Antimicrobial resistance of invasive Streptococcus pneumoniae in Slovenia, 1993-1995

The susceptibility of 108 Streptococcus pneumoniae strains isolated from normally sterile body sites during 1993-1995 in Slovenia has been studied. Overall resistance to penicillin, erythromycin, trimethoprim-sulfamethoxazole, cefuroxime, cefaclor and chloramphenicol was 16.6, 0.9, 26.8, 0, 4.5 and 4.6%, respectively. All penicillin-resistant isolates (intermediate resistance) mere susceptible to cefotaxime, ceftriaxone and vancomycin. Isolates less susceptible to penicillin were also significantly less sensitive to chloramphenicol, cefaclor and trimethoprim-sulfamethoxazole than penicillin-sensitive strains. Pneumococci isolated in children were significantly (p < 0.05) more resistant to trimethoprim-sulfamethoxazole than those isolated in adults. The study demonstrated moderate resistance rate of S. pneumoniae to penicillin and trimethoprim-sulfamethoxazole and a low-level resistance rate to erythromycin, cefaclor and chloramphenicol. No straightforward correlation between overall consumption of antibiotics and antimicrobial resistance was found.