II. Pathophysiology

  1. Characteristics
    1. No Lancefield Group assigned
    2. Gram Positive Cocci in Pairs (Diplococcus)
    3. Alpha-hemolytic Streptococcus
  2. Virulence Factors
    1. Polysaccharide Capsule protects it from Phagocytosis
    2. With infection, antibodies develop to capsule, but only protect against one of 84 serotypes
      1. Vaccines are polyvalent (21 of the most virulent serotypes as of 2024)
  3. Infections
    1. Penicillin Resistant Pneumococcus
    2. Bacterial Pneumonia (Pneumococcal Pneumonia)
    3. Bacterial Meningitis (Pneumococcal Meningitis)
    4. Otitis Media

III. Labs

  1. Microscopy
    1. Gram Positive Cocci in Pairs
    2. Alpha-hemolytic Streptococcus (like Viridans Streptococcus)
      1. Green coloration on Blood agar plate (BAP)
  2. Differentiated from Viridans Streptococcus (also Alpha-hemolytic Streptococcus)
    1. Quellung Reaction (Neufeld reaction)
      1. Bacterial slide mixed with capsular antibodies and methylene blue
      2. Pneumococcal capsule swells in response to specific antibodies
    2. Bile solubility (10% deoxycholate)
      1. Streptococcus Pneumoniae dissolves in bile acids, while Viridans remains intact
    3. Optochin or "P" disc susceptibility (ethylhydrocupreine hydrochloride impregnated plate)
      1. Streptococcus Pneumoniae growth is inhibited by Optochin

IV. Prevention

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Ontology: Streptococcus pneumoniae (C0038410)

Definition (NCI) A Gram-positive, alpha-hemolytic diplococcus aerotolerant anaerobe Streptococcus species.
Definition (NCI_CDISC) Any bacterial organism that can be assigned to the species Streptococcus pneumoniae.
Definition (MSH) A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.
Definition (CSP) gram positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.
Concepts Bacterium (T007)
MSH D013296
SnomedCT 9861002
LNC LP14410-2
English Diplococcus pneumoniae, Pneumococcus, STREP PNEUMONIAE, S. pneumoniae, Streptococcus pneumoniae (Klein 1884) Chester 1901, diplococcus pneumoniae, streptococcus pneumoniae, s. pneumoniae, streptococcus pneumoniae bacteria, pneumococcal, pneumococcus, Streptococcus (Diplococcus) pneumoniae, STREPTOCOCCUS PNEUMONIAE, Micrococcus pneumoniae, DIPLOCOCCUS PNEUMONIAE, Streptococcus pneumoniae (organism), Streptococcus pneumoniae
Swedish Streptococcus pneumoniae
Czech Streptococcus pneumoniae, pneumokok, Diplococcus pneumoniae
Finnish Pneumokokki
Italian Diplococcus pneumoniae, Pneumococcus, Streptococcus pneumoniae
Russian PNEVMOKOKKI, STREPTOCOCCUS PNEUMONIAE, ПНЕВМОКОККИ
Japanese ストレプトコッカス・ニューモニア, ストレプトコッカス・ニゥモニア, ストレプトコッカスニューモニエ, 肺炎球菌, 肺炎レンサ球菌, 肺炎双球菌, 肺炎連鎖球菌
Croatian STREPTOCOCCUS PNEUMONIAE
French Pneumococcus, Pneumocoque, Streptocoque pneumoniae, Diplococcus pneumoniae, Streptococcus pneumoniae
Polish Streptococcus pneumoniae, Pneumokoki, Dwoinki zapalenia płuc
Norwegian Pneumococcus, Streptococcus pneumoniae, Diplococcus pneumoniae
Spanish Streptococcus pneumoniae (organismo), neumococo, Streptococcus pneumoniae, Diplococcus pneumoniae, Pneumococcus
German Diplococcus pneumoniae, Pneumococcus, Streptococcus pneumoniae
Dutch Diplococcus pneumoniae, Pneumococcus, Pneumokok, Streptococcus pneumoniae
Portuguese Diplococcus pneumoniae, Pneumococcus, Streptococcus pneumoniae