Block B Flashcards
how much peptidoglycan in gram + cells
90%
what shape is coccus
spherical or ovoid
what shape is rod
cylindrical
what shape is spirillum
spiral
mycobacterium
- rod shaped
- acid fast due to mycolic acid in cell wall
filament actinobacterium
- inhabits soil
- makes a lot of anti-cancer drugs
major gram positive groups
actinobacterium, mycobacterium, firmicutes
Tenericutes : mycoplasms key feature
lacks cell walls (cant control its membrane)
- parasites that inhibit animals and plants
key features of lactobacillales
- fermentative bacteria that produces lactic acid (yoghurt)
- rod shaped and grows in chains
- resistant to acidic conditions
streptococcus
- coccus shaped, gram-positive
-bacteria commonly found on the skin or in the throat
Staphylococcus
gram-positive
These germs can live on contaminated implanted medical devices and improperly cleaned needles
coccus shape
Anthrax
-spores are difficult to kill
-gram-positive
-rod shaped
-It occurs naturally in soil
-People can get sick with anthrax if they come in contact with infected animals or contaminated animal products
Three forms of anthrax
cutaneous, gastrointestinal, inhalation
AB toxins
toxins with intracellular target that have 2 functionally distinct regions
tenericutes: mycoplasmas
Lack cell walls
Some of the smallest organisms capable of autonomous growth
Parasites that inhabit animal and plant hosts
Key components of peptidoglycan are missing
firmicutes- lactobacillales
Fermentative bacteria that produce lactic acid
Lactobacillus Rod-shaped and grow in chains
Common in dairy products
Sauerkraut
Resistant to acidic conditions
Grow in pH as low as 4
clostridium
Lacks a respiratory chain; anaerobic
produce ATP by substrate level phosphorylation
Metabolism of pair of amino acids
Mainly found in anaerobic pockets in the soil
Also lives in mammalian intestinal tract
Some species are pathogenic; diseases include botulism, tetanus, and gangrene
what are AB toxins
toxins with intracellular target that have two functionally distinct regions (A & B):
A has enzymatic activity
B is responsible for host cell binding or entry of A unit to cell
AB Toxins can operate in two ways
-Single polypeptide that is proteolytically cleaved at a later stage
-Separate polypeptides that subsequently assemble
4 gram positive phyla
Proteobacteria, actinobacteria, firmicutes, bacteroidetes
Gram stain
Add crystal violet, all cells purple, add iodine, all cells still purple, decolourise and gram positive will remain purple and gram negative are colourless, add safranin and gram positive are purple and negative are pink
Gram positive cell wall
contain 90% peptidoglycan, so is very thick and not easily penetrated by the alcohol, often have teichoic acids in the cells wall
Corynebacterium
diphtheria and glutamicum
Mycobacterium
tuberculosis, leprae
Yogurt
mixed culture of streptococcus salivarius subspecies thermopiles and lactobacillus delbrueckii subspecies bulgaricus
enterococcus
UTI, bacteremia, endocarditis, diverticulitis, meningitis
Streptococcus species
dental plaque
streptococcus viridans
scarlet fever
Streptococcus pyogenes
strep throat, necrotising fasciitis
Staphylococcus
epidermis usually found on skin, MRSA
Methiailin resistant s.aureus
resistant to a wide range of antibiotics (Superbug)
endospore forming
Bacillus and Clostridium
Clostridium
botulism, tetanus, gangrene