Objective: The first case reports of infection with penicillin-resistant pneumococci were made in Australia in 1967 and South Africa in 1977. Since this time the increasing emergence of penicillin- resistant strains of Streptococcus pneumoniae have been a serious therapeutic problem. Therefore, the aim of the present study was to determine the penicillin resistance of S. pneumoniae strains isolated in the laboratory. The effect of procaine penicillin treatment against these strains was also investigated.
Methods: Sensitivity testing was done by disc diffusion method using oxacillin discs. Minimal inhibitory concentration (MIC) values were determined in tests with penicillin by the use of E-test (AB Biodisc, Solna, Sweden). Patients were treated with 2 x 800,000 U of i.m. procaine penicillin every 12 h for 10 days.
Results: Thirty-seven strains of S. pneumoniae were isolated from the sputa of adult patients who had pneumonia. Moderately resistant (0.12-1.00 microg/mL) and penicillin-sensitive (< or = 0.06 microg/mL) strains were identified in nine (24.3%) and 28 (75.7%) isolates, respectively. There were no high-level penicillin-resistant strains in the study. There was no therapeutic failure.
Conclusion: These results suggest that procaine penicillin may still be useful in the empirical therapy of pneumococcal pneumonia.