Penicillium marneffei infection and recent advances in the epidemiology and molecular biology aspects

HIV-Negative Case of Talaromyces marneffei Pulmonary Infection with Liver Cirrhosis in China: A Case Report and Literature Review

Background

Talaromyces marneffei (TM) is the third most prevalent opportunistic infection in HIV-positive patients after tuberculosis and cryptococcosis. However, such infection of non-HIV individuals has rarely been reported.

Case Presentation

We describe a very rare case of a 52-year-old male who presented with a single space-occupying lesion on the right lung and was eventually diagnosed with pulmonary TM infection. The patient was HIV-negative and had liver cirrhosis with portal vein thrombosis. Lung tissue next-generation sequencing (NGS) revealed TM infection. We successfully treated the patient with voriconazole for 8 weeks and observed lesion absorption via subsequent CT. The patient consumed wild bamboo rats two months before admission. Mutations related to congenital immune deficiency were not detected by whole-exome sequencing.

Conclusion

Early and timely diagnosis is critical for improving patient prognosis. NGS plays a vital role in the diagnosis of pulmonary TM infection in patients. To our knowledge, this is the first published case of pulmonary TM infection in an HIV-negative patient with liver cirrhosis.

Talaromycosis from Wuhan: two-case report and literature review

Background

Talaromycosis is a serious opportunistic infectious disease caused by Talaromyces marneffei, which mostly occurs in immunocompromised patients. The disease is mainly prevalent in tropical countries and regions of Southeast Asia and South Asia, but non-endemic areas also have patients with Talaromycosis. The disease has no characteristic clinical manifestations and is difficult to diagnose. Delayed diagnosis often leads to death.

Case presentation

Both patients had cellular immunodeficiency. Case 1 had a history of acquired immune deficiency syndrome, and case 2 had a history of renal transplantation and glucose-6-phosphate dehydrogenase deficiency. They all had fever, anemia, fatigue, and skin lesions. Case 1 had gastrointestinal bleeding, enlarged lymph nodes, and hepatosplenomegaly. Case 2 had cough and dyspnea. Both patients had thrombocytopenia and hypoalbuminemia; an increased neutrophil ratio, procalcitonin, and C-reactive protein; and abnormal liver function and coagulation dysfunction. Case 1 sputum culture, blood culture, and bronchoalveolar lavage fluid were positive for T. marneffei. T. marneffei was detected in the blood culture of case 2, with infection of Candida parapsilosis and Pneumocystis jirovecii. Chest computed tomography scan mainly showed pulmonary exudative lesions. Although these two patients were actively treated, they died of poor efficacy.

Conclusion

Talaromycosis has an insidious onset, long course, atypical clinical symptoms, imaging performance and laboratory results, difficult diagnosis, and high mortality. Therefore, it is important to promptly consider and treat Talaromycosis in immunocompromised patients upon infection in order to reduce mortality.

Talaromyces marneffei endocarditis initially detected by Next Generation Sequencing: A case report

BACKGROUND

Talaromyces marneffei (T. marneffei) is a thermal dimorphic fungus, which can cause lung or blood stream infection in patients, often life-threatening. However, endocarditis caused by T. marneffei has not been reported. For elderly patients with implanted cardiac devices or artificial valves, the prevention and treatment of infective endocarditis should not be ignored.

METHODS

This is a descriptive study of a T. marneffei endocarditis by joint detection of cardiac ultrasound examination, peripheral blood DNA metagenomics Next Generation Sequencing (mNGS), and in vitro culture.

RESULTS

We describe an 80-year-old female patient with an unusual infection of T. marneffei endocarditis. After intravenous drip of 0.2 g voriconazole twice a day for antifungal treatment, the patient showed no signs of improvement and their family refused further treatment.

CONCLUSION

Infective endocarditis is becoming more and more common in the elderly due to the widely use of invasive surgical procedures and implantation of intracardiac devices. The diagnosis and treatment of T. marneffei endocarditis is challenging because of its rarity. Here, we discussed a case of T. marneffei endocarditis, and emphasized the role of mNGS in early diagnosis, which is of great significance for treatment and survival rate of patients.

Structural, functional, molecular docking analysis of a hypothetical protein from Talaromyces marneffei and its molecular dynamic simulation: an in-silico approach

Telaromyces marneffei (formerly Penicillium marneffei) is an endemic pathogenic fungus in Southern China and Southeast Asia. It can cause disease in patients with travel-related exposure to this organism and high morbidity and mortality in acquired immune deficiency syndrome (AIDS). In this study, we analyzed the structure and function of a hypothetical protein from T. marneffei using several bioinformatics tools and servers to unveil novel pharmacological targets and design a peptide vaccine against specific epitopes. A total of seven functional epitopes were screened on the protein, and 'STGVDMWSV' was the most antigenic, non-allergenic and non-toxic. Molecular docking showed stronger affinity between the CTL epitope 'STGVDMWSV' and the MHC I allele HLA-A*02:01, a higher docking score -234.98 kcal/mol, revealed stable interactions during a 100 ns molecular dynamic simulation. Overall, the results of this study revealed that this hypothetical protein is crucial for comprehending biochemical, physiological pathways and identifying novel therapeutic targets for human health. Communicated by Ramaswamy H. Sarma.

The pathology biopsy represents the "gold standard" for diagnosis: a case report

A 70-year-old male with previously unknown immunodeficiency presented with multiple pulmonary nodular shadows observed on chest and abdomen radiography. Fungal infection was detected in brushing specimens, bronchial lavage, and transbronchial lung biopsy samples. Through next-generation sequencing (NGS) analysis, the patient was ultimately diagnosed with disseminated Talaromyces marneffei infection. Treatment with voriconazole at a dosage of 200 mg every 12 hours was initiated. However, after three months of treatment, the patient still had enlarged retroperitoneal lymph nodes, and a lymph node aspiration biopsy was performed to further clarify the diagnosis, which ultimately led to the diagnosis of Talaromyces marneffei infection and B-cell non-Hodgkin's lymphoma. The main significance of this study is to emphasize the importance for clinicians to obtain comprehensive specimens from patients presenting with multiple masses in order to ensure accurate clinical diagnosis.

Disseminated Talaromyces marneffei infection associated with haemophagocytic syndrome in an HIV-negative patient in northern China: a case report

BACKGROUND

Talaromyces marneffei is endemic to eastern India, Southeast Asia, and Guangdong and Guangxi provinces in China. It is common in immunocompromised individuals, especially in HIV-infected patients.

CASE PRESENTATION

A 66-year-old male who had a history of hypertension and resided in Shandong Province (Northern China) was admitted for recurrent fever for one month. The patient had recurrent fever, multiple lymphadenopathies, hepatosplenomegaly, a back rash, and a progressive decrease in white blood cells and platelets. Talaromyces marneffei was isolated from peripheral blood and bone marrow after admission, and suspected fungal cells were found via lymph node pathology. The patient's infection secondary to haemophagocytic syndrome continued to worsen despite antifungal, anti-inflammatory, and symptomatic treatment, leading to death due to multiple-organ failure.

CONCLUSION

Although rare, infection due to Talaromyces marneffei in HIV-negative patients has been increasing in recent years, and we should be vigilant about "new" infections in nonendemic areas.

Evolution of the ability to evade host innate immune defense by Talaromyces marneffei

Talaromyces (Penicillium) marneffei is an intracellular pathogenic fungus. Some strains of this fungus have been misidentified due to the similarity between Talaromyces and Penicillium. T. marneffei has mainly been found to afflict immunocompromised individuals, causing respiratory, skin, and systemic mycosis. Mp1p is a key virulence factor that can help T. marneffei evade clearance by the normally functioning immune system. Understanding how novel functions arise is an intriguing question in many fields of biology. Mp1p has two homologous domains (Mp1p-LBD1 and Mp1p-LBD2). Sequence similarity searches with Mp1p-LBD sequences revealed Mp1p homologs in many other pathogenic fungi. Integrated information on the taxonomic distribution, phylogenetic relationships, and sequence similarity of Mp1p domains revealed that the ancestor of Mp1p-LBDs was acquired through horizontal gene transfer (HGT). Additional evidence revealed that Mp1p homologs have undergone extensive gene duplications in T. marneffei. Mp1p might be a result of gene fusion following gene duplication. Furthermore, we propose a new method for identifying Talaromyces and identify 4 strains with misclassification errors. Our results characterize the evolutionary mechanism of T. marneffei evasion of host innate immune defense and clearly demonstrate the role of gene duplication and HGT in the evolution of host immune escape by T. marneffei.

