Clinical and lab aspect of
anaerobic infection
Ali Somily MD, FRCPC,ABMM
Classification
1. Anaerobic spore forming bacilli
2.
3.
4.
5.
6.
(Clostridia)
Gram negative bacilli non-sporing
(Bacteroides)
Anaerobic streptococci
(Peptostreptococcus)
Anaerobic staphylococcus (Peptococcus)
Gram negative diplococci (Veillonella)
Gram positive bacilli (Actinomyces)
Propionibacterium
Bacteroides fragilis
Fusobacterium nucleatum
Antimicrobiolial Sensitivity
• 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 flavoprotein so 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
Anaerobic chamber
NONSPORING ANAEROBES
HABITAT I :
• 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
INFECTIONS CAUSED BY
,NONSPORING ANAEROBES
• A. The head, neck and respiratory tract
• B. The lower abdomen and the pelvis
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 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
1.
2.
3.
4.
5.
6.
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
1.
2.
3.
4.
5.
6.
Infection of the female genital tract
Septic abortion
Puerperal infection 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
1.
2.
3.
4.
5.
DENTAL ABSCESSES
ROOT CANALS
JUVENILE PERIODONTITIS
ADULT PERIODONTITIS
CLENCHED FIST INJURIES
ENT – HEAD & NECK
1. CHRONIC OTITIS MEDIA
2. CO-PATHOGENS WITH CHRONIC
STREP TONSILLITIS
3. 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
Ludwig’s Angina
Lemierre Syndrome
Expansion of the retropharyngeal soft
tissues
PLELRO PULMONARY I FECTION
•
•
•
•
•
ASPIRATION LUNG ABSCESS
ASPIRATION PNEUMONIA
M ETASTATIC LUNG ABSCESS
BRONCHIACTSIS
ALL OF ABOVE CAN CAUSE EMPYEMA
LUNG & PLEURAL
1.
2.
3.
4.
5.
ASPIRATION PNEUMONIA
EMPHYSEMA
LUNG ABSCESSES
MALIGNANCIES
LEUKOPENIA
THORACIC ACTINOMYCOSIS
THORACIC ACTINOMYCOSIS
ACTINOMYCOSIS
Molar tooth appearance of Actinomyces israeIii
Macroscopic colony (left)
Gram stain (right) of Actinomyces
SKIN & SOFT TISSUE
• TRAUMATIZED & DEVITALIZED
TISSUE
1. TRAUMATIC WOUNDS
2. HUMAN/ANIMAL BITES
3. ISCHEMIA OF EXTREMITIES
• DIABETES
• ATHEROSCLEROSIS
CLENCHED FIST INJURIES
DIABETIC FOOT
HUMAN BITE
NECROTIZING CELLULITIS
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
1.
2.
3.
4.
TRAUMA
SURGERY
APPENDICITIS
MALIGNANCIES
• COLON CANCER
CNS
1. HEAD TRAUMA
2. HEMATOGENOUS SPREAD
– FROM ANY INFECTED BODY SITE
3. GEOGRAPHIC SPREAD
– SINUS INFECTIONS
– DENTAL ABSCESSES
BONE & JOINT
•
•
•
•
HEMATOGENOUS SPREAD
TRAUMA
PERIVASCULAR DISEASE
JUVENILE PERIODONTITIS
OTHER INFECTIONS
•
•
•
•
GRAM NEGATIVE BACTREMIA
BREAST ABSCESS
AXILLARY ABSCESS
INFECTION OF DIABETIS EG.DIABETIC
ULCERS
• INFECTION OF PILONIDAL SINUS
• PARONYCHIA
CLASSIFICATION
1. Anaerobic spore forming bacilli
2.
3.
4.
5.
6.
(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 fragilis
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
BACTEROIDES FRAGILIS GP
• GLC = MAJOR ACETIC & SUCCINIC,
LACTIC & PROPIONIC ACIDS
• NO PIGMENTATION OF COLONIES OR
FLUORESCENCE
BACTEROIDES OTHER SP
• BACTEROIDES SPECIES OTHER, NOT B.
