SW - Bacteriology I Flashcards
What is microbiology? (3)
Often described as the study of organisms and agents too small to be seen by unaided eye (i.e. < 1 mm)
- However, some microorganisms (e.g. algae and fungi) have macroscopic life stages.
Microbiology is more broadly defined as the techniques for the isolation, culture and study of microorganisms
How can microbes be grown in the laboratory?
Nutritious laboratory media – can be general or selective
- Agar media in Petri dish - colonies
- Growth in broth – becomes turbid
What are limiting factors of microbial growth?
Nutrients and availability of nutrients are the limiting factors and prevent theoretical growth
What are bacterial diseases caused by? (2)
Bacteria cause half of all diseases
They cause disease by:
- Disrupting the physiology of the cell by invasion and growth
e.g. leprosy, syphilis, typhoid fever - Growing inside the host and producing toxins (exotoxin and endotoxin)
e.g. tetanus, botulism
Where can microbes be found? (8)
Microbes are not found throughout the body but are localised to certain regions
- nose
- throat
- eye surface
- mouth
- skin
- large intestine
- urinary
- genital systems
How does location of microbes determine their affect on the human body? (3)
Have a ‘symbiotic’ relationship with us, they provide a protective layer in return for nutrients
- e.g. E. coli produces vitamin K
In the gut, it produces compounds that kill pathogens
- such as Salmonella, Shigella and Clostridium
Can cause disease if they end up in another part of the body
- e.g. E. coli in the urinary tract
