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The family Actinomycetaceae |
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Includes several genera (genuses) |
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Often exist as normal oral flora but can cause
disease |
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Gram-positive |
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Nonspore-forming |
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Bacilli |
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Tend to grow as branched filaments |
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Either strict anaerobes or facultative anaerobes |
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Anaerobic and facultatives |
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4 species |
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A. israelii |
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A. naeslundii |
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A. viscosus |
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A. odontolyticus |
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Involved in 3 disease(s) |
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A. Actinomycosis |
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B. Periodontal Diseases |
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C. Root Caries |
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The various species of Actinomyces are normally
found in the mouth |
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Following traumatic injury, (a punch to the
face) these organisms are forced into the tissues, where they proliferate
resulting in Actinomycosis |
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Actinomycosis is a chronic infection that drains
into the mouth or through the outer skin |
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The pus often contains yellow granules called sulfur
granules because of their color (bright yellow) |
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The granule is composed of a mass of the tangled
filaments of the organism |
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Organisms involved have included A. israelii, A.
naeslundii, and A. viscosus |
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Actinomycosis can also affect the lower
respiratory tract via aspiration or inhalation of contaminated material |
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A. viscosus |
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Involved in gingivitis, possibly |
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in mild cases of periodontitis |
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Promotes adhesion of the periodontal pathogen Porphyromonas
gingivalis to dental plaque - therefore may set the stage for the
development of periodontitis |
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Produces succinate, a growth-stimulating factor
for P. gingivalis |
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A. viscosus |
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The presence of A. viscosus in periodontal
pockets may make one more prone to getting actinomycosis if struck in the
face |
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A. viscosus, A. naeslundii, A. odontolyticus Isolated
from human root caries |
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A. viscosus and A. naeslundii
induce root surface caries in laboratory rodents |
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Arachnia propionica (only species) |
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Facultative anaerobe |
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Isolated from human actinomycosis and
periapical endodontic lesions |
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Not known whether it plays a role in either |
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Obligate anaerobes |
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At least 10 species of Bifidobacterium have been
isolated from the human mouth |
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B. dentium has been isolated from plaque and
deep dentinal carious lesions |
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Rothia dentocariosa (only species) |
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Facultative anaerobe |
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Isolated from root caries and dental plaque when
periodontal disease was present |
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Not considered a cause of either disease |
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Both of these genera, Bacillus and Clostridium,
are Gram-positive rods that produce endospores |
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These are the only genera that produce
endospores |
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There are 34 species |
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2 are significant |
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B. cereus
and |
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B. anthracis |
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Aerobic or facultatively anaerobic |
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B. cereus |
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Can cause |
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Food poisoning |
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Infections of a large number of organs |
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Usually produces penicillinase, making it
difficult to treat |
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B. anthracis |
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Causes anthrax |
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Two main forms of anthrax |
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Cutaneous form |
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usually seen as a pustule on a finger |
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Pulmonary form |
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seen as a pneumonia |
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usually fatal if untreated |
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B. anthracis produces |
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lethal factor |
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edema factor |
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protective antigen |
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There are 85 species |
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20 are important human pathogens |
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They are normal flora on the mucosal surfaces of
the body including the mouth, intestine, and female genital tract |
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They can also produce toxemias - a condition
arising from a bacterial toxin |
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Clostridial infection of wounds or soft tissues
occurs primarily in an anaerobic tissue environment due to impaired
arterial or venous circulation |
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This occurs when the tissue is damaged |
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All species of Clostridium produce a number of
enzymes and toxins, many similar to those of the staphylococci and
streptococci |
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C. tetani and C. botulinum |
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Produce their devastation via toxins that are
among the most potent known to mankind |
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one million times more potent than rattlesnake
poison |
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Both toxins lead to death |
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Produces its toxin during infection and causes
profound muscle rigidity (called “Tetanus” or “Lockjaw”) |
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Tetanus may result from infected gingiva or
teeth or from oral surgery of the gums or teeth if the tetanus spores are
on the surgical instruments and get into the wound |
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Traveller, the horse of the confederate general
Robert E. Lee, died nine months after her master when she stepped on a
rusty nail and contracted lockjaw (tetanus) |