FRAGILIS GROUP
– GLC = MAJOR ACETIC & SUCCINIC ONLY
– BILE SENSITIVE
– RESISTANT TO KANAMYCIN ONLY
– SOME PIGMENTED
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
Bacteroides and other anaerobic bacilli
BACTEROIDES AND
FUSOBCTERIUM
B.FRAG
B.NECROPH
ORUS
B.MELANINO B.CORRODE
GENICUS
NS
FUSOBACTE
RIUM
BLACK
PIG.
-
-
+
-
-
PITTING
-
-
-
+
-
INDOLE+
-
-
+
-
-
LYSINE+
BILE GROWTH
+
+
Growth of Bacteroides fragilis on
Bacteroides bile-esculin agar
Bacteroides fragilis
• Special-potency kanamycin,
vancomycin, and colistin
antimicrobial agent disks to
first quadrant of this plate.
PORPHYROMONAS
• GLC = ACETIC, SUCCINIC PLUS
PROPIONIC, BUTYRIC, ISOBUTYRIC,&
ISOVALERIC
• BILE SENSITIVE
• USUALLY BLACK PIGMENTED
COLONIES
– P. GINGIVALIS, P. ENDODONTITIS &
P.ASACCHAROLYTICA
PREVOTELLA
• GLC = ACETIC, SUCCINIC, ISOVALERIC,
NO BUTYRIC
• BILE SENSITIVE
• BLACK PIGMENT & FLUORESCENCE
– Pr. INTERMEDIA – LIPASE +
– Pr. MELANINOGENICA – BRICK RED
FLUORESCENCE
FUSOBACTERIUM
• GLC = ACETIC, PROPIONIC, &BUTYRIC,
NO SUCCINIC
• ANTIBIOTICS
– SENSITIVE TO KANAMYCIN
– RESISTANT TO VANCOMYCIN
– COLISTIN VARIABLE
Fusobacterium nucleatum
FUSOBACTERIUM
• F. NUCLEATUM = LIPASE Ø
• F. NECROPHORUM = LIPASE +
• F. NUCLEATUM >> F. NECROPHORUM
ISOLATES
• COMMON IN ASPIRATION PNEUMONIAS
MISCELLANEOUS GNB
• BUTYRIVIBRIO
– CURVED GNB
– GLC = MAJOR BUTYRIC
• SUCCINOMONAS
– CURVED GNB
– GLC = ACETIC & SUCCINIC
PEPTOCOCCUS NIGER
• GRAM POSITIVE COCCI
• GLC = ACETIC, BUTYRIC, ISOBUTYRIC,
ISOVALERIC, CAPROIC
• BLACK PIGMENT
PEPTOSTREPTOCOCCUS
•
•
•
•
GRAM POSITIVE COCCI
GLC = ACETIC, SOME BUTYRIC
Ps. ASACCHAROLYTICUS INDOLE +
Ps. ANAEROBIUS, Ps. MAGNUS,
Ps.PREVOTI, Ps. INDOLECUS
STREP & STAPH
• ANAEROBIC SPECIES OF STAPH AND
STREP
• STREPTOCOCCUS INTERMEDIUS
• STAPHYLOCOCCUS
SACCHAROLYTICUS
VEILLONELLA PARVULA
•
•
•
•
•
GRAM NEGATIVE COCCI
GLC = ACETIC & PROPIONIC
NITRATE +
HEAD AND NECK INFECTIONS
DENTAL ABSCESSES
CLOSTRIDIUM SPECIES
• LARGE GRAM POSITIVE RODS
• SPORE FORMATION
• SPECIFIC DISEASES
– PSEUDOMEMBRANOUS COLITIS
– TETANUS
– BOTULISM
– GANGRENE - MYONECROSIS
C. difficile
CLOSTRIDIA
CLOSTRIDIA
• Causative Agents For
– 1.Gas gangrene :
Cl. perfringens and other
e.g septicum
– 2.Tetanus :
Cl. tetani
– 3.Botulism :
Cl. botulinum
– 4.Toxic enterocolitis : Cl. difficile
(Pseudomembernous colitis)
Clostridium perfringens (CI . welchii)
•
•
•
•
Morphology large rods gram +ve
With bulging endospores
