Influence of cadmium on resistance to antibiotics in salmonellae isolated from pigs.

Repeated cultivations (4 passages) of salmonellae (18 strains) resistant to cadmium, streptomycin and beta-lactam antibiotics in Müller-Hinton Broth (MHB) and Mac-Conkey Broth (MCB) without and with CdSO4 (2, 20 and 100 mg/L) showed a higher toxic effect of cadmium in MCB. The strains survived at CdSO4 100 mg/L in MHB for four transfers, in MCB only a single transfer. In dependence on the medium used and amount of metal added, the increase of resistance to antibiotics was different.