Infectious Diseases Flashcards
Erythromycin/Clindamycin site of action
50s subunit of ribosome, protein synthesis inhibitors
Linezolid side effects
Myelosuppression, peripheral neuropathy, seretonin syndrome,
Rare optic neuropathy
Aminoglycoside/tetracycline site of action
30s subunit of ribosome, protein synthesis inhibitors
Linezolid site of action
Both 50s and 30s subunit of ribosome, protein synthesis inhibitors
Method of action of beta lactams, vancomycin
Cell wall synthesis
Daptomycin method of action
Loss of cell wall selective permeability
Note: binds to surfactant and cannot be used in lung infections
Quinolone method of action (ciprofloxacin, etc.)
Inhibits gyrase, unwinding enzyme in DNA replication
Rifampicin method of action
Inhibit RNA polymerase in DNA transcription
Method of action sulfamethoxazole, trimethoprim
Inhibits folate synthesis
Which antibiotics efficacy determined by peak concentration?
Fluoroqinolones, aminoglycosides (ciprofloxacin, gentamicin, etc)
Which antibiotics efficacy determined by time above MIC?
Beta-lactams
Method of MRSA resistance
Alteration of penicillin binding protein
MecA Gene encodes for PBP2a
Resistance to all penicillins/cephalosporins/carbapenem
What gene predominated in community-acquired MRSA?
Panton-valentine leucocidin (PVL)
Daptomycin: side effects
Myopathy, eosinophilic pneumonia, peripheral neuropathy
What gene confers vancomycin resistance?
Amino acid substitution: D-ala D-ala to D-ala D-lac
Prevents vancomycin binding to cross links
Van A gene - vanc and teicoplanin resistance
Van B/C gene - vanc resistant only
What is the mechanism of S. pneumoniae resistance to macrolides?
MefA gene - efflux pump (low resistance)
ErmB gene - alteration of binding site (high resistance)
List ESCHAPPPM organisms
Inducible AMP-C beta lactamase Enterobacter Serratia marcescens Citrobacter freundii Hafnia alvei Acinetobacter and Aeromonas Proteus vulgaris (not mirabilis) Providencia Pseudomonas Morganella morganii
What high risk criteria require a TOE in S. aureus bacteremia?
Community acquired bacteremia IV drug use High risk cardiac condition (valve, PPM, transplant, prev IE) Indeterminate or positive TTE Prolonger bacteremia>72 hours
What are the indications for IE prophylaxis?
High risk heart condition:
Prosthetic heart valve, rheumatic heart disease, prev IE, unrepaired cyanotic congenital heart disease
AND
High risk procedure:
Dental procedure (manipulate gingival tissue, periapical teeth, perforates mucosa)
Tonsillectomy, adenectomy
Surgery at site of established infection
