A Study on the Dependability and Usefulness of Primary Antibiotic Sensitivity Tests with Clinical Specimens

PRIMARY sensitivity tests were done with 300 specimens from different clinical sources, of which 185 (61.7%) gave successful reproducible results. 158 specimens (52.6%) gave pure growth of single organism, 74 (24.6%) gave mixed growths and 68 (22.6%); gave no growth. Identical results were obtained when some of the primary sensitivity tests were compared with those of the pure culture using the same method. Quick results, identification of resistant mutants, selective growth of mixed culture, and the possibility of an early efficient start of treatment for acute infections are the advantages claimed. Economy of effort and materials was achieved by a preliminaty microscopic screening, avoiding specimens with possible heavy contamination, including specimens for those who needed quick early treatment avoiding repetition of the tests by including special antibiotics and drugs for those expecting bacterial growths of marked drug resistance.