Contamination of chlorhexidine cream used to prevent ascending urinary tract infections

Chlorhexidine-containing cream is often used as an antimicrobial barrier to ascending urinary tract infection in patients with indwelling urethral catheters. The cream is dispensed in small tubes for personal use but repeated use of a tube still entails a potential infection hazard. The extent of cream contamination was analysed by emulsifying it in 1% peptone broth with 1% Tween-80 added as a wetting agent, and culturing quantitatively for bacteria and fungi by membrane filtration. Twenty-three per cent of cream samples and 35% of swabs taken from outside the tube beneath the screw cap demonstrated microbial contamination. Isolates included potential pathogens such as enterococci, staphylococci, Proteus mirabilis, Pseudomonas aeruginosa, opportunists like Moraxella spp. and diphtheroids, and contaminants such as Bacillus spp., micrococci, and a mould of the genus Cladosporium. Contamination of cream with a particular bacterial strain was found to precede urinary tract infection with the same microbe. We recommend that chlorhexidine cream for this use be dispensed in single dose units to ensure sterility.