Introduction: Lactococcus garvieae is an uncommon cause of infective endocarditis (IE) and, despite the fact that synergy between beta‐lactam antibiotics and aminoglycosides has not been demonstrated for lactococci, combination therapy is often used. Case presentation: We report a case of suspected L. garvieae IE in an 82‐year‐old man, which was successfully treated with a combination of ampicillin and gentamicin. Despite careful dosing and monitoring of gentamicin levels, the patient developed a transient decrease in renal function and permanent bilateral vestibular deficiency. The combination of gentamicin and ampicillin did not demonstrate synergistic killing effects in vitro against the L. garvieae isolate from this patient. However, synergy was noted against two of the four L. garvieae isolates tested. Unfortunately, an Etest‐based method, which would be easy to use in a routine laboratory, was unable to predict synergy in the time‐kill methods. Conclusions: The use of combination therapy in IE is based solely on in vitro synergy between beta‐lactams and aminoglycosides. Here we demonstrate that a combination of ampicillin and gentamicin induces synergistic killing only of some L. garvieae isolates. Since synergy does not seem to be omnipresent, the risks for aminoglycoside toxicity must be carefully weighed against the potential theoretical benefit of combination therapy in L. garvieae IE.

No abstract

No abstract