Antiseptic and antibiotic resistance in gram-negative bacteria causing urinary tract infection in spinal cord injured patients.

Fifty-seven isolates of Gram-negative bacterial species from urinary tract infections in spinal cord injured patients were tested for their sensitivity to chlorhexidine, cetrimide, glutaraldehyde, phenyl mercuric nitrate (PMN), a phenolic disinfectant (Hycolin) and a proprietary antiseptic containing a mixture of picloxydine, octylphenoxypolyethoxyethanol and benzalkonium chloride (Resiguard). None of the isolates were resistant to glutaraldehyde, Hycolin or PMN but a substantial percentage were resistant to chlorhexidine (44 per cent), cetrimide (26 per cent) and Resiguard (42 per cent). The resistant organisms were members of the genera Proteus, Providencia and Pseudomonas and they were also generally resistant to five, six or seven antibiotics. Significant correlations were observed between multiplicity of antibiotic resistance and the minimum inhibitory concentrations of the three cationic antiseptics. It is suggested that an antiseptic policy for the bladder management of spinal cord injured patients that relies on the extensive use of cationic agents might lead to the selection of a flora of notoriously drug-resistant species.