Legionella pneumophila :: Essays Papers

Legionella pneumophila GRAPHIntroductionLegionella pneumophila be gram-negative rods. They are very difficult to culture because of their complex food for apprehension requirements, such as cysteine, high concentrations of iron, and the use of playactivated charcoal agar. They stand up as intracellular pathogens of either protozoa or human macrophages. They are most often found in stagnant water reservoirs handle air conditioning cooling towers, whirlpool spas, humidifiers, faucets and shower heads, and are pathogenic when inhaled. L. pneumophila was first identified and named after the American Legion convention of 1976, held in Philadelphia, PA. 182 people became infected, and 29 died (most of which were older men or pansy smokers). Although this beingness was named in the 70s, retrospective studies showed cases since 1943. GRAPHDiseasesL. pneumophila has a very enormous range of effects. Healthy individuals usually go through an asymptomatic seroconversion, epoch less healthy people may undergo Pontiac Fever or Legionnaires Disease (LD). In 1968, employees at the county health department in Pontiac, dinero came down with a fever, but the responsible pathogen was non identified at the time. It was frozen and later diagnosed as L. pneumophila. Pontiac Fever, being milder than LD, generally does not bring treatment. Infected individuals will show fever, muscle aches, and headaches, and usually recover among 2-5 days. Pontiac Fever will present symptoms anywhere from a couple of hours to a couple of days after exposure, while LD takes 2-10 days to incubate. LD patients have fever, chills and a cough, with x-rays showing pneumonia. This more severe form usually prevails in elderly, cigarette smokers, people with chronic lung disease, or those who are immunocompromised, such as crab louse or AIDS patients.VirulenceBeing a gram-negative bacterium, L. pneumophila has lipopol ysaccharides (LPS) that act as endotoxin within a human host. The presence of a flagella is thought to mediate adherence to human lung cells, thereby causing infection, since flagella-less strains do not cause disease. Once attached to human cells, the organism is engulfed by a macrophage where is utilizes the internal environment to multiply.