Deadly Fungus Candidozyma auris Shows Higher Adjusted Mortality Risk in Bloodstream Infections

A formidable fungal pathogen that has alarmed infection-control specialists around the world has come under fresh scrutiny in a new retrospective cohort study published in BMC Infectious Diseases. Researchers at Ankara Etlik City Hospital in Turkey compared patients with bloodstream infections caused by Candidozyma auris, formerly known as Candida auris, against those infected with other Candida species, and their findings paint a nuanced picture of a pathogen whose true lethality may be masked by the severity of the patients it attacks. The study, which analyzed 301 consecutive adults with candidemia, including 77 cases caused by C. auris and 224 caused by non-auris Candida species, offers one of the most detailed real-world comparisons to date of how this emerging threat behaves in a busy tertiary hospital setting.

Candidozyma auris has earned a reputation as one of the most concerning healthcare-associated fungal pathogens of the modern era. Unlike many of its fungal relatives, it persists stubbornly in the hospital environment, colonizes surfaces and medical equipment, spreads between patients in healthcare facilities, and frequently displays resistance to the antifungal drugs clinicians rely upon most. First recognized as a human pathogen less than two decades ago, it has since been reported on multiple continents, triggering outbreaks in intensive care units and prompting public health agencies to classify it as a serious global health threat. Its ability to survive routine disinfection and to be misidentified by conventional laboratory methods has made containment exceptionally difficult, and each new clinical dataset contributes valuable intelligence about how the organism behaves in actual patient care.

The Turkish research team set out to answer a question that has divided the field: does C. auris candidemia actually kill more patients than candidemia caused by other Candida species, or does it merely appear more lethal because it disproportionately infects patients who are already gravely ill? To address this, the investigators conducted a single-center retrospective cohort study, identifying every adult patient with candidemia seen at their institution and classifying infections by species. Identification was performed using MALDI-TOF mass spectrometry, a rapid proteomic technique that has become the gold standard for distinguishing C. auris from look-alike yeasts that older biochemical panels frequently confuse with it. Accurate speciation matters enormously here, because misidentification has historically hampered both surveillance and appropriate treatment.

The clinical profiles of the two patient groups differed in telling ways. Patients with C. auris candidemia had spent significantly longer in the hospital before their bloodstream infection developed, a pattern consistent with a healthcare-associated pathogen that colonizes patients during extended stays. They also more frequently had central venous catheters, the indwelling lines that provide fungi with a direct portal into the bloodstream, and greater exposure to corticosteroids, which suppress immune defenses. These exposures are classic risk factors for invasive candidiasis in general, but their heightened frequency in the C. auris group underscores how thoroughly this organism is woven into the fabric of modern intensive medical care. The findings reinforce the picture of C. auris as an opportunist that exploits the very devices and drugs that keep critically ill patients alive.

When the researchers examined crude outcomes, the headline number was striking in its symmetry: 30-day all-cause mortality was 62.3 percent among patients with C. auris candidemia and 62.5 percent among those with non-auris Candida infections, a difference of essentially zero. On the surface, this suggests the emerging pathogen is no deadlier than its established cousins. But crude comparisons in observational data can be deeply misleading, and the investigators knew that the patients harboring C. auris arrived at their infections with a different constellation of vulnerabilities. To disentangle the effect of the organism itself from the effect of patient characteristics, they turned to more sophisticated statistical machinery.

The team employed a multivariable Firth-penalized logistic regression model, a technique designed to produce more stable estimates when outcomes are imbalanced or sample sizes are modest, and they handled missing data through multiple imputation. The model was constructed with clinical input to ensure that the variables adjusted for reflected genuine medical knowledge rather than statistical convenience. After adjustment, C. auris candidemia was associated with higher estimated odds of 30-day mortality, with an adjusted odds ratio of 1.967, meaning the odds of death were nearly doubled relative to non-auris candidemia. However, the 95 percent confidence interval ranged from 0.954 to 4.055 and included the null value of one, with a p value of 0.067, meaning the association fell just short of conventional statistical significance.

