Microbial Symbiosis & Normal Flora Flashcards
It is generally defined as a condition where two dissimilar organisms live together in an intimate associate that sees both organisms benefit.
Microbial Symbiosis
Microbial Symbiosis
+ is the co-existence of two microorganisms.
- Mutualistic relationship
- Commensalistic relationship
- Pathogenic/Parasitic relationship
describes the microorganisms that are frequently found in/on the bodies of healthy persons.
Normal Flora
Normal Flora
Also known as:
- Normal microbiota
- Normal microflora
- Physiological microbiota
• Colonize an area for months or years.
• Consists of relatively fixed types of microorganisms regularly found in a given area at a given age.
• If disturbed, it promptly re- establishes itself.
Resident Normal Flora
• Present at a site temporarily.
• Consists of non-pathogenic or potentially pathogenic micro- organisms that inhabit the skin or mucous membranes for hours or days.
• It is mostly derived from the environment.
Transient Normal Flora
5 Beneficial Role
+ Immunostimulation
+ Protection from External Invaders
+ Nutrition
+ Inhibitory Action
+ Stimulate Development of Certain Tissues
Harmful Effects
+ May be a Source of Opportunistic Infections
+ May act as Pathogens
+ Interferes with Therapy
+ Use of Broad-Spectrum
+ May cause Diagnostic Confusion
E. coli
+ Helps in food digestion
Escherichia coli
contains a wide variety of microorganisms that are not removed by washing or superficial antisepsis.
Skin
S. epidermidis
Staphylococcus epidermidis
S. mutans
Streptococcus mutants
Most microorganisms are destroyed in the stomach due to the acidic pH. The survivors multiply in the colon.
GI Tract
More than 90-95% of the microbial population is comprised of anaerobes.
GI Tract
• Oral administration of living organisms to promote health.
• Mechanism: Competition with other bacteria; stimulation of non-specific immunity.
• Example: Yakult, Yogurt, Fermented foods
Probiotics
