B2.5 Streptococcus pneumoniae; Abiotrophia and Granulicatella Flashcards
Streptococcus pneumoniae also known as
PNEUMOCOCCUS and DIPLOCOCCUS
encapsulated, characteristically lancet-shaped which occurs singly, on pairs and short chains
contains antigen referred to as C substance which reacts with CRP
facultative anaerobe requiring an increase CO2 tension (Candle Jar)
Streptococcus pneumoniae
Streptococcus pneumoniae VIRULENCE FACTORS
- Polysaccharide Capsule
- Adherance
- Enzymes
- Pneumolysin O
- Autolysin
- C-substance
- Hemolysin
Enzymes found in Streptococcus pneumoniae
Neuraminidase
Protease
Hyaluronidase
Streptococcus pneumoniae enzyme in charge of degrading surface structures of host tissue
Neuraminidase
Streptococcus pneumoniae enzyme in charge of facilitating bacterial colonization on mucosal surfaces by eliminating Ig
Protease
oxygen-sensitive toxin found in Streptococcus pneumoniae that is cytolytic for cells
Pneumolysin O
S. pneumoniae component that facilitates the release of pneumolysin O and other toxic proteins or inflammatory substance from cells
Autolysin
component of cell wall of S. pneumoniae which is teichoic acid that reacts with CRP resulting in the activation of some nonspecific host immune response
C-substance
RELATED INFECTIONS AND DISEASES with S. pneumoniae
- Lobar Pneumonia
- Meningitis
- Otitis Media
- Endocarditis, Peritonitis, and Bacteremia
- Secondary Atypical Hemolytic Uremic Syndrome
characterized by the presence of voluminous fluid which hastens in the spread of bacteria in the lungs
sudden onset with chills, dyspnea, and cough
most common cause of bacterial pneumonia in elderly and immunocompromised individual
Lobar Pneumonia
Microscopy of sputum from patients with Lobar Pneumonia
large number of S. pneumonia cells and WBC;
absence of oropharyngeal microbiota
follows other S. pneumonia otitis media or pneumonia
most common cause of meningitis in adults
Meningitis
most common isolate in children under 3 years old with recurrent otitis
media
Otitis Media
Specimen of choice for S. pneumoniae
Sputum, Swabs, Pus, CSF and Blood
Specimen characteristic that may indicate S. pneumonia
RUST-TINGED SPUTUM
LABORATORY DIAGNOSIS of S. pneumoniae
- Gram-Stain
- Culture Medium
- Biochemical Test
- Serologic Test
Gram-Stain observations for S. pneumoniae
Gram(+) cocci in pairs = DIPLOCOCCI
cells are slightly pointed = LANCET SHAPE
Culture Medium used for S. pneumoniae
BHIA, TSA with 5% sheep’s RBC and CAP