A rare case of breakthrough fungal pericarditis due to fluconazole‐resistant Candida auris in a patient with chronic liver disease

Introduction: Candida pericarditis is a rare clinical entity with a high fatality, primarily attributed to difficulty in diagnosis. Unfortunately, the diagnosis is made post‐mortem in more than 50% of cases, and thus a high index of clinical suspicion is crucial. Case presentation: We report a rare case of fungal pericardial effusion caused by the recently recognized multidrug‐resistant Candida auris, which was cultured from pericardial fluid, blood, bronchoalveolar lavage and urine of a chronic liver disease patient while on empiric fluconazole therapy. The yeast was misidentified as Candida haemulonii by the VITEK2 commercial identification system, and was confirmed as C. auris by internal transcribed spacer and large ribosomal subunit sequencing. In addition, the VITEK2 AST card erroneously revealed a high amphotericin B MIC (16 µg ml−1) and low caspofungin MIC (0.25 µg ml−1) that did not correlate with results from the reference Clinical and Laboratory Standards Institute (CLSI) microbroth dilution method. Based on VITEK2 MIC data, the patient was administered caspofungin. However, in vitro antifungal susceptibility data for C. auris by the CLSI method exhibited high MICs to fluconazole (64 µg ml−1) and caspofungin MIC (1 µg ml−1) but low MICs to amphotericin B (MIC range, 0.125−0.5 µg ml−1). The patient’s repeat pericardial fluid culture, despite caspofungin therapy for 12 days, grew C. auris and he died on day 13 of therapy. Conclusion: C. auris is a recently reported agent of fungaemia and deep‐seated infections and is notable for its antifungal resistance. Although early species identification and rapid antifungal susceptibility testing are needed in cases of critical infections, the reporting of rare yeast isolates exhibiting high MICs to antifungals by automated systems needs a cautionary approach.