Klebsiella pneumoniae has serious clinical and infection control implications affecting respiratory or urinary tract. These patients have increased tendency to develop lung abscess, cavitation and empyema. Legionella is the causative agent of Legionaires disease and Pontiac fever. Pneumocystis jiroveci (PCP) caises life threatening opportunistic infections in immunocompromised patients worldwide. Salmonella species are the etiologic agents of Typhoid and Paratyphoid fevers & food borne diseases. They are also known to cause pneumonia.