DRUG-RESISTANT STREPTOCOCCUS-PNEUMONIAE - THE BEGINNING OF THE END FOR MANY ANTIBIOTICS

Objective: To determine the levels of antibiotic resistance in Strepto coccus pneumoniae in Australia. Design: Prospective, Australia-wide, l aboratory-based survey. Setting: 27 hospital and private laboratories around Australia, from January 1994 to August 1995. Subjects: First 10 0 patients with clinically significant isolates of S. pneumoniae at ea ch laboratory. Outcome measures: Resistance to penicillin (determined from penicillin minimum inhibitory concentration [MIC] measured by the Etest), erythromycin, trimethoprim-sulfamethoxazole, tetracycline, ch loramphenicol, cefotaxime and ceftriaxone. Results: A total of 2396 is olates were tested (including 537 invasive isolates and 740 from child ren). Penicillin resistance was seen in 161 isolates (6.7%), including 17 with high level resistance. Penicillin resistance rates were signi ficantly lower in invasive than in non-invasive strains (3.7% versus 7 .6%; odds ratio [OR], 0.47; 95% confidence interval [CI], 0.28-0.77; P =0.001), There was no significant difference in penicillin resistance rates between children (< 15 years) and adults (7.3% versus 6.5%; OR, 1.14; 95% CI, 0.80-1.63; P=0.47). Resistance rates were higher for mos t other antibiotics than for penicillin (chloramphenicol, 6%; erythrom ycin, 11%; tetracycline, 15%; and trimethoprim-sulfamethoxazole, 42%). No high level resistance was seen to third generation cephalosporins, but 17 of 109 penicillin-resistant isolates tested (16%) displayed in termediate resistance to cefotaxime. Rates of antibiotic resistance va ried between States, with the lowest rates in Tasmania. Conclusions: A ntibiotic resistance levels in S. pneumoniae are increasing in Austral ia and high level penicillin resistance is being encountered for the f irst time (including in invasive strains). This will lead to an increa sing number of therapeutic dilemmas and possible therapeutic failures, especially important in meningitis.