Gram Positive Cocci (GPC)

1. Gram Positive Cocci(GPC) Streptococcus (GPC in chains) Streptococcus pyogenes (Group A ) Streptococcus agalactiae (Group B) Enterococcus (Group D) Streptococcus pneumoniae (Pneumococcus) Streptococcus viridans Staphylococcus (GPC in clusters) Staphylococcus aureus Staphylococcus epidermidis Staphylococcus saprophyticus Dr B V Navaneeth Dept of Microbiology

2. Streptococcus 1 Dr B V Navaneeth Dept of Microbiology

3. Gram positive cocci in chains (short or long) & pairs Grow on blood agar (fastidious) Catalase negative Usually sensitive to penicillin General features Dr B V Navaneeth Dept of Microbiology

4. Clinically Important Species Streptococcus pyogenes (Group A) • Respiratory infections Pharyngitis (sore throat) • Non suppurative complications • Skin & subcutaneous infections Pyoderma Erysipelas, impetigo Acute rheumatic fever Cellulitis, necrotising fasciitis (flesh eating bacteria) Acute glomerulonephritis Streptococcus agalactiae (Group B) Puerperal sepsis Neonatal meningitis Dr B V Navaneeth Dept of Microbiology

5. Clinically Important Species Viridans streptococci Endocarditis & Dental caries Streptococcus pneumoniae Pneumonia & Meningitis Empyema, pericarditis, otitis media, sinusitis, conjunctivitis, arthritis, peritonitis Enterococcus fecalis UTI, wound infection, endocarditis Septicemia, peritonitis, intra-abdominal abscess Dr B V Navaneeth Dept of Microbiology

6. Group A Streptococcus 1 Dr B V Navaneeth Dept of Microbiology

7. Lab diagnosis – GABHS Specimens: throat swab, pus, blood, Smears: GPC in chains BA culture: beta hemolysis Catalase Negative Bacitracin sensitive Penicillin sensitive Grouping by LA ASO titre / ADNase B test No vaccine to prevent Dr B V Navaneeth Dept of Microbiology

8. Group B Streptococcus 1 Normal flora in GIT, lower genital tract Neonatal meningitis (early / delayed) Puerperal sepsis Dr B V Navaneeth Dept of Microbiology

9. Lab diagnosis GBS Specimens: CSF, blood, vaginal smears, urine Smears: GPC in Chains BA culture: beta hemolysis Catalase Negative Bacitracin resistance CAMP Test + Hydrolysis of sodium hippurate Penicillin sensitive No vaccine available Dr B V Navaneeth Dept of Microbiology

10. Group D Streptococcus 1 Dr B V Navaneeth Dept of Microbiology

11. Group D Streptococcus Enterococcus E fecalis E faecium Normal flora in GIT, lower genital tract Nosocomial / opportunistic pathogen UTI, wound infection, endocarditis Septicemia, peritonitis, intra-abdominal abscess Dr B V Navaneeth Dept of Microbiology

12. Lab diagnosis -Enterococcus Specimens: urine, pus, blood Smears: GPC in pairs or short chains BA culture: alpha / beta / no hemolysis Catalase Negative Bile esculin positive Positive growth in 6.5% Nacl Penicillin resistance Penicillin + gentamicin or vancomycin Dr B V Navaneeth Dept of Microbiology

13. Pneumococcus 1 Dr B V Navaneeth Dept of Microbiology

14. Streptococcus pneumoniae Upper respiratory tract Carriers Diseases Pneumonia & Meningitis Empyema, pericarditis, otitis media, sinusitis, conjunctivitis, arthritis, peritonitis Penicillin, 3GC, imipenem, vancomycin Treatment Prevention Killed pneumococcal vaccine (23 most prevalent types) Dr B V Navaneeth Dept of Microbiology

15. Lab diagnosis - SP Specimens: CSF, blood, sputum, pus, swabs Smears: GPC in pairs, lanceolate, capsulated BA culture: alpha hemolysis Catalase Negative Optochin sensitive Bile solubility + Quellungs reaction + Dr B V Navaneeth Dept of Microbiology

16. Differences between Viridans Gp & Pneumococci Dr B V Navaneeth Dept of Microbiology

17. Staphylococcus 1 Dr B V Navaneeth Dept of Microbiology

18. General features Gram positive cocci in clusters Facultative anaerobes Catalase positive Major components of normal flora – skin & nose Resistant to dry, many drugs and disinfectants Dr B V Navaneeth Dept of Microbiology

19. Clinically Important Species Staphylococcus aureus • Cutaneous infections • Toxic mediated infections Folliculitis, furuncle, carbuncle, impetigo, burns and wounds Staphylococcal scalded skin syndrome (SSSS) Toxic Shock Syndrome (TSS) • Deep infections Osteomyelitis, abscessess, pneumonia, endocarditis, pyomyositis Food poisoning Kawasaki disease Staphylococcus epidermidis Device associated infections Heart valve, hip prosthesis, pace maker, vascular graft, I.v catheter Staphylococcus saprophyticus UTI in young women Dr B V Navaneeth Dept of Microbiology

20. Lab diagnosis – S aureus Specimens: wound swab, pus, blood, Smears: GPC in clusters BA culture: beta hemolysis NA culture: golden yellow non diffusible pigment Mannitol Salt Agar: yellow colonies Catalase postive Coagulase positive Antibiotic susceptibility test Phage typing Dr B V Navaneeth Dept of Microbiology

21. Treatment Drain infected area Antibiotics: penicillins , cephalosporins, erythromycin, clindamycin, vancomycin Methicillin resistant staphylococcus aureus (MRSA): Resistance to penicillinase resistance group of antibiotics like methicillin. Hospital acquired infections, Vancomycin drug of choice. Prevention • Carrier status prevents complete control • Proper hygiene, segregation of carrier from highly susceptible individuals • Good aseptic techniques when handling surgical instruments • Control of nosocomial infections • Treatment with: Bacitracin, Chlorhexidine (locally), Vancomycin Dr B V Navaneeth Dept of Microbiology

22. Staphylococcus epidermidis Major component of skin flora Opportunistic infection < common than S.aureus Nosocomial infections: shunts, catheters, artificial heart valves / joints (device associated infections) Identification BA: Non - hemolytic NA: Non-pigmented Mannitol: No yellow colonies Coagulase negative Beta lactam antibiotics or vancomycin Dr B V Navaneeth Dept of Microbiology

23. Staphylococcus saprophyticus Urinary tract infections in young women Coagulase-negative Differentiated from S. epidermidis by Novobiocin resistant Beta lactam antibiotics or vancomycin Dr B V Navaneeth Dept of Microbiology

24. Dr B V Navaneeth Dept of Microbiology