Bacteria- Oral Bacteria B Flashcards
what are dentoalveolar infections
pyogenic infections associated with the teeth and surrounding supporting structures
endodontic infections are _________ that are _____
endogenous infections; opportunistic
what bacteria are cultivated most frequently in root canal infections
-bacteriodes and prevotella
what microbe is found when PCR is used
treponema denticola
what microbe is found in chronic apical infection and failed root canal treatments
enterococcus faecilis
what is the new species associated wth failed root canal treatments
actinomyces radicidentis
what is the presentation of dentoalveolar infections
-abscess localized to tooth that intiated the infection
- diffuse cellulitis which spreads along fascial planes
what are dentoalveolar abscesses caused by
- spread from carious lesion
- tooth fracture/wear
- through periodontal membrane and accessory root canals
- anachoresis during bacterima from extraction at different site
what are the facultative anaerobes isolated from dentoalveolar abscesses
-streptococcus
- actinomyces
what are the obligate anaerobes isolated from dentoalveolar abscesses
- peptostreptococcus
- porphyromas gingivalis
- prevotella
- fusobacterium nucleatum
what is ludwigs angina
a spreading, bilateral infection of the sublingual and submandibular spaces
- cellulitis of the fascial spaces rather than true abscess formation
what is the mixed endogenous infection of ludwigs angina
- porphyromonas
- prevotella
- fusobacterium
-anaerobic streptococci
what is a result of ludwigs angina
airway obstruction- death by asphyyxiation
what is a periodontal abscess
localized collection of pus caused by acute or chronic destruction of periodontium
- endogenous, subgingival plaque bacteria
what microbes cause periodontal abscesses
-porphyromonas
- prevotella
- fusobacteria
- anaerobic streptococci
what organisms cause supprative osteomyelitis of the jaws
-porphyromonas
- prevotella
- fusobacteria
- anaerobic streptococci
what is cervicofacial actinomyces and what microbe causes it
- endogenous, granulomatous disease
- 65% in cervicofacial region
-actinomyces - sulphur granules
what are oral manifestations of syphilis
hutchinsons incisors, mulberry molars
- primary and secondary syphilis lesions
- gummas
what are oral manifestations of tuberculosis
oral lesions in up to 5% of primary and secondary tuberculosis cases
- ulcers on palate and gingiva
what microbe causes bacterial infection of salivary glands
staphylococcus
what are diseases or situations associated with oral bacteria or their components
- infective endocarditis
- disseminated intravascular coagulation
- nephritis
- RA
- Behcet’s disease
- atherosclerosis
- low birth weight infants
oral bacteria change their gene expression patterns once they enter ____
blood or other systemic compartments
what have IVET promotor trapping been used for
to identify potential virulence associated genes for oral bacteria when they enter blood or tissue
- infective endocarditis
what has signature tagged mutagenesis (STM) used for
to identify potential virulence associated genes for oral bacteria when they enter blood or other tissue
- used in streptococcus sanguis
what happens in infective endocarditis
-platelets adhere to collagen exposed daamged heart valves
- forms a platelet clot
what do heat shock proteins do
-antibodies elicited by bacterial HSPs can cross react with human HSPs
- if immune complexes are deposited in the arterial wall, joints or mucous membranes, HSP mimicry can contribute to systemic disease
what happens in autorecognition induced by oral microorganisms
- streptococcus sanguis express an epitope within PAAP which is similar to the arthritogenic epitope of type II collagen
what is the possible mechanism for the link between local dental disease and systemic pathology
- high levels of inflammatory mediators such as TNF alpha and IL-1beta may enter the cirulation and induce the liver to produce CRP, IL-1beta and TNF alpha
what does the mucosal barrier in oral surfaces contain
toll like receptors
what do TLRs recognize
PAMPs
what does TLR2 recognize
petidoglycan
what does TLR4 recognize
LPS, lipoteichioc acid
what does TLR6 recognize
LPS
what does TLR10 recognize
LPS
what are defensins
-small peptides that form pores in bacterial membranes and disrupt cells
-HBD-1 is the main defensin produced by epithelial cells
- bacterial membranes are susceptible due to their high phospholipid content
what is the adherent mucin layer
- mucins attached to mucosal surface form a selectively permeable layer
- mucins are glycoproteins and carbohydrates portion form a sticky slippery gel
what are the mucins in the oral cavity
MG1 and MG2
what do commensal oral microbiota do
endogenous bacteria keep out new bacteria and stimulate the immune system, but they can cause disease when the balance shifts
what is desquamination
compare numbers of bacteria on the buccal mucosa to the numbers in the dental plaque biofilm
what are epithelial antibody receptors
microbes captured by tethered antibody are removed when desquamination occurs
how much saliva is secreted per day
0.5-1.5 liters per day
what do MG1 and MG2 do
aggregate and clear oral microbes via lectin-like interactions
what is agglutinin cloely related to
MG2
what are histatins
small proteins with fungicidal and bactericidal activites. inhibit bacterial aggregation and hemagglutination
- also form pores
what do cystatins do
inhibit cysteine proteases
what does lysozyme do
degrades peptidoglycan by cutting bond between NAG and NAM
what do peroxidases do
create peroxidation products using bacterially produced H2O2
-OSCN- inhibits growth of and acid production by MS and lactobacilli by oxidizing bacterial glycolytic enzymes
what is humoral mucosal immunity in the mouth mediated by
S-IgA
what are the mucosal lymphocytes and what do they do
- lamina propria lymphocytes: resting memory cells awaiting exposure, cytokine production upon rexposure
- intraepithelial lymphocytes: surveillance for pathogens and removal of stressed and infected epithelial cells
what does GCF do
flushes gingival crevice removing microbes and products
- major source of leukocytes in oral cavity: 95% are nuetrophils
what are components of acquired specific immunity
- mucosal lymphocytes
-GCF - dental plaque fluid
