STREPTOCOCCUS PNEUMONIAE

WHAT IS IT?

• The route by which this organism is spread is from human to human in the form of aerosol droplets. When inside the host the organism’s primary site of pneumococcal colonization is the nasopharynx. From this site it can aspire to the lungs, eventually spread to the blood and traverse the blood-brain barrier to the meninges, once inside the blood it can cause infections throughout the body.

MICROBIOLOGICAL CHARACTERISTICS

• Gram-positive
• Usually found as diplococci
• Either short chains or single
• When cultured on blood agar they demonstrate alpha hemolysis
• Non-motile

DISEASES

• Leading cause of pneumonia
• Meningitis
• Otitis media
• Bacteremia
• Peritonitis
• Sinusitis

SYMPTONS

• Sudden chill
• Fever
• Cough
• Pleuritic pain
• Red/Brown sputum

DIAGNOSIS

• A gram stain is performed from the sputum of the infected patient
• The presence of neutrophils and greater than ten gram-positive diplococci
• When on blood agar the organism should exhibit alpha-hemolysis, which is characterized as a zone of green coloring around the colonies of bacteria on the agar
• The streaked organisms must also exhibit bile or optochin sensitivity

TREATMENT

• For severe pneumococcal infections penicillin G is used
• For mild pneumococcal infections penicillin V is used

SOURCES

• http://web.uconn.edu/mcbstaff/graf/Student%20presentations/Streptococcuspne...
• http://wwwnc.cdc.gov/travel/diseases/pneumococcal-disease-streptococcus-pne...