Chaetomium globosum Cutaneous Fungal Infection Confirmed by Molecular Identification: A Case Report from Malaysia

Infective endocarditis caused by Chaetomium globosum

Chaetomium globosum is a dematiaceous, filamentous fungus belonging to the large genus saprobic ascomycetes and is rarely involved in human infection. We present the case of a 25-year-old man undergoing tricuspid valve replacement due to recurrent prosthetic ring endocarditis. Initially, it was considered culture-negative endocarditis; however, the diagnosis of Chaetomium globosum could only be provided by DNA isolation of the mold isolate grown in culture and the valve tissue samples taken from the patient. This report describes the first documented tricuspid endocarditis caused by Chaetomium species and discusses the importance of molecular tools to enhance the diagnostic process in culture-negative endocarditis, especially for fastidious and nonculturable microorganisms.

Epipolythiodioxopiperazine-Based Natural Products: Building Blocks, Biosynthesis and Biological Activities

Epipolythiodioxopiperazines (ETPs) are fungal secondary metabolites that share a 2,5-diketopiperazine scaffold built from two amino acids and bridged by a sulfide moiety. Modifications of the core and the amino acid side chains, for example by methylations, acetylations, hydroxylations, prenylations, halogenations, cyclizations, and truncations create the structural diversity of ETPs and contribute to their biological activity. However, the key feature responsible for the bioactivities of ETPs is their sulfide moiety. Over the last years, combinations of genome mining, reverse genetics, metabolomics, biochemistry, and structural biology deciphered principles of ETP production. Sulfurization via glutathione and uncovering of the thiols followed by either oxidation or methylation crystallized as fundamental steps that impact expression of the biosynthesis cluster, toxicity and secretion of the metabolite as well as self-tolerance of the producer. This article showcases structure and activity of prototype ETPs such as gliotoxin and discusses the current knowledge on the biosynthesis routes of these exceptional natural products.

Protothecosis algaemia in a patient presenting with septic arthritis: A rare case of Prototheca zopfii isolated from Malaysia

Prototheca species have been reported to cause infections in human. Typically, clinical symptoms of protothecosis include cutaneous infection, olecranon bursitis, tenosynovitis and disseminated systemic disease. We report a case of septic arthritis in which Prototheca zopfii was isolated from blood. Joint aspirate was also sent for cultures but did not yield any growth. No other organisms were isolated from this patient during his admission. The blood isolate was identified to species level via Polymerase Chain Reaction (PCR) method. The patient improved with administration of intravenous itraconazole.

A Fatal Case of Candida auris and Candida tropicalis Candidemia in Neutropenic Patient

We report a fatal case of Candida auris that was involved in mixed candidemia with Candida tropicalis, isolated from the blood of a neutropenic patient. Identification of both isolates was confirmed by amplification and sequencing of internal transcribed spacer and D1/D2 domain of large subunit in rRNA gene. Antifungal susceptibility test by E-test method revealed that C. auris was resistant to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole and voriconazole. On the other hand, C. tropicalis was sensitive to all antifungal tested. The use of chromogenic agar as isolation media is vital in detecting mixed candidemia.

Visualization of the structural changes in plywood and gypsum board during the growth of Chaetomium globosum and Stachybotrys chartarum

Fungal growth in indoor environments is associated with many negative health effects. Many studies focus on brown- and white-rot fungi and their effect on wood, but there is none that reveals the influence of soft-rot fungi, such as Stachybotrys spp. and Chaetomium spp., on the structure of building materials such as plywood and gypsum wallboard. This study focuses on using micro-computed tomography (microCT) to investigate changes of the structure of plywood and gypsum wallboard during fungal degradation by S. chartarum and C. globosum. Changes in the materials as a result of dampness and fungal growth were determined by measuring porosity and pore shape via microCT. The results show that the composition of the building material influenced the level of penetration by fungi as shown by scanning electron microscopy (SEM). Plywood appeared to be the most affected, with the penetration of moisture and fungi throughout the whole thickness of the sample. Conversely, fungi grew only on the top cardboard in the gypsum wallboard and they did not have significant influence on the gypsum wallboard structure. The majority of the observed changes in gypsum wallboard occurred due to moisture. This paper suggests that the mycelium distribution within building materials and the structural changes, caused by dampness and fungal growth, depend on the type of the material.

First isolation of Candida wangnamkhiaoensis from the blood of immunocompromised paediatric patient

Candida wangnamkhiaoensis is a species clustered under the Hyphopichia clade has not ever been isolated from any clinical specimens. To the best of our knowledge, this is the first report of C. wangnamkhiaoensis associated with fungaemia in immunocompromised paediatric patient. The isolate was assigned a strain name as UZ1679/14, in which the identification was confirmed by a polymerase chain reaction-sequencing of the internal transcribed spacer (ITS) and large subunit (LSU) regions of the rRNA gene. Antifungal susceptibility pattern showed that the isolate was sensitive to anidulafungin, caspofungin, fluconazole and voriconazole. The patient clinically improved after the antifungal treatment with caspofungin.

Chaetomium atrobrunneum and Aspergillus fumigatus in multiple tracheal aspirates: Copathogens or symbiosis

Chaetomium atrobrunneum has never been reported to be associated with pneumonia. We report the isolation of C. atrobrunneum and Aspergillus fumigatus from a Chinese elderly patient with fatal pneumonia. Branched, long, and septate hyphae were observed in potassium hydroxide preparations and Gram-stained smears, and confluent C. atrobrunneum growth and a few A. fumigatus colonies were found in tracheal aspirates (nine separate occasions). These isolates were identified by conventional morphological methods and by sequencing the internal transcribed spacer and the D1/D2 domain of the 26S rRNA gene. The patient responded poorly to the combination therapy of amphotericin B and caspofungin. This report adds C. atrobrunneum to the list of fungal pneumonia in immunocompromised hosts. This case report also illustrated the presence of a growth symbiosis between Chaetomium species and A. fumigatus.

Invasive pulmonary mycosis due to Chaetomium globosum with false-positive galactomannan test: a case report and literature review

In this case, the authors report Chaetomium globosum as a cause of invasive pulmonary infection in a patient with Wegener's granulomatosis. Fungal hyphae (KOH and Calcofluor) were seen on direct microscopy of lung biopsy sample and bronchoalveolar lavage (BAL) sample. C. globosum isolated on culture clinched the diagnosis of invasive pulmonary infection by Chaetomium spp. A positive galactomannan of serum and BAL was repeatedly seen and was utilised for follow-up and as prognostic marker in patient management. The patient was successfully treated with liposomal amphotericin B followed by voriconazole. All the Chaetomium infections reported till date since 1980 are reviewed. Chaetomium spp. with its unique ecology has a hidden clinical potential to cause invasive mould infections.

Subcutaneous Infection Associated with Trichosporon ovoides: A Case Report and Review of Literature

Trichosporon species are opportunistic yeasts which can cause infections, especially in immunocompromised patients. This is a report of Trichosporon ovoides that caused subcutaneous infection in a patient with underlying ischemic heart disease. The identification of fungal isolate was confirmed by PCR sequencing of ITS and large subunit regions in rRNA gene. In vitro susceptibility study showed that the isolate was susceptible to amphotericin B, fluconazole and voriconazole, and resistant to caspofungin, anidulafungin and itraconazole. The lesion improved after treatment with oral fluconazole and topical miconazole.