut

Centre National de la Recherche Scientifique

Institut für Medizinische Informatik, Biometrie und Epidemiologie

National Institute of Infectious Diseases

Inserm

Klinik und Poliklinik für Psychotherapie und Psychosomatik

Institut für Hygiene und Umwelt

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Subtyping of Legionella pneumophila serogroup 1 strains isolated in Germany using monoclonal antibodies

Zentralblatt für Bakteriologie (1992)

Paul Christian Lück Jürgen H. Helbig W. Ehret R. Marre Wolf Witzleb

Legionella

Subtyping

10.1016/s0934-8840(11)80611-0

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Citations (16)

Contribution of Legionella's Surface to the Pregnant Pause Virulence Strategy

ASM Press eBooks (2014)

Esteban Fernández-Moreira Jürgen H. Helbig Michele S. Swanson

Legionella pneumophila has a complex life cycle composed of at least three developmental states, each characterized by a different cell type: the replicative, transmissive, and mature intracellular forms. This chapter talks about how during its life cycle in mouse macrophages L. pneumophila first delays and then exploits phagosomelysosome fusion, a virulence strategy that the authors have named "the pregnant pause''. The authors tested whether these vesicles retain the same surface properties and activities as whole microbes. Specifically, the hypothesis that L. pneumophila releases LPS-rich vesicles that arrest phagosome maturation while also remodeling the bacterial surface during differentiation to the replicative form, was also tested. Vesicles shed by L. pneumophila or Escherichia coli into broth were purified by gradient ultracentrifugation. As it differentiates to the transmissive form, L. pneumophila gains the capacity to inhibit phagosome maturation and also alters the composition of the glycoconjugates on its surface. Like Salmonella, L. pneumophila fills its phagosome with membrane vesicles. The O-chain of L. pneumophila LPS is a homopolymer of legionaminic acid, a unique sugar structurally similar to sialic acid whose striking features are the lack of free hydroxyl groups and a high degree of O-acetylation. During this pregnant pause, L. pneumophila alters the composition of its LPS not only to release the block to fusion but also to tolerate the harsh conditions of the lysosomal compartment, which the progeny exploit as a source of nutrients and membrane to support proliferation.

Legionella

10.1128/9781555815660.ch67

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Lipopolysaccharide of Legionella pneumophila shed in a liquid culture as a nonvesicular fraction arrests phagosome maturation in amoeba and monocytic host cells

FEMS Microbiology Letters (2010)

Eva M. Seeger Maria Thuma Esteban Fernández-Moreira Enno Jacobs Marc Schmitz

After uptake by susceptible host cells, Legionella pneumophila displays the ability to arrest phagolysosome fusion. To elucidate the role of lipopolysaccharide (LPS) in this mechanism, we investigated its influence on Acanthamoeba castellanii, A/J mouse macrophages and human monocytes. For this, legionellae were cultured in broth to the replicative, noninfectious phase or to the infectious phase expressing virulence traits. Shed LPS-enriched outer membrane vesicles (OMV) and LPS species <300 kDa were obtained from L. pneumophila Corby strains possessing the virulence-associated LPS epitope recognized by monoclonal antibody (MAb) 3/1 and its mutant TF 3/1, which has lost this epitope due to a mutation in the lag-1 gene. The shed LPS components were attached by specific antibodies to latex beads and added to the host cells for phagocytosis. We demonstrated for the first time that evasion of lysosomal degradation of phagosomes for up to 5 h can also be set off by LPS that is not tied up in OMV. Moreover, our cell culture models showed that the influence of MAb 3/1-positive and -negative LPS was identical. Our data clearly substantiate that LPS is an independent factor for evading lysosomal degradation, which is independent of the bacterial expression of known virulence traits.

Phagolysosome

Virulence factor

Legionella

10.1111/j.1574-6968.2010.01976.x

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Citations (26)

Identification of an α-d-Manp-(1 → 8)-Kdo disaccharide in the inner core region and the structure of the complete core region of the Legionella pneumophila serogroup 1 lipopolysaccharide

Carbohydrate Research (1997)

Hermann Moll Yuriy A. Knirel Jürgen H. Helbig Ulrich Zähringer

Disaccharide

Strain (injury)

Legionella

Lipid A

10.1016/s0008-6215(97)00210-3

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Citations (29)

Immunofluorescent staining of influenza virus antigen in fixed and paraffin-embedded tissue of experimentally infected hamsters

Acta Histochemica (1989)

Paul Christian Lück Jürgen H. Helbig Wolf Witzleb

Microtome

10.1016/s0065-1281(89)80097-2

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Citations (2)

Typing of Legionella Strains Isolated from Patients and Environmental Sources in Germany, 1990-2000

ASM Press eBooks (2014)

