Infectious Diseases: Bacterial Diversity
0.0 / 5
- Created by: Bhickling
- Created on: 15-04-21 14:33
What are the 3 domains of life?
- Bacteria
- Archae
- Eukaryotes
- Archae
- Eukaryotes
1 of 24
What are cyanobacteria?
- photosynthetic bacteria
- account for up to 30% photosynthetic productivity
- responsible for oxygenating atmosphere
- one of the most abundant bacteria
- account for up to 30% photosynthetic productivity
- responsible for oxygenating atmosphere
- one of the most abundant bacteria
2 of 24
Describe the structure if cyanobacteria
- cytoplasm has an extensive thylakoid membrane where photosynthesis occurs
- usually forms communities + extensive structures- sheets, filaments, hollow balls
- usually forms communities + extensive structures- sheets, filaments, hollow balls
3 of 24
Describe the bacillus species
- gram +ve bacteria
-aerobic spore former
- isolated from soil, water + GI tract of animals
- some are extremophiles- adapted to extreme conditions by evolving enzymes that function under these condition, change in cell envelope + DNA
-aerobic spore former
- isolated from soil, water + GI tract of animals
- some are extremophiles- adapted to extreme conditions by evolving enzymes that function under these condition, change in cell envelope + DNA
4 of 24
How are spores formed?
- asymmetrical cell division with endospore forming at one end
- septum forms to seal off the endospore
- lysis of mother cell releases endospore
- roughly 8 hours
- septum forms to seal off the endospore
- lysis of mother cell releases endospore
- roughly 8 hours
5 of 24
Describe the structure of spores
consists of:
- core (contains nucleotid)
- cytoplasma
- ribosomes
- surrounded by cytoplasmic membrane, core wall, peptidoglycan cortex, spore coat + exosporium
- core (contains nucleotid)
- cytoplasma
- ribosomes
- surrounded by cytoplasmic membrane, core wall, peptidoglycan cortex, spore coat + exosporium
6 of 24
What does the core area of a spore contain?
Dipicolinic acid
Purpose= dehydrate core contents + bind with DNA to stabilise it against heat
Purpose= dehydrate core contents + bind with DNA to stabilise it against heat
7 of 24
What is the main function of a spore?
aid dispersal- spread easily + can live in the environment for long periods of time
8 of 24
Name the 3 main bacillus species
1. B. anthracis
2. B. cereus
3. B. thuringiensis
2. B. cereus
3. B. thuringiensis
9 of 24
Describe B. anthracis
- causative agent of anthrax- affects animals + humans
- contracted through inhalation of spores (pulmonary a.), consumption of contaminated meat (GI a.), penetration of skin via break/ insect bite (cutaneous a.)
- contracted through inhalation of spores (pulmonary a.), consumption of contaminated meat (GI a.), penetration of skin via break/ insect bite (cutaneous a.)
10 of 24
What is the most serious type of anthrax?
Pulmonary- difficult to treat once clinical signs are evident
11 of 24
How does anthrax cause disease?
- capsule can prevent phagocytosis of bacteria + is encoded on plasmid
- produces toxin encoded on different plasmid- 3 components: edema factor, protective antigen (PA), lethal factor
- protective antigen is required for other toxins to be taken up by ho
- produces toxin encoded on different plasmid- 3 components: edema factor, protective antigen (PA), lethal factor
- protective antigen is required for other toxins to be taken up by ho
12 of 24
Describe B. cereus
- causes gastroenteritis
- food-borne- contamination of food from environment, not animal sources
- causes 2 types of disease: 1. emetic (vomiting 30 mins- 6 hrs after consuming food containing emetic toxin) 2. diarrhoeal- consumption of spores in food th
- food-borne- contamination of food from environment, not animal sources
- causes 2 types of disease: 1. emetic (vomiting 30 mins- 6 hrs after consuming food containing emetic toxin) 2. diarrhoeal- consumption of spores in food th
13 of 24
What does B. thuringiensis cause?
attacks insect larvae by protein crystals associated with outside of spores + undergo proteolytic cleavage in insect larval gut
- toxin finds to intestinal epithelial cell to make it leak stomach acid + enzymes into body
- toxin finds to intestinal epithelial cell to make it leak stomach acid + enzymes into body
14 of 24
Name the 3 types of parasitic gram -ve bacteria and describe what they do
1. Vampirococcus- attaches to outside of bacteria + absorb contents
2. Bdellovibrio- penetrates outer membrane of prey bacteria to obtain nutrients
3. Daptobacter- collides with prey bacterial cells + penetrates through cytoplasm to use for energy + nutr
2. Bdellovibrio- penetrates outer membrane of prey bacteria to obtain nutrients
3. Daptobacter- collides with prey bacterial cells + penetrates through cytoplasm to use for energy + nutr
15 of 24
What is a bacteriophage?
a virus that infects bacteria
16 of 24
What is the definition of commensal?
a symbiotic relationship b/w two organisms in which one/ both can benefit
17 of 24
What is an example of commensal with E coli?
E coli in GI tract gains nutrients + produces Vitamin K which is used by host
18 of 24
What does normal bacterial flora do?
prevent overgrowth of certain bacteria, including pathogens
19 of 24
How do bacterial cells communicate with each other?
They produce small molecular weight compounds which can detect the number of cells present = quorum sensing
- allows bacteria to ensure there is a significant number of cells available before expressing certain genes/ exhibiting certain behaviours
- allows bacteria to ensure there is a significant number of cells available before expressing certain genes/ exhibiting certain behaviours
20 of 24
How do nitrogen- fixing bacteria communicate with plants?
signal to fine hairs on plant roots to stimulate growth of root nodules where bacteria fix nitrogen for the plant in exchange for nutrients
21 of 24
What are bacterial biofilms?
structured microbial communities that form on surfaces + are protected by a polysaccharide matrix
22 of 24
How are biofilms formed?
formed when a cell adheres to a surface + micro-colonies are formed once a certain density is reached- polysaccharide produced + coated over cells for protection
23 of 24
What is the purpose of biofilm
helps trap nutrients, keep bacteria attached to surfaces in flowing surfaces (e.g. rivers, teeth)
24 of 24
Other cards in this set
Card 2
Front
What are cyanobacteria?
Back
- photosynthetic bacteria
- account for up to 30% photosynthetic productivity
- responsible for oxygenating atmosphere
- one of the most abundant bacteria
- account for up to 30% photosynthetic productivity
- responsible for oxygenating atmosphere
- one of the most abundant bacteria
Card 3
Front
Describe the structure if cyanobacteria
Back
Card 4
Front
Describe the bacillus species
Back
Card 5
Front
How are spores formed?
Back
Similar Other resources:
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
0.0 / 5
Comments
No comments have yet been made