Increased Resistance to Penicillin of Pneumococci Isolated from Man

Abstract

Strains of Diplococcus pneumoniae relatively insensitive to penicillin were isolated from an aboriginal child in Australia and from 15 New Guineans. The concentration of penicillin required to inhibit growth was 25 times that which inhibited sensitive pneumococci. These pneumococci were also partially resistant to cephalosporin antibiotics. All the relatively insensitive pneumococci from New Guinea were identified as Type 4, suggesting that transmission of the partially resistant strain had occurred. The isolations were made from persons who lived in remote areas where penicillin had frequently been used.