To translate the regression results into more intuitive risk terms, the researchers used g-computation to estimate standardized marginal mortality risks. Under this approach, the adjusted 30-day mortality was estimated at 69.7 percent for C. auris candidemia compared with 59.3 percent for non-auris Candida candidemia, corresponding to an adjusted risk difference of 10.4 percentage points, with a confidence interval spanning from minus 0.2 to plus 21.3 points. In other words, once patient severity was accounted for, the data hinted that C. auris infections carry a genuinely elevated mortality burden, potentially adding roughly ten deaths per hundred patients, but the uncertainty around that estimate means the true effect could range from negligible to substantial. The authors are explicit that these findings should be interpreted as associative rather than causal, and that larger prospective multicenter studies across diverse healthcare settings are needed to confirm them.

Beyond the comparison between species, the study identified the factors that independently predicted death within 30 days across the entire cohort. Older age, higher scores on the Sequential Organ Failure Assessment, or SOFA, scale, the presence of septic shock, corticosteroid use, and hemodialysis were all associated with higher adjusted odds of mortality. These determinants are familiar from the broader candidemia literature: they reflect the reality that bloodstream fungal infections are most lethal in patients whose organs are already failing and whose immune systems have been blunted by illness or medication. The consistency of these predictors with prior research lends credibility to the study’s methodology and suggests the dataset behaves as expected, strengthening confidence in the species-specific comparisons.

The antifungal susceptibility findings carry important practical implications for treatment. Among C. auris isolates, echinocandin non-wild-type phenotypes were uncommon, which is welcome news because echinocandins are the recommended first-line therapy for invasive candidiasis and are often the drug class of choice against C. auris. However, elevated minimum inhibitory concentrations for amphotericin B were observed in approximately one-third of tested isolates, a troubling signal for an older but still-used antifungal that clinicians may reach for when first-line options fail or are unavailable. Meanwhile, resistance to fluconazole was frequent among tested Candida parapsilosis isolates, a reminder that antifungal resistance is not confined to the emerging pathogen and that susceptibility testing remains essential for guiding therapy across all Candida species. Susceptibility results were interpreted using applicable EUCAST clinical breakpoints or epidemiological cut-off values, and where no interpretive criteria existed, results were reported descriptively, reflecting the ongoing challenge that interpretive standards for some antifungal-organism combinations are still evolving.

The study’s conclusions are measured but consequential. C. auris candidemia, the authors report, is characterized by a distinct profile of healthcare-associated exposures and a distinct antifungal susceptibility pattern, and while crude mortality appears similar to other candidemia, adjusted estimates point toward higher mortality that remains statistically imprecise. For clinicians, the message is twofold: patients colonized or infected with C. auris deserve vigilant attention to modifiable risk factors such as catheter management and careful stewardship of corticosteroids, and treatment decisions should be anchored in susceptibility data rather than assumptions. For public health officials, the findings add to the accumulating evidence that C. auris is not simply another Candida species but a pathogen with its own epidemiology, its own resistance landscape, and potentially its own mortality penalty. As the global footprint of this fungus continues to expand, studies like this one, grounded in real-world clinical data and rigorous statistical adjustment, will be essential for calibrating the response. The research received no specific funding, was approved by the Etlik City Hospital clinical research ethics committee, and was conducted in accordance with the Declaration of Helsinki, with the requirement for informed consent waived given its retrospective design.

Subject of Research: Comparison of clinical characteristics, antifungal susceptibility, and 30-day mortality in Candidozyma auris versus non-auris Candida candidemia

Article Title: Clinical characteristics, treatment strategies, and factors associated with 30-day mortality in Candidozyma auris versus non-auris Candida candidemia: a retrospective cohort study

Article References: Kuzi, S., Çiçek Şentürk, G., Kul, G., Haykır, A., Yılmaz, N., Korkmaz, N., Bulut, D., Aslan, M., Yapar Toros, G., Şencan, İ., & Tütüncü, E. E. (2026). Clinical characteristics, treatment strategies, and factors associated with 30-day mortality in Candidozyma auris versus non-auris Candida candidemia: a retrospective cohort study. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14401-4

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14401-4

Keywords: Candidozyma auris, candidemia, antifungal resistance, 30-day mortality, bloodstream infection, echinocandins, amphotericin B, fluconazole resistance, septic shock, healthcare-associated infection, MALDI-TOF, risk factors