Bacteria and Diseases Flashcards
What is the aim of gram staining?
- To identify the shape, structure of cell, or if gram negative or gram positive
- Identify to treat infection with appropriate antibiotics, due to antibiotic resistance
Explains the results from a sensitivity test
The larger the margin, the more sensitive the bacteria is to the antibiotic used.
How would you treat bacterial infections?
- Antiseptics e.g., iodine, chlorhexidine and flushing
- Targeting therapy e.g., antibiotics, bacteriostatic and bactericidal
Discuss cocci gram positive diseases
- Staphylococcus: Cause pyoderma and otitis externa in dogs
- Staphylococcus: Causes strangles in horses
Discuss bacilli gram positive diseases
- Corynebacterium: Causes mastitis in cows
- Clostridium: Causes tetanus toxin, which causes spastic paralysis
- Listeria: Causes septicemia, abortion and meningitis
Discuss enterobacteriaceae gram negative diseases
- Salmonella
- Escherichia coli
- Klebsiella pneumoniae
- Yersinia: Cause bubonic or pneumonic plague
What are the three basic shapes of bacteria and describe them?
- Bacilli: Rod-shaped cells (some are curved which are called vibrios)
- Cocci: Spherical cells
- Spirilla: Spiral or helical cells (If cell wall is flexible, they are known as spriochetes)
What is a facultative anaerobe?
An organism that makes ATP by aerobic respiration when oxygen is present, but is capable of fermenting or anaerobic respiration if oxygen is absent.
What is an obligate aerobe?
Cannot make ATP in the absence of oxygen
What is an obligate anaerobe?
Die in the presence of oxygen
What does staphylo-…. mean?
A cluster of said shapes of bacteria
What does strepto-….. mean?
A line of said shapes of bacteria
How does pathogenic bacteria cause disease?
- Colonization: cause cell lysis and tissue damage
- Toxin formation: endotoxins and exotoxins
What are exotoxins?
- Produced by both gram negative and positive bacteria
- Body produces antibodies known as antitoxins to neutralize the toxins
- Can be treated by formaldehyde
What are endotoxins?
- Produced from gram negative bacteria
- Less toxic than exotoxins
- High levels result in serious drop in blood pressure causing endotoxic shock.
