Distribution of resistances to metals and antibiotics of staphylococcal strains in Japan.

Clinical isolates of 565 staphylococcal strains were studied for the resistance to four metals and eight antibiotics. Distribution patterns of their susceptibilities to Hg, As and Pb clearly revealed two peaks. But in the case of Cd resistance, there were three groups of Cd sensitivity. Frequencies of metal resistances were 36.6% to Hg, 95.6% to Cd, 48.8% to As and 91.9% to Pb. On the other hand, those of drug resistances were 87.3% to PC, 28.5% to SM, 33.5% to TC, 22.7% to CP, 23.9% to KM, 43.0% to EM, 38.8% to JM and 0% to GM. Most of tested cultures were metal-resistant (92.9%), moreover, these multiple-metal-resistant strains were also found to be multiple-drug-resistant. And about 10% of total isolates were metal-resistant and drug-senstitive strains, whereas the frequency of the metal-sensitive and drug-resistant strains was only 1.8%.