Reference isolates of Talaromyces marneffei

Talaromyces marneffei (previously known as Penicillium marneffei) causes talaromycosis, a globally significant, endemic fungal infection that is fatal if left untreated in disseminated infections. The disease primarily affects immunocompromised individuals, especially those living with HIV/AIDS in Southeast Asia, Southern China, and Northeast India. Even with antifungal treatment, talaromycosis has an estimated mortality rate of 30% (1). In a multicenter clinical trial comparing itraconazole and amphotericin B, approximately 25% of patients experienced poor outcomes, defined as prolonged hospitalization, disease relapse, or death .²

Until recently, research into antifungal resistance in T. marneffei was challenging due to the absence of standardized susceptibility testing guidelines. A 2023 report addressed this gap by establishing methods for evaluating antifungal drugs against T. marneffei clinical isolates ³. BEI Resources now offers two reference clinical isolates, NR-60072 and NR-60073, which were included in the study and previously sequenced using whole-genome sequencing ⁴. These isolates will support the standardization of antifungal assays and screening of new therapeutic compounds against talaromycosis.

References:

1. Narayanasamy S., et al. “A Global Call for Talaromycosis to be Recognised as a Neglected Tropical Disease.” Lancet Glob. Health. 9 (2021): e1618-e1622. PubMed: 34678201.

2. Le T., et al. “A Trial of Itraconazole or Amphotericin B for HIV-Associated Talaromycosis.” N. Engl. J. Med. 376 (2017): 2329-2340. PubMed: 28614691.

3. Thu N.T.M., et al. “Development and Validation of a Colorimetric Antifungal Susceptibility Testing Method for the Dimorphic Fungus Talaromyces marneffei.” Med. Mycol. 61 (2023): myad111. PubMed: 37994652.

4. Cuomo C.A., et al. “Complete Genome Sequences for Two Talaromyces marneffei Clinical Isolates from Northern and Southern Vietnam.” Microbiol. Resour. Announc. 9 (2020): e01367-19. PubMed: 31919177.

Image Alt Text: Left panel, colonies of Talaromyces marneffei 03-130 (NR-60072) growing on potato dextrose agar. Right panel, light microscopy of yeast cells of NR-60072 growing at 37 °C showing oval to ellipsoidal morphology with a central dividing septum. (BEI Resources)

Image Credit: Colonies and light microscopy of T. marneffei. (BEI Resources)