09/03/2008 Dr Ekta Chourasia, Microbiology 1 Non Sporing

09/03/2008 Dr Ekta Chourasia, Microbiology 1 Non Sporing Anaerobes

09/03/2008 Dr Ekta Chourasia, Microbiology 2 Introduction Anaerobes bacteria that lack the enzymes superoxide dismutase or catalase or both, makes them susceptible to oxygen derived free radicals Obtain energy from fermentation process Nonsporing anaerobes - Anaerobic bacteria that do not form spores

09/03/2008 Dr Ekta Chourasia, Microbiology 3 Habitat of nonsporing anaerobes Normal flora of skin, mouth, mucous surfaces, respiratory tract, GIT, genital tract Outnumber aerobes in many habitats Mouth & skin – 10 to 30 times > aerobes Intestines – 1000 times > aerobes Estimated no. of anaerobes in: Saliva – 108/ ml Small intestine – 105/ ml Colon – 1011/ gm

09/03/2008 Dr Ekta Chourasia, Microbiology 4 Classification of Non - sporing Anaerobes

09/03/2008 Dr Ekta Chourasia, Microbiology 5 Gram negative anaerobic bacilli Bacteroides Most common anaerobes isolated from clinical specimens Pleomorphic, capsulated Grows on Brain Heart Infusion agar in 10% CO2 Prevotella & Porphyromonas – pigmented anaerobes Porphyromonas melanogenica – black or brown color colonies (due to hemin derivative) Colonies & even dressings from wounds infected with this bacillus gives a characteristic red fluorescence when exposed to UV light.

09/03/2008 Dr Ekta Chourasia, Microbiology 6 Pathogenicities of Gram negative anaerobic bacilli Bacteroides fragilis Prevotella melaninogenica Porphyromonas Fusobacterium necrophorum Fusobacterium nucleatum Brain abscess, intra abdominal abscess, infections of female genitalia, cellulitis, diabetic ulcer, septicaemia Lung or liver abscess, empyema, pelvic infections in females, breast abscess, wound infections Aspiration pneumonia, lung/ liver abscess, oral infections, chronic sinusitis, abdominal infections Dental root canal infections, periodontal disease

09/03/2008 Dr Ekta Chourasia, Microbiology 7 Gram positive anaerobic rods Bifidobacterium – pleomorphic bacilli showing true & false branching Lactobacillus (Doderlein’s bacilli) – normal flora in mouth, intestine & adult vagina Mobiluncus – motile, curved, gram variable bacilli

09/03/2008 Dr Ekta Chourasia, Microbiology 8 Pathogenicities of Gram positive anaerobic rods Propionibacterium acne Propionibacterium propionicum Cervico - fascial, Pulmonary abscess Mobiluncus Bacterial Vaginosis along with Gardenerella vaginalis Eubacterium Acne Periodontitis

09/03/2008 Dr Ekta Chourasia, Microbiology 9 Anaerobic cocci Peptococcus & Peptostreptococcus – usually produce mixed infections along with clostridia or anaerobic gram negative bacilli Puerperal sepsis & other genital infections Wound infections Gangrenous appendicitis UTI Osteomyelitis Abscesses in brain, lungs & other internal organs

09/03/2008 Dr Ekta Chourasia, Microbiology 10 Laboratory Diagnosis Specimen - Deep aspirates, tissue bits Collection & transport – Pre-reduced transport medium Gassed out vials Needle & syringe with rubber bunk

09/03/2008 Dr Ekta Chourasia, Microbiology 11 Laboratory Diagnosis Microscopy – Gram stain: many pus cells, variety of different micro-organisms Culture media Blood agar Phenyl ethyl alcohol agar (PEA) Kanamycin / vancomycin BA Thioglycollate broth RCM Culture methods – Anaerobic jar, Gaspak, Bactec (anaerobic blood culture)

09/03/2008 Dr Ekta Chourasia, Microbiology 12 Anaerobic blood culture vials

09/03/2008 Dr Ekta Chourasia, Microbiology 13 Laboratory Diagnosis All cultures must be incubated for 7-10 days as most of the anaerobes are slow growing. Detection of metabolic products – gas liquid chromatography (GLC) can be directly carried out on pus & other clinical specimens to detect metabolic products like butyric & propionic acid.

09/03/2008 Dr Ekta Chourasia, Microbiology 14 Treatment & Prevention Surgical – Drainage of pus from abscess Wound debridement Curettage & removal of necrotic tissues Antibiotics – Metronidazole Penicillin (cocci) Clindamycin Cefamycin

09/03/2008 Dr Ekta Chourasia, Microbiology 15 Summary of Anaerobic infections Usually endogenous Normal flora of the body Poly-microbial Precipitating factors Trauma Tissue necrosis Impaired circulation Diabetes, malnutrition, malignancy Hematoma or presence of foreign bodies Prolonged treatment with Aminoglycosides Lab diagnosis Anaerobic methods of specimen collection & culture Results may take weeks Metronidazole, Clindamycin, Cefamycin Wound debridement

09/03/2008 Dr Ekta Chourasia, Microbiology 16 Summary - Non Sporing Anaerobes CNS Abscess: cerebral, epidural subdural Fusobacterium, Peptostreptococcus Propionibacterium SSI Wounds, ulcers, abscess Peptostreptococcus Propionibacterium RT Pneumonia, empyema, abscess: lung, dental peritonsillar Bacteroides Actinomyces, Fusobacterium, Prevotella, Porphyromonas, Eubacterium Propionibacterium GIT Abscess: abdominal, liver, appendicitis Fusobacterium, Eubacterium, Propionibacterium FGT Bacterial vaginosis, abscess, septic abortion Bacteriodes, Eubacterium Lactobacillus, Mobiluncus, Veillonella