The changes in
coagulase-negative staphylococcal flora induced by
cefamandole prophylaxis were compared with those induced by
pefloxacin prophylaxis among patients undergoing heart valve surgery. Twenty-five patients (15 receiving
cefamandole prophylaxis and 10 receiving
pefloxacin prophylaxis) were included in the study. In the
pefloxacin group, colonization rates in anterior nares and in chest skin or
wound that were 60% and 50% respectively before surgery, became 50% and 20% respectively after surgery. In the
cefamandole group, colonization rates in anterior nares and chest skin or
wound were 53.3% and 60% respectively before surgery and became 53.3% and 40% respectively after surgery.
Cefamandole did not appear to induce the emergence of
oxacillin or
pefloxacin resistant
coagulase-negative staphylococcal colonization in any cultured site. On the other hand
pefloxacin appeared somewhat more efficacious than
cefamandole in eradicating staphylococcal flora of anterior nares and chest skin or
wound.
Pefloxacin and
oxacillin resistant strains were found in the perianal area in 0% of patients before
pefloxacin prophylaxis and in 70% of patients after
pefloxacin prophylaxis. However, further studies are necessary to confirm the emergence of
antibiotic resistant
coagulase-negative staphylococci in the intestinal microflora after
quinolone administration. The clinical implications of such apparently disturbing phenomenon remain to be evaluated.