Clinical and lab aspect of anaerobic infection

1. Clinical and lab aspect of anaerobic infection Ali Somily MD, FRCPC,ABMM

2. Classification • Anaerobic spore forming bacilli (Clostridia) • Gram negative bacilli non-sporing forming (Bacteroides) • Anaerobic streptococci (Peptostreptococcus) • Anaerobic staphylococcus (Peptococcus) • Gram negative diplococci (Veillonella) • Gram positive bacilli (Actinomyces)

3. Anaerobiosis • Lack cytochrome-cannot use oxygen as hydrogen acceptor • Most Lack • Catalase • Peroxidase • Contain flavoproteinso in the presence of oxygen produce H2O2 which is toxic • Some lack enzyme superoxide dismutase so many killed , peroxide and toxic radicales enzyme like fumaratereductase must be in reduced form to work

4. HABITATI : • These organism are normal flora in: • A. Oropharynx • eg. 1. Bacteroides melaninogenicus • Now called provetella melaninogenicus • 2. Fusobacteria • 3. Veillonella

5. HABITAT II: • B. Gastrointestinal tract • Found mainly in the large colon in large numbers • Total number of anaerobes = 10 11 • While all aerobes (including E. coli) = 10 4 • examples are • (1) B acteroides fragilis • (2) Bifidobacterium species • C. Female genital tract (mainly in the vagina)

6. INFECTIONS CAUSED BY ,NONSPORING ANAEROBES • A. The head, neck and respiratory tract • B. The lower abdomen and the pelvis

7. FEATURES OF ANAEROBIC INFECTIONS Characterized by • Infections are always near to the site of the body which are habitat. • Infection from animal bites. • Deep abscesses • The infections are also polymicrobial foul smell • Gas formation • Detection of "Sulphur granules"' due to actinomycosis • Failure to grow organism from pus if not culture anaerobically. • Failure to respond to usual antibiotics.

8. INFECTIONS BEGIN • DISRUPTION OF BARRIERS • TRAUMA • OPERATIONS • CANCEROUS INVASION OF TISSUES • DISRUPTION OF BLOOD SUPPLY • DROPS OXYGEN CONTENT OF TISSUE • DECREASE IN Eh POTENTIAL • TISSUE NECROSIS

9. WHAT ARE THE INFECTION CAUSED BY THESE ANAEROBIC ORGANISMS I • Post operative wound infection • Brain abscess • Dental abscesses • Lung abscess • Intra abdominal abscess, appendicitis, diverculitis • All these infection can cause bacteriaemia

10. WHAT ARE THE INFECTION CAUSED BY THESE ANAEROBIC ORGANISMS II • Infection of the female genital tract • Septic abortion • Puerperalinfection or sepsis • Endometritis • Pelvic abscess • 12. Other infections • a)Breast abscess in puerperal sepsis • b) Infection of diabetic patients (diabetic foot infections). • c) Infection of pilonidal sinus

11. ORAL & DENTAL • > 400 SPECIES OF ANO2 IN MOUTH • MOST INFECTIONS = POLYMICROBIC • MIXED ORGANISMS • ENTER AS A GROUP • ANO2 NOT INITIAL INVADER • USUALLY SECONDARY • 1ST ORGANISM DECREASES [O2] & Eh

12. ORAL & DENTAL • COMMONLY ASSOCIATED WITH • DENTAL ABSCESSES • ROOT CANALS • JUVENILE PERIODONTITIS • ADULT PERIODONTITIS • CLENCHED FIST INJURIES

13. ENT – HEAD & NECK • CHRONIC OTITIS MEDIA • CO-PATHOGENS WITH CHRONIC STREP TONSILLITIS • ACUTE SINUSITIS • POST-DENTAL EXTRACTIONS OR TRAUMA • 2o INVADER

14. ENT – HEAD & NECK • VINCENT’S ANGINA • COMBINATION OF FUSOBACTERIUM & SPIROCHETE SPECIES OVERGROWTH • ANAEROBIC PHARYNGITIS • GRAY MEMBRANE • FOUL ODOR

15. Vincent’s disease • Trench mouth • Sudden onset of pain in the gingiva (mastication) • Necrosis of the gingiva • interdental papilla • a marginated, punched-out, and eroded appearance • A superficial grayish pseudomembrane • altered taste sensation is present • Fever, malaise, and regional lymphadenopathy

16. Ludwig’s Angina

17. Lemierre Syndrome

18. Expansion of the retropharyngeal soft tissues

19. PLELRO PULMONARY I FECTION • ASPIRATION LUNG ABSCESS • ASPIRATION PNEUMONIA • M ETASTATIC LUNG ABSCESS • BRONCHIACTSIS • ALL OF ABOVE CAN CAUSE EMPYEMA

