In vitro action of a combination of selected antimicrobial agents and chondroitin sulfate

Chondroitin sulfate (CS), a highly anionic polymer and the most predominant sulfated glycosaminoglycan in connective tissues, was investigated regarding to its interaction with cationic disinfectants, which are used as antiinfectives in humans. Combinations of cetylpyridiniumchloride (CPC), chlorhexidine (CHex), and polyhexamethylene biguanide (PHMB) with CS, respectively, were prepared and the resulting microbicidal activity of the mixtures was tested in the quantitative suspension test without organic matter. Polyvidone-iodine and Ringer's solution were used as controls. Even precipitated, the resulting test combinations behave differently against Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. CPC/CS demonstrated only microbicidal activity against Gram-positive bacteria, and CHex/CS was more active against Gram-negative bacteria and C. albicans. PHMB/CS, especially in combination with CS-A, only revealed an antimicrobial effect against P. aeruginosa after 60 min action. The interaction of cationic disinfectants with CS showed depending on the investigated microorganism a more or less controlled sustained release manner of the microbicidal agent from the precipitated complex, with the only exception of PHMB in combination with CS-C, which is completely neutralized. Polyvidone-iodine and Ringer's solution were not affected by CS.