A case of TM infection with challenging differential diagnosis from lymphoma post-renal transplant

BACKGROUND

Lymphomas involving the gastrointestinal tract may be manifested as anti-inflammatory tract bleeding, abdominal lymph node enlargement, or even perforation of the gastrointestinal tract. After organ transplantation, the likelihood of post-transplant lymphoproliferative disorders increases, and some rare infections may also appear.

CASE PRESENTATION

Herein, we report a living transplant patient with talaromycosis marneffei (TSM) or Talaromyces marneffei (TM) infection with gastrointestinal hemorrhage and systemic lymph node enlargement, which presented clinically as lymphoma.

CONCLUSION

This case is TSM in a kidney transplant patient, confirmed by lymph node biopsy and blood culture. The patient discharged from hospital successfully under the treatment of antifungal therapy and immunosuppressive therapy. Physicians should be aware that TSM can mimic lymphoma, and early diagnosis and treatment can benefit the outcomes.

Ultrasound characterization of superficial lymph nodes in HIV patients with Talaromyces marneffei infection

Objectives

This study aimed at exploring the ultrasound characteristics of superficial lymph nodes (LNs) in HIV patients with Talaromyces marneffei infection to provide assistance and understanding for diagnosis and therapy.

Methods

A retrospective analysis was conducted on 26 patients with confirmed HIV and T.marneffei coinfection. These patients underwent ultrasound examination and ultrasound-guided puncture biopsies at our hospital from March 2015 to March 2023.

Results

In all 26 patients, lymphadenectasis was observed. Among the 21 cases (80.76%), LNs showed a diffusely hyperechoic appearance with a tulle-like change, and 6 cases (23.07%) showed liquefaction. When the hila were present or thinned, the blood flow signals were primarily hilar, whether rich or poor, and when the hila were absent, the blood flow signals were peripheral or poor. The axillary LN long-to-short diameter (L/S) ratios exhibited a significant positive correlation with CD4+T cell counts (r = 0.8214, p = 0.0341). Patients with retroperitoneal lymphadenectasis showed decreased NK cell counts (p = 0.03).

Conclusion

In summary, the T.marneffei infection of LNs in HIV patients often manifests with superficial LN enlargement, mostly affecting the cervical LNs. The T.marneffei-infected LNs exhibit several characteristics such as echogenicity, hilum, and blood flow signal. Furthermore, there might be associations between lymphocyte subsets and enlarged superficial LNs. Ultrasound examinations should be paid attention to if patients have superficial LN enlargement, and the diagnosis of the T.marneffei infection is considered.

Clinical characteristics of tracheobronchial Talaromyces marneffei infection in non-HIV-infected patients in South China

OBJECTIVES

Tracheobronchial Talaromyces marneffei (T. marneffei) infections among non-HIV-infected patients are rare. To improve understanding, we analysed the clinical features, immune mechanisms, treatment, and prognosis.

METHODS

Data on hospitalized patients with tracheobronchial T. marneffei infections from September 2013 to May 2022 were collected. The clinical and imaging features were analysed.

RESULTS

Nineteen patients were enrolled, with a median age of 52 years (45-62 years). The most common symptoms were cough, expectoration, fever, weight loss, and anaemia. The total white blood cell and neutrophil counts, erythrocyte sedimentation rate, C-reactive protein, procalcitonin and globulin were increased, and the serum albumin levels were decreased. Chest CT manifestations included patchy shadows, masses, obstructive atelectasis, cavities, pleural effusion, and hilar and mediastinal lymphadenopathy. The fibreoptic bronchoscopy findings included masses, polyps or nodules with mucosal oedema, hypertrophic bulges, lumen stenosis or obstruction, and purulent secretions. T. marneffei infection was confirmed in 10 patients by positive culture, in five by both culture and metagenomic next-generation sequencing (mNGS), in two by mNGS, in one by culture and pathology and in 1 by histopathology. BALF (15/19, 78.9%) had the highest culture positive rate, followed by sputum (3/19), bronchial mucosa (1/1), lung biopsy (1/2); 36.8% of the patients were coinfected with other pathogens. For induction therapy, 7, 6, 2, and 4 patients received voriconazole, amphotericin B, voriconazole combined with amphotericin B, and fluconazole therapy, respectively, and 26.3% received treatment combined with nebulization and/or administration of amphotericin B under fibreoptic bronchoscopy. Four patients were treated for underlying diseases or coinfection, 31.6% were cured, 42.1% improved, and 26.3% died.

CONCLUSIONS

T. marneffei infection is common in the tracheobronchial airway tissue or secretions, and bronchoscopy has important diagnostic and treatment value. Antifungal therapy, including systemic therapy, involves triazoles and amphotericin administration, and aerosol inhalation and administration of amphotericin B under bronchoscopy are important.

Development and validation of a colorimetric antifungal susceptibility testing method for the dimorphic fungus Talaromyces marneffei

Antifungal drug resistance is an emerging cause of treatment failure in invasive fungal infections, and antifungal susceptibility testing (AFST) may inform treatment decisions. Currently, there are no established AFST guidelines for Talaromyces marneffei (Tm) or other dimorphic fungi. We developed a colorimetric AFST method using a fluorescent redox indicator alamarBlue, which changes from blue to pink in proportion to cellular metabolic activity. We determined the optimal time for alamarBlue addition to be 24 h post-inoculation and for MIC reading to be 72 h post-inoculation. Our method allows three ways to determine minimum inhibitory concentration (MIC): visual inspection of color change, optical density, and fluorescence intensity. We validated the assay by determining the MICs for seven antifungals against 32 Tm clinical isolates and assessed the essential agreement (EA) and inter-rater reliability between our alamarBlue and the Clinical Laboratory Standard Institute (CLSI) broth microdilution methods. The MIC ranges (from low to high) were: 0.008-0.025 μg/ml for itraconazole, 0.004-0.13 μg/ml for voriconazole, 0.03-0.13 μg/ml for posaconazole, 0.06-0.5 µg/ml for flucytosine, 0.5-1 µg/ml for amphotericin B, 0.5-4 µg/ml for caspofungin, and 0.5-16 µg/ml for fluconazole. The EAs were 100% between all three MIC readouts of the alamarBlue method, and 94%-100% between the alamarBlue and CLSI methods. Our alamarBlue method had substantially higher inter-rater agreement and offers a more reliable method that can be standardized across laboratories in both high- and low-resource settings compared to the established CLSI methodology.

Differential innate immune responses of human macrophages and bronchial epithelial cells against Talaromyces marneffei

Talaromyces marneffei is a thermally dimorphic fungal pathogen endemic in Southeast Asia. As inhalation of airborne conidia is believed as the major infection route, airway epithelial cells followed by pulmonary macrophages are the first cell types which the fungus encounters inside the host. In this study, we established an in vitro infection model based on human peripheral blood-derived macrophages (hPBDMs) cultured with the supplementation of autologous plasma. Using this model, we determined the transcriptomic changes of hPBDMs in response to T. marneffei infection by quantitative real-time reverse-transcription polymerase chain reaction as well as high-throughput RNA sequencing. Results showed that T. marneffei infection could activate hPBDMs to the M1-like phenotype and trigger a potent induction of chemokine and pro-inflammatory cytokine production as well as the expression of other immunoregulatory genes. In contrast to hPBDMs, there was no detectable innate cytokine response against T. marneffei in human bronchial epithelial cells (hBECs). Using a green fluorescent protein-tagged T. marneffei strain and confocal microscopy, internalization of the fungus by hBECs was confirmed. Live cell imaging further demonstrated that the infected cells exhibited normal cellular physiology, especially that the process of cell division could be observed. Moreover, T. marneffei also survived better inside hBECs than hPBDMs. Our results illustrated a potential role of hBECs to serve as reservoir cells for T. marneffei to evade immunosurveillance by phagocytes, from which the fungus reactivates when the host immunity is weakened and causes infection. Such immunoevasion and reactivation may also help explain the long incubation period observed for talaromycosis, in particular the travel-related cases. IMPORTANCE Talaromyces marneffei is an important fungal pathogen especially in Southeast Asia. To understand the innate immune response to talaromycosis, a suitable infection model is needed. Here, we established an in vitro T. marneffei infection model using human peripheral blood-derived macrophages (hPBDMs). We then examined the transcriptomic changes of hPBDMs in response to T. marneffei infection with this model. We found that contact with T. marneffei could activate hPBDMs to the M1-like phenotype and induced mRNA expressions of five cytokines and eight immunoregulatory genes. Contrary to hPBDMs, such immunoresponse was not elicited in human bronchial epithelial cells (hBECs), despite normal physiology observed in infected cells. We also found that infected hBECs did not eliminate T. marneffei as efficiently as hPBDMs. Our observation suggested that hBECs may potentially serve as reservoir cells for T. marneffei to evade immunosurveillance. When the host immunity deteriorates later, then the fungus reactivates and causes infection.

