Streptococcus pneumoniae

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