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Clinical and lab aspect of anaerobic infection. ALI SOMILY MD. Classification. Anaerobic spore forming bacilli (Clostridia) Gram negative bacilli non-sporing (Bacteroides) Anaerobic streptococci ( Peptostreptococcus ) Anaerobic staphylococcus (Peptococcus)
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Clinical and lab aspect of anaerobic infection ALI SOMILY MD
Classification • Anaerobic spore forming bacilli (Clostridia) • Gram negative bacilli non-sporing (Bacteroides) • Anaerobic streptococci (Peptostreptococcus) • Anaerobic staphylococcus (Peptococcus) • Gram negative diplococci (Veillonella) • Gram positive bacilli (Actinomyces)
AntimicrobiolialSensitivity • All of them resistant to aminoglycosides • Gentamicine • Tobramycin • Amikacin • Almost all are sensitive to metranidazole (flagyl)
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 fumarate reductase must be reduced form to work
HABITATI : • These organism are normal flora in: • A. Oropharynx • eg. 1. Bacteroides melaninogenicus • Now called provetella melaninogenicus • 2. Fusobacteria • 3. Veillonella
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)
CLINICAL ASPECTS • ANAEROBES ARE INDIGENOUS FLORA OF SKIN & MUCOUS MEMBRANES • NORMALLY CONTAINED AWAY FROM INTERNAL STERILE BODY SITES • HIGH MORBIDITY & MORTALITY
FEATURES OF ANAEROBIC INFECTIONS • Characterized by foul smell • Gas formation • Infections are always near to the site of the body which are habitat. • Deep abscesses • The infections are also polymicrobial • Failure to grow organism from pus if not culture anaerobically. • Failure to respond to usual antibiotics. • Infection from animal bites. • Detection of "Sulphur granules"' due to actinomycosis
INFECTIONS CAUSED BY ,NONSPORING ANAEROBES • A. The head, neck and respiratory tract • B. The lower abdomen and the pelvis
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
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
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
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.
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.
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
ORAL & DENTAL • COMMONLY ASSOCIATED WITH • DENTAL ABSCESSES • ROOT CANALS • JUVENILE PERIODONTITIS • ADULT PERIODONTITIS • CLENCHED FIST INJURIES
ENT – HEAD & NECK • CHRONIC OTITIS MEDIA • CO-PATHOGENS WITH CHRONIC STREP TONSILLITIS • ACUTE SINUSITIS • POST-DENTAL EXTRACTIONS OR TRAUMA • 2o INVADER
ENT – HEAD & NECK • VINCENT’S ANGINA • COMBINATION OF FUSOBACTERIUM & SPIROCHETE SPECIES OVERGROWTH • ANAEROBIC PHARYNGITIS • GRAY MEMBRANE • FOUL ODOR
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
PLELRO PULMONARY I FECTION • ASPIRATION PNEUMONIA • ASPIRATION LUNG ABSCESS • M ETASTATIC LUNG ABSCESS • BRONCHIACTSIS • ALL OF ABOVE CAN CAUSE EMPYEMA • MALIGNANCIES LEUKOPENIA
SKIN & SOFT TISSUE • TRAUMATIZED & DEVITALIZED TISSUE • TRAUMATIC WOUNDS • HUMAN/ANIMAL BITES • ISCHEMIA OF EXTREMITIES • DIABETES • ATHEROSCLEROSIS
FEMALE UROGENITAL • CHORIOAMNIOTIC INFECTIONS • ENDOMETRITIS • PID – ABDOMINAL INFECTIONS • BACTERIAL VAGINOSIS WITH GARDNERELLA & BACTEROIDES SP.
PUERPERAL INFECTION SEPTIC ABORTION • PUERPERAL ABSCESS • SEPTIC ABORTION • BACTERAEMIA • PELVIC ABSCESS • ADENXAL ABSCESS • PERITONITIS • ENDOMETRITIS
ABDOMINAL INFECTIONS • MANIPULATION, INVASION OR TRAUMA TO GI TRACT • TRAUMA • SURGERY • APPENDICITIS • MALIGNANCIES • COLON CANCER
CNS • HEAD TRAUMA • HEMATOGENOUS SPREAD • FROM ANY INFECTED BODY SITE • GEOGRAPHIC SPREAD • SINUS INFECTIONS • DENTAL ABSCESSES
BONE & JOINT • HEMATOGENOUS SPREAD • TRAUMA • PERIVASCULAR DISEASE • JUVENILE PERIODONTITIS
OTHERINFECTIONS • GRAM NEGATIVE BACTREMIA • BREAST ABSCESS • AXILLARY ABSCESS • INFECTION OF DIABETIS EG.DIABETIC ULCERS • INFECTION OF PILONIDAL SINUS • PARONYCHIA
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)
ORGANISM GROUPS • GRAM NEGATIVE RODS • BACTEROIDES • PREVOTELLA • PORPHYROMONAS • FUSOBACTERIUM • BUTYRIVIBRIO • SUCCINOMONAS
BACTEROIDES • STRICT ANAEROBE • PLEOMORPHIC • GRAM NEGATIVE BACILLI (COCCO BACILLI) • NORMAL FLORA IN • OROPHARYNX • GASTROINTESTINAL TRACT • VAGINA
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