Post on 01-Jun-2015
Prof. Abdullah Akhtar AhmedProf. Abdullah Akhtar Ahmed
Professor of MicrobiologyProfessor of Microbiology
Ibrahim Medical CollegeIbrahim Medical College
Shahbagh, DhakaShahbagh, Dhaka
A. Gram Positive Cocci PeptostreptococcusPeptostreptococcus
P. magnusP. magnus P. P.
asaccharolyticusasaccharolyticus P. prevotiiP. prevotii P. anaerobiusP. anaerobius
PeptococcusPeptococcus P. nigerP. niger
Sarcina ventriculiSarcina ventriculi
Peptostreptococcus Peptostreptococcus N flora of mouth, upper N flora of mouth, upper
respiratory tract, respiratory tract, intestinal tract, vagina & intestinal tract, vagina & skinskin
20-40% of anaerobic 20-40% of anaerobic infectionsinfections Brain abscessBrain abscess Pleuropulmonary Pleuropulmonary
infectionsinfections Female genital tract Female genital tract
infectioninfection
Non Sporing Anaerobe
Non Sporing Anaerobe
VeillonellaVeillonella
C. Gram Positive BacilliC. Gram Positive Bacilli 1. Lactobacillus1. Lactobacillus 2. Bifidobacterium2. Bifidobacterium 3. Actinomyces3. Actinomyces
D. Gram Negative BacilliD. Gram Negative Bacilli 1. Bacteroides1. Bacteroides 2. Fusobacterium2. Fusobacterium 3. 3. PrevotellaPrevotella 4. Porphyromonas4. Porphyromonas
E. SpirochetesE. Spirochetes 1. Treponema1. Treponema 2. Borrelia2. Borrelia
B. Gram negative cocci
Gram positive bacilli. Gram positive bacilli. MicroaerophilicMicroaerophilic Grow in presence of COGrow in presence of CO2 2 and at pH 3.0and at pH 3.0 Widely distributed as saprophytes in fermenting Widely distributed as saprophytes in fermenting
animal and vegetable material (e.g. milk, cheese)animal and vegetable material (e.g. milk, cheese) Normal flora of man and animal in the mouth, gut Normal flora of man and animal in the mouth, gut
and vagina.and vagina. Older textbooks have used the term “Older textbooks have used the term “Doderleins Doderleins
bacillusbacillus” for a variety of human vaginal strains of ” for a variety of human vaginal strains of Lactobacillus.Lactobacillus.
Lactobacillus
Gram Stained Vaginal smear
Role
L. acidophilus L. acidophilus synthesize biotin, Vit. B synthesize biotin, Vit. B1212 and Vit. K in the intestine.and Vit. K in the intestine.
It ferment glycogen which is deposited in It ferment glycogen which is deposited in the vaginal epithelial cells and form lactic the vaginal epithelial cells and form lactic acid. This lactic acid prevent growth of acid. This lactic acid prevent growth of other bacteria by maintains highly acidic other bacteria by maintains highly acidic pH of the vagina. pH of the vagina.
Bacteroides
B. fragilis B. fragilis is most significant.is most significant. Pale irregularly stainingPale irregularly staining Gram negative bacilli/ Gram negative bacilli/
coccobacilli with polysaccharide capsule.coccobacilli with polysaccharide capsule. PleomorphicPleomorphic
Normal flora of large intestine & female genitalNormal flora of large intestine & female genital tract. Normal stool contain 11tract. Normal stool contain 1110 10 B. fragilis B. fragilis organisms per gram. organisms per gram.