Talaromyces marneffei suppresses macrophage inflammation by regulating host alternative splicing

Talaromyces marneffei (T. marneffei) immune escape is essential in the pathogenesis of talaromycosis. It is currently known that T. marneffei achieves immune escape through various strategies. However, the role of cellular alternative splicing (AS) in immune escape remains unclear. Here, we depict the AS landscape in macrophages upon T. marneffei infection via high-throughput RNA sequencing and detect a truncated protein of NCOR2 / SMRT, named NCOR2-013, which is significantly upregulated after T. marneffei infection. Mechanistic analysis indicates that NCOR2-013 forms a co-repression complex with TBL1XR1 / TBLR1 and HDAC3, thereby inhibiting JunB-mediated transcriptional activation of pro-inflammatory cytokines via the inhibition of histone acetylation. Furthermore, we identify TUT1 as the AS regulator that regulates NCOR2-013 production and promotes T. marneffei immune evasion. Collectively, these findings indicate that T. marneffei escapes macrophage killing through TUT1-mediated alternative splicing of NCOR2 / SMRT, providing insight into the molecular mechanisms of T. marneffei immune evasion and potential targets for talaromycosis therapy.

Clinical features of HIV positive talaromycosis marneffei patients and development of a risk prediction model

Aims

The purpose of this study was to establish and verify a nomogram to predict the prognosis of patients with human immunodeficiency virus (HIV)-related talaromycosis marneffei and evaluate the prognosis.

Methods

We examined the acquired immune deficiency syndrome (AIDS) patients hospitalized in the Fourth People's Hospital of Nanning from 2018 to 2020 with an aetiological diagnosis of Talaromyces marneffei infection. Logistic regression analysis was used to identify the independent risk factors for relapse or death of the prognosis of Talaromyces marneffei infection. According to the regression coefficient, the corresponding nomograph prediction model was drawn.

Results

A total of 400 patients were included, including 321 males and 79 females. Recurrence or death occurred in 70 cases (17.5%). The area under the receiver operator characteristic curve (ROC) of the established model was 0.716 with good discrimination, calibration, and clinical effectiveness. The risks of age between 45 and 60 years old and <40 years old were successively higher than that of >60 years old, and the risks of G test <50 pg/ml and >100 pg/ml were higher than that of 50-100 pg/ml. Respiratory failure, decreased albumin and elevated total bilirubin are risk factors for relapse or death in HIV patients infected with Talaromyces marneffei.

Conclusion

This model can accurately predict the prognosis of HIV complicated with Talaromyces marneffei infection.

Identification of glutathione metabolic genes from a dimorphic fungus Talaromyces marneffei and their gene expression patterns under different environmental conditions

Talaromyces marneffei is a human fungal pathogen that causes endemic opportunistic infections, especially in Southeast Asia. The key virulence factors of T. marneffei are the ability to survive host-derived heat and oxidative stress, and the ability to convert morphology from environmental mold to fission yeast forms during infection. Glutathione metabolism plays an essential role in stress response and cellular development in multiple organisms. However, the role of the glutathione system in T. marneffei is elusive. Here, we identified the genes encoding principal enzymes associated with glutathione metabolism in T. marneffei, including glutathione biosynthetic enzymes (Gcs1 and Gcs2), glutathione peroxidase (Gpx1), glutathione reductase (Glr1), and a family of glutathione S-transferase (Gst). Sequence homology search revealed an extended family of the TmGst proteins, consisting of 20 TmGsts that could be divided into several classes. Expression analysis revealed that cells in conidia, mold, and yeast phases exhibited distinct expression profiles of glutathione-related genes. Also, TmGst genes were highly upregulated in response to hydrogen peroxide and xenobiotic exposure. Altogether, our findings suggest that T. marneffei transcriptionally regulates the glutathione genes under stress conditions in a cell-type-specific manner. This study could aid in understanding the role of glutathione in thermal-induced dimorphism and stress response.

Identification of Talaromyces marneffei Infection in an HIV-Negative Patient by ITS Sequencing

Disseminated ankle mycosis is a life-threatening systemic infection caused by the emerging opportunistic and lethal fungal pathogen Talaromyces marneffei which is more common in HIV-positive patients. However, an increasing number of infections are occurring in HIV-negative patients. Here, we report a case of Talaromyces marneffei infection in HIV-negative patient. A 50s HIV-negative male patient with fever, cough, bloody sputum expectoration, pulmonary sarcoidosis and body rashes was hospitalized at Zhejiang Provincial People's Hospital. CT scanning showed pulmonary multiple nodules with apical bronchial occlusion, patchy infiltration and pathological biopsy demonstrated bronchiolitis obliterans with organized pneumonia and chronic active inflammation of lung tissue with infiltration of numerous lymphocytes, plasma cells, phagocytes and neutrophils. Laboratory tests revealed significantly increased white blood cells count 18.3 ×109/L, neutrophil count 15.34 ×109/L, monocyte count 0.66 ×109/L, platelet count 517 ×109/L, C-reactive protein 116 mg/L, erythrocyte sedimentation rate 112mm/h. The β-D-glucan test was negative (33.06 pg/mL) while fungal culture of broncho alveolar lavage fluid revealed colonies with temperature-dependent dimorphic growth character and Talaromyces marneffei was confirmed by ITS sequencing of the colonies. The patient exhibited radiological improvement and clinical recuperation after intravenously guttae of voriconazole. Talaromycosis in immunocompetent and HIV-negative individuals is relatively rare and is characterized by an insidious onset, various clinical manifestations, and is clinically challenging. Fungal culture and ITS sequencing are warranted for diagnosis Talaromyces marneffei infection. This is the first report on identification of Talaromyces marneffei infection in an HIV-negative patient with skin involvement by ITS sequencing in Zhejiang.

Impact of pathogen genetics on clinical phenotypes in a population of Talaromyces marneffei from Vietnam

Talaromycosis, a severe and invasive fungal infection caused by Talaromyces marneffei, is difficult to treat and impacts those living in endemic regions of Southeast Asia, India, and China. While 30% of infections result in mortality, our understanding of the genetic basis of pathogenesis for this fungus is limited. To address this, we apply population genomics and genome-wide association study approaches to a cohort of 336 T. marneffei isolates collected from patients who enrolled in the Itraconazole vs Amphotericin B for Talaromycosis trial in Vietnam. We find that isolates from northern and southern Vietnam form two distinct geographical clades, with isolates from southern Vietnam associated with increased disease severity. Leveraging longitudinal isolates, we identify multiple instances of disease relapse linked to unrelated strains, highlighting the potential for multistrain infections. In more frequent cases of persistent talaromycosis caused by the same strain, we identify variants arising over the course of patient infections that impact genes predicted to function in the regulation of gene expression and secondary metabolite production. By combining genetic variant data with patient metadata for all 336 isolates, we identify pathogen variants significantly associated with multiple clinical phenotypes. In addition, we identify genes and genomic regions under selection across both clades, highlighting loci undergoing rapid evolution, potentially in response to external pressures. With this combination of approaches, we identify links between pathogen genetics and patient outcomes and identify genomic regions that are altered during T. marneffei infection, providing an initial view of how pathogen genetics affects disease outcomes.

Case report: Diagnosis of Talaromyces marneffei infection in an HIV-negative patient with septic shock and high-titer anti-interferon gamma autoantibodies by metagenomic next-generation sequencing

Background

Sepsis is a life-threatening condition caused by a dysfunctional response to infection from the host. Septic shock, a subset of sepsis, caused by Talaromyces marneffei infection (talaromycosis) has rarely been reported. Owing to its slow culture and low yield, talaromycosis is typically misdiagnosed in HIV-negative patients as other infections, such as tuberculosis, bacterial pneumonia, and lung cancer, especially in non-endemic regions. Early and accurate diagnosis as well as efficient treatment options are required to improve prognosis.

