THE EFFECT OF ORALLY ADMINISTERED STREPTOMYCIN AND SULFATHALIDINE UPON THE BACTERIAL FLORA OF THE COLON

Abstract

A simple method is descr. for making coliform and "total" counts of fecal specimens from individuals receiving streptomycin by mouth which employs semicarbazide HC1 as the inactivator. 36 patients being prepd. for large bowel surgery were divided into 3 oral medication groups as follows: (1) sulfathalidine, 0.1 g./kg./day; (2) streptomycin, 2 g./day; (3) a combination of the 2 drugs in full dosage. The time required to bring about 99.99% reduction in coliform bacilli was 3.5 days, 1.9 days, and 1.1 days, resp. There were 2 failures in the streptomycin group. Subsequent reversion in coliform count, indicating development of resistance, was not observed in the sulfathalidine group over an avg. observation period of 6 days, or in the streptomycin group observed for an avg. of 3 days. Reversion did occur in 2 of 12 individuals who received both drugs for an avg. period of 6 days. The oral admn. of a combination of sulfathalidine and streptomycin had an irregular and temporary effect upon the "total" counts. The coliform count does not appear to be an adequate index of the effect of these drugs upon the total bacterial population. Bacteria resistant to 1 of the 2 drugs were occasionally observed to disappear from the bowel because they were susceptible to the other. Since bacteria rapidly develop resistance to streptomycin, even in the presence of sulfathalidine, it does not appear advisable to igive this drug for more than 2 days before an operative procedure upon the large bowel. The serious consequences resulting from prolonged admn. are illustrated by 1 case.