Bacteriology + Virology Stuff Flashcards
1
Q
Proteobacteria
A
- Gram -ve, has an outer membrane with some form of lipopolysaccharide
- Frequently motile + has gliding motility
- Highly diverse in metabolism ie Oligotrophic, Fastidious, Photosynthetic, Chemoheterotrophs, Obligate anaerobes, Facultative anaerobes, Aerobes, microaerophilic
- Diverse lifestyles ie Free living, Obligate, Intracellular, Pleomorphic, Budding
2
Q
Proteobacteria Classes
A
Includes:
- Alphaproteobacteria
- Betaproteobacteria
- Gammaproteobacteria
- Deltaproteobacteria
- Epsilonproteobacteria
3
Q
Rickettsia Genus
A
- Alphaproteobacteria, very small
- Can be rod, coccoid or pleomorphic
- Obligate intracellular pathogens (parasitic) or mutualistic
- Potential descendant to free-living anaerobe that parasitised ancestral eukaryotic cells to form mitochondrion
- No glycolytic pathways, oxidises glutamate or succinate
- Has transport carrier to exchange ADP for host ATP
- R. typhi + R. prowazekii are pathogenic + enter cell by phagocytosis
4
Q
Nitrobacter Genus
A
- Alphaproteobacteria in soil
- Rod-shaped, internal membranes are enhanced for e- transport
- Chemolihoautotroph + obligate anaerobes
- Oxidises nitrites into nitrates
- Contributes to nitrification + nitrogen cycle with nitrifying cycle
5
Q
Rhizobium Genus
A
- Symbiotic alphaproteobacteria, lives in root nodules
- Aerobic + freely motile
- Pleomorphic rods
- Bacteroid physiology/metabolism optimised for N2 fixation to NH3, nitrogenase, leghaemoglobin
- Transfers NH3 to plant which is important to agriculture
6
Q
Betaproteobacteria
A
- Also diverse, many are aerobic but there are fewer families
- Phylogenetically close to gammaproteobacteria
- Has chemolitotropic, pathogenic genera
7
Q
Nitrosomonas genus
A
- Chemolithotrophic Betaproteobacteria
- Oxidises NH3 to NO2-
8
Q
Thiobacillus genus
A
- Chemolithotrophic Betaproteobacteria
- Thiobacillus denitrification is a well-studied example
+ Flexible e- donor
+ It’s acitivity can be detrimental however as it produces sulphuric acid
+ Denitrification of NO2- to N2
+ Can also enhance soil fertility
9
Q
Neisseria genus
A
- Pathogenic Betaproteobacteria
- Piliated diplococci
- Non-motile
- N. lactamica is commensal to humans
- Only lives in human hosts
- Requires fastidious conditions to grow and survive
- Has highly variable proteins on cells surface for immune evasion
- N. meningitidis can cause bacteremia + sepsis + can cross BBB to cause meningitis
- Associated with meningitis + gonorrhoea
10
Q
Burkholderia genus
A
- Pathogenic Betaproteobacteria
- Aerobic
- Straight rods
- Mostly motile with polar flagella
- B. cepacia cand egrade >100 different nutrient sources
+ In the wrong places it can become a plant pathogen or cause cystic fibrosis in immunocompromised patients
11
Q
Bordetella genus
A
- Pathogenic Betaproteobacteria
- Coccobacilli
- B. pertussis multiplies in respiratory epithelial cells
+ Secretes pertussis toxin that may cause whooping cough
12
Q
Deltaproteobacteria
A
- Smaller group but still very diverse
- Contains some sulphur/sulphate reducing bacteria (ie Delsufovibrio) which are important in the sulphur cycle
- Can prey on other bacteria
+ B.dellovibrios can multiply in the periplasm of other bacteria
+ Myxobacteria can secrete enzymes + antibiotics to kill bacteria + can aggregate/form fruiting bodies
13
Q
Epsilonproteobacteria
A
- Often inhabit extreme environments
- Includes Campylobacterales:
+ Campylobacteriaceae ie C. jejuni - Can cause gastroenteritis
+ Helicobacteraceae ie H. pylori - can cause gastritis, stomach ulcers + linked to stomach
+ Slender curved rods, spiral shaped coccoid when old
+ Microaerophilic
+ Motile polar, has corkscrew flagella
+ C. coli prefers pigs, C. jejuni prefer poultry + cattle
+ Non-pathogenic in many animal guts, but pathogenic to us
14
Q
Gammaproteobacteria
A
- One of the biggest groups
- Includes
+ Purple sulphur bacteria ie chromatiales
+ Intracellular pathogens legionellales - Has 2 superfamilies
+ 1st superfamily: Vibrionaceae, Enterobacteriaceae, Pasterullaceae
+ 2nd superfamily: Pseudomonaceae, Moraxellaceae - 1st superfamily are faculatative anaerobes + has a genome of approx. 4-5 mbp
- 2nd superfamily have heterogenous taxon (>60 in pseudomonas), mostly aerobic growth, catabolise exceptionally wide range of organic compounds, free living + large genomes
15
Q
Purple Sulphur Bacteria
A
- Photolithoautotrophs, strict anaerobes
- Live in aquatic environments
- uses hydrogen sulphate as an e- donor for NADP reduction, then oxidises to sulphur which stored in deposits in the cell
- Purple pigments are used for photosyntheic CO2 fixation
- Primariy producers of fixed CO2
- Intracellular membarne vesicles/lamellae
- Motile polar flagella
- Important bioremediation + biotech applications
