INFLUENCE OF SUBINHIBITORY CONCENTRATIONS OF BRODIMOPRIM AND TRIMETHOPRIM ON THE ADHESIVENESS, HYDROPHOBICITY, HEMAGGLUTINATION AND MOTILITY OF ESCHERICHIA-COLI

In the present study the ability of subinhibitory concentrations (sub- MICs) of brodimoprim (a new 2,4-dimethoxybenzylpyrimidine) to interfer e with some important aspects of bacterial cell function, such as surf ace hydrophobicity, fimbriation, motility and adhesiveness to mucosal cells, was investigated in comparison with those of trimethoprim. The inhibitory behavior of both diaminopyrimidines concerning hydrophobici ty and hemagglutination (fimbriation) were essentially the same, while for adhesiveness and motility brodimoprim was more effective than tri methoprim. Diaminopyrimidines have high affinity for the bacterial enz yme dihydrofolate reductase, and this reduces the synthesis of essenti al purines and as a consequence of DNA and proteins. Our findings indi cate that the synthesis and/or the expression of surface adhesins, whi ch are proteins, was also affected by both brodimoprim and trimethopri m, the former being more active.