Biofilms Flashcards
What are biofilms?
organized multicellular community of bacteria attached to a living or inert surface, surrounded by self produced extracellular, polymer matrix.
Where do biofilms form?
Diverse environments with fluid flow.
hot springs, pipe walls, catheters
Organic molecules depositing on a clean surface creates __________ _________ allowing bacteria to adhere.
conditioning film
___________ adsorption occurs in seconds and are held together by ___________ and other weak forces.
__________ occurs in seconds to minutes and utilizes specific adhesion to molecules.
reversible adsorption; Van der Waals
Irreversible attachment
What is a difference between primary colonizers and secondary colonizers?
Primary attach to conditioned surface and secondary attach to the primary.
What are some factors secondary colonizers require?
- waste products of primary colonizers
- decreased oxygen tension
- physical anchorage
___________ has a lot of binding sites and is associated with biofilms. Referred to as “bridge species”
F. nucleatum
What percent of biofilm microcolonies are extracellular polymer vs bacteria?
75-95 extracellular polymer
5-25 bacteria
what is cooperative consortia?
anaerobic layer deep to the aerobic layer and provides nutritional advantage
How can biofilm bacteria spread?
- active enzyme degradation of polysaccharide matrix
- bacteria break from mature biofilm and become new pioneer cells in a different location
- High fluid flow, bacteria sloughing off via streaming, rippling
- Object coming into contact could cause detachment of biofilm.
What are some advantages to microbes of biofilm?
- resistant to antimicrobials
- resistant to host defenses
- resistant to mechanical removal
- nutritional advantage
What are some advantages to host of biofilm?
- presence of beneficial species in an in vivo biofilm can prevent colonization by harmful organisms through occupying space, stimulate a basal level immune response, produce molecules that kill other species
