In vitro quantitative adherence of microorganisms to intrauterine contraceptive devices

The in vitro adherence of seven different microbial species to three material types of intrauterine contraceptive devices (IUCDs) was investigated. After 6 h of incubation, adherence of two species was greater on the IUCD made of polyethylene (PE) than on the ones made of polypropylene (PP) (p<0.005) and of ethylene-vinyl acetate (EVA) (p<0.005); adherence of two species was greater on EVA than on PE (p<0.01) and on PP (p<0.01) whereas three species showed identical adherence to the three materials tested. Also, the number of Group-BStreptococcus cells adherent to any of these IUCD materials was significantly greater than the number of adherent cells of all the other microorganisms studied at analogous inocula (p<0.001). The initial attachment of microorganisms to IUCDs appears to involve cell surface hydrophobicity and lodgment of microbial cells in surface irregularities. It was found that the number of adherent microorganisms depended on the type of IUCD material, the type of microorganism, and the duration of contact.