The killing of Ureaplasma urealyticum and Mycoplasma hominis by povidone-iodine

Povidone-iodine killed Ureaplasma urealyticum and Mycoplasma hominis organisms. In addition to the eight known U. urealyticum serotypes, eight untyped ureaplasma strains and one M. hominis strain all of which had been freshly isolated, were tested. The concentration of povidone-iodine needed to kill the organisms in serum-broth varied slightly according to the strain or serotype, but 0.6% killed all organisms irrespective of strain or serotype or whether of U. urealyticum or M. hominis species. Most organisms were killed immediately after mixing and, with one exception, all of them were killed within five minutes. On subculture the treated organisms failed to multiply which confirmed the mycoplasmacidal effect of the compound. One of 5 urine samples inhibited the effect of povidone-iodine, a 2% concentration being required to kill the mycoplasmas. This is relevant to some circumstances in which elimination of these organisms from the genito-urinary tract could be worthwhile.