Electrophoretic analysis of lipopolysaccharide (LPS) extracts from 430 previously serotyped Legionella isolates and 28 American Type Culture Collection (ATCC) non-Legionella pneumophila Legionella reference strains representing different Legionella species and serogroups has been performed. LPS was prepared from Legionella suspensions by sonication and proteinase K digestion. Following sodium d...

The Legionella genus comprises more than 60 species. In particular, Legionella pneumophila is known to cause severe illnesses in humans. Legionellaceae are ubiquitous inhabitants of aquatic environments. Some Legionellaceae are motile and their motility is important to move around in habitats. Motility can be considered as a potential virulence factor as already shown for various human pathogen...

Many respiratory diseases are caused by extracellular bacterial pathogens; however, two very important lung infections are due to intracellular pathogens, Legionnaires' disease and tuberculosis. Legionnaires' disease remains problematic due to our inability to predict where sporadic epidemics will occur and the speed at which the bacterium debilitates its victims. The development of better meth...

Legionella pneumophila is the causative pathogen of Legionnaires' disease, which is characterized by severe pneumonia. In regard to the pathophysiology of Legionella infection, the role of inflammatory phagocytes such as macrophages has been well documented, but the involvement of dendritic cells (DCs) has not been clarified. In this study, we have investigated the immune responses that DCs gen...

In this study, the photoinactivation of Legionella by visible light is investigated. The success of this approach would offer new prospects for technical water disinfection and maybe even for therapeutic measures in cases of Legionella infections. Therefore, Legionella rubrilucens was dispensed on buffered charcoal yeast extract medium agar plates and illuminated with different doses of violet ...

We report here the draft genome sequences of two Legionella pneumophila variant strains (JR32 and Lp01_666) originally derived from a Philadelphia-1 clinical isolate, domesticated in Japan, with distinct susceptibility to amoebae. Detailed genomic analysis will allow us to better understand Legionella adaptation and survival mechanisms in host cells.

In France, the clinical distribution of Legionella species and serogroups does not correspond to their environmental distribution. Legionella pneumophila serogroup 1 is more prevalent among clinical isolates (95.4%) than in the environment (28.2%), whereas L. anisa is more frequent in the environment (13.8%) than in the clinical setting (0.8%).

Previous reports have suggested that nosocomial and community Legionella pneumonia cases are similar. However, community and hospital characteristics, such as aquatic environment, antibiotic pressure (usage) and populations, are quite different, leading to the suspicion that Legionella infection may differ in the two settings. Univariate and multivariate analyses were performed to compare demog...

Similar to Ipaf and caspase-1, the Nod-like receptor protein Naip5 restricts intracellular proliferation of Legionella pneumophila, the causative agent of a severe form of pneumonia known as Legionnaires' disease. Thus, Naip5 has been suggested to regulate Legionella replication inside macrophages through the activation of caspase-1. In this study, we show that cytosolic delivery of recombinant...

Six strains of a new species, Legionella sainthelensi, were isolated from freshwater in areas affected by the volcanic eruptions of Mt. St. Helens in the state of Washington. Strains of L. sainthelensi are culturally and biochemically similar to other legionellae. They grow on buffered charcoal yeast agar but not on media that lack cysteine. They are gram-negative, nonsporeforming, motile rods ...