Method

A 30-year-old HIV-negative Chinese woman from a non-endemic area of T. marneffei was initially misdiagnosed with tuberculosis. She had a poor response to anti-tuberculosis treatment. On July 16, 2022, she was admitted to our hospital; the patient developed septic shock on the third day after hospitalization and was ultimately diagnosed with talaromycosis via metagenomic next-generation sequencing (mNGS).

Result

The condition of the patient improved after appropriate treatment with amphotericin B. Furthermore, enzyme-linked immunosorbent assay results confirmed that the patient had a high-titer of anti-interferon gamma (IFN-γ) autoantibodies.

Conclusion

HIV-negative individuals with anti-IFN-γ autoantibodies typically have relapsing, refractory, and fatal infections, such as talaromycosis, which is typically misdiagnosed in the initial course of the disease. This can lead to septic shock. Clinicians should be aware that they may encounter HIV-negative patients with T. marneffei infection in non-endemic areas. Thus, mNGS is an effective technology for detecting T. marneffei infection. Additionally, the detection of anti-IFN-γ autoantibodies in these patients would aid in knowing their susceptibility to fatal infections.

Cutaneous cryptococcosis in an adult male of sub-saharan origin

Cryptococcosis is caused by the inhalation of the desiccated encapsulated yeast or basidiospores, which are found in the environment. After the infectious particles reach the lungs, get disseminated hematogenously in various organs. Meningoencephalitis is one of the most common manifestations, especially in sub-Saharan Africa. The dermal lesions can be either primary due to the traumatic implantation of infectious propagule or secondary in patients with disseminated infection due to cryptococcus. The typical presentations of the cutaneous lesions are like umbilicated lesions of molluscum contagiosum. The dermal lesions can also be similar to Kaposi sarcoma or talaromycosis (formerly penicilliosis). Here, we present a 34-year-old male HIV-positive and antiretroviral therapy-naive. The patient had a very low CD4 cell count and a high viral load. The patient was referred to the dermatology clinic for multiple eruptions due to umbilicated skin colored lesions 3-5 mm in diameter on the nose.The patient was first treated for the opportunistic infection. The causes of the dermal umbilicated skin lesions are several. We must find out whether the dermal lesion is due to infection with a single organism or more than one. It can be colesional also. Punch biopsy, India ink, and culture on Sabouraud dextrose agar confirmed the diagnosis of Cryptococcus neoformans.

Extracellular vesicles derived from Talaromyces marneffei contain immunogenic compounds and modulate THP-1 macrophage responses

Pathogenic eukaryotes including fungi release extracellular vesicles (EVs) which are composed of a variety of bioactive components, including peptides, nucleic acids, polysaccharides, and membrane lipids. EVs contain virulence-associated molecules suggesting a crucial role of these structures in disease pathogenesis. EVs derived from the pathogenic yeast phase of Talaromyces (Penicillium) marneffei, a causative agent of systemic opportunistic mycoses "talaromycosis," were studied for their immunogenic components and immunomodulatory properties. Some important virulence factors in EVs including fungal melanin and yeast phase specific mannoprotein were determined by immunoblotting. Furthermore, fluorescence microscopy revealed that T. marneffei EVs were internalized by THP-1 human macrophages. Co-incubation of T. marneffei EVs with THP-1 human macrophages resulted in increased levels of supernatant interleukin (IL)-1β, IL-6 and IL-10. The expression of THP-1 macrophage surface CD86 was significantly increased after exposed to T. marneffei EVs. These findings support the hypothesis that fungal EVs play an important role in macrophage "classical" M1 polarization. T. marneffei EVs preparations also increased phagocytosis, suggesting that EV components stimulate THP-1 macrophages to produce effective antimicrobial compounds. In addition, T. marneffei EVs stimulated THP-1 macrophages were more effective at killing T. marneffei conidia. These results indicate that T. marneffei EVs can potently modulate macrophage functions, resulting in the activation of these innate immune cells to enhance their antimicrobial activity.

Rare cases of Talaromyces pneumonia in individuals with underlying cancer and no travel to endemic areas

Introduction

Talaromyces marneffei causes a systemic fungal infection, referred to as talaromycosis, in immunocompromised individuals. Talaromycosis is an AIDS (acquired immunodeficiency syndrome) defining illness for patients living in the Southeast Asian region. Here we present two rarely reported cases of pulmonary talaromycosis in Southern California in patients with active cancer, negative HIV status, and no prior travel history to endemic regions.

Case description

Case 1: A 76-year-old male with a past medical history of emphysema and latent tuberculosis status post rifampin treatment, presented with a necrotic lung mass. He was diagnosed with squamous cell lung carcinoma and bronchoalveolar lavage cultures grew Talaromyces marneffei. He had no animal exposure or prior travel history to Asia. Due to a transfusion reaction to liposomal amphotericin (the mainstay of treatment), he required a transition to posaconazole. He was HIV-negative and expired due to underlying cancer and infection complications.Case2: A 63-year-old male with a past medical history of tuberculosis, diabetes, and cavitary pneumonia with bronchoscopy positive for Talaromyces presented with worsening back pain and was found to have multiple sites of poorly differentiated adenocarcinoma likely originating from gastric adenocarcinoma. He was HIV-negative and expired due to complications from underlying cancer and infection.

Conclusion

We demonstrate that patients with pulmonary Talaromyces are becoming more prominent outside of endemic areas even in the setting of no prior travel. In addition, since patients with this infection are severely immunosuppressed, they require extensive workup for other comorbidities such as possible underlying cancer or tuberculosis.

Environmentally Resilient Microfluidic Point-of-Care Immunoassay Enables Rapid Diagnosis of Talaromycosis

Point-of-care tests (POCTs) are increasingly being used in field settings, particularly outdoors. The performance of current POCTs─most commonly the lateral flow immunoassay─can be adversely affected by ambient temperature and humidity. We developed a self-contained immunoassay platform─the D4 POCT─that can be conducted at the POC by integrating all reagents in a capillary-driven passive microfluidic cassette that minimizes user intervention. The assay can be imaged and analyzed on a portable fluorescence reader─the D4Scope─and provide quantitative outputs. Here, we systematically investigated the resilience of our D4 POCT to varied temperature and humidity and to physiologically diverse human whole blood samples that span a wide range of physiological hematocrit (30-65%). For all conditions, we showed that the platform maintained high sensitivity (0.05-0.41 ng/mL limits of detection). The platform also demonstrated good accuracy in reporting true analyte concentration across environmental extremes when compared to the manually operated format of the same test to detect a model analyte─ovalbumin. Additionally, we engineered an improved version of the microfluidic cassette that improved the ease-of-use of the device and shortened the time-to-result. We implemented this new cassette to create a rapid diagnostic test to detect talaromycosis infection in patients with advanced HIV disease at the POC, demonstrating comparable sensitivity and specificity to the laboratory test for the disease.

Antibody screening reveals antigenic proteins involved in Talaromyces marneffei and human interaction

Talaromycosis is a fungal infection that generally affects immunocompromised hosts and is one of the most frequent systemic mycoses in HIV patients, especially in endemic areas such as Southeast Asia. Talaromyces marneffei, the causative agent of talaromycosis, grows as a mold in the environment but adapts to the human body and host niches by transitioning from conidia to yeast-like cells. Knowledge of the human host and T. marneffei interaction has a direct impact on the diagnosis, yet studies are still lacking. The morbidity and mortality rates are high in taloromycosis patients if the diagnosis and treatments are delayed. Immunogenic proteins are excellent candidates for developing detection tools. Previously, we identified antigenic proteins that were recognized by antibodies from talaromycosis sera. Three of these identified proteins have been previously characterized in detail, while the others have not been explored. To expedite the progress of antigen discovery, the complete list of antigenic proteins and their features was fully reported in this study. Functional annotation and Gene Ontology examination revealed that these proteins showed a high association with membrane trafficking. Further bioinformatics analyses were performed to search for antigenic protein characteristics, including functional domains, critical residues, subcellular localization, secretory signals, and epitope peptide sequences. Expression profiling of these antigenic encoding genes was investigated using quantitative real-time PCR. The results demonstrated that most genes were expressed at low levels in the mold form, but were highly upregulated in the pathogenic yeast phase, consistent with the antigenic role of these genes during the human-host interaction. Most transcripts accumulated in the conidia, suggesting a role during phase transition. The collection of all antigen-encoding DNA sequences described here is freely accessible at GenBank, which could be useful for the research community to develop into biomarkers, diagnostic tests, research detection tools, and even vaccines.

