The document summarizes information about Streptococcus pneumoniae (pneumococcus): 1. It is a gram-positive coccus that appears in pairs (diplococci) or chains under microscopy. It is identified by being alpha-hemolytic, optochin-sensitive, and exhibiting a Quellung reaction showing its polysaccharide capsule. 2. Pneumococcus is a common cause of pneumonia as well as other invasive diseases. Virulence factors like its polysaccharide capsule allow it to evade the immune system and cause disease. 3. Treatment involves penicillins or other antibiotics. Vaccines targeting the 90+ capsular serotypes help prevent pneumococcal disease.

1. DR KAMRAN AFZAL ASST PROF MICROBIOLOGY Streptococcus pneumoniae

2. Gram positive cocci Catalase Negative Streptococci (Chains) Catalase Positive Staphylococci (Clusters) Haemolysis on Blood agar Alpha or incomplete Strept pneumoniae Or viridans Beta or complete Gropu A, B, C, D Coagulase

4. Clinically Important Streptococci Group Species Lancefield Group Type of Haemolysis Pyogenic S. pyogenes S. agalactiae S. eqisimilus A B C β β β Mitis S. pneumoniae S. mitis S. sanguis O O H α α α Anginosus S. anginosus G, F α Salivarius S. salivarius K γ Bovis S. bovis D α Mutans S. mutans No γ

10. Transmission And Colonisation

11. Pathogenesis

13. Pneumococcal Disease Wenger et al., J Infect Dis, 1990 Pathogenic agents in bacterial meningitis in persons aged  60 years in the USA Others 26% Streptococcus pneumoniae 49% Group B streptococcus 3% Haemophilus influenzae 4% Neisseria meningitidis 4% Listeria monocytogenes 14%

14. Clinical Features Septicemia Pneumonia Fever Hypotension Acute confusion Chills Dyspnea Tachypnea Headache Tachycardia Fever Dyspnea Lung consolidation Hemoptysis chills Chest pain Cyanosis malaise Rust colored sputum

32. X-ray chest

33. Sputum Gram’s Stain

34. Culture

35. Susceptible to Optochin

36. Sensitivity testing

38. Special technique..