Introduction Flashcards
clostridium difficile
- shape
- spores
- gram
- respiration
- symptoms
- mechanism of infection
- rod shape
- spore forming
- gram positive
- strict anaerobe
- causative agent of antibiotic associated diarrhea and pseudomembranous colitis
- synthesizes two large toxin proteins (TcdA and TcdB) that disrupts the intestinal epithelium
differences between proks and euks
- proks have no nuclear mem
- proks have no mem bound organelles
- proks can not do endocytosis
- a thousand times smaller
shape of
- bacilli
- cocci
- bacilli = rods
- cocci = spheres
gram positive bacteria
- lipoteichoic acid shell
- cytoplasmic membranes containing proteins
gram negative
- lipopolysaccharide
- endotoxin
- porin in outer mem
- peptidoglycan between outer and inner membrane
- cytoplasmic membrane
antibiotic target
-bacterial cell wall
cell wall
- peptidoglycan
- polysaccharide chains cross linked by short chains of amino acids
- some barrier function
- gives cell shape
- shape determined by pattern of cross link
polysaccharide chains of peptidoglycan
MGMGMG
- M= N acetylmuramic acid
- G= N acetylglucosamine
peptide side chains are attached to…
N acetylmuramic acid
cross linking between side chains
- happens between the side chains attached to M’s
- specifically between D-ala and L-lys
- this give a staggered orientation to the peptidoglycans
Penicillin
-mimics the structure of D-ala, D-ala chains and inhibits cross linking
bacterial growth
- done via binary fission
- exponential
- determined by the medium that the bacteria is exposed to
- begins with ecponential then becomes stationary then they begin to die
prototrophs
-have no requirements for organic compounds other than a simple carbon source
auxotrophs
bacteria that have more complex nutritional requirements, typically requiring amino acids and or vitamins and or pyrimidines/purines
fermentation
some bacteria satisfy all of their energy needs by synthesizing ATP through the enzymatic rections of glycolysis
- also known as substrate level phosphorylation
- 1,3BPG to 3PG
respiration
some bacteria generate additional ATP through an electron transport chain and membrane bound ATP synthase
- Aerobic: electron acceptor is O, producing H2O
- Anaerobic: electron acceptor is fumarate, nitrate and others
different bacteriums response to oxygen
- strict aerobes
- strict anaerobes
- facultative anaerobes
- strict aerobes (mycobacterium tuberculosis), the temrinal electron acceptor for respiration is oxygen
- strict anaerobes (bacteroides, clostridium in colon) terminal e acceptor are organic molecules
- facultative anaerobes (escherichia coli in small intestine, vibrio cholerae, streptococcus pneumoniae, pseudomonas aeruginosa
- some respire when aerobic and ferment when anaerobic
- some respire both aerobically and anaerobically
spores
- hardy, non growing structures that some gram pos bacteria, noteably bacillus and clostridium produce
- survive for very long time periods of time under conditions of extreme heat, dehydration, toxic chemicals and radiation
- the low water content of spores allows them to survive harsh environmental conditions
- sporulation is triggered by nutritional limitation
stationary phase
- motility and chemotaxis
- secretion of degrative enzymes
- transport of secondary nutrients
- intracellular catabolic pathways
- genetic competence
- antibiotic and toxin production
- spore formation
clostridium difficile
- spore forming
- speudomembranous colitis
clostridium botulinum
- spore forming
- botulism
- flaccid paralysis
clostridium tetani
- spore forming
- tetanus
- spastic paralysis
bacillus anthracis
- spore forming
- anthrax
bacillus cereus
- spore forming
- food poisoning
