Talaromyces marneffei infection in non-HIV-infected patients in mainland China.

BACKGROUND: Talaromyces marneffei, formerly known as Penicillium marneffei, is a significant emerging pathogenic fungus in Southeast Asia which can generate life-threatening systemic infections. Human immunodeficiency virus (HIV) infection is considered as the most underlying disease among systemic infections. However, infections due to T. marneffei without HIV are increasing in recent years. OBJECTIVES: Research the characteristics of T. marneffei infection in non-HIV individuals in mainland China. METHODS: In this study, we searched Pubmed, China National Knowledge Infrastructure (CNKI) and WanFang from inception to 31 December 2019 for studies reporting T. marneffei infection. Our research concentrates on non-HIV-infected cases and their epidemiology, clinical manifestations, laboratory findings, treatment methods and prognosis. RESULTS: T. marneffei infections in non-HIV individuals are increasing. Due to frequent present with atypical symptoms, these non-HIV-infected cases were usually misdiagnosed as other diseases, containing tuberculosis (80.7%), bacterial pneumonia (20.5%), lung cancer (5.1%) or other diseases (5.1%). CONCLUSIONS: T. marneffei infection in non-HIV individuals should be taken seriously. Their symptoms and signs are not typical. Accurate diagnosis and timely antifungal agent treatment is the key to the treatment for the disease.

Evaluation of quantitative real-time PCR and Platelia galactomannan assays for the diagnosis of disseminated Talaromyces marneffei infection.

Talaromyces (Penicillium) marneffei is an emerging pathogen that causes significant morbidity and mortality in immunocompromised patients in endemic regions such as southeast Asia. The diagnosis of disseminated T. marneffei infection remains challenging in clinical practice. In the study, a well-validated real-time quantitative polymerase chain reaction (qPCR) target region of ITS1-5.8S-ITS2 and a Platelia galactomannan (GM) assay were compared for their diagnostic performance using serum samples from patients with or without human immunodeficiency virus (HIV). The results showed that this novel qPCR method is highly sensitive and specific for T. marneffei DNA detection in serum samples, and the limit of detection and species-specificity of qPCR were five copies of DNA and 100%, respectively. For detection in serum samples from 36 talaromycosis patients, the sensitivity of qPCR was 86.11% (31/36), including 20/20 (100%) patients with fungemia and 11/16 (68.75%) patients without fungemia. For the GM assay, the sensitivity was 80.56% (29/36) when the GM optical density cutoff index was ≥0.5, including 19/20 (95%) patients with fungemia and 10/16 (62.5%) patients without fungemia. These results indicate that the novel qPCR and GM assays can be used as a valuable tool in the diagnosis of T. marneffei infection. Serum samples are convenient hematological specimens for T. marneffei DNA quantification. Combining the GM assay and qPCR is more scientific and appropriate for diagnosing T. marneffei infection in endemic areas.

In vitro interactions of calcineurin inhibitors with conventional antifungal agents against the yeast form of Penicillium marneffei.

Penicillium marneffei can cause a life-threatening disseminated mycosis in immunocompromised hosts. However, therapeutic strategies for the treatment of this infectious disease are limited. Reports of other fungi suggest that calcineurin inhibitors interact with antifungal agents to improve the treatment outcomes. Here, we evaluated the in vitro interaction of the calcineurin inhibitors cyclosporine A and tacrolimus (FK506) combined with conventional antifungal agents against the pathogenic yeast form of P. marneffei. We demonstrate that the combination of cyclosporine A with amphotericin B, itraconazole, or fluconazole was synergistic for 85, 65, and 30 % of P. marneffei strains, respectively. In contrast, no synergism was observed in all the combinations containing tacrolimus. Furthermore, antagonism was not observed for any combination. In conclusion, the therapeutic potential of a combinatory approach using the calcineurin inhibitor cyclosporine A with conventional antifungal drugs may lead to improved treatment regimens for P. marneffei infections. We propose that mechanism of action studies with cyclosporine A and antifungal agents is needed.