Antibacterial Action of Spermine: Effect on Urinary Tract Pathogens

Abstract

The basic polyamine spermine was tested for antibacterial activity at two p H levels by the modified cup method against a variety of gram-positive and gram-negative organisms isolated from urine. At p H 6.4, with concentrations ranging from 39 to 2,500 μg per 0.1 ml, there were no clear zones of inhibition seen with any of the gram-negative test organisms, although some adverse effect on growth within the area of the cylinder was noted in 36%. Three of 17 gram-positive strains were inhibited at this p H. Spermine was more active at p H 7.4, but even at the highest concentrations only 16% of the gram-negative and 47% of the gram-positive bacteria tested showed definite zones of inhibition. It is concluded that spermine probably plays little, if any, role in natural resistance to urinary tract infections in vivo.