[Clinical and experimental studies on the pathogenicity of clinical isolated Citrobacter freundii]

Clinical and fundamental studies were performed using Citrobacter freundii isolated from urine specimens of in- and out-patients between January 1980 and July 1981. The C. freundii (greater than 10(4)/ml) isolated from urine was closely related to chronic complicated urinary tract infection. MICs of pyridonecarbonic acids (ENX, OFLX and NFLX) and CMX against C. freundii were low. Pyridonecarbonic acids (ENX, OFLX and NFLX) and CMX showed good therapeutic effects against the experimental ascending pyelonephritis of mice according to their MICs. Against the experimental ascending pyelonephritis of cyclophosphamide-treated mice, pyridonecarbonic acids (ENX, OFLX and NFLX) showed good therapeutic effects. Experimental intraperitoneal infection of mice was made easily with a low inoculation dose by adding mucin. Pyridonecarbonic acids (ENX, OFLX and NFLX) and CMX showed good therapeutic effects against this experimental model. Experimental respiratory tract infection could not be made in the mice with the organism isolated from urine.