RESISTANCE TO PENICILLIN AND CEPHALOSPORIN AND MORTALITY FROM SEVERE PNEUMOCOCCAL PNEUMONIA IN BARCELONA, SPAIN

Background. Penicillin-resistant strains of Streptococcus pneumoniae a re now found worldwide, and strains with resistance to cephalosporin a re being reported. The appropriate antibiotic therapy for pneumococcal pneumonia due to resistant strains remains controversial. Methods. To examine the effect of resistance to penicillin and cephalosporin on m ortality, we conducted a 10-year, prospective study in Barcelona of 50 4 adults with culture-proved pneumococcal pneumonia. Results. Among th e 504 patients, 145 (29 percent) had penicillin-resistant strains of S . pneumoniae (minimal inhibitory concentration [MIG] of penicillin G, 0.12 to 4.0 mu g per milliliter), and 31 patients (6 percent) had ceph alosporin-resistant strains (MIG of ceftriaxone or cefotaxime, 1.0 to 4.0 mu g per milliliter). Mortality was 38 percent in patients with pe nicillin-resistant strains, as compared with 24 percent in patients wi th penicillin-sensitive strains (P = 0.001). However, after the exclus ion of patients with polymicrobial pneumonia and adjustment for other predictors of mortality, the odds ratio for mortality in patients with penicillin-resistant strains was 1.0 (95 percent confidence interval, 0.5 to 1.9; P = 0.84). Among patients treated with penicillin G or am picillin, the mortality was 25 percent in the 24 with penicillin-resis tant strains and 19 percent in the 126 with penicillin-sensitive strai ns (P = 0.51). Among patients treated with ceftriaxone or cefotaxime, the mortality was 22 percent in the 59 with penicillin-resistant strai ns and 25 percent in the 127 with penicillin-sensitive strains (P = 0. 64), The frequency of resistance to cephalosporin increased from 2 per cent in 1984-1988 to 9 percent in 1989-1993 (P = 0.002). Mortality was 26 percent in patients with cephalosporin-resistant S. pneumoniae and 28 percent in patients with susceptible organisms (P = 0.89), Among p atients treated with ceftriaxone or cefotaxime, mortality was 22 perce nt in the 18 with cephalosporin-resistant strains and 24 percent in th e 168 with cephalosporin-sensitive organisms (P = 0.64). Conclusions. Current levels of resistance to penicillin and cephalosporin by S. pne umoniae are not associated with increased mortality in patients with p neumococcal pneumonia, Hence, these antibiotics remain the therapy of choice for this disease.