Multidrug resistant tuberculosis in France 1992-4: two case-control studies.

resistant to both gentamicin and streptomycin. Aminoglycosides have no therapeutic benefit in infections involving such strains, and unnecessarily expose patients to possible ototoxic or nephrotoxic side effects. A further 28% of the isolates were highly resistant to either gentamicin or streptomycin, emphasising the value of testing both of these compounds in determining appropriate treatment. Current guidelines recommend that endocarditis caused by enterococci with high level resistance to aminoglycosides should be treated with high dose amoxycillin or ampicillin for 6-12 weeks. 3 However, 11% of the enterococci were E faecium, which typically is resistant to ampicillin. Moreover, amoxycillin or ampicillin would be unsuitable for patients allergic to penicillin. This latter constraint applies to other proposed regimens that combine ampicillin with imipenem or ciprofloxacin. Although glycopeptides may be considered in place of penicillin, the finding of glycopeptide resistance in several isolates, including three of the E faecium isolates, means that their efficacy cannot be guaranteed. The picture revealed is disturbing, with frequent resistance to the recommended synergistic combinations. Evaluation in endocarditis of unconventional regimens—for example, ampicillin plus carbapenems, ampicillin plus ciprofloxacin, or ciprofloxacin plus co-trimoxazole—is desirable, although the use of such broad spectrum agents may risk selecting resistance in the body microflora. Also desirable is early evaluation, in endocarditis, of novel narrow spectrum anti-Gram positive agents, such as streptogramins, oxazolidinones, and everninomycins.