New guidelines for the antibiotic treatment of streptococcal, enterococcal and staphylococcal endocarditis.

guidelines do not include empirical treatment recommendations, perhaps implying that the results of blood cultures should be awaited, which is not usually the policy in the UK. Apart from these differences, the two reports, which were initiated by independent working groups, include broadly similar recommendations. In both publications, antibiotic treatment is indicated for patients with a diagnosis of infective endocarditis based on the Duke diagnostic criteria, 3,4 and early surgical intervention is emphasized for some patients, especially if their haemodynamic condition deteriorates. The main purpose of this article is to discuss important changes in the latest BSAC Working Party recommendations on antibiotic treatment compared with those in previous guidelines. 5 The main recommendations of the 1998 BSAC Working Party Report for the treatment of streptocccal, enterococcal and staphylococcal endocarditis are summarized in Tables I and II. The most important differences from the previous guidelines concern the abandonment of routine MBC testing and the adoption of a 2-week treatment regimen for uncomplicated endocarditis caused by penicillin-susceptible viridans streptococci and Strepto coccus bovis. Streptococci are now defined as penicillin susceptible if their MIC of penicillin is 0.1 mg/L. There are many more technical pitfalls with MBC determinations than with MIC determinations, including the use of suboptimal inocula, difficulties with interpreting a 99.9% bactericidal endpoint that involves both a baseline surface viable count and counting any persisting colonies, and uncertainties over the efficiency of the methods used to prevent carryover of antibiotics from the broths to the subculture plates. There has also been a problem over the lack of standardization of the techniques used. The BSAC Working Party, like the AHA Committee, could not find any advantage for the patient in carrying out routine MBC determinations.