title: Alcaligenes xylosoxidans endocarditis of a prosthetic valve and pacemaker in a 62-year-old woman.
abstract: The bacterium Alcaligenes xylosoxidans is known to cause several nosocomial infections; however, it rarely causes endocarditis, which has a very high mortality rate. Early isolation of the infection source and prompt identification of the patient's antibiotic sensitivities are paramount if the infection is to be treated adequately. We present what is apparently only the second documented case of the successful eradication of bioprosthetic valve endocarditis that was caused by pacemaker lead infection with Alcaligenes xylosoxidans. A 62-year-old woman with multiple comorbidities presented with endocarditis of a recently placed bioprosthetic aortic valve. The infection was secondary to pacemaker lead infection. She underwent antibiotic therapy, but an unusual pattern of antibiotic resistance developed. Despite initially adequate therapy, the infection recurred because of virulence induced by antibiotic resistance. Emergent, high-risk surgical treatment involved excising the infected valve and removing the source of the infection (the pacemaker leads). The patient eventually recovered after prolonged antibiotic therapy and close vigilance for recurrent infection. In addition to the patient's case, we discuss the features of this bacteremia and the challenges in its diagnosis.
authors: Department of Internal Medicine, Community Regional Medical Center, Fresno, California 93701, USA. acsawant@gmail.com
authors: Abhishek C
authors: AC
authors: Sawant
authors: Sanjay S
authors: SS
authors: Srivatsa
authors: Luis J
authors: LJ
authors: Castro
mesh_terms: D000421:Alcaligenes / Q000302:isolation & purification* / Q000472:pathogenicity; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D020878:Device Removal; D024881:Drug Resistance, Bacterial; D017548:Echocardiography, Transesophageal; D004697:Endocarditis, Bacterial / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy; D012008:Recurrence; D012086:Reoperation; D016896:Treatment Outcome; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents
keywords: Alcaligenes/drug effects; anti-bacterial agents/therapeutic use; bacteremia/complications/diagnosis/drug therapy/etiology; endocarditis, bacterial/diagnosis/ultrasonography; gram-negative bacterial infections/complications/etiology; heart valve prosthesis; opportunistic infections/epidemiology; pacemaker, artificial/microbiology; treatment outcome