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Flashcards in Oral Ecology Deck (26)
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1

Principles of Ecology

H____
N____
E____

 

P____
C____

 

C_____
P___

C____
S_____


¡Habitat
¡Niche
¡Ecosystem

¡Population
¡Community
¡
¡Competition
¡Predation
¡Cooperation
¡Symbiosis
 

2

Microbial Ecology

  • The study of _____ between ____ and their___ and____ environments.
  • Understanding ____  organisms occur and ___ ____ organisms occur
  • Explaining the factors that determine the____ ____ _____ that organisms occupy and that determine ___ ____ organisms are within those ranges.
  • Functional interactions between __________organisms.
     


¡Microbial ecology
§The study of interrelationships between microorganisms and their living and nonliving environments.
§Understanding where organisms occur and how many organisms occur
§Explaining the factors that determine the range of environments that organisms occupy and that determine how abundant organisms are within those ranges.
§Functional interactions between co-occurring organisms.
§
¡
§
 

3

 

  • Ecosystem
    • A functional system that includes a _____ of organisms and the ____ _____, interacting as a unit.
    • Ecosystems are characterized by ____ and _____ behaviors within the community.
  • Habitat
    • the ____ of _____in which an microorganism occurs.
  • Niche
    • The____ a microorganism ____ within a ____
    • Characterized by
      • t
      • r
      • a
      • i


¡Ecosystem
§A functional system that includes a community of organisms and the physical environment, interacting as a unit.
§Ecosystems are characterized by competitive and cooperative behaviors within the community.
¡
¡
¡Habitat
§the type of environment in which an microorganism occurs.
§
¡Niche
§The role a microorganism plays within the habitat.
§Characterized by
▪tolerance for the environment
▪resources needed
▪ activities
▪ interactions with other organisms
§
§
§
 

4

Oral Ecology


¡What bacterial ____ ____ are in the mouth, and what conditions influence ___ ____ of ___ that ____ ____?
¡
¡What bacteria can ____ ____ the mouth, and what ____allow them to do so?
¡
¡How do different microorganisms____within the oral cavity?
 


¡What bacterial colonization sites are in the mouth, and what conditions influence the type of bacteria that live there?
¡
¡What bacteria can permanently colonize the mouth, and what qualities allow them to do so?
¡
¡How do different microorganisms interact within the oral cavity?
 

5

Oral Ecology Overview


¡The mouth is a ___ ____environment
§Many distinct____
§Different bacteria colonize______________
§Type of bacteria in the mouth __________
§Type of bacteria________________
▪____ group that are able to____ in the mouth


¡The mouth is a highly complex environment
§Many distinct niches
§Different bacteria colonize different parts of the mouth
§Type of bacteria in the mouth changes over time
§Type of bacteria varies from person to person
▪Conserved group that are able to live in the mouth
 

6

The Human as Habitat

Mouth

Steptococcus

Actinomyces

Prevotella

Fusobacterium

7

Oral Ecology Overview II


¡Approximately ____ different species of bacteria can colonize the mouth
§Identified by ____ methods
▪________ sequence)
§Many cannot be 
§Most healthy people have ~____ species
¡
¡Oral bacteria are ____
§Most can act as _____  _____


¡Approximately 1000 different species of bacteria can colonize the mouth
§Identified by molecular methods
▪(16S rDNA sequence)
§Many cannot be cultured in the lab
§Most healthy people have ~400 species
¡
¡Oral bacteria are commensal
§Most can act as opportunistic pathogens
 

8

True or False ?

More bact in your mouth than people in world

Saliva contains approximately  __________bacteria per milliliter

The US population contains ______ people

The entire human mouth  is estimated to contain over_____ bacteria

  (depends on oral hygiene) 

The World  Population is estimated to contain over_____ people

Saliva contains approximately 100 million bacteria per milliliter

The US population contains 318 million people

The entire human mouth  is estimated to contain over 6 billion bacteria

  (depends on oral hygiene) 

The World  Population is estimated to contain over 7 billion people

9

The Mouth as a Habitat


Oral cavity has many unique ____ for ____ _____

  • T
  • T
  • S
  • M


Characteristics vary by habitat

  • O_____ 
  • p (large____ in ___, less in ___)
  • S (___ or ___ tissues, ___ or ____)
  • F
  • N (Exposed to ___ or not)
  • T
     


¡Oral cavity has many unique habitats for bacterial colonization
§Tooth surface
§Tongue
§Sub-gingival crevice
§Mucosal surfaces
§
¡Characteristics vary by habitat
§Oxygen (aerobic or anaerobic)
§pH (Large pH shifts in saliva, less in sulcus)
§Surface material (hard or soft tissues, keratin or nonkeratin)
§Fluid flow rates
§Nutrient sources (Exposed to saliva or not)
§Temperature
 

