Term
| _ kills; _ inhibits growth |
|
Definition
bactericidal
bacteriostatic |
|
|
Term
| resistance of gram negatives to vancomycin is an example of _ resistance |
|
Definition
|
|
Term
| bacteria can become resistant by (2) |
|
Definition
mutation
receiving a resistance gene |
|
|
Term
| resistance gene transfer may be mediated by (2) |
|
Definition
|
|
Term
| 3 mechanisms of microbial resistance to a drug: |
|
Definition
altered uptake of drug
convert drug to an inactive compound
alter the enzyme target |
|
|
Term
| 3 ways bacteria change the enzyme that is targeted by a drug (in order to be more resistant to the drug) |
|
Definition
-mutated enzyme
-using a new, different enzyme that performs same general function(often received from a plasmid)
-increased production of the enzyme |
|
|
Term
| cell-wall biosynthesis inhibitors in gram-negatives have to be able to get across the _ _ through _ |
|
Definition
|
|
Term
| peptidoglycan cross-linking is from ~ of one side-chain to ~ of another side chain |
|
Definition
terminal D-Ala D-Ala
NH2 group |
|
|
Term
| beta lactams produced by fungi |
|
Definition
|
|
Term
|
Definition
PCN
cephalosporin
carbapenem
monobactam
cephamycin |
|
|
Term
| beta lactams inhibit PBPs such as _ & _ |
|
Definition
transpeptidases
carboxypeptidases |
|
|
Term
| beta lactams resemble the ~ part of peptidoglycan |
|
Definition
|
|
Term
| PBPs all act via the ~ of peptidoglycan |
|
Definition
|
|
Term
| beta lactams become _ bound to the PBP |
|
Definition
|
|
Term
| block in cell-wall biosynthesis by beta lactams leads to cell _ by endogenous _ |
|
Definition
|
|
Term
| endogenous autolysins (that hydrolyze peptidoglycan bonds) such as endopeptidases are required for bacterial (2) |
|
Definition
|
|
Term
| for (3) beta lactams are bacteriostatic rather than bacteriocidal -- why? |
|
Definition
enterococci
some streptococci & staphylococci
they don't produce active autolytic enzymes |
|
|
Term
| inactivation of beta lactams by _ is the most common mechanism of resistance |
|
Definition
|
|
Term
| beta-lactamases are found in g-, g+ or both? |
|
Definition
|
|
Term
| staph aureus 2 resistance mechanisms |
|
Definition
beta lactamases
(PBP2a in MRSA) |
|
|
Term
| gram-negative bacteria have various unique beta lactamases, e.g. (2) |
|
Definition
cephalosporinases
penicillinases |
|
|
Term
| cephalosporinases are found on the chromosome of virtually all |
|
Definition
|
|
Term
| beta lactamases are often encoded plasmids or transposons? |
|
Definition
|
|
Term
| alterations (which enhance resistance) of PBP genes occur by mutation but also by _ between _ |
|
Definition
|
|
Term
| recombination to alter PBP genes is an important beta lactam resistance mechanism in _ _ |
|
Definition
|
|
Term
| _ for beta lactam resistance is lacking in strep pneumoniae |
|
Definition
|
|
Term
| 2 bacteria that are naturally transformable and therefore take up DNA which can alter their PBP genes |
|
Definition
strep pneumoniae
n. meningitidis |
|
|
Term
| the molecular basis for MRSA is ... |
|
Definition
| acquisition of a new PBP (PBP2a) |
|
|
Term
| PBP2a (famously seen in _) exhibits reduced affinity for _ _ |
|
Definition
|
|
Term
| PBP2a is notably found in MRSA but is also found in _ _ |
|
Definition
| staphylococcus epidermidis |
|
|
Term
| _ _ is often found in prosthetic devices |
|
Definition
| staphylococcus epidermidis |
|
|
Term
| 2 complex glycopeptide antimicrobials |
|
Definition
|
|
Term
| vancomycin binds to what? thereby...? |
|
Definition
D-ala D-ala
preventing cross-linking |
|
|
Term
| in contrast to most antimicrobials, which bind to enzymes, _ binds _ |
|
Definition
|
|
Term
| _ bacteria are intrinsically resistant to vancomycin why? |
|
Definition
g-
it cannot get through outer membrane |
|
|
Term
| vancomycin resistant _ have arisen and are an increasing problem. how do they do it? |
|
Definition
enterocci
their peptide terminates in D-ala D-lactate |
|
|
Term
| enteroccus resistance gene against vancomycin is carried on a _ and has been known to be transmitted to _ _ |
|
Definition
|
|
Term
cell wall biosynthesis inhibitors include
(5) |
|
Definition
beta lactams
vancomycin
teicoplanin
cycloserine
bacitracin |
|
|
Term
| cycloserine molecular structure |
|
Definition
|
|
Term
|
Definition
blocks:
alanine racemase
D-Ala ligase |
|
|
Term
bacteriostatic or bactericidal?
vancomycin |
|
Definition
|
|
Term
bacteriostatic or bactericidal?
cycloserine |
|
Definition
|
|
Term
| bacterial topological disadvantage of cycloserine (3 details) |
|
Definition
| D-Ala ligase is in the bacterial cytoplasm so cycloserine must penetrate cytoplasmic membrane |
|
|
Term
|
Definition
| prevents recycling of undecaprenol carrier that transports peptidoglycan precursor across cytoplasmic membrane |
|
|
Term
|
Definition
amoxicillin
clavulanic acid (which inhibits beta lactamases) |
|
|
Term
| virtually all g- bacteria feature this particular type of beta lactamase |
|
Definition
|
|
Term
| this cell wall biosynthesis inhibitor has a target that is cytosolic |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
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