Human Microbiome and Infection Control Flashcards
What is not found in a prokaryotic cell?
Membrane bound nucleus, mitochondria and other organelles.
Bacillus
Rod
Coccus
Spherical
What is the cell wall of a prokaryotic cell made up of?
Peptidoglycan
What is a heterotroph?
A heterotroph is an organism that cannot manufacture its own food by carbon fixation and therefore derives its intake of nutrition from other sources of organic carbon, mainly plant or animal matter.
Define commensalism.
Living in a relationship in which one organism derives food or other benefits from another organism without hurting or helping it.
Commensal Flora
Found on all epithelial surfaces of the body.
Generally do not harm the host and are protective and beneficial.
May be associated with non-infectious diseases such as inflammatory bowel disease and obesity.
What disrupts commensal flora?
Antibiotics.
What are the main bacteria of the skin?
Staphylococcus epidermis
Cutibacterium acnes
Corynebacterium
What does skin bacteria break sweat down into?
Odoriferous amines and steroids.
How does deodorant work?
Deodorants contain aluminium salts to prevent sweating and antiseptics to inhibit bacterial growth.
Outline the appearance of staphylococcus epidermis
Staphy = clustered Coccus = round Epidermis = found on the skin
Is staphylococcus epidermis gram negative or positive?
Gram Positive
When does staphylococcus epidermis cause problems?
When it enters the blood of newborns and immune compromised individuals.
It can also contaminate indwelling medical devices e.g intravenous catheters.
What can bacteremia lead to?
Sepsis Pneumonia Meningitis Ineffective endocarditis Septic arthritis
What is the treatment for staphylococcus epidermis?
Vancomyocin (antibiotic) and replacing intravenous catheters with new ones (especially in newborns).
Where are lactobacilli found?
Lining the vagina
What do lactobacilli do?
Lactobacilli break down glycogen in the vagina into lactic acid helping maintain the acidic pH of the vagina protecting it from pathogens.
What is the negative effect of antibiotics on commensals?
- effect on women?
Antibiotics can kill commensal bacteria allowing pathogens to take their place.
In women administering antibiotics can lead to development of thrush in this way.
What does C difficile cause?
Diarrhoea
Is C difficile gram positive of negative?
Gram Positive
What are the signs and symptoms of someone infected with C difficile?
Lower abdominal pain Fever Diarrhoea Leucocytosis Occurs 5-10 days after administration of antibiotics.
What is an opportunistic infection?
Where a pathogen takes advantage of a situation not normally available to it e.g a host with a weakened immune system.
What is used to treat C difficile?
Vancomyocin and ideally stopping any other current antibiotic treatments.
