Survey of resistance to metals and antibiotics in clinical isolates of Klebsiella pneumoniae in Japan.

Clinical isolates of K. pneumoniae (746 isolates) were studied for the resistance to four metals and four drugs. The distribution patterns of their susceptibility to Hg, Cd and As clearly revealed two peaks, but only a single peak of resistance to Pb. It can be seen that resistance was demonstrable in media containing the following concentrations of the metals (micrograms/ml): HgCl2, 10; CdCl2, 400; and Na2HAsO4, 400. In K. pneumoniae, the frequency fo resistance to these concentrations of Hg, Cd and As were 65,8%, 98,3% and 83,8%, respectively. On the other hand, the frequency to antibiotic resistance of K. pneumoniae were 68,1% of SM, 51,2% of TC, 49,7% of CP and 36,7% of KM. Furthermore, many isolates (99,6%) were metal-resistant. Most of these metal-reisitant strains were multiple-metal-resistant and also multiple-drug-resistance. And about 30% of total isolates were metal-resistant but drug-sensitive, whereas the frequency of the metal-sensitive and drug-resistant strains was 0%.