Pleurostomophora richardsiae - an insidious fungus presenting in a man 44 years after initial inoculation: A case report and review of the literature

Degradation of polypropylene by fungi Coniochaeta hoffmannii and Pleurostoma richardsiae

The urgent need for better disposal and recycling of plastics has motivated a search for microbes with the ability to degrade synthetic polymers. While microbes capable of metabolizing polyurethane and polyethylene terephthalate have been discovered and even leveraged in enzymatic recycling approaches, microbial degradation of additive-free polypropylene (PP) remains elusive. Here we report the isolation and characterization of two fungal strains with the potential to degrade pure PP. Twenty-seven fungal strains, many isolated from hydrocarbon contaminated sites, were screened for degradation of commercially used textile plastic. Of the candidate strains, two identified as Coniochaeta hoffmannii and Pleurostoma richardsiae were found to colonize the plastic fibers using scanning electron microscopy (SEM). Further experiments probing degradation of pure PP films were performed using C. hoffmannii and P. richardsiae and analyzed using SEM, Raman spectroscopy and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). The results showed that the selected fungi were active against pure PP, with distinct differences in the bonds targeted and the degree to which each was altered. Whole genome and transcriptome sequencing was conducted for both strains and the abundance of carbohydrate active enzymes, GC content, and codon usage bias were analyzed in predicted proteomes for each. Enzymatic assays were conducted to assess each strain's ability to degrade naturally occurring compounds as well as synthetic polymers. These investigations revealed potential adaptations to hydrocarbon-rich environments and provide a foundation for further investigation of PP degrading activity in C. hoffmannii and P. richardsiae.

A New Proposed Symbiotic Plant-Herbivore Relationship between Burkea africana Trees, Cirina forda Caterpillars and Their Associated Fungi Pleurostomophora richardsiae and Aspergillus nomius

Burkea africana is a tree found in savannah and woodland in southern Africa, as well as northwards into tropical African regions as far as Nigeria and Ethiopia. It is used as fuel wood, medicinally to treat various conditions, such as toothache, headache, migraine, pain, inflammation, and sexually transmitted diseases, such as gonorrhoea, but also an ornamental tree. The current study investigated the possible symbiotic relationship between B. africana trees and the C. forda caterpillars and the mutual role played in ensuring the survival of B. africana trees/seedlings in harsh natural conditions and low-nutrient soils. Deoxyribonucleic acid isolation and sequencing results revealed that the fungal species Pleurostomophora richardsiae was highly predominant in the leaves of B. africana trees and present in the caterpillars. The second most prominent fungal species in the caterpillars was Aspergillus nomius. The latter is known to be related to a Penicillium sp. which was found to be highly prevalent in the soil where B. africana trees grow and is suggested to play a role in enhancing the effective growth of B. africana trees in their natural habitat. To support this, a phylogenetic analysis was conducted, and a tree was constructed, which shows a high percentage similarity between Aspergillus and Penicillium sp. The findings of the study revealed that B. africana trees not only serve as a source of feed for the C. forda caterpillar but benefit from C. forda caterpillars which, after dropping onto the soil, is proposed to inoculate the soil surrounding the trees with the fungus A. nomius which suggests a symbiotic and/or synergistic relationship between B. africana trees and C. forda caterpillars.

Prospects for fungal bioremediation of unburied waste packages from the Goiânia radiological accident

Goiânia, the Goiás State capital, starred in 1987, where one of the largest radiological accidents in the world happened. A teletherapy machine was subtracted from a derelict radiotherapy clinic and disassembled by scavengers who distributed fragments of the 50 TBq ¹³⁷CsCl source among relatives and acquaintances, enchanted by the blue shine of the substance. During the 15 days before the accident was acknowledged, contaminated recycling materials were delivered to recycling factories in four cities in the state of São Paulo, Brazil, in the form of recycling paper bales. The contaminated bales were spotted, collected, and stored in fifty 1.6 m³ steel boxes at the interim storage facility of the Nuclear and Energy Research Institute (IPEN). In 2017, a check of the content was performed in a few boxes and the presence of high moisture content was observed even though the bales were dry when conditioned and the packages were kept sealed since then. The main objective of this work was to report the fungi found in the radioactive waste after they evolved for 30 years in isolation inside the waste boxes and their role in the decay of the waste. Examination of the microbiome showed the presence of nematodes and fungal communities. The fungi species isolated were Aspergillus quadricinctus, Fusarium oxysporum, Lecanicillium coprophilumi, Scedosporium boydii, Scytalidium lignicola, Xenoacremonium recifei, and Pleurostoma richardsiae. These microorganisms showed a significant capacity to digest cellulose in our trials, which could be one of the ways they survive in such a harsh environment, reducing the volume of radioactive paper waste. These metabolic abilities give us a future perspective of using these fungi in biotechnology to remediate radioactively contaminated materials, particularly cellulose-based waste.

