scholarly journals The role of Legionella pneumophila-infected Hartmannella vermiformis as an infectious particle in a murine model of Legionnaire's disease.

1997 ◽  
Vol 65 (12) ◽  
pp. 5330-5333 ◽  
Author(s):  
J K Brieland ◽  
J C Fantone ◽  
D G Remick ◽  
M LeGendre ◽  
M McClain ◽  
...  
Keyword(s):  
Murine Model ◽  
Legionella Pneumophila ◽  
Infectious Particle ◽  
Hartmannella Vermiformis ◽  
Legionnaire's Disease ◽  
Legionnaire’S Disease

scholarly journals Identification of a Gal/GalNAc Lectin in the Protozoan Hartmannella vermiformis as a Potential Receptor for Attachment and Invasion by the Legionnaires' Disease Bacterium

1997 ◽  
Vol 186 (4) ◽  
pp. 537-547 ◽  
Author(s):  
Chandrasekar Venkataraman ◽  
Bradley J. Haack ◽  
Subbarao Bondada ◽  
Yousef Abu Kwaik
Keyword(s):  
Host Cell ◽  
Legionella Pneumophila ◽  
Mammalian Cells ◽  
Kinase Inhibitors ◽  
Tyrosine Phosphatase ◽  
Bacterial Attachment ◽  
Host Proteins ◽  
Hartmannella Vermiformis ◽  
Legionnaire's Disease ◽  
Legionnaire’S Disease

The Legionnaire's disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen which invades and replicates within two evolutionarily distant hosts, free-living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaire's disease. Although attachment and invasion of human macrophages by L. pneumophila is mediated in part by the complement receptors CR1 and CR3, the protozoan receptor involved in bacterial attachment and invasion has not been identified. To define the molecular events involved in invasion of protozoa by L. pneumophila, we examined the role of protein tyrosine phosphorylation of the protozoan host Hartmannella vermiformis upon attachment and invasion by L. pneumophila. Bacterial attachment and invasion were associated with a time-dependent tyrosine dephosphorylation of multiple host cell proteins. This host cell response was highly specific for live L. pneumophila, required contact with viable bacteria, and was completely reversible following washing off the bacteria from the host cell surface. Tyrosine dephosphorylation of host proteins was blocked by a tyrosine phosphatase inhibitor but not by tyrosine kinase inhibitors. One of the tyrosine dephosphorylated proteins was identified as the 170-kD galactose/N-acetylgalactosamine–inhibitable lectin (Gal/GalNAc) using immunoprecipitation and immunoblotting by antibodies generated against the Gal/GalNAc lectin of the protozoan Entamoeba histolytica. This Gal/GalNAc–inhibitable lectin has been shown previously to mediate adherence of E. histolytica to mammalian epithelial cells. Uptake of L. pneumophila by H. vermiformis was specifically inhibited by two monovalent sugars, Gal and GalNAc, and by mABs generated against the 170-kD lectin of E. histolytica. Interestingly, inhibition of invasion by Gal and GalNAc was associated with inhibition of bacterial-induced tyrosine dephosphorylation of H. vermiformis proteins. High stringency DNA hybridization confirmed the presence of the 170-kD lectin gene in H. vermiformis. We conclude that attachment of L. pneumophila to the H. vermiformis 170-kD lectin is required for invasion and is associated with tyrosine dephosphorylation of the Gal lectin and other host proteins. This is the first demonstration of a potential receptor used by L. pneumophila to invade protozoa.

Legionnaire’s Disease

2001 ◽  
Vol 58 (10) ◽  
pp. 592-598
Author(s):  
Andreas F. Widmer
Keyword(s):  
Legionella Pneumophila ◽  
Legionnaire's Disease ◽  
Legionnaire’S Disease ◽  
Legionella Micdadei

Legionellen sind Wasserkeime und können zwei typische Krankheitsbilder auslösen: Das Pontiac-Fieber und die Legionärskrankheit. Letztere ist eine seltene (3–7%), potentiell lebensbedrohliche Pneumonie. In fast allen Fällen ist Legionella pneumophila Serogruppe I für die Pneumonie verantwortlich. Es gibt aber 42 Arten und 64 Serotypen, wobei Legionella micdadei der zweithäufigste Erreger ist. Die Letalität der Legionellenpneumonie liegt immer noch um 5% bis 10% und ist bei hospitalisierten Patienten höher. Etablierte Risiken sind Nikotinabusus, chronisch-obstruktive Pneumopathie, sowie Immunsuppression. Die Kultur bedingt Spezialnährmedien, so dass die Diagnose nicht mit Routinemethoden gestellt werden kann. Die Einführung des Antigentestes im Urin hat die Diagnostik wesentlich verbessert. Eine PCR für Sputum ergänzt die neuen diagnostischen Möglichkeiten, wobei hier die Kosten und die Spezifität die Anwendung auf Spezialfälle einschränkt. Therapie der Wahl sind neuere Makrolide oder alternativ neuere Quinolone, die sich vor allem bei transplantierten Patienten auch als Therapie der ersten Wahl durchgesetzt haben. Die Primärprävention umfasst das Halten der Warmwasserversorgung am Boiler bei 60°C, und an Hähnen zwei Minuten nach Öffnen 50°C.

