Progress towards agreement in reports of antibiotic sensitivity.

Results of three quality control trials of antibiotic sensitivity testing carried out on staphylococci by the Birmingham Regional Bacteriologists Group are presented. An overall reduction in the number of discrepant results from 5.2 to 1.2% when retesting the same organisms was thought to be due largely to the alteration in methods of testing for resistance to neomycin- and penicillinase-resistant antibiotics. Improvements were noted in the performance of all laboratories, which were felt to be due partly to participation in the trials.