Legionella feeleii : pneumonia or Pontiac fever? Bacterial virulence traits and host immune response

AbstractGram-negative bacteriumLegionella is able to proliferate intracellularly in mammalian host cells and amoeba, which became known in 1976 since they caused a large outbreak of pneumonia. It had been reported that different strains ofLegionella pneumophila, Legionella micdadei, Legionella longbeachae, andLegionella feeleii caused human respiratory diseases, which were known as Pontiac fever or Legionnaires ’ disease. However, the differences of the virulence traits among the strains of the single species and the pathogenesis of the two diseases that were due to the bacterial virulence factors had not been well elucidated.L. feeleii is an important pathogenic organism in Legionellae, which attracted attention due to cause an outbreak of Pontiac fever in 1981 in Canada. In published researches, it has been found thatL. feeleii serogroup 2 (ATCC 35849, LfLD) possess mono-polar flagellum, andL. feeleii serogroup 1 (ATCC 35072, WRLf) could secrete some exopolysaccharide (EPS) materials to the surrounding. Although the virulence of theL. feeleii strain was evidenced that could be promoted, the EPS might be dispensable for the bacteria that caused Pontiac fever. Based on the current knowledge, we focused on bacterial infection in human and murine host cells, intracellular growth, cytopathogenicity, stimulatory capacity of cytokines secretion, and pathogenic effects of the EPS ofL. feeleii in this review.
Source: Medical Microbiology and Immunology - Category: Microbiology Source Type: research