Topic 3: Bacteria Flashcards
What does it mean when we say Bacteria can be pathogenic?
means that bacteria can cause disease
How does pathogenic bacteria make us sick?
By producing toxins and damaging tissues that lead to you feeling sick.
How do bacteria reproduce? How many cells does it require?
Binary Fission. Requires 1 cell.
How often does binary fission happen?
Every 20 minutes.
How does the cell split in Binary Fission?
They copy their DNA and then the chromosome attatches to the cell membrane that creates a new cell wall plate, splitting the cell into two - each with its own DNA.
What is a gram stain?
A gram stain identifies different types of bacteria. It identifies the thickness of the cell wall (amount of peptidoglycan) by the different colours of pink and purple.
What does a gram stain show about bacteria?
- Bacteria is positive or negative
- The cell wall structure. (+) = thick peptidoglycan (-) = thinner peptidoglycan
- The shape and arrangement of bacteria
- Type of Bacteria present
Gram Positive (+)
- DARK PURPLE
- large amount of peptidoglycan (thick cell wall)
Gram Negative (-)
- LIGHT PINK
- less amount of peptidoglycan (thin cell wall)
List 3 reasons why bacteria grows so fast on agar plates?
- It is full of nutrients that provide essential growth for bacteria. Sugars, proteins and water as a food source.
- Kept at a suitable temperature of 37 degrees that promotes bacterial growth
- It has a large surface area for bacteria colonies to grow.
How are bacteria infections treated?
Antibiotics that target specific bacteria. Some work on Gram P, some work on Gram N.
What do antibiotics do to bacteria specifically?
- Target bacterial structures such as cell walls blocking cell wall synthesis or rupturing the cell wall
- stop bacterial enzymes working, slowing down bacterial reactions
- bind to the surface of thr bacterial cell alerting it as foreign
Give 2 examples of Antibiotics
- Penicillin
- Ampicillin
Why is antibiotic-resistant bacteria a big threat to our health?
- Are not controlled, are fast spreading
- We can’t develop antibiotics fast enough to deal with these emerging superbugs that are killing many patients.
How do bacteria resist antibiotics?
- They have a pump to remove the antibiotic
- Produce an enzyme to breakdown the antibiotic
- Produce a thicker cell wall making it hard for the antibiotic to enter.
How does a bacteria become resistant to an antibiotic
When antibiotics are taken, bacteria are able to grow in the presence of the antibiotic, becoming resistant to it.
The larger the zone of inhibition =
the more effective the antibiotic is in killing the bacteria.
A small or no zone of inhibition =
the bacteria is RESISTANT to the effect of that antibiotic
What is the zone of inhibition
a circular area around the spot of the antibiotic in which the bacteria colonies do not grow. (clear zones)
Define Superbugs
strains of bacteria that are resistant to most of the antibiotics and other medications commonly used to treat the infections they cause.
What has led to the appearance of superbugs?
- A misuse and overuse of antibiotics. The more the bacteria exposed to antibiotics, they develop a resistance to them, evolving into superbugs
Examples of superbugs include resistant bacteria than can cause:
pneumonia, urinary tract infections, and skin infections
Ways to protect yourself from harmful germs and lower risk of illnesses
- wash your hands often with soap or water
- handle food properly, use clean water
- avoid close contact with ppl who are ill
Ways to tackle antibiotic resistance:
- using antibiotics as directed and only when needed
- complete the full treatment course
- do not share antibiotics
Name the pathogen that causes cholera
Vibrio Cholera
What body part is affected by cholera
The intestine
What is cholera incubation period
Less than 1 day to 5 days
Symptoms of Cholera
- Watery diarrhea
- severe dehydration
- death
- vomitting
Two ways in which cholera may be treated
- Antibiotics
- Intravenous fluids (for those who are severly dehydrated)
- oral rehydration salts
