Antibiotic use as an inducer of resistant urinary tract infections

Urinary tract infection is second in frequency only to respiratory infection as an indication for antimicrobial chemotherapy. As a result, a significant proportion of both domiciliary and hospital patient populations are exposed to chemotherapy which, in turn, may act as a potent selection pressure for development of resistance mediated by intrinsic mechanisms or acquisition of R-plasmids or transposons. The widespread use of broad spectrum agents has encouraged the development of such resistance in enterobacteria, notably but not exclusively amongst the Klebsiella-Enterobacter-Serratia group, leading to the creation of patient reservoirs of multiply-antibiotic-resistant bacteria. Such situations occur frequently in urological units, amongst catheterised individuals receiving chemotherapy, and, via cross-infection, may rapidly spread to other units and other hospitals. The use of antibiotic combinations, such as co-trimoxazole, may not prevent such problems, which are however amenable to policies which restrict, either selectively or globally, antibiotic use. Such policies can be expected to control the spread of multiply-antibiotic-resistant infection.