10

Colonization sites

11

Tooth 

  • Non-____ surface exposed to:
    • ___
    • ___
    • _____
  • Enamel structural features
    • ___ ____
    • ____ ____
  • Pellicle
     


¡Non-shedding surface exposed to:
§Fluids
§Nutrients
§Non-sterile environment
§
¡Enamel structural features
§Crown fissures
§Smooth surfaces
§
¡Pellicle
 

12

Pellicle

  • Forms on ____ ____ of tooth
  • ____ film derived from ____
  • Composed of:
    • P
    • L
    • A
    • H
    • S
    • M
    • S
    • A
       


¡Forms on enamel surface of tooth
¡
¡Protein film derived from saliva
¡
¡Composed of:
§Proline-rich proteins
§Lysozyme
§Albumin
§Histatins
§Statherin
§Mucins
§S-IgA
§Alpha-amylase
 

13

 Subgingival crevice

  • Gingival tissue forms a ____ around teeth
  • Surface gingiva are _____
  • Sub-surface gingiva attached to ____ ____ by ____ _____ _____ _____.
  • Free gingiva- ____ ___ to ____
    • Forms the___ ____ ___(____)
    • ___ deep in health
    • Can be____ deep in disease
    • ___robic
    • pH ___-___
    • Little____ penetration
    • ___ ____ ____-similar to ____
       


¡Gingival tissue forms a collar around teeth
§Surface gingiva are keratinized
§Sub-surface gingiva attached to tooth root by non-keratinized junctional epithelium
§Free gingiva- not attached to tooth
▪Forms the sub-gingival crevice (sulcus)
▪2 mm deep in health
▪Can be >5 mm deep in disease
▪Anaerobic
▪pH 7.2-7.8
▪Little saliva penetration
▪Gingival crevicular fluid (GCF)-similar to serum
 

14

Tongue

  • _____ epithelial cells
  • Differs from other mucosa by having a ___ ____
    • ____
    • _____ ____
  • ¡Creates ___  and ____ that provide ____sites, may become _____
     


¡Keratinized epithelial cells
¡Differs from other mucosa by having a complicated surface
§Papillae
§Taste buds
¡Creates crypts and trenches that provide protected sites, may become anaerobic 
 

15

Mucosal surface (Buccal)

 

  • _________epithelial cells
    • Ducts of ___ and ____
    • Also coated with ___ ____
    • Cells express surface ____, such as____, that may act as ___ ____ ____
    • Usually____ ____ colonized
      • Turn over approximately every_____
      • Can produce ____ ____
         


¡Non-keratinized epithelial cells
§Ducts of major and minor salivary glands
§Also coated with pellicle proteins
§Cells express surface proteins, such as glycolipids, that may act as bacterial binding receptors
§Usually not highly colonized
▪Turn over approximately every 3 days
▪Can produce antimicrobial peptides
 

16

Parameters affecting colonization


T____-___ ___, ______
p___-normal is ~____,____,  _____ may influence
O____-varies by ____, ____
M____ ____/__-tooth ____
S______ ____ and ____-normal is__ ml/min unstimulated, ___ ml/min stimulated
____ A____-presence of ___, ____, ____ ____, ____ ____
 


¡Temperature-tooth location, inflammation
¡pH-normal is ~7.2, diet, inflammation may influence
¡Oxygen-varies by location, inflammation
¡Mechanical forces/shear-tooth position
¡Saliva flow and composition-normal is 0.3 ml/min unstimulated, >1.0 ml/min stimulated
¡Host age-presence of teeth, dentures, hormonal stage, immune function
 

17

18

pH and Oxygen Variation

19

Host Influences on Flora

___
____
____
____ ____

Teeth

Diet 
Epidemiology

Host Defense

20

Where do our “flora” come from?

 

  • ____ to infant
    • “Window of infectivity” ____months
  • ___ ____
  • ____
     


¡Mother to infant
§“Window of infectivity” 6-18 months
§
¡Close contacts
¡
¡

¡“Other”
 

21

Niches & Communities


¡Teeth/Pellicle
____ 
____

§Streptococci
▪S. gordonii
▪S. sanguis
▪S. oralis
▪S.mitis bv.1
§Actinomyces
▪A. naeslundii
 

22


¡Caries lesions
___
____
____


¡Caries lesions
§S. mutans
§Actinomyces
§Lactobacillus
 

23

¡Tongue surface
 

____
____
____

§Streptococci
▪S. mitis bv. 2
▪S. salivarius
§Yeast (Candida albicans)
§Actinomyces
 

24


¡Tongue crypts-anaerobes
____
_____
______


¡Tongue crypts-anaerobes
§Veillonella
§Prevotella
§Porphyromonas
 

25


¡Subgingival crevice/pocket-anaerobes
§Streptococci
§Actinomyces
§Capnocytophaga
§Eikenella
§Fusobacterium
§Prevotella
§Porphyromonas
§Spirochetes
 

26

Communities?


¡What is a community of microbes adhering to each other and a solid surface?