Not motile
Capsulated
Clostridium perfringens
C. perfringens
C. perfringens
Culture:
• A) Blood agar with haemolytic colonies
(double zone of haemolysis
• B) Cooked meat medium
• Gives the NAGLAR'S Reaction & toxin
neutralization on Egg yolk medium & toxin is
a phospholipase
C. perfringens
NAGLAR'S Reaction
Lipase and/or lecithinase (EYA),
Diseases Caused by C. perfringens
•
•
•
•
•
1) Wound Contamination
2) Wound infection
3) Gas Gangrene - most important disease
4) Gas Gangrene of the uterus in criminal abortion
5) Food Poisoning
• Spores are swallowed
Germinate in gut after 18 hours
• Toxin
• abdominal pain and diarrhoea
GAS GANGRENE
• Causes mainly
–
–
–
–
(Cl perfringens) (Cl. welchil)
CI. novyl,
CI. Septicum
CI oedemaritians
–
–
–
–
Traumatic open wounds
Compound fractures
Muscle damages
Contamination with dirt etc,
• Pathogenesis:
• Mainly in war wounds,
• Old age,
– Low blood supply
• Amputation of thigh
– Prophylaxis with
penicillin
NECROTIZING FASCIATITIS
NECROTIZING FASCIATITIS
MYOSITIS
Gram Stain of vaginal aspirate
1. Clostridiae necrotizing (myonecrosis)
Prevention and Treatment
•
•
•
•
•
Remove dead tissue
Remove debris
Foreign bodies
Penicillin
Hyperbaric oxygen
TETANUS
Cl.tetani
• Causative organism Cl.tetani
• Morphology gram +ve anaerobic with terminal spore
•
•
•
Drum Stick appearance
Lives in soil and animal feaces. e,g horse
Any wound can infected if contaminated by spores
Face & neck wounds are more dangerous why ?
C. tetani
Clinical Features
• Incubation period 1-2 weeks
• Symptoms: Painful muscle spasm around
infected wound
• Contraction of muscles
of face=
– Trismus (Lockjaw)
– Risus Sardonicus strychnine
• Back
– Araching of Back
Opisthotonus
• opistho meaning
•
•
"behind" and tonos
meaning "tension",
Extrapyramidal effect
and is caused by
spasm of the axial
along the spinal
column .
Caused by
– Tetanus.
– Cerebral palsy
– Traumatic brain
injury
Pathogenesis
• 1 ) Tetanospasmin most important powerful
•
•
•
•
exotoxin
2) Totanolysin
No invasion or Bacteraernia
Toxin is a protein
It inhibits transmission of normal inhibitory
messages from central nervous system at
anterior horn cells of cord
Pathogenesis
Diagnosis
• Mainly by clinical
• Laboratory not important
• Lab
– Organism strict anaerobe
– Very motile , spread on agar.
C. tetani
Prevention
•
•
•
•
Toxoid vaccine:
Vaccination D P T
2 , 4 , 6 , 18 months & 5 Year
Booster every 10 years
Treatment .
