The first reported case of candidemia caused by the novel Candida tropicalis diploid sequence type 1515

Area of Science:

• Medical Mycology
• Infectious Diseases
• Critical Care Medicine

Background:

• Candida species are increasingly recognized as opportunistic pathogens, particularly in healthcare settings.
• Risk factors include indwelling devices, immunosuppression (corticosteroids, chemotherapy), and broad-spectrum antibiotics.
• Candida tropicalis is a significant pathogen associated with high morbidity, mortality, and drug resistance.

Purpose of the Study:

• To report a case of candidemia caused by Candida tropicalis in a patient with severe COVID-19 pneumonia.
• To highlight the antifungal resistance profile of the isolated Candida tropicalis strain.
• To characterize the genetic type of the Candida tropicalis isolate.

Main Methods:

• A case report of a 43-year-old male patient with severe COVID-19 pneumonia.
• Treatment included systemic corticosteroids and broad-spectrum antibiotics.
• Blood cultures identified Candida tropicalis; antifungal susceptibility testing was performed.

Main Results:

• The patient developed recurrent fever and Candida tropicalis bloodstream infection (candidemia).
• The isolate exhibited high resistance to fluconazole and voriconazole but remained susceptible to echinocandins.
• Despite susceptibility to echinocandins, the patient could not receive this treatment and unfortunately died.

Conclusions:

• Candida tropicalis can cause severe, drug-resistant infections in immunocompromised patients, including those with COVID-19.
• The isolated strain was identified as a novel diploid sequence type (ST 1515) via multilocus sequence typing.
• This case underscores the challenges in treating invasive candidiasis with limited therapeutic options.