[Streptococcus pneumoniae of lesser sensitivity to penicillin in the Sfax region, Tunisia (1994-1995)].

In the last fifteen years, the frequency of Streptococcus pneumoniae resistance to penicillin has been regularly increasing with various degrees in different geographical zones. In order to determine the epidemiological situation in our region, we studied penicillin G susceptibility of S. pneumoniae strains isolated in our laboratory for 2 years 1994 and 1995. The S. pneumoniae strains with reduced susceptibility to penicillin G (PSDP) were detected by oxacillin screen test (using 1 microgram oxacillin disk) and completed with the determination of penicillin G MIC. We isolated 107 S. pneumoniae strains (41 in 1994 and 66 in 1995); 12 of them had reduced susceptibility to penicillin (11.2%). The study showed a difference in the percentage of penicillin susceptibility between invasive (5.1%) and non invasive strains (28.6%). The rate of strains with reduced susceptibility to penicillin increased from 7.3% in 1994 to 13.6% in 1995 with a higher degree of resistance in 1995. We concluded that our region is not spared from the problem of the decreased susceptibility to penicillin G of S. pneumoniae. These results should prompt us to survey the evolution of such resistance.