Biofilms Made Easy Q & A
What medical devices are biofilms found on the surface of?
1. urinary catheters 2. contact lenses 3. intrauterine devices (IUDs) 4. endotracheal and tympanostomy tubes 5. orthopedic or breast implants 6. sutures
Develop the initial EPS and become increasingly tolerant to biocides?
1. within 12 hours 2. biocide: chemical agent, such as pesticide, that is capable of destroying living organisms
Are biofilms more frequent in acute wounds or in chronic wounds?
chronic- 60% acute- 6%
How quickly do planktonic bacteria do the following?
list the following
Are most biofilms made of one species or many (polymicrobial)?
polymicrobial
What is the term for bacterial communication that develops in stage two?
quorum sensing
Under natural conditions, do most microbes remain planktonic? Explain.
under natural conditions, most microbes tend to attach to surfaces and eventually form biofilms, so no.
What does the microbial term "sessile" mean?
when bacteria become firmly attached
Form strongly attaches microcolonies?
within 2-4 hours
How quickly can a wound biofilm reform after debridement? -- End listing
within 24 hours
Evolve into mature biofilms with extreme resistance to biocide?
within 4 days depending on species and growth conditions
Attach to a surface?
within minutes
Describe 3 ways in which mature biofilms offer "mutual protection" to the microbes
*1.* Antibiotic resistant bacteria may secrete protective enzymes or antibiotic binding proteins that can protect neighboring non-antibiotic resistant bacteria in a biofilm *2.* Transfer genes to other bacteria that confer antibiotic resistance, even between different species *3.* The specific characteristics of the EPS of biofilms established by one species can play a significant role in the ability of other species to attach and incorporate into an existing biofilm
Describe what is meant by "hibernation" in biofilms, and the significance of hibernation
*1.* to become metabolically quiescent *2.* Bacteria need to be metabolically active for antibiotics to act, hibernating bacteria in biofilms are unaffected by antibiotics that would normally kill active bacteria
List the molecules that the EPS of the mature biofilm resists by "blocking"
1. antibodies 2. inflammatory cells- white blood cells
What two categories of microbes are found in biofilms?
1. bacteria 2. fungi
What does the microbial term "planktonic" mean?
1. free floating 2. solitary
What chronic diseases are associated with biofilms?
1. periodontal disease 2. cystic fibrosis (CF) 3. chronic acne 4. osteomyelitis
Describe how microbes spread from a biofilm to another part of the wound bed or two other wounds.
1. they shed planktonic bacteria, microcolonies, and fragments of biofilm 2. this leads to them dispersing and attaching to wounds, forming new biofilm colonies
***** NEED TO KNOW ***** Reform mature biofilms after mechanical disruption?
24 hours
***** important ***** How can the presence of a biofilm cause the production of wound slough (fibrin slough)?
Biofilms stimulate inflammations, which increases vascular permeability & production of wound exudate & build up of wound slough
How does a biofilm benefit from the wound exudate?
It provides a source of nutrition and helps to perpetuate the biofilm.
Describe the source, location, and texture of the Extracellular polymeric substance (EPS). 2. location
Location: the outside of cells
Do all chronic skin woulds show overt signs of infection?
No -- they often lack overt clinical signs of infection & often have low bacterial burdens as measured by standard clinical microbiology laboratory assays
In stage one of biofilm formation, are the microbes sessile? Explain.
No, because they are just beginning to attach which leads to step two of multiplication
Describe the source, location, and texture of the Extracellular polymeric substance (EPS). 1. source
Source: microbes in biofilms
Describe the characteristics of stage two that differ from stage one.
Stage 2 is where the microbes are: 1. multiplying 2. firmly attaching 3. differentiate (to change gene expression patters in a way to promote survival) 4. quorum sensing (bacterial communication)
Describe the source, location, and texture of the Extracellular polymeric substance (EPS). 3. texture
Texture: slimy
Name a biofilm that forms each day in the mouth and is visible to the naked eye
Tooth plaque!
True or False: Conditions which impair the immune system can make a patient more likely to develop biofilms in wounds.
True
True or False: Tissue ischemia (reduced blood supply), tissue necrosis (destruction), poor nutrition are factors which increase the risk of developing biofilms.
True
Describe how reactive oxygen species (ROS) and proteases naturally secreted during an inflammatory response to a biofilm can result in impaired wound healing
While detaching the biofilms from the tissue, they also damage normal and healing tissues, proteins, and immune cells and have "off targets" effects that impair healing.
Do chronic skin wounds usually involve biofilms?
Yes - pg. 1 states that biofilms are extremely common in chronic conditions
Describe the general principles of wound biofilm management (biofilm-based wound care) - Use Figure 3, p.4.
You have a chronic and probably a biofilm. The first thing you need to do is reduce the biofilm by debridement and extensive cleaning. The second thing you need to do is send it off to a micro lab to figure out what kind of microbes the biofilm is made up of. Next, to prevent re-contamination with microorganisms, you will apply a barrier dressing, and to suppress biofilm reformation you will use topical antimicrobials. Finally, you reassess the wound to make sure it's healing properly.
What are biocides?
a chemical agent, such as a pesticide, that is capable of destroying living organisms