scholarly journals Community-acquired pneumonia caused by Legionella pneumophila (“Legionnaire's Disease”): a brief overview and clinical observation

2020 ◽  
Vol 30 (3) ◽  
pp. 350-360
Author(s):  
I. S. Tartakovskiу ◽  
S. A. Rachin ◽  
A. I. Sinopal'nikov ◽  
S. A. Rachina ◽  
Y. A. Yanovich ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Clinical Observation ◽  
Community Acquired Pneumonia ◽  
Legionnaire's Disease ◽  
Legionnaire’S Disease

scholarly journals Outbreak of Legionnaire’s Disease Caused by Legionella pneumophila Serogroups 1 and 13

2017 ◽  
Vol 23 (2) ◽  
pp. 349-351 ◽  
Author(s):  
Toshiro Kuroki ◽  
Junko Amemura-Maekawa ◽  
Hitomi Ohya ◽  
Ichiro Furukawa ◽  
Miyuki Suzuki ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Legionnaire's Disease ◽  
Legionnaire’S Disease

scholarly journals Comparative Analysis of Legionella pneumophila and Legionella micdadeiVirulence Traits

1999 ◽  
Vol 67 (8) ◽  
pp. 4134-4142 ◽  
Author(s):  
Amrita D. Joshi ◽  
Michele S. Swanson
Keyword(s):  
Legionella Pneumophila ◽  
Genomic Library ◽  
Intracellular Growth ◽  
Phenotypic Analysis ◽  
Phenotypic Differences ◽  
Sodium Sensitivity ◽  
Legionnaire's Disease ◽  
Epidemiological Profile ◽  
Legionnaire’S Disease ◽  
Legionella Micdadei

ABSTRACT While the majority of Legionnaire’s disease has been attributed toLegionella pneumophila, Legionella micdadei can cause a similar infection in immunocompromised people. Consistent with its epidemiological profile, the growth of L. micdadei in cultured macrophages is less robust than that of L. pneumophila. To identify those features of theLegionella spp. which are correlated to efficient growth in macrophages, two approaches were taken. First, a phenotypic analysis compared four clinical isolates of L. micdadei to one well-characterized strain of L. pneumophila. Seven traits previously correlated with the virulence of L. pneumophilawere evaluated: infection and replication in cultured macrophages, evasion of phagosome-lysosome fusion, contact-dependent cytotoxicity, sodium sensitivity, osmotic resistance, and conjugal DNA transfer. By nearly every measure, L. micdadei appeared less virulent than L. pneumophila. The surprising exception wasL. micdadei 31B, which evaded lysosomes and replicated in macrophages as efficiently as L. pneumophila, despite lacking both contact-dependent cytopathicity and regulated sodium sensitivity. Second, in an attempt to identify virulence factors genetically, an L. pneumophila genomic library was screened for clones which conferred robust intracellular growth on L. micdadei. No such loci were isolated, consistent with the multiple phenotypic differences observed for the two species. Apparently, L. pneumophila and L. micdadei use distinct strategies to colonize alveolar macrophages, causing Legionnaire’s disease.

Legionella pneumophila Pneumonia in Pregnancy: A Case Report and Review of the Literature

2020 ◽  
Vol 20 (2) ◽  
pp. 247-252
Author(s):  
Katherine A. Kleinberg ◽  
Suresh J. Antony
Keyword(s):  
Legionella Pneumophila ◽  
Positive Serology ◽  
X Ray ◽  
Appropriate Treatment ◽  
History Of ◽  
Chest X Ray ◽  
Legionnaire's Disease ◽  
Legionnaire’S Disease ◽  
In Pregnancy

: L. pneumophila is an unusual cause of pneumonia with a prevalence of 2.7%, and it is even more uncommon in pregnancy. To date, only 11 cases of Legionnaire’s Disease in pregnancy have been reported, though this small number could possibly be attributed to underdiagnoses and under documentation. Case Presentation: In this paper, we present a 31-year-old Hispanic female, gravida 4, para 1 from the southwest United States who presented with a 3-week history of fever, worsening cough, dyspnea on exertion, and hypoxemia. Chest x-ray showed bibasilar infiltrates, with positive serology for Legionella IgM and IgG (1:250 and 1:640 respectively), as well as positive urinary antigen. Despite appropriate treatment with azithromycin 500 mg, she continued to have dyspnea and mild respiratory distress. Conclusion: Upon follow up, mother and fetus initially remained stable without any signs of sequelae from Legionnaire’s disease, but the patient miscarried 5 weeks after the second admission to the hospital. The chest x-ray eventually cleared up after almost 21 days of azithromycin.

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