Phaeohyphomycosis caused by a plant pathogen, Corynespora cassiicola

Phaeohyphomycosis caused by Corynespora cassiicola, a plant pathogen worldwide

Although rare, trans-kingdom infection features an interesting infection biology concept, in which highly versatile pathogenic attributes allow successful infections in evolutionarily highly divergent species. Corynespora cassiicola is a phytopathogenic fungus and occasionally causes human infections. Herein, we report a phaeohyphomycosis case caused by C. cassiicola. Given that sporadic reports may contribute to a lack of awareness of the transmission route, clinical manifestations, and diagnostic and clinical management, we systematically reviewed the cases reported thus far. Nine patients were identified and included in the pooled analysis, 88.9% (8/9) of whom were reported after 2010. All patients were from Asian, African, and Latin American countries, among whom 77.8% (7/9) were farmers or lived in areas with active agriculture. Exposed body parts were the major affected infection area, and clinical manifestations were mainly non-specific inflammatory reactions. Although biochemical and morphological examinations confirmed the presence of fungal infection, molecular analysis was used for the final diagnosis, with 77.8% (7/9) being identified by internal transcribed spacer sequencing. Whereas voriconazole, terbinafine, and AmB, either alone or in combination, resulted in successful infection resolution in most cases (5/9; 55.5%), those suffering from invasive facial infections and CARD9 deficiency showed poor outcomes. Our patient is the third case of invasive facial infection caused by C. cassiicola and was successfully treated with intravenous LAmB followed by oral voriconazole combined with topical antifungal irrigation. Molecular identification of fungus and prompt antifungal treatment is pivotal in the clinical success of patients suspected to have phaeohyphomycosis. Moreover, as evidenced by our data, itraconazole treatment is not recommended.

Case report: A case of ocular infection caused by Corynespora cassiicola

Objective

The aim of this study is to identify the pathogen causing ocular infection in a Chinese patient and to describe its morphological characteristics.

Methods

Samples from the patient's intraoperative pus were collected for microscopic examination and culture. Morphology and drug sensitivities of the isolated fungus were analyzed. Ribosomal DNA (rDNA) sequencing was performed and blasted in GenBank.

Results

A strain of fungi was repeatedly isolated from pus samples in different types of medium. No conidia were shown when the isolate cultured on normal PDA medium, whereas pseudoseptate thick-walled conidia were shown when cultured on medium containing leaf leachate. The results of BLAST and phylogenetic trees based on internal transcribed spacer, beta-tubulin, translation elongation factor 1-alpha, and RNA polymerase II gene demonstrated that the isolated fungus was Corynespora cassiicola. Minimum inhibitory concentration results of this organism were as follows: anidulafungin, 0.06 μg/ml; amphotericin B, 0.12 μg/ml; micafungin, 0.06 μg/ml; caspofungin, 0.5 μg/ml; 5-fluorocytosine, >64 μg/ml; posaconazole, 2 μg/ml; voriconazole, 0.25 μg/ml; itraconazole, 0.5 μg/ml; fluconazole, 64 μg/ml.

Conclusion

The case was infected with Corynespora cassiicola and led to eye suppurative endophthalmitis and blindness. Combined applications of morphological and molecular biology techniques facilitate accurate diagnosis of fungal infections.

Phaeohyphomycosis in China

Background

Due to more attentions paid to melanized fungi over the past few decades and under the background of the global coronavirus disease 2019 pandemic (COVID-19) the fact that the virus itself and the immunosuppressive agents such as glucocorticoids can further increase the risk of infections of deep mycoses, the number of patients with phaeohyphomycosis (PHM) has a substantial increase. Their spectrum is broad and the early diagnosis and treatments are extremely sticky. This study aims to more comprehensively understand the clinical features of phaeohyphomycosis in China over 35 years and to establish a more applicable systematical classification and severity grades of lesions to guide treatments and prognosis.

Methods

We reviewed 174 cases of proven phaeohyphomycosis reported in Chinese and English language literature from 1987 to 2021 and we also made the accurate classification definitions and detailed information about the epidemiology, species of clinical dematiaceous fungi, minimum inhibitory concentration values, clinical features, treatments, and prognosis.

