A rare case of Trichosporon mycotoxinivorans and Cryptococcus neoformans co-infection in lung

Meningitis Due to Apiotrichum mycotoxinivorans: A Rare Case Report

A young adult male presented as a case of meningitis in the background of a ventriculoperitoneal shunt in situ, uncontrolled type 1 diabetes and a history of treated abdominal tuberculosis. The patient presented with complaints of high-grade fever, non-projectile vomiting, headache and drowsiness. He was eventually diagnosed as a case of fungal meningitis. The patient's cerebrospinal fluid analysis (CSF) analysis revealed budding yeast cells and the culture revealed Apiotrichum mycotoxinivorans. This is a yeast-like fungus that is known to cause opportunistic infections in an immunocompromised host. This is a rare cause of fungal meningitis and very few cases have been reported worldwide. This is the first case of Apiotrichum mycotoxinivorans-associated meningitis reported from India.

The first report of Apiotrichum mycotoxinivorans isolation from human cerebrospinal fluid

Fungal infections due to Apiotrichum mycotoxinivorans are clinically rare. Here, we report a case of invasive blood and cerebrospinal fluid infection by Apiotrichum mycotoxinivorans in a girl with B-cell acute lymphoblastic leukemia. This is the first report of the isolation of Apiotrichum mycotoxinivorans from human cerebrospinal fluid. MRI features of meningitis caused by this fungus are presented. Three small isoquinoline alkaloids inhibited the growth of this rare fungus in vitro, providing a starting point for the application of natural products to treat this highly fatal fungal infection. Our case presentation confirms Apiotrichum mycotoxinivorans as a potential emerging pathogen in patients with hematological malignancy undergoing chemotherapy.

The Th2 Response and Alternative Activation of Macrophages Triggered by Strongyloides venezuelensis Is Linked to Increased Morbidity and Mortality Due to Cryptococcosis in Mice

Cryptococcosis is a systemic mycosis that causes pneumonia and meningoencephalitis. Strongyloidiasis is a chronic gastrointestinal infection caused by parasites of the genus Strongyloides. Cryptococcosis and strongyloidiasis affect the lungs and are more prevalent in the same world regions, i.e., Africa and tropical countries such as Brazil. It is undeniable that those coincidences may lead to the occurrence of coinfections. However, there are no studies focused on the interaction between Cryptococcus spp. and Strongyloides spp. In this work, we aimed to investigate the interaction between Strongyloides venezuelensis (Sv) and Cryptococcus gattii (Cg) in a murine coinfection model. Murine macrophage exposure to Sv antigens reduced their ability to engulf Cg and produce reactive oxygen species, increasing the ability of fungal growth intracellularly. We then infected mice with both pathogens. Sv infection skewed the host's response to fungal infection, increasing lethality in a murine coinfection model. In addition to increased NO levels and arginase activity, coinfected mice presented a classic Th2 anti-Sv response: eosinophilia, higher levels of alternate activated macrophages (M2), increased concentrations of CCL24 and IL-4, and lower levels of IL-1β. This milieu favored fungal growth in the lungs with prominent translocation to the brain, increasing the host's tissue damage. In conclusion, our data shows that primary Sv infection promotes Th2 bias of the pulmonary response to Cg-infection and worsens its pathological outcomes.

Bronchial Artery-Pulmonary Artery Shunt by Apiotrichum mycotoxinivorans Infection in a Recurrent Hemoptysis Case

Background

Apiotrichum mycotoxinivorans is a rare mycotoxinivorans, and its pathogenicity is unknown. Bronchial artery shunt is a pathophysiological state following congenital or acquired chronic infection. We report a rare case of bronchial artery shunt by A. mycotoxinivorans infection in a recurrent hemoptysis patient.

Case Presentation

A 45-year-old female presented with recurrent cough and hemoptysis for 4 years. Before admission, she had been treated in several hospitals for pulmonary tuberculosis and bronchiectasis and received standardized anti-tuberculosis treatment for 1 year, but it was ineffective. After admission, CTPA and bronchial arterial angiography showed left bronchial artery–left pulmonary artery shunt and right bronchial artery–right pulmonary artery shunt. Fiber-optic bronchoscopy was performed, which revealed a large amount of purulent secretions, bronchoalveolar lavage fluid fungi (1-3)-β-d glucan: 728.06, and GM test: 3.239. Fungal hyphae and spores were observed by gram staining of BALF smear. Acid-fast bacilli were not found in BALF smear and brush smear. Two consecutive BALF fungal cultures grew A. mycotoxinivorans, the identity of which was confirmed by internal-transcribed-spacer (ITS) sequencing. Intravenous amphotericin B liposome (30mg; 0.5mg/kg, QD) was given for 2 weeks, embolization was performed, and itraconazole (voriconazole allergy) was taken orally for 9 months after operation. Hemoptysis and pulmonary lesions gradually improved after treatment.

