Normal Flora vs. Pathogens Flashcards
Natural microbial habitats
Natural microbial habitats
soil
water
air
animals and animal products
Define:
Flora
Indogenous Microbiota
Transient Flora
Niche
Opportunistic
Flora: AKA Microbiota. microorganisms present in a special location
Indogenous Microbiota: AKA Resident Flora. microbial flora typically occupying a certain niche.
Transient Flora: microbial flora temporarily occupying a niche.
Niche: place of an organism within its community.
Opportunistic: microbes that are normally harmless, but become invasive when given an opportunity (weakened immune defense)
Roles of resident flora
Roles of Resident Flora
- Common source of infection
* oportunistic infections (ex. ecoli=UTI) - Immune stimulation
* ex. ABO blood type - Keeping out invaders
* produce substance inhibiting new invaders (ex. antibiotic) - Role in nutrition and metabolism
* ex. E.coli synthesizes vitamin K
Acquiring Infectious Agents
Acquiring Infectious Agents
- Entry: by ingestion, inhalation, or direct penetration
- Colonization: occupation of new habitat
- Invasion: entry/spread throughtout cells and tissue
- Multiplication: microorganism reproduction during infection
transmission of diseases: vocab
Transmission of diseases: vocab
Vector: carrier of disease that transfers agent from host to host
Carrier: symptomless individual who passes pathogen to others
Nosocomial Infections: infections aquired in a hospital setting
Koch’s postulates
Koch’s postulates
= criteria to identify causative agent of a particular disease.
- microorganism must be present in ALL cases of disease
- pathogen can be isolated from host and GROWN in pure culture.
- pathogen from pure culture cause same disease when INOCULATED into another animal.
- pathogen must be REISOLATED from new host and shown to be the same as isolate from primary host.
BASICALLY
- all these sick things have IT
- take it out of sick thing and grow IT
- put IT into heathy thing and IT makes thing sick
- take IT out of new sick thing and make sure IT is the same as IT was in the first sick things.
Host- Microbe Relationships
Host- Microbe Relationships
Symbiosis: relationship between two dissimilar organisms
Mutualism: both benefit (+/+)
Commensalism: one benifits (+/0)
Parasitism: one benifits and other suffers (+/-)
Steril Sites
Steril Sites should not have any flora!
- Brain
- Blood/tissue/organ systems
- sinuses and inner ear
- lower respitory tract
- internal urinary tract- kidney, ureters, bladder, posterior urethra
- uterus, cervix, fallopian tubes
List Resident Flora
(locations/examples)
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List Resident Flora
- Skin
- microbes colonize epidermis
- Oral Cavity
- colonize cheeks and gums
- Upper Respiratory Tract
- strep and staph
- Eye + Outer Ear
- Intestinal Tract
- E.coli, Lactobacillus etc.
- Genitourinary Tract
- vaginal flora
- microbes near urethral orifice (opportunistic UTI)
Infection vs. Disease
Infection vs. Disease
Infection: colonization and/or invasion and multiplication of pathogenic microorganisms in a host WITH OR WITHOUT MANIFESTATION OF DISEASE.
Disease: ABNORMAL condition of body function or structure that is harmful to the host.
Factors controlling growth of microorganisms
Factors controlling growth of microorganisms
- Nutrient Availability
- Environmental Parameters
- Competition
- Host Immune System
Define: epidemic, endemic, pandemic
epidemic: disease that occurs suddenly, in numbers greater than normal expectancy.
endemic: disease present in a pop or geographic area at all times.
pandemic: widespread epidemic, throughout region, country, continent, or globe.
