Legionella pneumophila :: Essays Papers

legionella pneumophila GRAPHIntroductionLegionella pneumophila ar disconfirming rods. They are very difficult to culture because of their compound nutrient requirements, such as cysteine, high concentrations of iron, and the use of activated oxford gray agar. They survive as intracellular pathogens of either protozoa or man macrophages. They are most often found in stagnant water system reservoirs like air conditioning cooling towers, whirlpool spas, humidifiers, faucets and shower heads, and are infectious when inhaled. L. pneumophila was first set and named after the American Legion conventionalism of 1976, held in Philadelphia, PA. 182 people became infected, and 29 died (most of which were older men or tail end smokers). Although this organism was named in the 70s, retrospective studies showed cases since 1943. GRAPHDiseasesL. pneumophila has a very wide range of effects. Healthy individuals usua lly go through an symptomless seroconversion, while less healthy people may undergo Pontiac feverishness or Legionnaires Disease (LD). In 1968, employees at the county health department in Pontiac, Michigan 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 need treatment. Infected individuals will show fever, muscle aches, and headaches, and usually determine between 2-5 days. Pontiac Fever will present symptoms anywhere from a equal of hours to a couple of days after exposure, while LD takes 2-10 days to incubate. LD patients hire 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 cancer or AIDS patients.VirulenceBeing a gram-negative bacterium, L. pneumophila has lipopolysaccharide s (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.