8 - Microbes And Disease Flashcards
Significant advances in medical microbiology and dates
Physical, chemical and anatomical barriers to infection
Bacteria in different body sites
Bacteria location in respiratory tract
Bacteria in the gut
More bacteria as you go through the digestive system
- increases from the stomach to the small and large intestine
Uses of some bacteria in the gut - which areas
Stomach: low pH - acidic conditions
- secretion of acid (HCl)
- digestion of macromolecules
Small intestine:
- continued digestion
- absorption of monosaccharides, amino acids, fatty acids, water etc.
Large intestine:
- absorption of bile acids, vitamin B12
Microbiome def
The ecological community of commensal, symbiotic and pathogenic microorganisms that literally share our body space
Health benefits of the microbiome
- shield body tissues against invasion of bad pathogens and bacteria
- production of vitamins by bacteria (e.g. vitamin K in gut)
Implicated health benefits of microbiome (?)
What research is done on the microbiome
- use of probiotics and prebiotics - e.g. actimel, yakult
- effects of antibiotic (mis)use
How is virulence determined in pathogens
Many factors including:
- adhesion to and entry into cells
- antiphagicytic activity, immune system evasion
- production of toxins in body
Some conventional virulence factors
- bacterial toxins
- adhesins
- cell surface carbohydrates and capsules
- secrete hydrologic enzymes
- LPS (lipopolysaccharide)
Other (less common) virulence factors
- secretion machineries
- siderophores
- catalyses - can damage cells
- genetic regulators
Genetic elements encoding virulence factors
- …
MRSA meaning
Methicillin Resistant Staphylococcus aureus