Results

The mortality of cerebral, disseminated and pulmonary phaeohyphomycosis are 55%, 36%, and 25%. Nearly 19% of patients had poor quality of life caused by the complications such as disability, disfigurements, and blindness. The overall misdiagnosis rate of phaeohyphomycosis was 74%. Moderate to severe rashes are accounting for 82% of subcutaneous phaeohyphomycosis. The areas of the head and face are mostly affected accounting for 16% of severe rashes. Nearly 30% of invasive infections of phaeohyphomycosis are triggered by recurrent lesions. Voriconazole, itraconazole, amphotericin B deoxycholate (AmB-DOC), and terbinafine were most commonly used but diagnosis and treatments of phaeohyphomycosis remain challenging in reality.

Conclusions

Our classifications are likely to be more practical and easier to popularize, and there are still also plenty of characteristics in these non-specific lesions. There’re no significant variations in cure rates, or death rates between three grades of lesions. But patients with severe rashes have longer courses and lower effective rates.

Pulmonary Cladosporium infection coexisting with subcutaneous Corynespora cassiicola infection in a patient: A case report

BACKGROUND

Cladosporium and Corynespora cassiicola (C. cassiicola) infections rarely occur in humans. Mutations in human caspase recruitment domain protein 9 (CARD9) are reported to be associated with fungal diseases. Pulmonary Cladosporium infection coexisting with subcutaneous C. cassiicola infection in a patient with a CARD9 mutation has not been reported in the literature.

CASE SUMMARY

A 68-year-old male patient was hospitalized for hypertrophic erythema and deep ulcers on the left upper extremity. He was diagnosed with pneumonia caused by Cladosporium, as identified through bronchoalveolar lavage fluid analysis, and deep dermatophytosis caused by C. cassiicola, as identified through morphological characteristics of the wound secretion culture. He underwent antifungal therapy (voriconazole) and recovered successfully. He carried two mutations in CARD9 (chr9:139266425 and chr9:139262240) and was therefore susceptible to fungal infections.

CONCLUSION

This case study is the first to report the coexistence of pulmonary Cladosporium infection and subcutaneous C. cassiicola infection in a patient with CARD9 mutation. Our findings will be helpful in enriching the phenotypic spectrum of fungal infections underlying CARD9 deficiency.

Successful Terbinafine Treatment for Cutaneous Phaeohyphomycosis Caused by Trematosphaeria grisea in a Heart Transplanted Man: Case Report and Literature Review

Phaeohyphomycosis is a chronic infectious disease caused by dematiaceous fungi. It is characterized by the presence of pigmented septate mycelia within tissues. In the case of superficial infection, the lesion(s) chronically evolve(s) toward painless pseudo-tumor(s) of the soft parts. We report herein the original case of a heart transplanted man who exhibited phaeohyphomycosis of the left hand, with no mention of travels in endemic areas. Trematosphaeria grisea was identified as the causative agent, which is quite innovative since this species has been rather described in mycetoma. The antifungal treatment initially based on isavuconazole alone was not sufficient to cure the patient. In contrast, its association with local terbinafine ointment allowed total clinical improvement. This finding is unusual as diagnosis of phaeohyphomycosis caused by T. grisea is uncommon in nontropical countries, and as the outcome appeared successful by the means of add-on therapeutic strategy with terbinafine.

Subcutaneous Fungal Infection Caused by a Non-sporulating Strain of Corynespora cassiicola Successfully Treated with Terbinafine

Corynespora cassiicola is a common plant pathogen, but C. cassiicola infection in human hosts is extremely rare. In this report, we present an 84-year-old male with long-term use of inhaled corticosteroids who developed a subcutaneous infection caused by C. cassiicola. The organism was isolated from both wound culture and biopsy specimen from the skin lesion. However, no microscopic diagnostic characters could be obtained because the isolates failed to sporulate on different culture media. Molecular diagnosis by amplification and sequencing of the internal transcribed spacer regions of ribosomal DNA was performed, and the sequences of the isolates were identical to those of C. cassiicola. The patient was treated successfully with oral terbinafine therapy for 12 weeks. In this report, we also review the epidemiology, clinical and therapeutic facets of cutaneous C. cassiicola infection.

Early-Onset Invasive Infection Due to Corynespora cassiicola Associated with Compound Heterozygous CARD9 Mutations in a Colombian Patient

PURPOSE

CARD9 deficiency is an inborn error of immunity that predisposes otherwise healthy humans to mucocutaneous and invasive fungal infections, mostly caused by Candida, but also by dermatophytes, Aspergillus, and other fungi. Phaeohyphomycosis are an emerging group of fungal infections caused by dematiaceous fungi (phaeohyphomycetes) and are being increasingly identified in patients with CARD9 deficiency. The Corynespora genus belongs to phaeohyphomycetes and only one adult patient with CARD9 deficiency has been reported to suffer from invasive disease caused by C. cassiicola. We identified a Colombian child with an early-onset, deep, and destructive mucocutaneous infection due to C. cassiicola and we searched for mutations in CARD9.

