Streptococcus pneumoniae

1. CHAPTER: 5
Streptococcus pneumoniae
Amjad Khan Afridi

2. What is Streptococcus pneumoniae?
 Streptococcus pneumoniae, also called
pneumococcus, is a type of bacteria that
causes many common illnesses, including
pneumonia, ear infections, and sinus
infections.
 Streptococcus pneumoniae can cause serious
infections, such as bloodstream infections
and brain infections, called meningitis.

3. General Characteristics
• Streptococcus pneumoniae, or pneumococcus, are gram-positive, facultative
anaerobic bacteria.
• Pneumococci are common found in respiratory tract and may be isolated from
the nasopharynx of 5–90% of healthy persons.
• Among school-aged children, 20–60% may be carriers.
• Facultative anaerobic member of the genus Streptococcus.
• Alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic
conditions)

4. • They are usually found in pairs (diplococci) and do not form
spores and are nonmotile.
• As a significant human pathogenic bacterium S. pneumoniae
was recognized as a major cause of pneumonia in the late 19th
century.
• Inoculate sample onto blood agar and chocolate agar plate.
• Incubate at 37°C with 5-10% CO2 for 24 – 48 hours.
General Characteristics

5. Colony morphology
• Colonies on blood agar plate are small (0.5
mm), round, shining with alpha-hemolysis (A
green discoloration of the agar around the
colonies).
• Young alpha-hemolytic colonies appear raised,
and in 24 – 48 hours colonies are flattened
with depressed center and is called
draughtsman colony.
• It is due to partial autolysis .

6. Transmission
• Streptococcus pneumoniae are most commonly
found in the human upper respiratory tract,
specifically in the nasopharynx (the nasal
passages).
• Pneumococcus bacteria are spread through
coughing, sneezing, and close contact with an
infected person.
• Symptoms of pneumococcal disease depend on
the part of the body that is infected.

7. Pathogenicity
• The process of Streptococcus pneumonia
infections involves by the following stages.
• (1) colonization,
• (2) local infection,
• (3) systemic dissemination and/or sepsis,

8. Symptoms
• Fever.
• chills and shaking.
• chest pain when breathing in or out.
• shortness of breath.
• cough.
• blood-stained or 'rusty' sputum (phlegm)
• Drowsiness (excessive sleepiness) or confusion
are common symptoms in the elderly.

9. Diagnosis
• Pneumococcal infection is diagnosed by
microscopic examination and growth of the
bacteria from blood, sputum or other
specimens.

10. • Pneumococcal pneumonia caused by
organisms that are susceptible or
intermediately resistant to penicillin responds
to treatment with penicillin, one million units
intravenously every 4 hours, ampicillin, 1g
every 6 hours, or ceftriaxone, 1g every 24
hours. Ease of administration favors the use of
ceftriaxone.

11. Thank You
12
th
April,
2022