Stenotrophomonas maltophilia pacemaker endocarditis in a patient with d-transposition of the great arteries after atrial switch procedure.

We report a case of pacemaker endocarditis due to Stenotrophomonas maltophilia in a 22-year-old Caucasian man with d-transposition of the great arteries after atrial switch procedure. S.maltophilia isolated from blood cultures was susceptible to trimethoprim-sulfamethoxazole and amikacin, and resistant to ciprofloxacin and all tested β-lactam antibiotics. The infected pacemaker system was completely removed by thoracotomy. Simultaneously, a new DDD pacemaker and epicardial electrodes were successfully implanted and selective antibiotic therapy consisting of trimethoprim-sulfamethoxazole (480 mg i.v. q 6 h) and amikacin (250 mg i.v. twice daily) was continued. However, the post-operative course was complicated by septic shock and the patient died on 9th day after surgery. Importantly, S.maltophilia isolated from extracted pacemaker leads was multidrug-resistant including to trimethoprim-sulfamethoxazole, ciprofloxacin, all tested aminoglycosides, and β-lactams, with the exception of ticarcillin-clavulanate. In conclusion, pacemaker endocarditis due to Stenotrophomonas maltophilia is an extremely rare but serious complication of permanent pacing therapy. The susceptibility of S.maltophilia isolates to antimicrobial agents can change during the course of infection. Despite the inherent resistance of S.maltophilia to most β-lactam antibiotics, multidrug-resistant strains may be susceptible in vitro to ticarcillin-clavulanate. Further studies are needed to determine the optimal management of patients with pacemaker endocarditis caused by Stenotrophomonas maltophilia.