METHODS

We reviewed the medical records and immunological findings in the patient. Microbiologic tests and biopsies were performed. Whole-exome sequencing (WES) was made and Sanger sequencing was used to confirm the CARD9 mutations in the patient and her family. Finally, CARD9 protein expression was evaluated in peripheral blood mononuclear cells (PBMC) by western blotting.

RESULTS

The patient was affected by a large, indurated, foul-smelling, and verrucous ulcerated lesion on the left side of the face with extensive necrosis and crusting, due to a C. cassiicola infectious disease. WES led to the identification of compound heterozygous mutations in the patient consisting of the previously reported p.Q289* nonsense (c.865C > T, exon 6) mutation, and a novel deletion (c.23_29del; p.Asp8Alafs10*) leading to a frameshift and a premature stop codon in exon 2. CARD9 protein expression was absent in peripheral blood mononuclear cells from the patient.

CONCLUSION

We describe here compound heterozygous loss-of-expression mutations in CARD9 leading to severe deep and destructive mucocutaneous phaeohyphomycosis due to C. cassiicola in a Colombian child.

A case of Phaeohyphomycosis caused by Corynespora cassiicola infection

BACKGROUND

Corynespora cassiicola infection is common in plants, but the human Corynespora cassiicola infection in our report is rare according to the literature.

CASE PRESENTATION

We report a case of subcutaneous phaeohyphomycosis caused by a plant pathogen in a patient with acute heart failure. The organism was isolated and identified as Corynespora cassiicola according to its morphological characteristics and gene analysis. The patient was treated successfully with systemic voriconazole.

CONCLUSIONS

This is the third reported case of subcutaneous infection caused by Corynespora cassiicola and the first reported case with accompanied renal impairment, which was associated with acute heart failure. Our case also suggests the importance of renal function monitoring in patients receiving intravenous voriconazole treatment.

Inherited CARD9 Deficiency: Invasive Disease Caused by Ascomycete Fungi in Previously Healthy Children and Adults

Autosomal recessive CARD9 deficiency underlies life-threatening, invasive fungal infections in otherwise healthy individuals normally resistant to other infectious agents. In less than 10 years, 58 patients from 39 kindreds have been reported in 14 countries from four continents. The patients are homozygous (n = 49; 31 kindreds) or compound heterozygous (n = 9; 8 kindreds) for 22 different CARD9 mutations. Six mutations are recurrent, probably due to founder effects. Paradoxically, none of the mutant alleles has been experimentally demonstrated to be loss-of-function. CARD9 is expressed principally in myeloid cells, downstream from C-type lectin receptors that can recognize fungal components. Patients with CARD9 deficiency present impaired cytokine and chemokine production by macrophages, dendritic cells, and peripheral blood mononuclear cells and defective killing of some fungi by neutrophils in vitro. Neutrophil recruitment to sites of infection is impaired in vivo. The proportion of Th17 cells is low in most, but not all, patients tested. Up to 52 patients suffering from invasive fungal diseases (IFD) have been reported, with ages at onset of 3.5 to 52 years. Twenty of these patients also displayed superficial fungal infections. Six patients had only mucocutaneous candidiasis or superficial dermatophytosis at their last follow-up visit, at the age of 19 to 50 years. Remarkably, for 50 of the 52 patients with IFD, a single fungus was involved; only two patients had IFDs due to two different fungi. IFD recurred in 44 of 45 patients who responded to treatment, and a different fungal infection occurred in the remaining patient. Ten patients died from IFD, between the ages of 12 and 39 years, whereas another patient died at the age of 91 years, from an unrelated cause. At the most recent scheduled follow-up visit, 81% of the patients were still alive and aged from 6.5 to 75 years. Strikingly, all the causal fungi belonged to the phylum Ascomycota: commensal Candida and saprophytic Trychophyton, Aspergillus, Phialophora, Exophiala, Corynesprora, Aureobasidium, and Ochroconis. Human CARD9 is essential for protective systemic immunity to a subset of fungi from this phylum but seems to be otherwise redundant. Previously healthy patients with unexplained invasive fungal infection, at any age, should be tested for inherited CARD9 deficiency.

