Proteus vulgaris urinary tract infections in rats; treatment with nitrofuran derivatives

Ascending urinary tract infections with stone formation have been produced experimentally in rats, using a modification of the method of Vermuelen & Goetz (1954a, b). A zinc disc infected with a culture of Proteus vulgaris was inserted into the bladder by suprapubic cystotomy under ether anaesthesia. The pH of the urine rises from 6.9 to 8 or 9 and calculi develop in the bladder within a few days of infection. The bladder and ureters become swollen, distended and inflamed, and renal abscesses develop. Death from renal failure generally occurs within 10 days of infection. Oral treatment with nitrofurantoin was commenced three days after infection and continued for one month. This arrested the initial rise in urine alkalinity and stone formation, and few, if any, macroscopic lesions were found at post-mortem examination. Of nine nitrofuran derivatives examined for activity against this infection several showed slight activity, but only one, N-(5-Nitrofurfurylidene)-gamma-butyric acid, was as active as nitrofurantoin when given at four times the dose, but it was also one-third as toxic. It is concluded that this technique is suitable for the examination of potential urinary antiseptics.

NITROFURAN DERIVATIVES AS RADIOMIMETIC AGENTS: CROSS-RESISTANCE STUDIES WITH ESCHERICHIA COLI

Mutants of Escherichia coli B selected on the basis of resistance to nitrofurazone, NFT, or ultraviolet light proved to be resistant to all three of these agents. Further tests showed that these mutants are also resistant to three other nitrofuran derivatives, nitrofurantoin, nihydrazone, and furazolidone, but not to nifuroxime. The mutants are also resistant to the chemically dissimilar radiomimetic agent, proflavin. Strain B and all the mutants derived from it are equally sensitive to streptomycin, a non-radiomimetic antibiotic. E. coli strain B/r (resistant to radiation and radiomimetic chemicals) shows the same resistance pattern as the new mutant strains. The results are discussed in terms of what is known concerning the basis for the resistance of strain B/r to ultraviolet light. It is concluded that radiomimetic nitrofurans probably exert their effect on E. coli through damage to DNA.

RED CELL GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY--A NEWLY RECOGNIZED CAUSE OF NEONATAL JAUNDICE AND KERNICTERUS IN CANADA

Seven male newborns of Chinese, Greek and Italian origin presented with severe hemolytic jaundice due to red cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. In five, the hemolysis was precipitated by inhalation of mothball vapours in the home. Kernicterus was evident upon admission in six infants and was fatal in four of these.G-6-PD deficiency should be suspected as a cause of jaundice in all full-term male infants of these ethnic groups. The diagnosis can be confirmed in any hospital by the methemoglobin reduction test. In areas similar to Toronto, Canada, where these high-risk ethnic groups prevail, the following measures are recommended: (1) detection of G-6-PD deficient newborns by screening cord bloods of all infants of these ethnic groups; (2) protection of affected infants from potentially hemolytic agents such as naphthalene, certain vitamin K preparations, and sulfonamides; and (3) observation of serum bilirubin levels to assess the need for exchange transfusion for hyperbilirubinemia.