Candida blankii: The Difficult Capture of a Fungus With Pathogenic Potential

Candida blankii has recently emerged as a pathogen of clinical significance, particularly in cases of candidemia. Here, we present two cases involving adult patients with complex medical histories. In one case, C. blankii was considered clinically significant, while in the other, it was regarded as a colonizer. The first case involves an 85-year-old male with multiple comorbidities, including chronic obstructive pulmonary disease and heart failure, who presented with a pleural effusion. Blood cultures revealed yeast which could not be identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), which was later identified as C. blankii after being sent to the provincial reference laboratory. The isolate showed high minimum inhibitory concentrations (MICs) to azoles. The second case involves a 60-year-old male with cirrhosis and multifocal pneumonia. C. blankii was isolated from bronchoalveolar lavage samples, though it was ultimately considered a colonizer rather than a pathogen in this instance. Initial identification via MALDI-TOF MS was inconclusive, necessitating further molecular sequencing. The pathogen exhibited high MICs to azoles and lower MICs to echinocandins and polyenes. Both cases highlight the challenges in identifying C. blankii using conventional laboratory methods. Given the increasing reports of C. blankii as a pathogen, particularly in immunocompromised patients, our findings emphasize the need for heightened awareness and improved diagnostic techniques. Accurate and timely identification is crucial for appropriate therapeutic management, given the organism's unique susceptibility profile. Further research is necessary to understand the epidemiology, pathogenesis, and optimal treatment strategies for C. blankii infections.