#IDTwitter #IDXposts How would you explain resistance to ampicillin in this isolate of MSSA? How would you treat if you find this in urine culture? @dralicehan @ABStewardess @BradSpellberg @DrToddLee @Cortes_Penfield @CosEpiID @IdVilchez @drtimothyli @edenhelmi @wr
@BJegorovic @dralicehan @ABStewardess @BradSpellberg @DrToddLee @Cortes_Penfield @CosEpiID @IdVilchez @drtimothyli @edenhelmi @wr Most staphylococci are penicillin resistant (and therefore amoxicillin/ampicillin resistant) because they secrete penicillinase. But they can still ben methicillin susceptible.
@BJegorovic @dralicehan @ABStewardess @BradSpellberg @DrToddLee @Cortes_Penfield @CosEpiID @IdVilchez @drtimothyli @edenhelmi @wr ~70% of MSSA are betalactamase producing hydrolyzing ampicillin. If needed would give flucloxacillin orally unless BSI.
@BJegorovic @dralicehan @ABStewardess @BradSpellberg @DrToddLee @Cortes_Penfield @CosEpiID @IdVilchez @drtimothyli @edenhelmi @wr Most Staph aureus produce penicillinases making them PCN-R. Methicillin was created to be molecularly stable vs them, but aminopenicillins are not. MSSA is uncommon in urine, and prompts an investigation for bacteremia imo.