Microbiology Flashcards
Virus
- Not living
- Can mutate
- No cellular structure
Bacteria
- Prokaryote
- Mostly unicellular
- Cell wall
Protozoa
- Eukaryotic cells
- Unicellular
- Example: malaria
Fungi
- Eukaryotic
- Uni- or multi-cellular
- Cell wall
Helminths
- Eukaryotic
- Multi-cellular
- Large
- Reproduction = lay eggs
Prokaryotic cell characteristics
- Small
- Unicellular
- Organelles have no membrane
- Asexual reproduction
Eukaryotic
- Large
- Multicellular
- Organelles have membranes
- Sexual reproduction
Bacteria growth requirements: Oxygen
Obligate aerobes
Can only grow in oxygen
Bacteria growth requirements: Oxygen
Obligate anaerobes
Can NOT grow in the presence of oxygen
Bacteria growth requirements: Oxygen
Facultative anaerobes
Prefer to grow in oxygen but they can still survive in no oxygen. They have the enzymes to deal with both scenarios.
Bacteria growth requirements: pH
Most close to neutral (pH7)
Bacteria growth requirements: Temperature
Most between 10°-39°
Bacteria: Gram Stain
Gram positive = thicker wall (holds more stain)
- More likely to get reinfected due to ability to survive in extreme conditions
- PURPLE
Gram negative = thinner wall
- PINK
Benefits of normal flora
- Reduces pH on skin (skin)
- Competes and inhibits pathogens & yeast (oral and vagina)
- Synthesise and secrete vitamins (especially Vitamin K) (intestine)
Modes of transmission
Contact - between people
Vehicle - such as air, water and food
Vector - via an animal
Fomite-borne - via an inanimate object
Vertical (transplacental) - postpartum