20. LUNG & PLEURAL • ASPIRATION PNEUMONIA • EMPHYSEMA • LUNG ABSCESSES • MALIGNANCIES • LEUKOPENIA

21. THORACIC ACTINOMYCOSIS

22. THORACIC ACTINOMYCOSIS

23. ACTINOMYCOSIS

24. Molar tooth appearance of Actinomyces israeIii

25. Macroscopic colony (left) Gram stain (right) of Actinomyces

26. SKIN & SOFT TISSUE • TRAUMATIZED & DEVITALIZED TISSUE • TRAUMATIC WOUNDS • HUMAN/ANIMAL BITES • ISCHEMIA OF EXTREMITIES • DIABETES • ATHEROSCLEROSIS

27. CLENCHED FIST INJURIES

28. DIABETIC FOOT

29. HUMAN BITE

30. NECROTIZING CELLULITIS

31. PUERPERAL INFECTION SEPTIC ABORTION • PUERPERAL ABSCESS • SEPTIC ABORTION • BACTERAEMIA • PELVIC ABSCESS • ADENXAL ABSCESS • PERITONITIS • ENDOMETRITIS

32. ABDOMINAL INFECTIONS • MANIPULATION, INVASION OR TRAUMA TO GI TRACT • TRAUMA • SURGERY • APPENDICITIS • MALIGNANCIES • COLON CANCER

33. CNS • HEAD TRAUMA • HEMATOGENOUS SPREAD • FROM ANY INFECTED BODY SITE • GEOGRAPHIC SPREAD • SINUS INFECTIONS • DENTAL ABSCESSES

34. BONE & JOINT • HEMATOGENOUS SPREAD • TRAUMA • PERIVASCULAR DISEASE • JUVENILE PERIODONTITIS

35. OTHERINFECTIONS • GRAM NEGATIVE BACTREMIA • BREAST ABSCESS • AXILLARY ABSCESS • INFECTION OF DIABETIS EG.DIABETIC ULCERS • INFECTION OF PILONIDAL SINUS • PARONYCHIA

36. LABORATORY DIAGNOSIS: • When anaerobic infection is suspected; • a) Specimens have to be collected from the site containing necrotic tissue. • b) Pus is better than swabs. • c) Specimens has to be send to the laboratory within 1/2 hour why? • d) Fluid media like cooked meat broth are the best culture media. • e) Specimens have to incubated anaerobically for 48 hours.

37. Anaerobic chamber

38. TREATMENT: • Bacteroides fragilis is always resistant to penicillin. • But penicillin can he used for other anaerobes • Flagyl (metronidazole) is the drug of choice. • Clindamycin can also be used.

39. CLASSIFICATION • Anaerobic spore forming bacilli (Clostridia) • Gram negative bacilli nonsporing (Bacteroides) • Anaerobic streptococci (Peptostreptococcus) • Anaerobic staphylococcus (Peptococcus) • Gram negative diplococci (Veillonella) • Gram positive bacilli (Actinomyces)

40. ORGANISM GROUPS • GRAM NEGATIVE RODS • BACTEROIDES • PREVOTELLA • PORPHYROMONAS • FUSOBACTERIUM • BUTYRIVIBRIO • SUCCINOMONAS

41. Bacteroides fragilis

42. Propionibacterium

43. Fusobacteriumnucleatum

44. BACTEROIDES • STRICT ANAEROBE • PLEOMORPHIC • GRAM NEGATIVE BACILLI (COCCO BACILLI) • NORMAL FLORA IN • OROPHARYNX • GASTROINTESTINAL TRACT • VAGINA

45. BACTEROIDES FRAGILIS GP • GROUP = B. FRAGILIS, B. VULGARIS, B.THETAIOTAMICRON, B. UNIFORMIS • ACCOUNT FOR 1/3 OF ALL ISOLATES • RESISTANT TO 20% BILE • RESISTANT TO MANY ANTIBIOTICS • PENICILLIN, KANAMYCIN, VANCOMYCIN, COLISTIN – AND MANY MORE

46. BACTEROIDES FRAGILIS GP • GLC = MAJOR ACETIC & SUCCINIC, LACTIC & PROPIONIC ACIDS • NO PIGMENTATION OF COLONIES OR FLUORESCENCE

47. BACTEROIDES OTHER SP • BACTEROIDES SPECIES OTHER THAN B. FRAGILIS GROUP • GLC = MAJOR ACETIC & SUCCINIC ONLY • BILE SENSITIVE • RESISTANT TO KANAMYCIN ONLY • SOME PIGMENTED

48. BACTEROIDES • B. FRAGILIS IN THE GUT AND VAGINA • B.MELANINOGESUS AND B.ORALIS IN THE MOUTH AND OROPHARYNX • B. FRAGILIS PENICILLIN RESISTANT, • OTHER ARE SENSITIVE, • IT IS THE COMMONEST ORGANISM IN THE GUT 10 12 ORGANISM /GRAM OF FAECES

49. Bacteroides and other anaerobic bacilli

50. BACTEROIDES AND FUSOBCTERIUM