The activity of two cephalosporins were tested in Klebsiella pneumoniae infected guinea pigs. Guinea pigs were intratracheally inoculated with 6x108 bacteries and treated once a day for cefodizime (30 mg/kg) and cefpirome (30 mg/kg). Apositive control group was infected but not received antibiotic. The negative control group was challenged with steril saline solution. At 0, 12, 24 and 48 h after bacterial challenge, guinea pigs were euthanised and the lungs were excised and weighed. The lungs were homogenized to determine the number of cfu per gram of tissue quantitatively.

In the present experimental animal model both cefodizime and cefpirome reduced the number of cfu per gram comparing with the control group but the difference was not found significant statistically (cefodizime-control p>0.05, cefpirome-control p>0.05).