Paul Christian Lück Jürgen H. Helbig

Legionella spp. are gram-negative bacteria responsible for epidemic and sporadic cases of pneumonia after inhalation of contaminated water droplets from a variety of water sources. This chapter presents the distribution of Legionella species, serogroups, and monoclonal subtypes of Legionella strains isolated in Germany and typed at the National Reference Laboratory for Legionella. Environmental strains were isolated on selective buffered charcoal-yeast extract agar from water samples collected at various locations in Germany. The monoclonal subtypes were named according to the reactivity with reference strains. For macrorestriction analysis, chromosomal DNAs were digested overnight with SfiI, AscI, and Notl (New England Biolabs, Schwahlbach, Germany) and separated with the CHEF III System (BioRad Laboratories, Munich, Germany). In this study, all patients had a radiographically confirmed pneumonia confirmed as legionellosis by isolating a Legionella strain from clinical specimens. Cases were classified as nosocomial if the patient had been hospitalized continuously for a minimum of 3 days at the time of disease onset or had been discharged from the hospital less than 10 days before the onset of symptoms. Of the 133 strains grown from clinical samples, 88 (66%) belonged to serogroup 1, 38 (29%) belonged to serogroups 2 to 15, and 7 (5%) were typed as other Legionella species. These data are in good agreement with results from Europe and the United States.

Legionella

Legionnaires' disease

10.1128/9781555817985.ch52

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Citations (9)

Typing Methods for Legionella

Methods in molecular biology (2012)

Christian Lück Norman K. Fry Jürgen H. Helbig Sophie Jarraud Timothy G. Harrison

Legionella

10.1007/978-1-62703-161-5_6

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Citations (46)

Nosocomial Pneumonia Caused by Three Genetically Different Strains of Legionella pneumophila and Detection of These Strains in the Hospital Water Supply

Journal of Clinical Microbiology (1998)

Paul Christian Lück Hans-Martin Wenchel Jürgen H. Helbig

ABSTRACT A 44-year-old woman developed Legionella pneumophila pneumonia after cerebral surgery. Initially, one colony from a clinical specimen and two colonies from water samples, all belonging to serogroup 12, did not match when their DNA restriction patterns were compared. When additional colonies from the water specimens were analyzed, a serogroup 12 strain complementary to that found in the clinical specimen was identified. Other colonies from the clinical specimen were identified as serogroup 12 strains complementary to those identified from the water. In addition, the same serogroup 1 strain was isolated from the patient and the water system.

Legionella

Legionnaires' disease

10.1128/jcm.36.4.1160-1163.1998

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Citations (32)

Localization of Legionella pneumophila Mip Protein Inside Phagosomes of Acanthamoeba castellanii

ASM Press eBooks (2014)

Jürgen H. Helbig Paul Christian Lück Enno Jacobs Martin Witt

More than 10 years ago, genetic analysis successfully characterized for the first time a virulence-associated gene in Legionella pneumophila. The Mip protein has been shown to contribute to the infection of both protozoa and human macrophages. To get morphological evidence for the virulence association of the Mip protein, the immunogold technique was applied to localize this protein on legionellae before and after invasion of Acanthamoeba castellanii, one of the protozoan species that serve as a natural host in the environment. Mip protein of in vitro cultured legionellae is regularly distributed in the bacterial cell wall/cytomembrane complex. Four hours after uptake of agar-grown legionellae by A. castellanii cells, Mip protein was localized inside phagosomes of the host cells. In the last years, many studies used transmission electron microscopy for demonstrating the sequence of events of the intracellular infection of amoeba with legionellae, as well as the immunogold technique for labeling of host cell proteins such as BiP, which is involved in a chaperoning function of proteins across the membrane of the endoplasmatic reticulum.

Legionella

10.1128/9781555817985.ch9

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Citations (0)

Addition of neuA , the Gene Encoding N -Acylneuraminate Cytidylyl Transferase, Increases the Discriminatory Ability of the Consensus Sequence-Based Scheme for Typing Legionella pneumophila Serogroup 1 Strains

Journal of Clinical Microbiology (2007)

Sandra Ratzow Valeria Gaia Jürgen H. Helbig Norman K. Fry Paul Christian Lück

The standard sequence-based method for the typing of Legionella pneumophila serogroup 1 strains was extended by using the gspA and neuA alleles. The use of neuA as a seventh allele for typing significantly increased the index of discrimination calculated for a panel of unrelated strains (from 0.932 to 0.963) and subdivided some known large common complexes (e.g., 1,4,3,1,1,1). This modification to the standard method is proposed as the method of choice in the epidemiological investigation of L. pneumophila infections.

Multilocus sequence typing

Legionella

Sequence (biology)

10.1128/jcm.00261-07

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Citations (250)