legionella pneumophila ( l. pneumophila ) is a gram-negative bacterium which causes ‎legionnaires’ disease as well pontiac fever. the legionella infections in patients suffering from ‎neutropenia- as a common complication of cancer chemotherapy- can distribute rapidly. we ‎aimed to detection of l. pneumophila in haematological malignancy suffering patients with ‎nuetropenic fever by targeting t...

UNLABELLED Garden soils were investigated as reservoirs and potential sources of pathogenic Legionella bacteria. Legionella bacteria were detected in 22 of 177 garden soil samples (12%) by amoebal coculture. Of these 22 Legionella-positive soil samples, seven contained Legionella pneumophila Several other species were found, including the pathogenic Legionella longbeachae (4 gardens) and Legion...

In order to determine the role of ferrous iron transport in Legionella pathogenesis, we identified and mutated the feoB gene in virulent Legionella pneumophila strain 130b. As it is in Escherichia coli, the L. pneumophila feoB gene was contained within a putative feoAB operon. L. pneumophila feoB insertion mutants exhibited decreased ferrous but not ferric iron uptake compared to the wild type....

Macrophages from C57BL/6J (B6) mice restrict growth of the intracellular bacterial pathogen Legionella pneumophila. Restriction of bacterial growth requires caspase-1 and the leucine-rich repeat-containing protein Naip5 (Birc1e). We identified mutants of L. pneumophila that evade macrophage innate immunity. All mutants were deficient in expression of flagellin, the primary flagellar subunit, an...

Extrapulmonary infections caused by Legionella spp. other than Legionella pneumophila are rare. We report what is, to our knowledge, the first description of a prosthetic joint infection due to Legionella spp. Systematic testing of samples with suspected prosthetic infection by molecular biology techniques was essential. Legionella micdadei should be added to the list of microorganisms causing ...

Legionella anisa is one of the most frequent species of Legionella other than Legionella pneumophila in the environment and may be hospital acquired in rare cases. We found that L. anisa may mask water contamination by L. pneumophila, suggesting that there is a risk of L. pneumophila infection in immunocompromised patients if water is found to be contaminated with Legionella species other than ...

The development of plasmid-mediated gene expression control in bacteria revolutionized the field of bacteriology. Many of these expression control systems rely on the addition of small molecules, generally metabolites or non-metabolized analogs thereof, to the growth medium to induce expression of the genes of interest. The paradigmatic example of an expression control system is the lac system ...

Rifampin in combination with erythromycin is a recommended treatment for severe cases of legionellosis. Mutations in the rpoB gene are known to cause rifampin resistance in Escherichia coli and Mycobacterium tuberculosis, and the purpose of the present study was to investigate a possible similar resistance mechanism within the members of the family Legionellaceae. Since the RNA polymerase genes...

Sir, Legionella species are responsible for 1%– 5% of cases of community-acquired pneumonia. Legionella pneumophila serogroup 1 (SG1) accounts for .90% of Legionnaires’ disease (LD) in North America and Europe and is the cause of significant mortality. The mortality rate among patients with L. pneumophila infections continues to be high, up to 26%. The antimicrobial agents most commonly used fo...

The genus Legionella comprises over 60 species, which are important human pathogens. Secretion systems in Legionella pneumophila have been studied extensively because of the essential role of protein secretion in bacterial infection. However, there are few reports describing the secretion systems in non-L. pneumophila species. In this study, we analyzed the distribution of secretion systems in ...