A rapid assay method for cephalosporins.

A simple, rapid assay for cephalosporins is described. The method is based on the inhibition by cephalosporins of the fermentation of glucose or inositol by a strain of Providence resistant to aminoglycoside antibiotics. The method gives answers which are as accurate as those obtained by standard agar diffusion techniques within four hours, and utilizes skills and resources readily available in most routine bacteriology departments. Results are not affected by gentamicin or kanamycin concurrently administered to the patient. This method will be of value in helping to monitor cephalosporin therapy in patients with serious sepsis, especially those with impaired renal function, and may help in elucidating and preventing the problem of nephrotoxicity associated with cephalosporin administration.