Non spore forming anaerobic bacteria

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Non spore forming anaerobic bacteria

  1. 1. NON-SPORE FORMING ANAEROBIC BACTERIA S.Y.Maselle
  2. 2. Anaerobic bacteria <ul><li>Gram positive sporulating bacilli </li></ul><ul><li>Gram positive non-sporulating bacilli </li></ul><ul><li>Gram negative non-sporulating bacilli(nm) </li></ul><ul><li>Gram negative non-sporulating bacilli(m) </li></ul><ul><li>Gram positive anaerobic cocci </li></ul><ul><li>Gram negative anaerobic cocci </li></ul>
  3. 3. Gram positive non-sporulating bacilli: <ul><li>● Actinomyces </li></ul><ul><li>● Bifidobacterium </li></ul><ul><li>● Proprionbacterium ( Corynebacterium) </li></ul><ul><li>● Arachnia ( Proprionbacterium propionica ) </li></ul><ul><li>● Eubacterium </li></ul>
  4. 4. Gram negative non-sporulating bacilli.( non motile) <ul><li>● Bacteroides ( Bacteroides fragilis). </li></ul><ul><li>● Fusobacterium </li></ul><ul><li>● Porphyromonas </li></ul><ul><li>● Prevotella </li></ul>
  5. 5. Gram negative non-sporulating bacilli (motile) <ul><li>● Treponema </li></ul><ul><li>● Borrelia </li></ul><ul><li>● Campylobacter </li></ul>
  6. 6. Anaerobic cocci <ul><li>Gram positive anaerobic cocci </li></ul><ul><li>● Peptostreptococcus </li></ul><ul><li>● Peptococcus </li></ul><ul><li>Gram negative anaerobic cocci </li></ul><ul><li>● Veillonella </li></ul><ul><li>● Acidaminococcus </li></ul>
  7. 7. Gram negative non-sporulating bacilli <ul><li>Prototype- Bacteroides fragilis </li></ul><ul><li>Will grow in 20% bile </li></ul><ul><li>On blood agar it is non-haemolytic </li></ul><ul><li>Gram negative and pleumorphic </li></ul><ul><li>Resistant to kanamycin, vancomycin and colistin </li></ul><ul><li>Catalase positive </li></ul><ul><li>Pigmented strains were formerly called Bacteroides melaninogenicus </li></ul><ul><li>But have now been re-classified to two new Genera: </li></ul><ul><li>Prevotella which is saccharolytic </li></ul><ul><li>Porphyromonas which is asaccharolytic. </li></ul>
  8. 8. Fusobacterium <ul><li>Long thin gram negative rods with pointed ends </li></ul><ul><li>May or may not grow in 20% bile </li></ul><ul><li>Catalase negative </li></ul><ul><li>Sensitive to kanamycin and colistin but resistant to vancomycin </li></ul>
  9. 9. Provisional identification of non-spore forming anaerobic Gram negative bacilli <ul><li>Growth in UV-light </li></ul><ul><li>20% bile kanamycin vancomycin colistin pigment fluorecsence catalase </li></ul><ul><li>B.fragilis Yes Resist. Resist. Resist. No No + </li></ul><ul><li>Prevotella No Resist Sens. Sens. Yes Yes - </li></ul><ul><li>Porphyromons No Resist. Sens. Sens. Yes Yes - </li></ul><ul><li>Fusobacterium No Sensit. Resist Sens. No No - </li></ul>
  10. 10. Anaerobes as normal flora <ul><li>Anaerobic bacteria are the predominant normal human bacterial flora. </li></ul><ul><li>Bacteroides and Prevotera spp are the most predominant. </li></ul><ul><li>In the mouth : Prevotella, Fusobacterium, Porphylomonas and anaerobic cocci. </li></ul><ul><li>In stomach: mostly facultative anaerobes in low counts. </li></ul><ul><li>Terminal ileum: Bacteroides, Bifidobacterium and facultative anaerobes. </li></ul><ul><li>Colon: Highest concentration of bacteria, mostly Bacteroides, Fusobacteria,Clostridia, anaerobic cocci, Bifidobacteria and facultative anaerobes. </li></ul><ul><li>Vagina : mostly anaerobes especially gram positive rods, but may vary depending on menstral cycle, pregnancy, menopause and other gynaecological conditions. </li></ul><ul><li>Distal urethra both male and female have small numbers of Bacteroides, Prevotera and Fusobacteria spp. </li></ul><ul><li>Uterine cavity : Sterile </li></ul>
  11. 11. Pathogenesis <ul><li>Synergy with aerobic bacteria is essential in the pathogenesis </li></ul><ul><li>But also there are several virulence factors involved in the pathogenesis </li></ul><ul><li>Capsular polysaccharide inhibits phagocytosis, enhences abscess formation. </li></ul><ul><li>Pili and fimbriae enhence adherence </li></ul><ul><li>Lipopolysaccharide endotoxin enhences abscess formation. </li></ul><ul><li>Succinic acid-inhibits phagocytosis </li></ul><ul><li>Enzymes like hyaluronidase, collagenase, neuraminidase, heparinase, fibrinolysins etc </li></ul>
  12. 12. ClinicalClues for anaerobic infections <ul><li>-Foul smelling pus </li></ul><ul><li>-Proximity to mucosal surfaces. </li></ul><ul><li>-Massive necrotic tissues </li></ul><ul><li>-Septic thrombophlebitis </li></ul><ul><li>- Infection following human bite </li></ul><ul><li>Septic abortion </li></ul><ul><li>Infection following lower GIT and female genital surgery </li></ul>
  13. 13. Laboratory clues <ul><li>Purulent exudate but no bacterial growth on culture </li></ul><ul><li>Foul smelling culture plates </li></ul><ul><li>Colonies fluoresce brick red under UV light </li></ul><ul><li>Failure to grow organisms seen on gram stain. </li></ul>
  14. 14. Infections <ul><li>Oral cavity eg dental abscess, periodontal disease, acute gingivitis. </li></ul><ul><li>Intra abdominal eg. peritonitis, abcsesses etc </li></ul><ul><li>Sinuses(chronic sinusitis) </li></ul><ul><li>Female genital tract eg pelvic inflamatory disease(PID), endometritis,pelvic abcsess, bacterial vaginosis etc. </li></ul><ul><li>Pleuro-pulmonary infections eg aspiration pneumonia, lung abcsess, empyema etc </li></ul><ul><li>Bacteraemia and septicaemia and metastatic abcsesses </li></ul>
  15. 15. Laboratory Diagnosis. <ul><li>Isolation: good specimen, use selective and non-selective media, good anaerobic incubation and identify by biochemical tests and gas-liquid-chromatography and molecular techniques if available. </li></ul>
  16. 16. Treatment <ul><li>Surgical drainage and removal of dead and necrotic tissues. </li></ul><ul><li>Combination of antibiotics to cover aerobes and anaerobes. </li></ul>
  17. 17. Anaerobic Gram positive non-spore forming bacilli. <ul><li>Actinomyces cause actinomycosis </li></ul><ul><li>Bifidobacterium –branched, normal flora in GIT. </li></ul><ul><li>Eubacterium- mouth and bowel normal flora. </li></ul><ul><li>Rothia- normal flora in mouth. Also in periodontal disease. </li></ul><ul><li>Lactobacillus-normal flora in vagina </li></ul><ul><li>Propionibacterium- on skin as normal flora </li></ul>
  18. 18. Anaerobic cocci <ul><li>Peptococci and Peptostreptococci present in mouth,gut, female genital tract together with other anaerobes may be responsible for all above mentioned infections. </li></ul>

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