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The botulinal toxin, called botulin, is preformed
- it is produced by the organisms growing in food that is eaten |
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It is not due to an infection |
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If the food, and thus the toxin, is ingested, it
causes complete paralysis of the body muscles, including those involved in
breathing, resulting in |
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respiratory failure |
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paralysis and |
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death in as little as 4 hours |
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Ingestion of botulinal toxin almost invariably
ends in death |
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A cup of this toxin in pure form would be
capable of killing everyone on Earth |
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Most other species of clostridia cause gas
gangrene, particularly C. histolyticum and C. perfringens |
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An additional group of clostridia produce
non-lethal food poisoning |
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This usually follows ingestion of contaminated
meat, poultry, or gravy |
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Pseudomembranous colitis - may result from
prolonged antibiotic therapy with certain antibiotics |
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The organism most often involved is |
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C. difficile |
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An instrument used in dentistry is the autoclave |
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An autoclave uses steam at 121OC for
a period sufficient to kill all life present |
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This killing of all life is called sterilizing |
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Almost all vegetative organisms would be killed
by simple boiling |
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The reason we sterilize things in an autoclave
is because of clostridial spores |
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Because the spores of |
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C. tetani |
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C. histolyticum |
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C. perfringens |
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cause such tremendous devastation |
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We must be certain that they are not present on
the instruments we use |
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So we autoclave all instruments |
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Slide 1 - B. mel on blood |
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Gram-negative |
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Non-spore forming |
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Anaerobic |
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Rods |
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Very small - coccobacilli to short rods |
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A major component of the microflora of |
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Oral cavity |
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GI tract |
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Play major roles in a variety of oral infections
including |
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Periodontal diseases |
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Endodontic infections |
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These organisms all require vitamin K1
and hemin for growth |
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Steroid based hormones have chemical structures
similar to vitamin K1 and can serve as substitutes for vitamin K1 |
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The significance of this is that these hormones
are elevated |
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at the time of puberty |
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during psychological stress, and |
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during pregnancy |
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People in these situations may have a gingivitis
-pregnancy gingivitis is one of the most common |
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Originally all of these organisms were thought
to be 1 organism which was named Bacteroides melaninogenicus |
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The black pigment was thought to be melanin, and
that’s how it got the first part of its species name |
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Genicus comes from Genesis, which is Greek for
producing |
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The name thus meant “producing melanin” |
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All of these organisms were referred to as the Black
Pigmented Bacteroides or "BPB” |
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We have since identified 10+ human species and
additional animal species and transferred them to 2 new genera - Prevotella
and Porphyromonas |
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Now refer to them collectively as the Black-Pigmenting
Anaerobes or |
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Black-Pigmenting Anaerobic Rods |
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Prevotella |
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melaninogenica No disease |
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loescheii No disease |
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denticola No disease |
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intermedia Gingivitis, ANUG,
Periodontitis |
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nigrescens Endodontic infections |
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corporis Endodontic infections |
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pallens ? (newly isolated) |
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Porphyromonas |
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asaccharolytica No disease |
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levii No disease |
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endodontalis Endodontic infections |
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gingivalis Periodontal disease |
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catoniae ? (newly isolated) |
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Bacteroides Disease association |
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forsythus Periodontal disease |
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salivosus None |
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Porphyromonas Prevotella |
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gingivalis intermedia |
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Colonization Factors |
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Capsules + + |
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Pili + + |
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P. gingivalis P. intermedia |
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Tissue Destructive Factors |
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Abscess formation Strong Moderate |
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Enzymes: |
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Acid Phosphatase + + |
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Alkaline Phosphatase + + |
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Aminopeptidases +/- - |
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Proteases: Collagenase + - |
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Elastase + - |
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Gelatinase Strong Moderate |
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Trypsinlike + + |
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P. gingivalis P. intermedia |
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Tissue Destructive Factors |
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Toxic factors: |
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Ammonia + + |
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Butyric acid + - |