An Overview of Diagnostic and Management Strategies for Talaromycosis, an Underrated Disease

Underrated and neglected, talaromycosis is a life-threatening fungal disease endemic to the tropical and subtropical regions of Asia. In China, it has been reported that talaromycosis mortality doubles from 24 to 50% when the diagnosis is delayed, and reaches 100% when the diagnosis is missed. Thus, the accurate diagnosis of talaromycosis is of utmost importance. Herein, in the first part of this article, we provide an extensive review of the diagnostic tools used thus far by physicians in the management of cases of talaromycosis. The challenges encountered and the perspectives which may aid in the discovery of more accurate and reliable diagnostic approaches are also discussed. In the second part of this review, we discuss the drugs used to prevent and treat T. marneffei infection. Alternative therapeutic options and potential drug resistance reported in the contemporary literature are also discussed. We aim to guide researchers towards the discovery of novel approaches to prevent, diagnose, and treat talaromycosis, and therefore improve the prognosis for those afflicted by this important disease.

Exosomes released from macrophages infected with Talaromyces marneffei activate the innate immune responses and decrease the replication

INTRODUCTION

Recent studies have demonstrated that exosomes play roles in pathogenesis and in the treatment of various diseases. We explored the influence of exosomes released from Talaromyces marneffei (T. marneffei)-infected macrophages on human macrophages to determine whether they play a role in the pathogenesis of T. marneffei infection.

METHODS

Exosomes derived from macrophages infected with T. marneffei were extracted and characterized by transmission electron microscopy and western blot. Moreover, we examined exosomes that modulated IL-10 and TNF-α secretion and activation of p42 and p44 extracellular signal-regulated kinase 1 and 2 (ERK1/2) and activation of autophagy.

RESULTS

We found that exosomes promoted activation of ERK1/2 and autophagy, IL-10 and TNF-α secretion in human macrophages. Further, exosomes decreased the multiplication of T. marneffei in T. marneffei-infected human macrophages. Interestingly, exosomes isolated from T. marneffei-infected but not from uninfected macrophages can stimulate innate immune responses in resting macrophages.

CONCLUSION

Our studies are the first to demonstrate that exosomes isolated from T. marneffei-infected macrophages can modulate the immune system to control inflammation, and we hypothesize that exosomes play significant roles in activation of ERK1/2 and autophagy, the replication of T. marneffei and cytokine production during T. marneffei infection.

Thalidomide promotes NLRP3/caspase-1-mediated pyroptosis of macrophages in Talaromyces marneffei infection

Macrophage-derived inflammatory cytokines are critical for host defense against Talaromyces marneffei (T. marneffei) infection among HIV/AIDS patients, and excessive inflammatory cytokines are associated with poor outcomes of AIDS-associated talaromycosis. However, the underlying mechanisms of macrophage-caused pyroptosis and cytokine storm are poorly understood. Here, in the T. marneffei-infected mice and macrophages, we show that T. marneffei induced pyroptosis in macrophages through the NLRP3/caspase-1 pathway. The immunomodulatory drug thalidomide could promote the pyroptosis of macrophages infected T. marneffei. In T. marneffei-infected mice, the splenic macrophages underwent increasing pyroptosis as talaromycosis deteriorated. Thalidomide ameliorated inflammation of mice, while amphotericin B (AmB) in combination with thalidomide did not improve overall survival compared with AmB alone. Taken together, our findings suggest that thalidomide promotes NLRP3/caspase-1-mediated pyroptosis of macrophages in T. marneffei infection.

Clinical Characteristics, Course, and Long-Term Outcomes in Patients with Talaromyces marneffei Infection: A 10-Year Retrospective Cohort Study

INTRODUCTION

Talaromyces marneffei (T. marneffei), a dimorphic fungus, causes local or disseminated infection in humans. We aimed to analyze the clinical characteristics, prognostic factors, and survival outcomes of patients with T. marneffei infection and compare the differences between human immunodeficiency virus (HIV)-positive and HIV-negative subgroups.

METHODS

We retrospectively analyzed 241 patients with T. marneffei infection at the First Affiliated Hospital of Guangxi Medical University between January 2012 and January 2022. The overall population was stratified into HIV-positive (n = 98) and HIV-negative (n = 143) groups according to HIV status. Kaplan-Meier analysis and multivariate Cox regression models were used to determine the prognostic factors for overall survival (OS) and progression-free survival (PFS).

RESULTS

With a median follow-up time of 58.9 months, 120 patients (49.8%) experienced disease progression and 85 patients (70.8%) died. The 5-year rates of OS and PFS were 61.4% (95% CI 55.0-68.6%) and 47.8% (95% CI 41.5-55.1%), respectively. As an independent factor, patients who were HIV positive had better PFS (HR 0.50, 95% CI 0.31-0.82; p < 0.01) than patients who were HIV negative. Compared with patients who were HIV positive, patients who were HIV negative were older and had more probabilities of underlying diseases, chest involvement, bone destruction, and higher count of neutrophils (all p < 0.05). Hemoglobin (PFS: HR 0.62; 95% CI 0.39-1.00; p < 0.05; OS: HR 0.45; 95% CI 0.22-0.89; p = 0.02) and lymphocyte count (PFS: HR 0.06; 95% CI 0.01-0.26; p < 0.01; OS: HR 0.08; 95% CI 0.01-0.40; p < 0.01) were independent prognostic factors for PFS and OS in patients who were HIV negative.

CONCLUSIONS

Patients with T. marneffei infection have a poor prognosis. Patients who are HIV positive and HIV negative have relatively independent clinical characteristics. Multiple organ involvement and disease progression are more common in patients who are HIV negative.

A Retrospective Study of Clinical and Immunological Features of a Pediatric Population with Talaromyces marneffei Infection

BACKGROUND

Talaromyces marneffei (T. Marneffei) infection is considered as an indicator of immunosuppression in immunocompromised individuals, leading to multiple organ damage. Our study aimed to evaluate both the clinical characteristics and immunological features of pediatric patients infected with T. marneffei from our institute, providing novel insights into diagnosis and treatment for this life-threatening disease.

METHOD

Thirteen pediatric patients with T. marneffei infection were enrolled in Guangzhou Women and Children's Medical Center during 2012 to 2020. Clinical data and laboratory findings were collected and further analyzed. Pearson correlation coefficient was calculated to determine the relationship between serum immunoglobulins (Igs) levels and white blood cell count, or the absolute lymphocyte count.

RESULTS

Patients were diagnosed as having T. Marneffei infection mainly based on the results of fungal culture and Gram stain of specimens. The most common presentations were fever (69%), pneumonia (38%) and immunodeficiency (38%). The total levels of Igs (IgE, IgA, and IgM) were positively correlated with both white blood cell count and absolute lymphocyte count.

CONCLUSION

Serum Ig expression Pattern in patients diagnosed with T. marneffei infection might serve as an effective prognostic marker which would help with the development of early interventions for children with this fatal disease.

Impact of pathogen genetics on clinical phenotypes in a population of Talaromyces marneffei from Vietnam

Talaromycosis, a severe and invasive fungal infection caused by Talaromyces marneffei , is difficult to treat and impacts those living in endemic regions of southeast Asia, India, and China. While 30% of infections result in mortality, our understanding of the genetic basis of pathogenesis for this fungus is limited. To address this, we apply population genomics and genome wide association study approaches to a cohort of 336 T. marneffei isolates collected from patients who enrolled in the Itraconazole versus Amphotericin B for Talaromycosis (IVAP) trial in Vietnam. We find that isolates from northern and southern Vietnam form two distinct geographical clades, with isolates from southern Vietnam associated with increased disease severity. Leveraging longitudinal isolates, we identify multiple instances of disease relapse linked to unrelated strains, highlighting the potential for multi-strain infections. In more frequent cases of persistent talaromycosis caused by the same strain, we identify variants arising over the course of patient infections that impact genes predicted to function in the regulation of gene expression and secondary metabolite production. By combining genetic variant data with patient metadata for all 336 isolates, we identify pathogen variants significantly associated with multiple clinical phenotypes. In addition, we identify genes and genomic regions under selection across both clades, highlighting loci undergoing rapid evolution, potentially in response to external pressures. With this combination of approaches, we identify links between pathogen genetics and patient outcomes and identify genomic regions that are altered during T. marneffei infection, providing an initial view of how pathogen genetics affects disease outcomes.

