Upper GI micro Flashcards
(72 cards)
What is it meant by normal flora?
part of the microbiome - the ecological community of commensal, symbiotic, and pathogenic microorganisms that literally share our body space.
Where are Peyer’s patches found? What are they?
small masses of lymphatic tissue found throughout the ileum region of the small intestine.
What are the 4 phyla in the stomach?
Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes
Wgat are some things in the normal flora of the large intestine
Microbe rich, “microbiome” studied here Anaerobes Gram-negative rods Enterococcus – can survive wide range of stressors and enviromental conditions Spirochetes
Define caries?
Infectious disease that causes tooth decay
Pain, tooth loss, spread of infection
what are the risk factors of developing caries
high-sugar diet, poor oral hygiene, reduced amount of saliva, smoking, periodontal disease
Who has the highest prelvance of caries?
children, common worldwild, at least 1 carried filled
What causes demineralization?
fementable sugars + acid producing bacteria
What is Periodontal Disease?
infectious disease destroying supporting structures of teeth- tissues and bone, -(common and mild form gingivitis- just the gums)
How common is gingivitis?
Affects more than 30% of population worldwide
Peridontisis is more severe than gingivitis- what else is peridontitis asscoaited with?
Heart attack
Stroke
Lung disease
Premature birth or having a baby with low birth weight, in women
What is a biofilm made up of?
consist of two or more species of bacterial microcolonies that are enclosed in a glycocalyx(polysacchrides)
What does a biofilm provide the bacteria?
Adherence
Protection from the immune system
Protection from antibiotics
Symbiotic (but also anti-symbiotic) relationships
Local conditions of pH, etc, in a normally inhospitable environment
What microbes are dominate in the mouth?
Anaerobic organisms predominate but also have gram pos lactobacilli and spirochetes. Some bacteria assoacited with pathogenic infections are there but in lower amlounts considered commensals
What groups of microbes play a role in protecting against dental caries and periodontitis
streptococci, they as producing hydrogen peroxide which inhibits the growth of other oral bacteria
S. sanguinis, S. oralis, S. gordonii, and S. mitis – the “mitis group”
Microbes that cause caries are usually located in plaques on tooth surfaces, often in crevices or between teeth are usually gram pos/neg?
postive!
Microbes that cause periodontal disease do their destruction primarily below the gumline – in the subgingival space are gram pos/neg
negative!
The bad strep is hard to identify-why?
that many oral streptococci are naturally transformable and readily exchange DNA with one another- this complicates 16S rRNA analysis
Strep mutans characterics?
gram pos, cocci beads on a string, cat neg, facultative anaerobe, alpha hemo, opotchin resistant
Different bwtn virulence factors and toxins?
Toxins are virulence factors- which enable the microbe to establish itself within a host
What are strep mutans virlence factors
adhesin-like surface-associated proteins (e.g. AgI/II family), extracellular glucosyltransferases (Gtfs)
What are extracellular glucosyltransferases (Gtfs)
constituents of the pellicle and are capable of synthesizing glucans (a type of polysaccharide) in situ from sucrose. Glucans provide additional S. mutans binding sites, as it binds avidly and in large numbers to these polymers
What are the “Keystone pathogens” in periodontal disease
Treponema denticola – a spirochete
Tannerella forsythia – anaerobic, gram negative
Porphyromonas gingivalis – best studied because it can be cultured
Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans is related to the severity of the periodontal disease
Porphyromonas gingivalis characteristics?
gram neg, bacillus, anerobic, assharolytic, black pigmented colonies on blood agar, bacitracin resistant