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Propionic
acids + - |
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Endotoxin Weak Weak |
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LPS bone
resorption + + |
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Epitheliotoxin + + |
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Fibroblast growth
inhibitor + + |
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Fibronectin
degradation + ? |
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Indole + + |
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P. gingivalis P. intermedia |
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Defeat Host-Defense Factors |
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C’3 degradation + ? |
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Fibrinolysin Strong Weak |
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IgA proteases + + |
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IgG proteases + + |
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PMNs |
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Leukotoxin - - |
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Decreased phagocytosis + + |
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Intracellular killing + + |
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Superoxide dismutase + + |
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Porphyromonas gingivalis and Bacteroides
forsythus are BANA positive (a protease that hydrolyzes benzoyl-DL-arginine-2-naphthylamide,
BANA) and are believed to play a role in periodontal disease |
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So the BANA test may be a good one for assessing
periodontal disease activity |
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One oral species: Actinobacillus
actinomycetemcomitans |
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Gram-negative |
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Nonspore-forming |
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Facultatively anaerobic |
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Rods |
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First isolated from human cases of actinomycosis
concomitantly (together) with Actinomyces, hence the name |
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It is usually abbreviated unofficially as A.a. |
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Oral colonization |
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One of the few bacteria capable of colonizing
buccal mucosa and dental plaque |
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Has both pili and capsules that aid in
attachment |
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Plasmids and Bacteriophages |
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Has both plasmids and prophages, though not all
strains have them |
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Some studies have related high levels of free
A.a. bacteriophage to actively progressing periodontal disease |
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Virulence Factors of A. a. |
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FACTOR ACTION |
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Leukotoxin Kills leukocytes |
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Immunosuppressive Factor Suppresses immune
response |
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Catalase Destroys peroxides |
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Superoxide dismutase Destroys the
superoxide radical |
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Virulence Factors of A. a. |
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FACTOR ACTION |
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Endotoxin Bone resorption |
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Unknown Bone resorption |
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Polyclonal antibody Stimulates an |
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stimulator inappropriate antibody |
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response yielding |
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excessive inflammation |
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Virulence Factors of A. a. |
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FACTOR ACTION |
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Several Inhibit
fibroblasts endothelial cells & epithelial
cell activities |
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Unknown Tissue invasion |
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Relation to Disease |
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Extremely high correlation with localized
juvenile periodontitis |
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Gram-negative |
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Spiral-shaped or straight rods |
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Microaerophilic to strict anaerobic |
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At least 11 species |
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6 are of human importance |
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Human Campylobacter and Their Diseases |
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ORGANISM DISEASE |
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C. concisus Normal oral flora |
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C. sputorum Normal oral flora |
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C. jejuni Gastroenteritis |
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C. coli Gastroenteritis |
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C. recta Periodontitis |
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Root canal infections |
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C. curva Periodontitis |
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Root canal infections |
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Armamentarium |
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Methyl mercaptans |
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H2S |
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Catalase ‑ some species |
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Gram-negative |
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Single thin rods |
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Facultative anaerobes |
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Capnophilic (require CO2 or HCO3
for aerobic or anaerobic growth) |
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Oral species of Capnocytophaga |
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C. sputigena |
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C. gingivalis |
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C. ochracea |
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C. haemolytica |
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C. granulosa |
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C. canimorsus |
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Their normal niche = human oropharynx |
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Several isolated from periodontitis |
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Some have the ability to cause rapid, severe
periodontal destruction in gnotobiotic rats |
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Able to produce a number of virulence factors |
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Virulence Factors of the Capnocytophaga |
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Endotoxin |
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Proteases: IgA1 |
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IgG |
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Collagen (weak) |
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Alkaline phosphatase |
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Acid phosphatase |
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Lipase |
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Hemolysin(s) |
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Adhesin |
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H2S |
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Virulence Factors of the Capnocytophaga |
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Bacteriocin vs Streptococcus sanguis, S. mitis, S.
