1.
Structure
a.
Gram-negative diplococcus (about 2 um)
b.
No capsule
c.
Non-motile
d.
Non-spore forming
2.
Pathobiology:
a.
Aerobic bacteria
b.
Has LOS (lipooligosaccharide)
c.
Produces beta-lactamase
d.
Binds to respiratory epithelium and to ECM
components via pili and outer membrane proteins (ex. UspA1 on bacteria binds to
CEACAM1 on human epithelia). This enables invasion of host epithelial cells and
formation of micro colonies and biofilms.
3.
Epidemiology
a.
Can be isolated from sputum
b.
Found in nasopharynx of children (more often
than adults); more often seen during winter months
c.
Found only in humans
d.
Transmitted by respiratory aerosol
4.
Laboratory
diagnosis
a.
Resembles cocci of the genus Neisseria
b.
Catalase positive
c.
Oxidase positive
d.
Blood agar- colonies are “nonhemolytic, round,
opaque, convex, greyish-white”
5.
Disease
manifestations
a.
Bacteremia – seen often in febrile children with
underlying immune dysfunction and URI
b.
Causes local infections – ex. Otitis media,
sinusitis, laryngitis, bronchopneumonia
– primarily in children
c.
More rare – systemic infections ex.
Asmeningitis, endocarditis
d.
In older patients with compromised immune system
(COPD)– will present as lower respiratory tract infections - bronchitis and pneumonia
6. Therapy
a.
Can treat with cotrimoxazole, erythromycin,
sulfadimidine, tetracycline
b.
Often resistant to penicillin, ampicillin,
amoxicillin, trimethoprim
7. Prevention and control
a.
Potential target for vaccine due to large
molecular weight surface protein expression