Streptococcus ldentification

Lab diagnosis of strepto

1. Lab. Diagnosis of Streptococcus

2. Classification Based on O 2 Aerobes Anaerobes Peptostreptococci Growth on BA α h emolysis β h emolysis γ h emolysis Incomplete h emolysis (green color) Complete h emolysis α / β / no h emolysis Strep. viridans Strep. pneumoniae Enterococcus fecalis Lancefield grouping specific C carbohydrate Ag on cell wall Group A – V ( except I & J, 20 groups ) Griffith typing of Group A on MTR proteins into > 100 serotypes

3. CASE - 1 A 5-year-old male c/o- sore throat and fever treated symptomatically with Paracetamol but still complaining of sore throat, fever, headache & abdominal pain. He was an only child and neither parent was ill. On physical examination, Temp.- 38.4°C. Red- anterior pharynx, tonsillar region, soft palate. Anterior cervical lymph nodes -enlarged and tender. No skin lesions or rashes. did not have a cough, runny nose, or conjunctivitis. Based on his clinical presentation, how to proceed your diagnosis and what organism was most likely causing this patient’s infection?

4. Throat swab G/S CULTURE on BA Small,Pin point, circular, β hemolytic colonies Gpc in chain catalase With pus cells Negative Positive BA with Bacitracin Sensitive Resistant CAMP TEST Gr. A streptococcus Gr. B streptococcus

5. Beta hemolytic Group A Streptococcus ( Streptococcus pyogenes ) 1

6. Lab diagnosis – Strep. pyogenes Specimens: throat swab, pus, blood Microscopy:Gram stain - GPC in chains Culture: BA - beta hemolytic colonies Identification tests - Catalase Negative Bacitracin sensitive Penicillin sensitive B B

7. Beta hemolytic Group B Streptococcus 1

8. Lab diagnosis – Group B Streptococci Specimens: CSF, blood, vaginal smears, urine Microscopy :Gram stain - GPC in chains Culture: BA - beta hemolytic colonies Identification tests Catalase negative Bacitracin resistance CAMP Test + Penicillin sensitive P B

9. Clinical isolate- G/s- GPC in short chain BA- Pin point, β hemolytic colonies Catalase - negative Bacitracin - sensitive CAMP test- negative Isolate ???? 18.05.09 Phase I/ Module VII Dr Ekta 9

10. CASE - 2 64-year-old presented with progressive shortness of breath, a persistent productive cough, purulent sputum, and fever to 39.0°C 2 days prior to admission. He had a 30-year history of smoking. On physical examination Temp.- 37.3°C RR- 18/minute PR- 103 beats/min BP- 154/107 mm Hg and Po2- 92 mm Hg. On Chest auscultation- coarse breath sounds with fine crackles at the left lower base. On chest radiograph -left lower lobe consolidation On admission- WBC count 13,600/ μl with 92% N, and Hb - 9.4 g/dl. Based on his clinical presentation, how to proceed your diagnosis and what organism was most likely causing this patient’s infection?

11. SPUTUM G/S Culture on BA Small,Pin point, circular,draughtsman shaped α hemolytic colonies Lanceolate gram+diplococci catalase With pus cells Negative Positive BA with optochin Sensitive Resistant Streptococcus viridans Bile solubility CA- bleaching effect Pneumococcus

12. Alpha hemolytic streptococci Streptococcus pneumoniae 1

13. Lab diagnosis Specimen: CSF, blood, sputum, pus, swabs Microscopy: Gram stain – GPC in pairs, capsulated, lanceolate shaped Culture BA/ CA – alpha hemolytic colonies CA- bleaching effect Identification tests Catalase – ve Optochin sensitive Bile solubility

14. 18.05.09 Phase I/ Module VII Dr Ekta 14

15. Capsulated 18.05.09 Phase I/ Module VII Dr Ekta 15

16. Differences between Viridans Gp & Pneumococci Point Pneumococci Viridans Gp Morphology Capsulated, lanceolate, diplococci Oval or rounded in chains Quellung test + - Colonies Dome shaped  Draughtsman Dome shaped Growth in liquid Uniform turbidity Granular turbidity with powdery deposits Bile solubility + - Inulin fermentation + - Optochin sensitivity + - Intraperitoneal inoculation in mice Fatal Infection Non-pathogenic

17. Clinical isolate- G/s- Lanceolate gram positive diplococci BA- Pin point, α hemolytic colonies Catalase - negative Optochin - sensitive Bile soluble Isolate ???? 18.05.09 Phase I/ Module VII Dr Ekta 17

18. Medically Important Gram Positive, catalase negative Cocci Family, Genus, species Characteristics Clinical manifestations Streptococcaceae Cocci in chains and in pairs, catalase -negative Streptococcus pneumoniae Diplococci , α - hemolysis Pneumonia , otitis media, sinusitis S. viridans Cocci in chains, α -hemolysis Endocarditis, dental caries S. pyogenes Cocci in chains, Lancefield group A, β - hemolysis Tonsillitis, scarlet fever, skin infections S. agalactiae Chain-forming cocci , group antigen B, β - hemolysis Meningitis/sepsis in neonates