Effect of four antibiotics on haemolysin production and adherence to human uroepithelial cells by Escherichia coli.

The effect of subinhibitory concentrations of chloramphenicol, gentamicin, netilmicin and streptomycin in artificial culture media on growth, haemolysin production and adherence to uroepithelial cells by Escherichia coli was examined. Only streptomycin inhibited haemolysin production without inhibiting growth of the bacteria. In contrast, the inhibition of haemolysin production by chloramphenicol, gentamicin or netilmicin was directly proportional to the degree of inhibition of growth. Bacterial adherence to human uroepithelial cells, measured microscopically, was affected by all four antibiotics but to different extents. There was no correlation between inhibition of haemolysin biosynthesis and the ability of the bacteria to adhere to uroepithelial cells after growth in the presence of the antibiotics.