Staph aureus has, it seems, got nastier. Some strains are now positive for something called PVL, which causes recurrent skin infections and which, for some reason which still mystifies microbiologists, causes the staph to be immune to flucloxacillin despite appearing sensitive to it on lab tests. Patients with recurrent skin infections should have a swab of the lesion, plus a nose swab, sent for C&S with specific request for testing for PVL genes (which is not routinely done).
And there’s a new drug interaction to worry about – co-prescribing nitrofurantoin with spironolactone increases the risk of hyperkalaemia. Trimethoprim may do so as well, although this isn’t certain as the studies were done on co-trimoxazole.