Laboratory and clinical studies were performed on ticarcillin, a new semi-synthetic penicillin with broad antibacterial spectrum, and the following results were obtained.
1) As to the distribution of ticarcillin sensitivity in clinical isolates, a peak was 6.25 pg/ml for Staph. aureus, 6.25 μg/ml and more than 100 μg/ml for E. coli, more than 100 μg/ml for Klebsiella, 0.78 μ/ml for Proteus sp., and 50 μg/ml for Pseudomonas aeruginosa. When the inoculum size was decreased, a peak of sensitivity moved to 3. 12 μg/ml for Staph. aureus, 3. 12 μg/ml and more than 100 μg/ml for E. coli, and 25μg/ml for Pseudomonas aeruginosa.
Compared these antibacterial activities of ticarcillin with those of CBPC, no wide difference was observed for Staph. aureus, Klebsiella and Proteus sp., while the antibacterial activity of ticarcillin was 2 times stronger than that of CBPC for sensitive E. coli and Pseudomonas aeruginosa.
2) Ticarcillin was adminstered intravenously by drip infusion of a daily dose of 2-10g to 5 cases of respiratory tract infection and 2 cases of urinary tract infection each due to Pseudomonas aeruginosa, 7 cases in total. The clinical effects obtained were good in 4 cases and failure in 3 cases. As to the bacteriological effect, Pseudomonas aeruginosa was eradicated in 5 cases out of 7 cases. As to the side effects, epigastric malaise, and phlebitis at injected site were observed each in 1 case.