Prokaryotic and eukaryotic microbial communities associated with coral species have high host specificity in the South China Sea

Reef-building corals are well known for their obligate association with Symbiodiniaceae, and an array of other microbes, including bacteria, fungi, and symbiotic algae (i.e., total microbiome), which together form the coral holobiont. The total microbiome plays an intricate part in maintaining the homeostasis of the coral holobiont and is closely associated with host health. However, the composition of the coral associated microbiome and interaction between its different members remains elusive because few analyses have bridged taxonomically disparate groups. This research gaps have prevented a holistic understanding of the total microbiome. Thus, to simultaneously characterize the bacterial, fungal and symbiotic algal communities associated with different coral species, and explore the relationship between these symbionts and coral health, healthy and bleached tissues from four coral species, Acropora muricata, Galaxea fascicularis, Platygyra daedalea, and Pavona explanulata, were collected from the Xisha Islands of the South China Sea. Using high throughput sequencing, a high degree of host-specificity was observed among bacterial, fungal, and algal groups across coral species. There were no obvious changes in the microbial community structure of apparently healthy and bleached corals, but host bleaching allowed colonization of the holobionts by diverse opportunistic microbes, resulting in a significant elevation in the α-diversity of microbial communities. In addition, co-occurrence analysis of the coral microbiota also identified more complex microbial interactions in bleached corals than in healthy ones. In summary, this study characterized the structure of coral-associated microbiomes across four coral species, and systematically studied microbiome differences between healthy and bleached corals. The findings improve our understanding of the heterogeneity of symbiotic microorganisms and the impact of coral's physiological status on its associated microbial communities composition.

A Repertoire of Clinical Non-Dermatophytes Moulds

Humans are constantly exposed to micromycetes, especially filamentous fungi that are ubiquitous in the environment. In the presence of risk factors, mostly related to an alteration of immunity, the non-dermatophyte fungi can then become opportunistic pathogens, causing superficial, deep or disseminated infections. With new molecular tools applied to medical mycology and revisions in taxonomy, the number of fungi described in humans is rising. Some rare species are emerging, and others more frequent are increasing. The aim of this review is to (i) inventory the filamentous fungi found in humans and (ii) provide details on the anatomical sites where they have been identified and the semiology of infections. Among the 239,890 fungi taxa and corresponding synonyms, if any, retrieved from the Mycobank and NCBI Taxonomy databases, we were able to identify 565 moulds in humans. These filamentous fungi were identified in one or more anatomical sites. From a clinical point of view, this review allows us to realize that some uncommon fungi isolated in non-sterile sites may be involved in invasive infections. It may present a first step in the understanding of the pathogenicity of filamentous fungi and the interpretation of the results obtained with the new molecular diagnostic tools.

Triple Trouble: Disseminated Penicilliosis in a Cancer patient with COVID-19

Penicilliosis is a fungal infection caused by the fungus Penicillium marneffei or Talaromyces marneffei. Penicillosis is commonly seen in immunocompromised patients such as in HIV(AIDS). Herein, we present a case of penicilliosis in an oral cavity cancer patient who was admitted for the management of SARS-CoV-2 infection at our hospital. A 50-year-old male patient operated on for squamous cell carcinoma of the oral cavity who completed his adjuvant chemoradiation 2 months ago, presented to our hospital with dry cough for more than 3 weeks. His nasopharyngeal swab was positive for the severe acute respiratory distress syndrome (SARS-CoV-2). During his hospital stay for SARS-CoV-2 infection, he was diagnosed with disseminated penicilliosis. The patient was treated with intravenous antifungals caspofungin and voriconazole. However, he succumbed to disseminated fungal sepsis. This case highlights the need to consider penicilliosis as a possible opportunistic pathogen, especially in immunocompromised patients such as cancer.

An Overlooked and Underrated Endemic Mycosis-Talaromycosis and the Pathogenic Fungus Talaromyces marneffei

Talaromycosis is an invasive mycosis endemic in tropical and subtropical Asia and is caused by the pathogenic fungus Talaromyces marneffei. Approximately 17,300 cases of T. marneffei infection are diagnosed annually, and the reported mortality rate is extremely high (~1/3). Despite the devastating impact of talaromycosis on immunocompromised individuals, particularly HIV-positive persons, and the increase in reported occurrences in HIV-uninfected persons, diagnostic and therapeutic approaches for talaromycosis have received far too little attention worldwide. In 2021, scientists living in countries where talaromycosis is endemic raised a global demand for it to be recognized as a neglected tropical disease. Therefore, T. marneffei and the infectious disease induced by this fungus must be treated with concern. T. marneffei is a thermally dimorphic saprophytic fungus with a complicated mycological growth process that may produce various cell types in its life cycle, including conidia, hyphae, and yeast, all of which are associated with its pathogenicity. However, understanding of the pathogenic mechanism of T. marneffei has been limited until recently. To achieve a holistic view of T. marneffei and talaromycosis, the current knowledge about talaromycosis and research breakthroughs regarding T. marneffei growth biology are discussed in this review, along with the interaction of the fungus with environmental stimuli and the host immune response to fungal infection. Importantly, the future research directions required for understanding this serious infection and its causative pathogenic fungus are also emphasized to identify solutions that will alleviate the suffering of susceptible individuals worldwide.

Comparison of in vitro Susceptibilities of Talaromyces marneffei in Mold and Yeast Forms in Malaysia

Purpose

This study was aimed to determine minimum inhibitory concentration (MIC) differences between yeast and mold forms of T. marneffei in Malaysia.

Patients and Methods

Ninety-seven clinical strains of T. marneffei were received from various Malaysian hospitals from the year 2020 until 2022. Their identities were determined using microscopic, macroscopic and molecular methods. Next, the susceptibility of yeast and mold forms of each isolate against amphotericin B, itraconazole, voriconazole, posaconazole, ketoconazole, isavuconazole, terbinafine, caspofungin and micafungin were tested according to the broth microdilution according to the Clinical and Laboratory Standards Institute (CLSI) M38 and M27 guidelines. The geometric means of minimal inhibitory concentration (GM MIC), MIC₅₀, and MIC₉₀ were determined for each antifungal. Additionally, Wilcoxon signed-rank test was used to compare the significant difference of GM MICs for each antifungal, GM MIC, MIC₅₀ and MIC₉₀ for the combined nine antifungals against different growth forms of T. marneffei. The significance was set at p<0.05.

Results

Micafungin had the highest GM MIC, MIC₅₀ and MIC₉₀ for mold form of T. marneffei. For yeast form, amphotericin B achieved the highest GM MIC and MIC₅₀ while micafungin achieved the highest MIC₉₀. However, the GM MIC, MIC₅₀ and MIC₉₀ of terbinafine and azole antifungals on T. marneffei were similar to each other, namely between 0.03 and 0.60µg/mL. The difference of GM MIC of all tested antifungals except caspofungin and micafungin was insignificant. Overall, GM MIC, MIC₅₀ and MIC₉₀ of the combined nine antifungals against two growth forms were insignificant.

Conclusion

The findings suggested either yeast or mold form can be used in the susceptibility testing of T. marneffei against amphotericin B, itraconazole, voriconazole, posaconazole, ketoconazole, isavuconazole and terbinafine.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Expression of Cytokine Profiles in Human THP-1 Cells during Phase Transition of Talaromyces marneffei

Talaromyces marneffei, a dimorphic fungus, exhibits temperature-dependent growth, existing in a filamentous form at 25 °C and as a yeast at 37 °C. Several studies have highlighted the important roles of macrophages in defense against T. marneffei infection. However, the immune responses to the interaction of macrophages with T. marneffei cells during phase transition require further investigation. This study reports the expression of cytokine profiles in human THP-1 cells during infection by T. marneffei. THP-1 cells were infected with T. marneffei conidia at different multiplicity of infections (MOIs). Surviving conidia transformed into yeasts after phagocytosis by macrophages, and the number of yeasts gradually increased over 36 h. The transcription and secretion levels of pro- and anti-inflammatory cytokines were examined at different times by qRT-PCR and ELISA. Transcription levels of IL-8, IL-12, IL-1β, and TNF-α increased significantly at 12 or 24 h and then slightly decreased at 36 h. In contrast, the transcription levels of IL-6, IL-10, and TGF-β gradually increased at all MOIs. The levels of IL-6 and IL-10 secretion corresponded to their levels of transcription. These results indicated that as the number of intracellular yeasts increased, the infected macrophages first underwent slight M1 polarization before shifting to M2 polarization. This polarization transition was confirmed by the fungicidal ability and the expression of macrophage surface markers. By inducing the M2-type polarization of macrophages, the intracellular T. marneffei cells can successfully evade the immune response. Our study provides a novel insight into the immune characterization during the transition of T. marneffei infection and could further contribute to possible diagnostic and therapeutic interventions for this infection.

