periodontal pathogens Flashcards
says that plaque control is important in periodontal treatment; all plaque bacteria considered bad; any accumulation of micro-organisms at or below the gingival margin causes inflammation
non-specific plaque hypothesis
says that specific organisms in dental plaque are the etiological agents; microbial composition of disease sites different from healthy sites
specific plaque hypothesis
the specific plaque hypothesis says that ____ and ____ could control local aggressive periodontitis
local debridement; systemic antibiotics
gingival health - microflora is predominantly ____ and ____
gram positive; facultative anaerobes
in gingivitis- microflora is predominantly _____ and ____
gram negative; obligate anaerobes
____, not ____, of the virulent periodontal pathogen are important in disease
strains; species
P. gingivalis with type __ and ___ ____ genotypes = healthy; types ___ and ____ seen in disease
type I and V fimA genotypes
types II and IV in disease
pathogen must express ____ and must be in the right location in the site which is :
virulence factors; adjacent to epithelium and apical part of pocket
____ formation by s. sanguis inhibits A.a
peroxide (beneficial species inhibit pathogens)
____ can increase outer membrane protein expression in P. gingivalis
iron
s. cristatus can inhibit ____ expression of P. gingivalis
fimA
things that affect host susceptibility
HIV infection
diabetes
smoking
in colonization, ____ on bacteria bind to ____
adhesions; host receptors
3 examples of host receptors
type I or IV collagen
sialic acid
galactosyl residues
bacteria have ____, outer membrane proteins
fimbriae
4 things that happen during colonization
adhesion
coaggregation
nutrient utilization
competitive inhibition
Veillonella uses ____ made by streptococci; campylobacter uses ____ made by selenomonas; porphyromonas uses ____ from blood in sulcus
lactate; formate; hemin
bacteria inhibit each other through competitive inhibition, by producing ____, or in the case of s. sanguis, _____ (to inhibit A.a.
bacteriocins; hydrogen peroxide
3 types of host defenses against bacteria
desquamation of epithelium
antibodies can prevent binding
phagocytic cells
bacteria overcome desquamation of epithelium by:
invading epithelium and binding to underlying cells
bacteria overcome antibodies by:
IgG and IgA proteases; mimic host antigens
bacteria overcome phagocytic cells by:
leukotoxin; non-lethal suppression of immune cells
world workshop 1996 designated 3 periodontal pathogens:
P. gingivalis
A. actinomycetemcomitans
T. forsythia
red complex bacteria
P. gingivalis
T. forsythia
T. denticola
characteristics of AA
small, non-motile
gram negative
saccharolytic
capnophilic
AA is a ____ rod that forms small, convex colonies with a _______ center
round-ended; star-shaped
high numbers of AA assoc with _____; detected in ____ and in _____
localized aggressive periodontitis; active sites; prospective studies
host response to AA produces high levels of ____ and ____
systemic; local antibody response
virulence factors of AA
tissue invasive- epithelial and endothelial cells leukotoxin fibroblast inhibiting factor endotoxin collagenase
AA inhibits growth of ____ and ____ in animal models
commensals (strep sanguis); induces disease
there are ___ serotypes of AA, based on _____ on surface of organism
5; polysaccharides
_____ are dominant antigens
serotype specific surface antigens (SPA)
patients are infected with ___ serotype and serotypes are ____ over time
one; stable
____ most commonly assoc with LAP in the US; has a role in resistance to ____ and killing by ____
serotype b; phagocytosis; PMNs
____ is health associated in Finland, disease assoc in Japan
serotype a
____ and _____ approach is vital to treatment of LAP (by AA)
mechanical ; chemotherapeutic
____ + _____ effective in reducing bacterial load
amoxicillin 500mg ; metronidazole 250 mg
____ is required to eliminate tissue reservoirs of AA
surgical approach
characteristics of P. gingivalis
gram negative
non-motile
anaerobic
asaccharolytic rods
P. gingivalis is a member of the much investigated ____ group
black pigmented bacteroides
____ important in protein degradation and in the maturation of _____ such as ____
cysteine proteinases (ARG-gingipain and LYS-gingipain); cell surface proteins; fimA fimbrillin
Presence of Pg indicates increased risk for ____
attachment loss
virulence factors of P. gingivalis are involved in:
- colonization and attachment
- evading (modulating) host responses
- multiplying
- damaging host tissues and spreading
characteristics of T. forsythia
gram negative
anaerobic
spindle-shaped
highly pleomorphic rod
T. forsythia requires _____ and co-cultivates with _____
N-acetylmuramic acid (NAM); F. nucleatum
T. forsythia has a serrated S-layer on cell surface that mediates ____ and _____; it is composed of ____
hemagglutination ; adhesion/invasion of epithelial cells; two glycoproteins
characteristics of treponema denticola
- species of spirochete
- gram-negative
- anaerobic
- highly motile microorganism
T. denticola first identified in _____
ANUG (acute necrotizing ulcerative gingivitis)
characteristics of prevotella intermedia/nigrescens
- gram negative
- short, round-ended anaerobic rod
P. intermedia is the ______ to receive considerable interest
second black-pigmented bacteroides
p. intermedia has luxuriant growth in _____ and is assoc with ______ gingivitis
naphthoquinone; puberty/pregnancy
P. intermedia elevated in _____
acute necrotizing ulcerative gingivitis
characteristics of Fusobacterium nucleatum
gram negative
anaerobic, spindle-shaped rod
F. nucleatum is an ____ in plaque and is a ____ organism
early colonizer; bridging
F. nucleatum can induce cell death in ____; releases ____, ____, and ____ from _____
leukocytes
releases cytokines, elastase, and oxygen radical from leukocytes
Gram-negative, capnophilic, assacharolytic, regular, small rod with blunt ends
Eikenella corrodens
Gram-negative, anaerobic, short, motile vibrio
campylobacter rectus
Gram-positive, anaerobic, small, assacharolytic coccus
peptostreptococcus micros
Gram-negative, curved, saccharolytic rods
selenomonas species
Gram positive, anaerobic, small, pleomorphic rods
Eubacterium species