Cause abdominal, lung and brain abscesses and Cause abdominal, lung and brain abscesses and wound infectionwound infection
Bacteroides
Bacteroides Virulence Factors
Polysaccharide capsulePolysaccharide capsule LipopolysaccharideLipopolysaccharide AgglutininAgglutinin Histolytic enzymeHistolytic enzyme Oxygen tolerance Oxygen tolerance ββ lactamase lactamase
Fusobacterium Delicate gram negative rodsDelicate gram negative rods
Tapering endsTapering ends F. nucleatumF. nucleatum
Mouth, Upper Resp. tract, GI tract, Mouth, Upper Resp. tract, GI tract, Genital tract Genital tract
Head, neck and lower respiratory Head, neck and lower respiratory tract infectionstract infections
F. necrophorumF. necrophorum Anaerobic tonsillitis/pharyngitisAnaerobic tonsillitis/pharyngitis Involve jugular vein Involve jugular vein Sepsis Sepsis
Lemierre's diseaseLemierre's disease
Lemierre's syndromeLemierre's syndrome (or (or Lemierre's diseaseLemierre's disease) is a disease usually ) is a disease usually caused by the bacterium caused by the bacterium Fusobacterium necrophorumFusobacterium necrophorum, and , and occasionally by other members of the genus occasionally by other members of the genus FusobacteriumFusobacterium ( (F. F. nucleatum, F. mortiferum and F. variumnucleatum, F. mortiferum and F. varium etc.) and usually affects etc.) and usually affects young, healthy adults. Lemierre's syndrome develops most often young, healthy adults. Lemierre's syndrome develops most often after a strep sore throat has created a peritonsillar abscess, a crater after a strep sore throat has created a peritonsillar abscess, a crater filled with pus and bacteria near the tonsils. Deep in the abscess, filled with pus and bacteria near the tonsils. Deep in the abscess, anaerobic bacteria (microbes that do not require oxygen) like anaerobic bacteria (microbes that do not require oxygen) like Fusobacterium necrophorum can flourish. The bacteria penetrate Fusobacterium necrophorum can flourish. The bacteria penetrate from the abscess into the neighboring jugular vein in the neck and from the abscess into the neighboring jugular vein in the neck and there they cause an infected clot (there they cause an infected clot (thrombosisthrombosis) to form, from which ) to form, from which bacteria are seeded throughout the body by the bloodstream bacteria are seeded throughout the body by the bloodstream (bacteremia). Pieces of the infected clot break off and travel to the (bacteremia). Pieces of the infected clot break off and travel to the lungs as emboli blocking branches of the pulmonary artery bringing lungs as emboli blocking branches of the pulmonary artery bringing the heart's blood to the lungs. This causes shortness of breath, chest the heart's blood to the lungs. This causes shortness of breath, chest pain and severe pain and severe pneumoniapneumonia. Fusobacteria are normal inhabitants of . Fusobacteria are normal inhabitants of the oropharyngeal flora. This is a very rare disease with only the oropharyngeal flora. This is a very rare disease with only approximately 160 cases in the last 100 years.approximately 160 cases in the last 100 years.[1][1]
Prevotella & Porphyromonas
Small, pale staining Small, pale staining gram negative gram negative coccobacillicoccobacilli
Dental plaque and Dental plaque and gingival crevices gingival crevices
Infections of oral cavity Infections of oral cavity and upper respiratory and upper respiratory tracttract
Prevotella and Porphyromonas
Some species produce a dark pigmentSome species produce a dark pigment
Pathogenicity
AdherenceAdherence : : agglutinate RBC agglutinate RBC fimbriaefimbriae
CapsuleCapsule : : acidic polysaccharides, acidic polysaccharides, phagocytosis by WBCphagocytosis by WBC
EnzymesEnzymes : : collaginase, protease, collaginase, protease, hyaluronidase, fibrinolysin, hyaluronidase, fibrinolysin, DNAse,…, etc.DNAse,…, etc.
EndotoxinEndotoxin (LPS) : (LPS) : activate C3 activate C3 pathway, PMNs pathway, PMNs
Pathogenicity
• Beta-lactamase productionBeta-lactamase production• B. fragilisB. fragilis – protect themselves and other – protect themselves and other
species in mixed infectionsspecies in mixed infections• Superoxide dismutase productionSuperoxide dismutase production
• Protects bacteria from toxic OProtects bacteria from toxic O22 radicals as radicals as
they move out of usual nichethey move out of usual niche
Anaerobes Commonly Encountered in Infection
Hundreds of anaerobes are part of normal human flora Hundreds of anaerobes are part of normal human flora Only few cause significant infectionsOnly few cause significant infections
Account for 2/3 of clinically significant anaerobic Account for 2/3 of clinically significant anaerobic infections:infections: Bacteroides fragilisBacteroides fragilis group group PrevotellaPrevotella and and PorphyromonasPorphyromonas Fusobacterium nucleatumFusobacterium nucleatum PeptostreptococcusPeptostreptococcus Clostridium perfringensClostridium perfringens
Pathogenic species have “virulence factors” that allow Pathogenic species have “virulence factors” that allow survival outside their niche and to cause diseasesurvival outside their niche and to cause disease
Importance of nonsporing anaerobes
Opportunistic pathogens cause disease in cases of Opportunistic pathogens cause disease in cases of lowered host’s immunity:lowered host’s immunity:
1.1. TraumaTrauma2.2. Tissue necrosisTissue necrosis3.3. Impaired circulationImpaired circulation4.4. AIDSAIDS5.5. Administration of antibiotics, corticosteroids & Administration of antibiotics, corticosteroids &
cytotoxic drugs. cytotoxic drugs. 6.6. DiabetesDiabetes7.7. MalnutritionMalnutrition8.8. MalignancyMalignancy
“MORE IS MISSED BY NOT LOOKING THAN BY NOT KNOWING”Anonymous
Patient examination in the Intensive Care Unit
“MORE IS MISSED BY NOT LOOKING THAN BY NOT KNOWING”Anonymous
Patient examination in the Intensive Care Unit
Thank you
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SAQ – Non sporing anaerobe
1. Classify non sporing anaerobic bacteria.
2. Enumerate the medically important non sporing bacteria.
3. Mention important role of Lactobacilli.
4. Write down the biological property and pathogenesis of B. fragilis.
5. Mention important characteristics and pathogenesis of Fusobacterium.
6. Why non sporing anaerobes are medically important?