Cefodizime: effects of sub-inhibitory concentrations on adhesiveness and bacterial morphology of Staphylococcus aureus and Escherichia coli: comparison with cefotaxime and ceftriaxone.

Exposure of Staphylococcus aureus and Escherichia coli strains to different subMICs of cefodizime, cefotaxime and ceftriaxone significantly reduced the bacterial attachment to human buccal cells, but the resultant patterns of inhibition were different for S. aureus and E. coli and for the behaviour of the three cephalosporins. Morphological anomalies such as clusters of enlarged S. aureus cells and filamentation with spheroplast-like structures and bulge formations in E. coli were also present. Analogies between the different patterns of inhibition of adhesiveness and the corresponding degree of morphological changes were observed. Cefodizime behaved differently from cefotaxime and ceftriaxone and this could be attributed to the presence in the cefodizime molecule of an additional substituent, a 3-methyl-5-carboxymethyl-1,3-thiazole-2-thio group in the 3' position, not present in cefotaxime or ceftriaxone.