General Flashcards
Gram Positive Cell Wall has:_______________
Which aids____________ and is therefore a virulence factor
Lipoteichoic acid (LTC)
Which aids adherence to target cells
Gram negative cells contain _______________ in the LPS, which is an ______________
Lipid A
Endotoxin
Gram- negative cell walls have __________________which are not found on gram positives
Lipopolysaccharides (LPS)
LPS are found in Gram___________ membranes
The function is ________
Gram negative outer membranes
Function = structural integrity + evasion of chemical attacks
LPS __________________ of the cell membrane, and helps stabilize the overall structure
Increases the negative charge
-requires association of divalent cations to stabilize change
Gram (-) molecular domains are _________, __________, and _______.
Lipid A:
The core:
The O-antigen:
What is Lipid A - what is it made up of
A phosphorylated glucosamine disaccharide and fatty acids
Conserved component of the LPS
What is the core (gram (-))
Attaches directly to Lipid A
KDO - sugar of the core
Mostly carbohydrate but can contain a.a.
What is the O-antigen
- attached to core oligosaccharide
- outermost domain of LPS
- varies between strains
- target for host antibodies (BUT HIGHLY VARIABLE)
Smooth vs. Rough LPS
Smooth = long o-antigen Rough= short o-antigen
-rough LPS usually more sensitive to hydrophobic antibiotics
Eg. Kanamycin
TLR 4 recognizes
LPS in Gram (-)
TLR 6 recognizes
PG in Gram (+)
Lipotheichoic acid
Lipoproteins
_______ and _________ affect Rab GTPase
TB and E.coli
Effluent pumps
ABC superfamily MFS -major facilitation subfamily MATE-multidrug and toxic compounds extrusion fam SMR-Small multi drug resistance RND-resistant nodule superfamily
Gyrase mutation resists?
Fluroquinolons
Small ribosomal subunit mutation resists?
Streptomycin
Example of covalent modification by bacteria of antibiotic
Acetyl tramsferases
Example of degradation of antibiotics by bacteria
beta lactamases cleave and inactivate penicillin and derivatives
3 types resistance sharing
- which needs similar sequence
- which needs most similar bacteria
Transformation -similar sequence, least related bacteria
Transduction-phage
Conjugation-most commonality btwn bacteria (same spp.)
No similar sequence needed
MDR
Multi drug resistant
XDR
Extensively drug resistant
PDR
Pan drug resistance
Narrow spec. Antibiotics
Arythromycin
Erythromycin
Vancomycin
Broad spec. Antibiotics
Ampicillin
Amoxicillin
P. aeruginosa when does it infect
What does it infect
- opportunistic pathogen
- in immunology com. Patience
- UTI and reps infection
Defending resistance
- D-alanine mod in gram pos increase net charge
- increase charge in LPS
- produce peptides or associate and neutralize AMPS
- Efflux pump AMPs/ or protyolitically degrade them
- produce pos membrane associated proteins
AMPs 5 main classes
Alpha-helictites. -in macrophage/lysosome Beta-sheet Mix alpha/beta Cyclic. -Kalata B2 Extended
CT Lipid A mod
Diglycine added
Yersina Lipid A modification
Hexa in humans
Helictobacter pylori Lipid A mod
Phosphorylated ethanolamine C1
Dephosphorylated
Two fewer lipid tails
L. Monocytogene PG
- glucosamine instead of acetylglucosamine
- deacytlated by PgdA enzyme
NOD2 -recognized
Gram - and +
MurNAc-L-Ala-D-gamma-Glu
NOD 1 recognized
Gram -
iE-DAP
TLR 4 recognizes
Gram -
TLR 6 recognized
Gram +
Gram pos PG has
pentaglyice
Cros-linkage in PG occurs at
Lactic Acid residue in in NAM