Invasive Fungal Diseases in Africa: A Critical Literature Review

Invasive fungal diseases (IFDs) are of huge concern in resource-limited settings, particularly in Africa, due to the unavailability of diagnostic armamentarium for IFDs, thus making definitive diagnosis challenging. IFDs have non-specific systemic manifestations overlapping with more frequent illnesses, such as tuberculosis, HIV, and HIV-related opportunistic infections and malignancies. Consequently, IFDs are often undiagnosed or misdiagnosed. We critically reviewed the available literature on IFDs in Africa to provide a better understanding of their epidemiology, disease burden to guide future research and interventions. Cryptococcosis is the most encountered IFD in Africa, accounting for most of the HIV-related deaths in sub-Saharan Africa. Invasive aspergillosis, though somewhat underdiagnosed and/or misdiagnosed as tuberculosis, is increasingly being reported with a similar predilection towards people living with HIV. More cases of histoplasmosis are also being reported with recent epidemiological studies, particularly from Western Africa, showing high prevalence rates amongst presumptive tuberculosis patients and patients living with HIV. The burden of pneumocystis pneumonia has reduced significantly probably due to increased uptake of anti-retroviral therapy among people living with HIV both in Africa, and globally. Mucormycosis, talaromycosis, emergomycosis, blastomycosis, and coccidiomycosis have also been reported but with very few studies from the literature. The emergence of resistance to most of the available antifungal drugs in Africa is yet of huge concern as reported in other regions. IFDs in Africa is much more common than it appears and contributes significantly to morbidity and mortality. Huge investment is needed to drive awareness and fungi related research especially in diagnostics and antifungal therapy.

Case report: Acute Talaromyces marneffei mediastinitis in an HIV-negative patient

Talaromyces marneffei (T. marneffei) is one of the most important opportunistic human pathogens endemic in Southeast Asia. Talaromycosis, which was once regarded as an opportunistic infectious disease in patients with acquired immunodeficiency syndrome, is being increasingly reported in HIV-negative populations. Since T. marneffei infection can be localized or disseminated, patients may present with a variety of symptoms. However, mediastinal infection attributed to T. marneffei is extremely rare. We report the case of a 32-year-old female who manifested a large mediastinal mass and was eventually diagnosed as acute T. marneffei mediastinitis. The patient was HIV-negative and had no direct contact with intermediate hosts. We successfully managed to treat the patient with inhaled amphotericin B deoxycholate and observed lesion absorption in subsequent CT examinations. To our knowledge, this is the first published case of T. marneffei mediastinitis and first use of inhaled antifungal monotherapy on patients with T. marneffei infection.

Clinical performance of metagenomic next-generation sequencing for the rapid diagnosis of talaromycosis in HIV-infected patients

Background

Talaromycosis is an invasive endemic mycosis caused by the dimorphic fungus Talaromyces marneffei (T. marneffei, TM). It mainly affects immunodeficient patients, especially HIV-infected individuals, which causes significant morbidity and mortality. Culture-based diagnosis takes a long turnaround time with low sensitivity, leading to treatment delay. In this study, we aimed to evaluate the performance of Metagenomic Next-Generation Sequencing (mNGS) for the rapid diagnosis of talaromycosis in HIV-infected patients.

Methods

Retrospectively analysis was conducted in HIV-infected cases at Changsha First Hospital (China) from January 2021 to March 2022. Patients who underwent routine microbiological examination and mNGS testing in parallel were enrolled. The clinical final diagnosis was used as a reference standard, and cases were classified into the TM group (60 cases) and the non-TM group (148 cases). The clinical performances of mNGS were compared with culture and serum Galactomannan (GM). The mixed infections detected by mNGS were analyzed. The impact of mNGS detection on treatment was also investigated.

Results

The sensitivity of mNGS test reached 98.3% (95% CI, 89.8-99.9), which was significantly higher than culture (66.7% [95% CI, 53.2-77.9], P < 0.001) and serum GM (83.3% [95% CI, 71.0-91.2], P < 0.05). The specificity of 98.6% (95% CI, 94.7-99.7) was similar to culture (100.0% [95% CI, 96.8-100.0], P = 0.156), and superior to serum GM (91.9% [95% CI, 85.9-95.5], P < 0.05). In bronchoalveolar lavage fluid (BALF) samples, the positive rate of mNGS was 97.6%, which was significantly higher than culture (28.6%, P <0.001). mNGS has excellent performance in the identification of mixed infection in TM group patients. Cytomegalovirus, Epstein-Barr virus and Pneumocystis jirovecii were the most common concurrent pathogens. In summary, 60.0% (36/60) patients were added or adjusted to antimicrobial therapy after mNGS test.

Conclusion

mNGS is a powerful technique with high specificity and sensitivity for the rapid diagnosis of talaromycosis. mNGS of BALF samples may be a good option for early identification of T. marneffei in HIV-infected individuals with manifestations of infection. Moreover, mNGS shows excellent performance in mixed infection, which benefits timely treatment and potential mortality reduction.

Interaction of Talaromyces marneffei with free living soil amoeba as a model of fungal pathogenesis

Talaromyces (Penicillium) marneffei is an important dimorphic mycosis endemic in Southeast Asia and Southern China, but the origin and maintenance of virulence traits in this organism remains obscure. Several pathogenic fungi, including Cryptococcus neoformans, Aspergillus fumigatus, Blastomyces dermatitidis, Sporothrix schenckii, Histoplasma capsulatum and Paracoccidioides spp. interact with free living soil amoebae and data suggests that fungal pathogenic strategies may emerge from environmental interactions of these fungi with ubiquitous phagocytic microorganisms. In this study, we examined the interactions of T. marneffei with the soil amoeba Acanthamoeba castellanii. T. marneffei was rapidly ingested by A. castellanii and phagocytosis of fungal cells resulted in amoeba death after 24 h of contact. Co-culture also resulted in a rapid transition for conidia to the fission-yeast form. In addition, well-established virulence factors such as melanin and a yeast specific mannoprotein of T. marneffei were expressed during interaction with A. castellanii at 37°C. Our findings support the assumption that soil amoebae environmental predators play a role in the selection and maintenance of particular features in T. marneffei that impart virulence to this clinically important dimorphic fungus in mammalian hosts.

Gastrointestinal Talaromyces marneffei infection in a patient with AIDS: A case report and systematic review

Talaromyces marneffei is a thermally dimorphic fungus that affects multiple organs and frequently invades immunocompromised individuals. However, only a few studies have reported the presence of intestinal infection associated with T. marneffei. Herein, we reported a case of intestinal T. marneffei infection in a man who complained of a 1-month history of intermittent fever, abdominal pain, and diarrhea. The result of the human immunodeficiency virus antibody test was positive. Periodic acid-Schiff and Gomorrah’s methylamine silver staining of the intestinal biopsy tissue revealed T. marneffei infection. Fortunately, the patient’s symptoms rapidly resolved with prompt antifungal treatment. In addition, we summarized and described the clinical characteristics, management, and outcomes of patients with intestinal T. marneffei infection. A total of 29 patients were identified, the majority of whom (65.52%) were comorbid with acquired immunodeficiency syndrome. The main clinical features included anemia, fever, abdominal pain, diarrhea, weight loss, and lymphadenopathy. The transverse and descending colon, ileocecum, and ascending colon were the most common sites of lesions. A considerable number of patients (31.03%) developed intestinal obstruction, intestinal perforation, and gastrointestinal bleeding. Of the 29 patients, six underwent surgery, 23 survived successfully with antifungal treatment, five died of T. marneffei infection, and one died of unknown causes. T. marneffei intestinal infection should be considered when immunodeficient patients in endemic areas present with non-specific symptoms, such as fever, abdominal pain, and diarrhea. Appropriate and timely endoscopy avoids delays in diagnosis. Early aggressive antifungal therapy improves the clinical outcomes of patients.

