Clearance of Persistent Methicillin-Susceptible Staphylococcus lugdunensis Bacteremia Using Nafcillin Plus Ertapenem Combination Therapy

Staphylococcus lugdunensis is a coagulase-negative staphylococcus that can cause serious infection similar to Staphylococcus aureus. Limited therapeutic options are available for patients with staphylococcal bacteremia who fail to respond to standard monotherapy, particularly when source control of infection is not feasible, driving the need for improved synergistic antibiotic combinations to enhance medical management. We present the case of a 58-year-old patient with persistent S. lugdunensis bacteremia for over 1 week despite appropriate therapy with nafcillin. Blood cultures were successfully sterilized following the addition of ertapenem salvage therapy, with rapid blood culture clearance within 2 days of initiation. To our knowledge, this is the first report of using ertapenem in combination with an antistaphylococcal penicillin to specifically clear persistent S. lugdunensis bacteremia. Similar success has been reported using this combination to treat methicillin-susceptible S. aureus infections; hence, our report provides further support for the benefit of this combination for staphylococcal infections.