[Recurring meningitis caused by Streptococcus pneumoniae during preventive penicillin therapy].

It is generally accepted, that Streptococcus pneumoniae is very sensitive to penicillin G; minimal inhibitory concentration (MIC) is normally about less than = 0.01 microgram/ml. Some years ago strains relatively resistant to penicillin (MIC 0.1 to 1.0 microgram/ml) were reported on. In 1977 strains isolated from blood and cerebrospinal fluid in South-Africa were found to have a higher resistance to penicillin (MIC 0.5-4 micrograms/ml). We report on an 6-year-old girl with septicemia and meningitis caused by a strain of S. pneumoniae relatively resistant to penicillin (MIC 0.5 microgram/ml). Aged 5 years the girl had a first meningitis caused by S. pneumoniae. The girl was then treated with penicillin (450,000 IU/d) to prevent a new infection. During this time the second meningitis caused by S. pneumoniae took place. In the agarose gel electrophoresis a plasmid was found (4.2 X 10(6) Dalton). No beta-lactamase-activity was detected (nitrocefin-test and acidimetric measurement). It is unlikely that there is a plasmid-dependent resistance to penicillin.