mutans, Propionibacterium acnes |
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A factor which inhibits the proliferation of
human fibroblasts which could result in impaired healing after microbial
challenge |
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Virulence Factors of the Capnocytophaga |
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A dialyzable factor found intracellularly and
extracellularly - In neutrophils it produces |
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changes in their morphology |
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defects in locomotion |
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and the ability to adhere to surfaces |
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The organism has been shown to cause the release
of lysosomal enzymes from PMNs which may mediate tissue damage |
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Gram-negative |
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Rods |
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Microaerophilic |
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Only one species, E. corrodens, has been
identified |
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Normal niche = unknown |
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Have been isolated from periodontitis sites with
much bone destruction but "minimal" inflammation |
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Virulence Factors of Eikenella |
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Adhesin Mitogen |
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Slime Lectinlike substances |
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Endotoxin H2S |
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Beta-lactamase (penicillinase) |
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Phospholipase C (epithelial cell and membrane
phospholipids) |
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Surface associated material (saline extract)
inhibits bone synthesis |
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Gram-positive in very young cultures |
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Gram-negative in older ones |
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Short to long rods |
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Anaerobic |
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Many species have been isolated from the mouth |
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19 different species have been isolated from
periodontal disease sites |
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Normal niche = oral cavity |
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genital tract |
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Implicated in periodontosis and |
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necrotic root canals |
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Virulence factors of Eubacterium |
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Mitogen(s) |
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Bone resorbing substance |
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H2S |
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Methyl mercaptans |
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Hyaluronidase |
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Protease: Caseinase |
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Gram-negative |
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Short to long rods, with pointed or rounded ends |
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Anaerobic |
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F. alocis |
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F. glutinosum |
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F. gonidiaformans |
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F. mortiferum |
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F. naviforme |
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F. necrogenes |
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F. necrophorum ss. necrophorum |
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ss. funduliforme |
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F. nucleatum ss. nucleatum |
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ss. polymorphum |
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ss. fusiforme |
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ss. animalis |
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ss. vincentii |
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F. periodonticum |
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F. russii |
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F. sulci |
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F. varium |
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Normal niches = oropharynx & intestine |
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Several have been isolated from many different
oral infections as shown in the next table |
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Oral infections due to fusobacteria |
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Tonsillitis |
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Mandibular osteomyelitis |
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Pharyngitis |
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Gingivitis |
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Gingival abscess |
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Juvenile periodontitis |
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Chronic periodontitis |
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ANUG |
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Pulpal infections (associated with cold
sensitivity) |
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Acid phosphatase |
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Alkaline phosphatase |
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Capsule |
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DNAse |
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Endotoxin |
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Hemagglutinin |
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Hemolysin |
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H2S |
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Leukocidin/leukotoxin |
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Lipase |
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Methyl mercaptans |
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Phospholipase A |
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Protease: Gelatin |
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Activate the alternate complement pathway |
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Gram-positive |
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Rods, often in chains |
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Microaerophilic to anaerobic |
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Oral species of Lactobacillus |
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L. oris |
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L. plantarum |
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L. salivarius ss. salivarius |
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ss. salicinius |
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L. casei ss. casei |
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ss. rhamnosus |
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L. acidophilus |
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L. gasseri |
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L. brevis |
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L. fermentum |
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L. uli |
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L. rimae |
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Normal niches = mouth |
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intestine |
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vagina |
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Implicated in caries |
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Isolated from gingival crevices and periodontal
pockets |
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Virulence Factors |
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Bacteriocins |
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Produce much lactic acid |
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Lactic acid lowers the pH sufficiently to cause
demineralization of the tooth enamel resulting in caries |
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Gram-negative (Gm+ in young cultures) |
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Rods with straight, curved, rounded or pointed
ends, arranged in pairs, chains or septate filaments |
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Anaerobic to capnophilic |
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Only one species, L. buccalis |
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Normal niche = plaque |
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Implicated in gingivitis |
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Not known if they possess virulence factors |
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Gram-positive |
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Anaerobic |
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Cocci, usually chains |
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Oral Species of Peptostreptococcus |
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P. anaerobius |
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P. asaccharolyticus |
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P. magnus |
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P. micros |
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P. prevotii |
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Normal occurrence = Oral cavity |
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Implication in Diseases |
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Endocarditis |
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Parotitis |
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Peritonsilar abscess |
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Pleuropulmonary infections |
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External otitis |
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Chronic periodontitis |
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Root canals |
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Armamentarium |
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Alkaline phosphatase |
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DNAse |
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Hyaluronidase |
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H2S |
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Protease: Gelatin |
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Collagen |
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Gram-negative |
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Curved rods |
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Anaerobic |
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Have a characteristic moon shape with tapered
ends |
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Selene = Greek for "moon" monas = unit |
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Flagella protrude from the concave side only |
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(= |
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=) |
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(= |
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=) |
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(= |
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Oral species of Selenomonas |
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S. sputigena |
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S. noxia |
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S. flueggei |
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S. infelix |
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S. dianae |
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S. artemidis |
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Normal niche = mouth |
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Isolated from gingivitis |
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periodontitis |
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pericoronitis |
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Virulence factors of Selenomonas |
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Endotoxin |
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Phosphatase |
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H2S |
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Protease: Gelatin |
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Gram-negative |
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Anaerobic |
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Cocci - diplococci and short chains |
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Human species of Veillonella |
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V. parvula |
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V. dispar |
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V. atypica |
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Association of
Veillonella with Disease |
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V. atypica No disease association |
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V. parvula Isolated from Periodontal Disease |
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V. dispar Isolated from Periodontal Disease |
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Notes