Successful Treatment of Recurrent Extensively Drug-Resistant Elizabethkingia anophelis Bacteremia Secondary to Ventricular Assist Device-Associated Infection.

Elizabethkingia anophelis is an emerging pathogen increasingly implicated in health care-associated infections. Here, we report a case of recurrent ventricular assist device-associated infection caused by multidrug-resistant Elizabethkingia anophelis and describe the clinical course, treatment challenges, and ultimate case resolution. Our results demonstrate that standard clinical methodologies for determining trimethoprim-sulfamethoxazole minimum inhibitory concentration, including VITEK2 and gradient diffusion tests, may be unsuitable for Elizabethkingia anophelis as they result in false-negative susceptibility results. The discrepancy between antimicrobial susceptibility testing reported here highlights the importance of investigating and validating the applicability of standard clinical antimicrobial susceptibility testing and interpretation when treating emerging pathogens such as Elizabethkingia anophelis.