On the Bactericidal Powers of Lipiodol and Iodipin in Vitro.

Abstract

A generous literature concerning the use of lipiodol and iodipin in diagnosis reveals the statements by many authors that these iodized oils are antiseptic.

One of us (A. M.) has used these oils in the injection of over 300 gynecologic patients and has occasionally felt some concern regarding the possibility of infection from the material forced through the tubes into the abdominal cavity. No such infection has taken place and we have been led to believe that the oils used actually had antiseptic powers. Nevertheless we felt that some quantitative work to determine more accurately the effects of these oils on bacteria would be of value.

Great difficulties are encountered at once in applying the ordinary methods of disinfectant testing to these heavy oils. Even long continued shaking of specimens of the oils with masses of bacterial growth taken from agar slants gave very poorly dispersed suspensions of the organisms. Visible clumps were invariably present. Staph. aureus (a hemolytic strain) and B. coli were the organisms used. Inoculations from such imperfect suspensions to broth gave growth in all cases, but since many organisms in the clumps may have been protected from contact with the oil, we did not feel that such tests were trustworthy. Better suspensions of the cultures could be obtained in the pure oils, such as sesame and poppy seed, of which the lipiodol and iodipin are addition products, and subsequent additions of these oily suspensions to the iodized products resulted in somewhat better, though still imperfect, dispersion of the organisms in the latter. Inoculations from these to broth at varying intervals yielded variable results. No growth at all was obtained with B. coli and only a portion of the Staph. tubes showed growth.