KEY POINTS

• Inherited CARD9 deficiency (OMIM #212050) is an AR PID due to mutations that may be present in a homozygous or compound heterozygous state. • CARD9 is expressed principally in myeloid cells and transduces signals downstream from CLR activation by fungal ligands. • Endogenous mutant CARD9 levels differ between alleles (from full-length normal protein to an absence of normal protein). • The functional impacts of CARD9 mutations involve impaired cytokine production in response to fungal ligands, impaired neutrophil killing and/or recruitment to infection sites, and defects of Th17 immunity. • The key clinical manifestations in patients are fungal infections, including CMC, invasive (in the CNS in particular) Candida infections, extensive/deep dermatophytosis, subcutaneous and invasive phaeohyphomycosis, and extrapulmonary aspergillosis. • The clinical penetrance of CARD9 deficiency is complete, but penetrance is incomplete for each of the fungi concerned. • Age at onset is highly heterogeneous, ranging from childhood to adulthood for the same fungal disease. • All patients with unexplained IFD should be tested for CARD9 mutations. Familial screening and genetic counseling should be proposed. • The treatment of patients with CARD9 mutations is empirical and based on antifungal therapies and the surgical removal of fungal masses. Patients with persistent/relapsing Candida infections of the CNS could be considered for adjuvant GM-CSF/G-CSF therapy. The potential value of HSCT for CARD9-deficient patients remains unclear.

Genomic insight into pathogenicity of dematiaceous fungus Corynespora cassiicola

Corynespora cassiicola is a common plant pathogen that causes leaf spot disease in a broad range of crop, and it heavily affect rubber trees in Malaysia (Hsueh, 2011; Nghia et al., 2008). The isolation of UM 591 from a patient's contact lens indicates the pathogenic potential of this dematiaceous fungus in human. However, the underlying factors that contribute to the opportunistic cross-infection have not been fully studied. We employed genome sequencing and gene homology annotations in attempt to identify these factors in UM 591 using data obtained from publicly available bioinformatics databases. The assembly size of UM 591 genome is 41.8 Mbp, and a total of 13,531 (≥99 bp) genes have been predicted. UM 591 is enriched with genes that encode for glycoside hydrolases, carbohydrate esterases, auxiliary activity enzymes and cell wall degrading enzymes. Virulent genes comprising of CAZymes, peptidases, and hypervirulence-associated cutinases were found to be present in the fungal genome. Comparative analysis result shows that UM 591 possesses higher number of carbohydrate esterases family 10 (CE10) CAZymes compared to other species of fungi in this study, and these enzymes hydrolyses wide range of carbohydrate and non-carbohydrate substrates. Putative melanin, siderophore, ent-kaurene, and lycopene biosynthesis gene clusters are predicted, and these gene clusters denote that UM 591 are capable of protecting itself from the UV and chemical stresses, allowing it to adapt to different environment. Putative sterigmatocystin, HC-toxin, cercosporin, and gliotoxin biosynthesis gene cluster are predicted. This finding have highlighted the necrotrophic and invasive nature of UM 591.

Molecular and Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry-Based Characterization of Clinically Significant Melanized Fungi in India

Melanized or black fungi are a heterogeneous group of fungi causing cutaneous to systemic diseases with high mortality. These fungi are rarely reported as agents of human infections, primarily due to difficulties in their classical identification. In this study, we examined, using molecular methods and matrix-assisted laser desorption ioniazation-time of flight mass spectrometry (MALDI-TOF MS), the diversity of melanized fungi (MF) isolated from patients in 19 medical centers in India. Overall, during a 4-year period, 718 (5.3%) clinical specimens yielded MF. Of these, 72 (10%) isolates had clinical significance and were identified primarily by sequencing the internal transcribed spacer and large subunit (LSU) regions. MF represented 21 genera comprising 29 species, the majority of them belonging to the orders Pleosporales (50%) and Chaetothyriales (22%). Among the 29 fungal species identified in this study, only 6 (20%) species were identified by the MALDI-TOF MS due to the limited commercial database of Bruker Daltonics for MF. However, a 100% identification rate of 20 additional species identified in this study was obtained by constructing an in-house database using 24- to 96-h-old liquid cultures. Further, the CLSI broth microdilution method revealed low MICs for posaconazole (≤1 μg/ml) and voriconazole (≤2 μg/ml) in 96% and 95% of isolates, respectively. Skin/subcutaneous and sino-nasal and pulmonary phaeohyphomycosis due to MF were diagnosed in 21.4% (n = 15) and 28.5% (n = 20) of cases. Also, 10% of patients had central nervous system involvement (n = 7), and 3 cases of fungal osteomyelitis due to Cladophialophora bantiana and Corynespora spp. were observed.