•
•
•
•
Cleaning of wound
Removal of Foreign body
Specific by antitoxin
– Horse serum can caused anaphylaxis & shock
must be tested first
– Human immunoglobulin
– Antibiotics . Penicillin
Supportive treatment
– 2. Dark pace, fluids
– 3. Sedative valium
CLOSTRIDIUM BOTULINUIM
Habitat
• Soil,Ponds AND Lakes
Toxin
• Exotoxin
• Protein
• Heat labile at 100 OC
– The most powerful toxin known Lethal dose 1 µg
human
• 3 kg kill all population of the world
• Dictated for by lysogenic phage
• Resist gastrointestinal enzymes
Botulism
•
•
•
•
From canned food., sea food e_g. salmon
Not well cooked
Spores resist heat at 100 oC
then multiply and produce toxin
ENFANTILE BOTULISM
• Ingestion of Spores  germination in the
•
•
•
•
gutBotulism
Week child
Cranial nerve
Constipation
Other
Botulism Pathogenesis
•
•
•
•
•
Ingested - incubation period 12-36 hour
7 Types
Mainly types A, B, E, F
Attacks neuromuscular junctions
Prevents release of acetylcholine
Symptoms
• Funny eye movement as if cranial nerve
affected when bulbar area of the brain affected
• Respiratory and circulatory collapse
SPECIMENS
• Suspected food
• From the patient
– Faeces
– Serum
growth
• Toxin detection by mouse
–
incubation
paralysis and death
INFANTILE BOTULISM
•
•
•
•
Week lethargic child
Constipation
Respiratory and cardiac arrest
Due to colonization of intestine by CI.
botulinum
• Diagnosis by -Culture of stools
• Detection of toxin in feaces
• Treatment
• 1) Supportive
• 2) Horse antitoxin
• Prevention
• 1) Adequate pressure
•
cooking autoclaving
2) Heating of food for
10 minutes at 100 OC
Botox
C. DIFFICILE
• PSEUDOMEMBRANOUS COLITIS
– 90% OF CASES CAUSED BY C. DIFF
– LONG TERM TREATMENT WITH BROAD
SPECTRUM ANTIBIOTICS OR CHEMO
• NOSOCOMIAL DISEASE
• KNOCK DOWN NORMAL FLORA
• CLINDAMYCIN, AMPICILLIN, CEPHALOSPORINS
• CHEMOTHERAPEUTIC AGENTS
C. DIFFICILE
• OVERGROWTH OF C. DIFFICILE
– TOXIN THEN PRODUCED
• A -FRAGMENT = ENTEROTOXIN
• B -FRAGMENT = CYTOLYTIC TOXIN
• PSEUDOMEMBRANE SIMILAR TO THAT
OF C. DIPHTHERIAE
– BACTERIA, FIBRIN, WBC, DEAD
– TISSUE CELLS - TOUGH
C. DIFFICILE
• DIARRHEA FIRST
– ELECTROLYTE & FLUID LOSS
– LEADS TO DEHYDRATION
• INTESTINAL BLOCKAGE
– CONTENTS BLOCKED
– COLON BULGES
• PERFORATION, RUPTURE  SEPSIS
Clinical pictures
C. DIFFICILE
• RAPID AGGRESSIVE COURSE IN YOUNG
CHILDREN
• DIFFICULT TO SELECTIVELY
• CULTURE
– 5-10% CULTURE + EVEN WITH CONFIRMED
DISEASE
– TOO MANY NORMAL ANO2 PRESENT
C. DIFFICILE
• SPECIALIZED ISOLATION MEDIA
– CCFA – CYCLOSERINE ,
CEFOXITIN,FRUCTOSE, EGG YOLK AGAR
– CCMA – CCFA BUT MANNITOL FOR
FRUCTOSE
– CDMN – CYSTEINE HYDROCHLORIDE,
MOXALACTAM, NORFLOXACIN AGAR
C. difficile
C. difficile
C. DIFFICILE
• C. DIFFICILE IS NORMAL FLORA
– ISOLATION NOT ENOUGH
• NEED TOXIN ASSAY TO CONFIRM
• CELL-FREE STOOL EXTRACT
– LATEX AGGLUTINATION SCREEN
• SOME CROSS-REACTIVITY
– EIA TO CONFIRM
Major Clostridial Diseases