Biofilm 3- Candida Flashcards
How big are yeast cells in comparison to bacteria?
25-50x.
What us the physical scaffold called that fungi provide for bacteria?
Mycofilm.
What are some risk factors for developing candidiasis?
Immuno-compromised patients Immunosuppressive drugs Advanced HIV infection Intra-abdominal surgery Central venous catheter Parenteral nutrition Broad-spectrum antibiotics Dialysis Colonisation at a sterile site Diabetes Burn unit patient Trauma patient Long-term corticosteroid use.
What are the different types of infections from candidal disease?
Periodontitis Dental implants Denture stomatitis CF lung infections Ventilator associated pneumonia UTI Infectious kidney stones/biliary tract infections Musculoskeletal infections/osteomyelitis Chronic wounds Sutures Endocarditis Implant/medical device Catheters and stents.
What are the two classifications of oral candidiasis and name some examples.
Confined to mouth and commissure (thrush, strophic, denture related and candidal leukoplakia)
Generalised candidasis with oral manifestations (chronic mucocutaneous).
What does pseudomembraneous candidasis appear like in the mouth?
White plaques on the surface of mucosa but when you scrape them away they will bleed.
Do you need to take a biopsy of chronic hyperplastic mucosa?
Yes.
What is angular chelitis, what type of bacteria causes it and what topical antifungal is most commonly used?
Angular cheilitis (AC) is inflammation of one or both corners of the mouth. Often the corners are red with skin breakdown and crusting. It can also be itchy or painful. The condition can last for days to years.
Angular cheilitis is a type of cheilitis (inflammation of the lips).
Candida
Gram positive bacteria that interact
Miconazole topical most used.
What do the different classes of Newton’s types for denture induced stomatitis mean?
1- localised inflammation
2- diffuse inflammation
3- granular inflammation.
What are some signs and symptoms of denture induced stomatitis?
Inflamed mucosa- particular under upper denture
Burning sensation
Discomfort
Bad taste
In most cases- the patient is unaware of the problem!
What is denture induced stomatitis?
Denture stomatitis is caused by a yeast or fungus called candida. It is not an infection that we get or pass on to others, because we all have some candida in our mouths. Thrush can appear in other parts of the body, but when it affects the mouth it may be called ‘denture stomatitis’.
What can denture induced stomatitis cause if the bacterial particles are inhaled?
Aspiration pneumonia.
What happens to the denture and the mucosa in denture induced stomatitis?
Trauma for changes in typography of PMMA Toxins Mucosal thinning Inflammation Exudate and squames.
What are some opportunistic pathogenic yeasts?
Candida albicans
Candida glabrata
Candida tropicalis etc.
What is the changing epidemiology of candida spp. in Scotland between 2005/06 and 2012-13?
More candida glabrata and less candida albicans.
What is candida albicans?
Present in 71% of healthy individuals
-oral carriage varies (35-55%)
Variable anatomical sites
-oral cavity, vagina, gut (mucosal surfaces)
Nutrient limitation/competition with bacteria.
35% mortality rate.
How does candida albicans get into the blood stream?
When candida albicans is stressed it can go to this hyphae- can invade through tissue- can get into blood stream- issues
Gibrata doesn’t from these hyphae
1. Adhesion and colonisation
2. Hyphal penetration and invasion
3. Vascular dissemination
4. Endothelial colonisation and penetration.
What is a hydrolytic enzyme?
An enzyme that catalyses the hydrolysis of a substate through the addition of water.
What is phospholipase, haemolysin and proteinase’s substrate and contribution to infection?
P- lipid, host cell penetration
H- red blood cells, facilitates hyphal invasion
P- proteins, adhesion to epithelial cells.
What candida related infection do some individuals in Finland possess that makes them more likely to develop oral cancer?
APECED.
What do you need to be careful as a clinican when prescribing for a candida infection?
Generally candida albicans are sensitive to fluconazole nitroconazole (unsure whether this is right or it should be myconazole)
Whereas canida glabrata is not
The key issue is that as a clinician you will generally want to treat the patient you want to give them anti-fungals but needs to consider if the patient has candida glabrata (which is more common than you would think) then all you are doing is suppressing everything else and letting candida glabrata grow.
What is Sabouraud agar used for?
Sabouraud agar or Sabouraud dextrose agar (SDA) is a type of agar growth medium containing peptones. It is used to cultivate dermatophytes and other types of fungi, and can also grow filamentous bacteria such as Nocardia. It has utility for research and clinical care. ONLY TELLS US IF WE HAVE CANDIDA NOT WHAT SPECIES IT IS.
Why is chromogenic agar good?
Has different colours for different colonies- lets us know if specific organisms are present.
What does chitin do?
Strengthens the cell wall.
What do azoles directly work upon?
They work indirectly on the ergesterol synthesis pathways (it is fungistatic)
Fluconazole, voriconazle and posaconazole.
How do polenes work and name some examples.
They work directly on ergesterol and bind to it which causes pores (it is fungicidal)
Nystatin, Amophotericin B and Liposomal AmB.
How do echinocandins work and name some examples.
They act on 13 beta glucan synthase synthesis and destabilise the cell wall- they are good against biofilms
Caspofungin, micafungin and anidulafungin.
What is the activity of fluconazole?
*there is a table on this slide with lots of different drug activities but this one is highlighted in red.
C. albicans generally sensitive but resistant strains can develop
C. krusei and C. glabrata naturally resistant.
What increases in the individual when they are repeatedly given an increased dose of fluconazole?
Relapsed in oral pharyngeal candidiasis 100mg per day for 9 visits then upped Sample taken Over these visits you see an increase in these multi drug resistant pumps Changes in ergosterol biosynthesis genes Massive increase in CDR pumps Inappropriate treatment Changes in genetics of organism.
What different factors drive the inability to treat candida infections?
Density Stress Persisters ECM Efflux Over expressed targets Physiology.
What is a dual-resistance mechanism?
Candida can live among things like staph aureus
Staph aureus can actually coat itself in candida polymers and can become resistant to vancomycin
Gene resistance when bacteria and candida live together
Mixed species biofilms can increase the resistance.
What are azoles ineffective against?
Biofilms.
Is chlorhexidine used to treat fungal infections?
Yes.
