Biomaterial-related infections: biofilms

fill in the blank about biofilms:

• communities of _________ microorganisms encased in self-produced ______ _______ _______

• on almost all ____ and ______ surfaces

• __% of earth microorganisms live in ____

• biofilms offer ____, protection against _____, ______ and ______ stresses

• ____(high/low) survival and persistence potential

• _____ adhesion

• surface-associated, extracellular polymeric substance

• natural, artificial

• 99, biofilms

• bacteria, environmental, chemical, mechanical

• high

• unwanted

causative pathogens (6)

1. s___

2. g_____ o_____

3. e______

4. p______ a_____

5. f_____

6. str_____

1. staphylococcus

2. grampositive organisms

3. enterobacteriaceae

4. pseudomonas aeruginosa

5. fungi

6. streptococci

list the infections rates for the following in order: hip/knee, shoulder, hernia mesh, cardiac electronic, breast implant

1. hernia mesh (6.7)

2. breast implant (5.2)

3. cardiac electronic (2.0)

4. shoulder (1.2)

5. hip/knee (0.9)

what are 3 significant clinical problems with biomaterial related infections?

device failure, host tissue damage, antibiotic and multi drug resistance

what are some bad things that can happen with dental implant infections?

• o_______

• ______ pain

• i_______

• s____

• implant _______

• limb _______

• d____

• osteomyelitis

• debilitating

• inflammation

• swelling

• loosening

• amputation

• death

fill in the blank: how antibiotic resistance happens

1. lots of ___. a few are ____ resistant

2. antibiotics kill _____ causing the illness, as well as ____ bacteria _____ the body from the infection

3. the ___-___ bacteria are now allowed to _____ and take over.

4. some bacteria give their _____-______ to other bacteria, causing more problems

1. germs, drug

2. bacteria, good, protecting

3. drug-resistant, grow

4. drug-resistance

immediate infections:

s____:

• in the ___ of the wound

• produced by ___ ______

d__:

• produced by ___ or __ _____ bacteria

• carried out during the _____ process

superficial:

• site

• skin

deep:

• skin, air borne

• implantation

late infections:

• ____ to ____ after implantation

• spread through _____ by ____ and other body fluids

• _____ risk for people with implants

• months, years

• contamination, blood

• long-term

fill in the blank: local infections can _____ to the blood stream reaching other ____

disseminate, organs

biofilms structure:

bacteria embedded in a _____ matrix of ____ _____ ______, mainly _______, proteins and _____ ___.

self-produced, extracellular polymeric substances, polysaccharides, extracellular DNA

biofilms isolate bacteria from ____ _____ and _____ therapy

immune defenses, antibiotic

what is phase one of bacterial attachment to biomaterials

reversible association

what is phase two of bacterial attachment to biomaterials?

irreversible molecular bridging

fill in the blank: biofilms formation

• initial ____ by ____ motility towards the ____

• ____ adsorption by _____ attraction and _____ forces

• _____ attachment adhesion mediated by specific _____

• formation of ______ surrounded by a self-produced ____ made of _____ substances

• a mature ____ with complex architecture composed of pillars an channels

• colonization, surface

• reversible, electrostatic, vanderwaals

• irreversible

• micro colonies, ECM, polymeric

• biofilm

architecture of biofilms:

____ at structural, _____ and ____ levels

heterogeneous, physiological, genetic

biofilm gradients allow (better/worse)_______ adaptation to environmental changes:

• _____ to antimicrobial agents

• ____ response

• ____ and nutrients

• presence of persister _____

better

• susceptibility

• stress

• oxygen

• bacteria

in the interior of a biofilm:

• ____ is limited or absent

• ____ limitation

• oxygen

• nutrient

persister bacteria escape the activity of the _____ agents ad serve as the ____ bacteria when the conditions are favorable

antimicrobial, initiator

how can you study biofilms in vitro?

microscopic visualizations and specific stainings

how can we study biofilms in vivo?

• m_____ v_____

• h_____ and i_____

• c_____ a_____

• microscopic visualization

• histology and immunohistochemistry

• colorimetric assays

treatments of bacterial biofilm infections:

• _____ treatment

• ____, mechanical, or ____ disruption: surgery, ultrasound, electric current, photodynamic therapy

• ____ solution: generate devices with surfaces that ____ the attachment of bacteria and formation of biofilms

• antimicrobial

• physical, biological

• engineering, prevent

there is higher bacterial adhesion in ____ and in _____ surfaces

rougher, hydrophobic

name 2 contact killing biomaterials that are toxic for bacterial metabolism

selenium and silver

name 3 antimicrobial-releasing coatings

chlorhexidine, gentamicin, triclosan

multifunctional coatings are designed to be _____ and _____ to a variety of stimuli such as _____

sensitive, responsive, bacteria

in vivo testing results of polymer resistant coatings:

• the coated groups were significantly ____less/more than the uncoated groups

• the uncoated groups remained roughly _____ _____ over four days

• the coated groups increased/decreased____ after day 0, then slightly increased/decreased_____ over four days

less, the same, decreased, decreased

bacteria synchronously control ___ ______ in response to changes in bacteria _____ and species _____

gene expression, density, complexity

steps for quorum sensing mechanism

high density of bacteria→autoinducers→QS mechanism

quorum sensing mechanism

modulation of genes associated with enzymes and metabolites

to prevent biofilm formation, use molecules interfering with ___

QS

disaggregate the biofilm matrix by destroying its _____ integrity with different enzymes that _____ the EPS matrix

physical, degrade

what are matrix disruptive agents?

• different _____ that _____ the EPS matrix

• _____ that penetrate within the biofilm matrix combined with _____/____ ______, ____ targeting, ________ and _____ therapy

enzymes, degrade

nanocarriers, antibiotic/drug delivery, magnetic, photodynamic, photothermal

superparamagnetic iron oxide nanoparticles (SPION) to prevent biofilm formation:

• small enough to _____ the _____

• large enough to have a ____ ______ ___-_____

• _______ ratio optimized for loading ____ and _________

• penetrate, biofilm

• long plasma half-life

• surface-to-volume, drugs, antibiotics

photodynamic therapy:

• has three components: _____, ________, and _____

• a large number of ____ radicals and _____ _____ species released when excited by ____ _____

light, photosensitizer, oxygen

free, reactive oxygen, light photons