Penicillin-insensitive pneumococci. Case report and review.

Infections due to pneumococci with decreased susceptibility (or resistance) to penicillin have been infrequently recognized. Our experience and that of others suggest that (1) penicillin susceptibility testing of significant pneumococcal isolates should become routine; (2) penicillin may not be adequate therapy for CNS infections due to pneumococci whose penicillin minimal inhibitory concentration is greater than 0.1 microgram/ml; and (3) long-term penicillin "prophylaxis" may be inappropriate in the splenectomized patient in areas where these organisms are prevalent.