<prompt> Most common causative organism of community acquired pneumonia isKlebsiella pneumoniaeStreptococcus pneumoniaeMycoplasma pneumoniaeLegionella pneumoniae  <response>: B Streptococcus pneumoniae Community acquired pneumonia: Occurs outside of the hospital or less than 48 hours after admission, in a patient who is not hospitalized or residing in a long-term care facility for more than 14 days before onset of symptoms. Risk factors for increased mortality and morbidity rates from community acquired pneumonia. Advanced age; Alcholism; Comorbid medical conditions; Altered mental status; Resp. rate 30min; Hypotension 9060 mm Hg; BUN 30 mgdl. A predictor of patients risk and mortality from community acquired pneumonia has been developed and validated by pneumonia patient outcome research team PORT. Community acquired pneumonia is characterized by: Sign and symptoms of acquired lung infection--fever, hypothermia, cough with or without sputum, dyspnea, sweatrigors. Bronchial breath sounds, rales. Parenchymal infiltrate on chest radiograph. Most common bacterial pathogen-- streptococcus pneumoniae in about two-thirds of cases. Other pathogens--H. influenza Mycoplasma, Pneumoniae, Chlamydia, Pneumoniae, Staph, aureus, N. meningitidis Klebsiella pneumoniae. 