From the Guidelines
Candida tropicalis is typically considered a pathogenic yeast that can cause infections, rather than a typical colonizer. It is one of the five species that account for 92% of cases of invasive candidiasis, along with Candida albicans, Candida glabrata, Candida parapsilosis, and Candida krusei 1. While Candida species, including C. tropicalis, can be part of the normal endogenous flora in the gut in 40-50% of humans, they are normally controlled by nearby bacteria and the host immune system 1. However, when the gastrointestinal microflora is altered by factors such as surgery, antibiotic treatments, or immunosuppression, Candida invasion and dissemination within the abdominal cavity may occur, leading to infections like intraabdominal candidiasis (IAC) 1. The pathogenicity of C. tropicalis is attributed to its ability to form biofilms, produce hydrolytic enzymes, and adhere to host tissues, making it particularly virulent compared to some other Candida species. Given the potential severity of C. tropicalis infections, including high mortality rates associated with invasive candidiasis, timely and effective treatment with antifungal medications is crucial to improve patient outcomes 1. Treatment options may include fluconazole or echinocandins like caspofungin, with the choice of agent depending on factors such as the severity of illness, local resistance patterns, and prior antifungal exposure 1. In critically ill patients, empiric antifungal therapy should be considered based on risk factors for invasive candidiasis, and the selection of the specific agent should be tailored to the individual patient's situation 1. Overall, while C. tropicalis can be present as part of the normal flora, its potential to cause severe infections necessitates careful consideration and management in at-risk patients. Key points to consider in managing C. tropicalis infections include:
- Prompt initiation of appropriate antifungal therapy to reduce mortality and improve outcomes 1
- Selection of antifungal agents based on local resistance patterns, severity of illness, and prior antifungal exposure 1
- Consideration of empiric antifungal therapy in critically ill patients with risk factors for invasive candidiasis 1
- Importance of infectious diseases consultation and collaboration with antimicrobial stewardship programs to ensure appropriate antimicrobial use 1
From the Research
Candida Tropicalis Characteristics
- Candida tropicalis is a non-albicans Candida species that is commonly found in immunocompromised patients, particularly those with neutropenia 2.
- It is the fourth most common cause of candidaemia in hospitalized patients and is associated with high mortality 3.
- C. tropicalis frequently causes biofilm-related infections, which can be challenging to treat 3.
Antifungal Susceptibility
- C. tropicalis has been shown to be susceptible to amphotericin B, with treatments containing this agent associated with reduced mortality 2.
- Echinocandins, such as micafungin, have also been found to be effective against C. tropicalis, particularly against biofilms 3.
- However, C. tropicalis has been found to have reduced susceptibility to azoles, such as fluconazole, with 11.6% of isolates being non-susceptible 4.
- Resistance to echinocandins is uncommon, but has been reported in some studies 4, 5.
Colonization and Pathogenicity
- C. tropicalis has been identified as an emerging pathogenic yeast, with increasing prevalence and resistance to fluconazole 6.
- The reasons for its dominance and increasing resistance are not fully understood, but may be related to various predisposing factors, such as immunocompromised status and prior antifungal use 6.
- C. tropicalis has been found to be a common cause of invasive candidiasis, particularly in patients with underlying medical conditions 4, 5.