Conclusion

We report the first case of bronchial artery–pulmonary artery shunt in a patient diagnosed with A. mycotoxinivorans infection. Phagocytosis of fungi by leukocytes was observed, and the pathogenicity of the fungus was confirmed in order to heighten the awareness of these infections.

Mixed Fungal Biofilms: From Mycobiota to Devices, a New Challenge on Clinical Practice

Most current protocols for the diagnosis of fungal infections are based on culture-dependent methods that allow the evaluation of fungal morphology and the identification of the etiologic agent of mycosis. Most current protocols for the diagnosis of fungal infections are based on culture-dependent methods that enable the examination of the fungi for further identification of the etiological agent of the mycosis. The isolation of fungi from pure cultures is typically recommended, as when more than one species is identified, the second agent is considered a contaminant. Fungi mostly survive in highly organized communities that provoke changes in phenotypic profile, increase resistance to antifungals and environmental stresses, and facilitate evasion from the immune system. Mixed fungal biofilms (MFB) harbor more than one fungal species, wherein exchange can occur that potentialize the effects of these virulence factors. However, little is known about MFB and their role in infectious processes, particularly in terms of how each species may synergistically contribute to the pathogenesis. Here, we review fungi present in MFB that are commensals of the human body, forming the mycobiota, and how their participation in MFB affects the maintenance of homeostasis. In addition, we discuss how MFB are formed on both biotic and abiotic surfaces, thus being a significant reservoir of microorganisms that have already been associated in infectious processes of high morbidity and mortality.

First report of collagenase production by Trichosporon sp. strain isolated from pollen of Amazonian bee (Melipona seminigra seminigra)

Trichosporon yeasts are widely employed to produce lipids, lipases, and aspartic peptidases, but there are no previous studies on collagenase production. This work aimed to select the best collagenase producing Amazonian Trichosporon strains. Moreover, a 2³-full factorial design (FFD) and a 2²-central composite design combined with Response Surface Methodology were applied to optimize production and find the best conditions for hydrolysis of type I bovine collagen. Most of the studied strains had some collagenolytic activity, but the selected one achieved the highest value (44.02 U) and a biomass concentration of 2.31 g/L. The best collagenase production conditions were 160 rpm of agitation, pH 5.5 and a substrate concentration of 4.0 g/L. The former experimental design showed that substrate concentration was the only statistically significant factor on both biomass concentration and collagenase activity, while the latter showed simultaneous effects of substrate concentration and pH on collagenolytic activity, which peaked at pH 5.5-6.4 and substrate concentration of 3.0-3.4 g/L. An additional 2³-FFD was finally used to optimize the conditions collagen hydrolysis, and pH 6, 25 °C and a substrate concentration of 7.5 (g/L) ensured the highest hydrolysis degree. This study is the first that describes optimized conditions of collagenase production by Trichosporon strains.

Complete Genome Sequencing and Comparative Analysis of the Clinically-Derived Apiotrichum mycotoxinivorans Strain GMU1709

Over the past decade, Apiotrichum mycotoxinivorans has been recognized globally as a source of opportunistic infections. It is a yeast-like fungus, and its association as an uncommon pulmonary pathogen with cystic fibrosis patients has been previously reported. Immunocompromised patients are at the highest risk of A. mycotoxinivorans infections. Therefore, to investigate the genetic basis for the pathogenicity of A. mycotoxinivorans, we performed whole-genome sequencing and comparative genomic analysis of A. mycotoxinivorans GMU1709 that was isolated from sputum specimens of a pneumonia patient receiving cardiac repair surgery. The assembly of Oxford Nanopore reads from the GMU1709 strain and its subsequent correction using Illumina paired-end reads yielded a high-quality complete genome with a genome size of 30.5 Mb in length, which comprised six chromosomes and one mitochondrion. Subsequently, 8,066 protein-coding genes were predicted based on multiple pieces of evidence, including transcriptomes. Phylogenomic analysis indicated that A. mycotoxinivorans exhibited the closest evolutionary affinity to A. veenhuisii, and both the A. mycotoxinivorans strains and the formerly Trichosporon cutaneum ACCC 20271 strain occupied the same phylogenetic position. Further comparative analysis supported that the ACCC 20271 strain belonged to A. mycotoxinivorans. Comparisons of three A. mycotoxinivorans strains indicated that the differences between clinical and non-clinical strains in pathogenicity and drug resistance may be little or none. Based on the comparisons with strains of other species in the Trichosporonaceae family, we identified potential key genetic factors associated with A. mycotoxinivorans infection or pathogenicity. In addition, we also deduced that A. mycotoxinivorans had great potential to inactivate some antibiotics (e.g., tetracycline), which may affect the efficacy of these drugs in co-infection. In general, our analyses provide a better understanding of the classification and phylogeny of the Trichosporonaceae family, uncover the underlying genetic basis of A. mycotoxinivorans infections and associated drug resistance, and provide clues into potential targets for further research and the therapeutic intervention of infections.