Population pharmacokinetics of voriconazole and initial dosage optimization in patients with talaromycosis

The high variability and unpredictability of the plasma concentration of voriconazole (VRC) pose a major challenge for clinical administration. The aim of this study was to develop a population pharmacokinetics (PPK) model of VRC and identify the factors influencing VRC PPK in patients with talaromycosis. Medical records and VRC medication history of patients with talaromycosis who were treated with VRC as initial therapy were collected. A total of 233 blood samples from 69 patients were included in the study. A PPK model was developed using the nonlinear mixed-effects models (NONMEM). Monte Carlo simulation was applied to optimize the initial dosage regimens with a therapeutic range of 1.0–5.5 mg/L as the target plasma trough concentration. A one-compartment model with first-order absorption and elimination adequately described the data. The typical voriconazole clearance was 4.34 L/h, the volume of distribution was 97.4 L, the absorption rate constant was set at 1.1 h^-1, and the bioavailability was 95.1%. Clearance was found to be significantly associated with C-reactive protein (CRP). CYP2C19 polymorphisms had no effect on voriconazole pharmacokinetic parameters. ‏Monte Carlo simulation based on CRP levels showed that a loading dose of 250 mg/12 h and a maintenance dose of 100 mg/12 h are recommended for patients with CRP ≤ 96 mg/L, whereas a loading dose of 200 mg/12 h and a maintenance dose of 75 mg/12 h are recommended for patients with CRP > 96 mg/L. The average probability of target attainment of the optimal dosage regimen in CRP ≤ 96 mg/L and CRP > 96 mg/L groups were 61.3% and 13.6% higher than with empirical medication, and the proportion of C_min > 5.5 mg/L decreased by 28.9%. In conclusion, the VRC PPK model for talaromycosis patients shows good robustness and predictive performance, which can provide a reference for the clinical individualization of VRC. Adjusting initial dosage regimens based on CRP may promote the rational use of VRC.

Important Mycoses of Wildlife: Emphasis on Etiology, Epidemiology, Diagnosis, and Pathology—A Review: PART 1

Simple Summary

The number of wild animals is steadily declining globally, so the early diagnosis and proper treatment of emerging diseases are vital. Fungal diseases are commonly encountered in practice and have a high zoonotic potential. This article describes aspergillosis, candidiasis, histoplasmosis, cryptococcosis, and penicilliosis, and is only the first part of a detailed review. The laboratory methods (fungal isolation, gross pathology, histopathology, histochemistry, cytology, immunohistochemistry, radiography, CT, PCR, or ELISA) used in the diagnosis and the clinical details that provide a complete view of the mycoses are presented.

Abstract

In the past few years, there has been a spurred tripling in the figures of fungal diseases leading to one of the most alarming rates of extinction ever reported in wild species. Some of these fungal diseases are capable of virulent infections and are now considered emerging diseases due to the extremely high number of cases diagnosed with fungal infections in the last few decades. Most of these mycotic diseases in wildlife are zoonotic, and with the emergence and re-emergence of viral and bacterial zoonotic diseases originating from wildlife, which are causing devastating effects on the human population, it is important to pay attention to these wildlife-borne mycotic diseases with zoonotic capabilities. Several diagnostic techniques such as fungal isolation, gross pathology, histopathology, histochemistry, cytology, immunohistochemistry, radiography, CT, and molecular methods such as PCR or ELISA have been invaluable in the diagnosis of wildlife mycoses. The most important data used in the diagnosis of these wildlife mycoses with a zoonotic potential have been re-emphasized. This will have implications for forestalling future epidemics of these potential zoonotic mycotic diseases originating from wildlife. In conclusion, this review will highlight the etiology, epidemiology, diagnosis, pathogenesis, pathogenicity, pathology, and hematological/serum biochemical findings of five important mycoses found in wild animals.

Anti-Interferon-γ Autoantibodies Impair T-Lymphocyte Responses in Patients with Talaromyces marneffei Infections

Background

Although anti-IFN-γ autoantibodies predispose patients to Talaromyces marneffei infection, whether this is mediated by T cell attenuation remains elusive.

Methods

Total peripheral blood mononuclear cells (PBMCs) from healthy donors or patients with T. marneffei infection were stimulated with M1₅₈₋₆₆, and immunodominant influenza H1N1 peptide, or heat-inactivated T. marneffei in the presence of serum from anti-IFN-γ autoantibody-positive patients or healthy controls. The percentages of IFN-γ⁺TNF⁺CD8⁺ T cells and IFN-γ⁺CD4⁺ T cells were determined by flow cytometry and cytokines released in the supernatant were detected by Cytometric Bead Array. Furthermore, PBMCs from patients with T. marneffei infection and healthy individuals were stimulated with IFN-γ and anti-CD3/CD28 beads, and the levels of STAT1 and STAT3 phosphorylation were detected by Western blot.

Results

The M1-reactive CD8⁺ T cells that expressed IFN-γ⁺ TNF-α⁺ of healthy controls were clearly reduced in serum with high-titer anti-IFN-γ autoantibodies. In addition, the CD4⁺ T cell response, designated by the expression of IFN-γ, against T. marneffei in PBMCs of patients were significantly decreased when cultured in high-titer anti-IFN-γ autoantibody serum culture, compared to the healthy compartments. Moreover, the release of the cytokines IFN-γ, TNF-α and IL-2 was significantly decreased, while IL-10 was significantly increased. There was no significant difference in the phosphorylation levels of STAT1 and STAT3 protein between patients and healthy controls after IFN-γ or anti-CD3/CD28 beads stimulation.

Conclusion

Anti-IFN-γ autoantibodies presence in the serum inhibited CD4⁺ Th1 and CD8⁺ T cell immune responses. There was no congenital dysfunction of STAT1 and STAT3 in anti-IFN-γ autoantibody-positive patients with T. marneffei infection. These results suggest that the production of anti-IFN-γ autoAbs impair T-lymphocyte responses.

MALDI-TOF MS-Based Clustering and Antifungal Susceptibility Tests of Talaromyces marneffei Isolates from Fujian and Guangxi (China)

Introduction

Talaromyces marneffei is a life-threatening pathogen that causes systemic talaromycosis in immunocompromised and acquired immunodeficiency syndrome (AIDS) patients. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a tool to cluster T. marneffei isolates is rarely reported and the data on antifungal susceptibility of T. marneffei isolated in the southern region of China, especially in Fujian, is hardly found.

Methods

MALDI-TOF MS was used to cluster 135 T. marneffei isolates, and the minimum inhibitory concentration (MIC) values of amphotericin B, itraconazole, posaconazole, voriconazole, fluconazole, anidulafungin, micafungin, caspofungin and 5-fluorocytosine with Sensititre YeastOne™ YO10 assay were measured during January 2017 to October 2020 in Fujian and Guangxi.

Results

MALDI-TOF MS correctly identified 100% of the T. marneffei isolates. Hierarchical clustering of MALDI-TOF peak profiles identified four different clusters. MICs for itraconazole, posaconazole, voriconazole and amphotericin B were as follows: ≤0.015–0.03 μg/mL, ≤0.008–0.03 μg/mL, ≤0.008–0.06 μg/mL, ≤0.12–1 μg/mL, respectively. MICs for echinocandins and fluconazole were comparatively high.

Conclusion

Since only simple sample preparation is required and since results are available in a short period of time, MALDI-TOF MS can be considered as a method for identification and clustering of T. marneffei. Itraconazole, posaconazole, voriconazole and amphotericin B can be used to treat T. marneffei infected patients due to the low MICs.

Talaromyces marneffei activates the AIM2-caspase-1/-4-GSDMD axis to induce pyroptosis in hepatocytes

Talaromyces marneffei tends to induce systemic infection in immunocompromised individuals, which is one of the causes of the high mortality. The underlying molecular mechanisms of T.marneffei-induced abnormal liver function are still poorly understood. In this study, we found that T.marneffei-infected patients could develop abnormal liver function, evidenced by reduced albumin and increased levels of aspartate aminotransferase (AST) and AST/alanine aminotransferase (ALT). T. marneffei-infected mice exhibited similar characteristics. In vitro investigations showed that T.marneffei induced the death of AML-12 cells. Furthermore, we determined that T.marneffei infection induced pyroptosis in hepatocytes of C57BL/6J mice and AML-12 cells, demonstrated by the increase of AIM2, caspase-1/-4, Gasdermin D(GSDMD) and pyroptosis-related cytokines in T.marneffei-infected mice/cells. Importantly, cell death was markedly suppressed in the presence of VX765 (an inhibitor of caspase-1/-4). Furthermore, in the presence of VX765, T.marneffei-induced pyroptosis was blocked. Nevertheless, necroptosis and apoptosis were also detected in infected animal model at 14 days post-infection. In conclusion, T.marneffei induces pyroptosis in hepatocytes through activation of the AIM2-caspase-1/-4-GSDMD axis, which may be an important cause of liver damage, and other death pathways including necroptosis and apoptosis may also be involved in the later stage of infection.