Hepatic phaeohyphomycosis due to a novel dematiaceous fungus, Pleurostoma hongkongense sp. nov., and importance of antifungal susceptibility testing

Pleurostoma species are wood-inhabiting fungi and emerging opportunistic pathogens causing phaeohyphomycosis. In this study, we isolated a dematiaceous fungus, HKU44T, from the subhepatic abscess pus and drain fluids of a liver transplant recipient with post-transplant biliary and hepatico-jejunostomy bypass strictures. Histology of the abscess wall biopsy showed abundant fungal hyphae. The patient survived after a second liver transplant and antifungal therapy. On SDA, HKU44T grew initially as white powdery colonies which turned beige upon maturation. Hyphae were septate and hyaline. Phialides were monophialidic and laterally located, generally closely associated to a cluster of conidia which were usually reniform. Phylogenetic analyses showed that HKU44T is most closely related to, but distinct from, Pleurostoma ootheca and Pleurostoma repens. These suggested that HKU44T is a novel Pleurostoma species, for which the name Pleurostoma hongkongense sp. nov. is proposed. Antifungal susceptibility testing showed that Pleurostoma species possessed high MICs/MECs for fluconazole, 5-flucytosine and the echinocandins; whereas they exhibited a high strain-to-strain variability to the susceptibilities to the other triazoles. As for amphotericin B, ∼65% of the Pleurostoma strains had low MICs (≤1 µg/mL). DNA sequencing should be performed to accurately identify fungi with Pleurostoma/Phialophora-like morphologies, so is antifungal susceptibility testing for patients with Pleurostoma infections.

Disseminated phaeohyphomycosis with hepatic artery and portal vein thrombosis caused by Pleurostomophora richardsiae in a liver transplant recipient: A case report

Pleurostomophora richardsiae is a dematiaceous mold that causes subcutaneous cystic phaeohyphomycosis. Few cases of invasive P richardsiae infection have been reported. Hepatic artery thrombosis following organ transplantation caused by a fungal organism is also very rare. We present here a 57-year-old man with refractory ascites and liver failure following liver transplantation for treatment of hepatocellular carcinoma. Abdominal computed tomography demonstrated total occlusion of hepatic artery and blood clot in the portal vein and inferior vena cava. P richardsiae was isolated from blood culture and the blood clot in his liver. The patient was treated successfully with a 4-week course of amphotericin B deoxycholate and liver retransplantation.

Rare Pleurostomophora richardsiae Mass Causing Transient Nasolacrimal Duct Obstruction

Transient nasolacrimal duct obstruction secondary to a mass lesion compressing the sac or sac-duct junction is rare. The authors report a case of a young female who presented to the authors with complaints of watering and a mass lesion in the lacrimal sac region. An organized perilacrimal mass filled with thick pultaceous material was noted during surgery. Following the drainage of the mass lesion, irrigation of the lacrimal system was freely patent. Microbiological examination and DNA sequencing targeting interspacer region was suggestive of Pleurostomophora richardsiae species. To the best of the authors' knowledge, this is only the second case report of a subcutaneous perilacrimal mass causing transient nasolacrimal duct obstruction by Pleurostomophora richardsiae.

Fungal Olecranon Bursitis in an Immunocompetent Patient by Knoxdaviesia dimorphospora sp. nov.: Case Report and Review

Bursitis is a common medical condition that can occur either with or without infection. We present a case of fungal olecranon bursitis in an immunocompetent individual caused by the new species Knoxdaviesia dimorphospora. It is a dematiaceous filamentous fungus characterized by the production of two different conidia: hyaline and cylindrical, which rise up from phialidic conidiogenous cells located in the upper part of differentiated and unbranched conidiophores, and pale brown and ellipsoidal conidia produced by phialidic conidiogenous cells which are born directly on hyphae. In addition to its morphological peculiarities, the novelty of the fungus was confirmed by sequence analysis of the internal transcribed spacer (ITS) regions and D1/D2 domains of the 28S of the nuclear rRNA gene. The fungal infection was confirmed by cytological examination and repeated cultures. The infection was resolved by surgical debridement and drainage, and the patient presented a complete functional recovery 3 months later. The in vitro antifungal susceptibility to this new human opportunist is provided, terbinafine being the drug with the most potent activity.

Dematiaceous fungal endophthalmitis: report of a case and review of the literature

Background

Pleurostomophora richardsiae (formerly Phialophora richardsiae) is a dematiaceous fungus that is an uncommon cause of ocular infection. Herein, we present a case of endogenous endophthalmitis associated with disseminated P. richardsiae infection.

Findings

This is a descriptive case report with a brief review of literature. A 43-year-old male admitted to the hospital following an acute cerebellar hemorrhage was found to have a swollen and tender wrist. The patient was afebrile with leukocytosis. Visual acuity was hand motion in the right eye and 20/20 in the left. Right eye examination noted anterior chamber cells and flare, vitreous haze and multiple large, and fluffy retinal infiltrates. Diagnostic vitrectomy revealed a mixed inflammatory cell infiltrate with numerous fungal elements. Blood cultures were negative, multiple transesophageal echocardiography studies revealed no vegetations, and synovial fluid aspiration of the wrist and biopsy of the radius were unremarkable. The patient was treated with intravitreal cefazolin, vancomycin, and amphotericin B, topical ciprofloxacin and natamycin, and intravenous amphotericin B and voriconazole. Visual acuity in the right eye declined to light perception, and examination revealed increasing anterior and posterior chamber inflammation. The patient died several weeks after presentation due to a massive intracranial hemorrhage. Fungal culture results from the vitrectomy were received post mortem and were positive for P. richardsiae.

Conclusions

P. richardsiae endophthalmitis is rare, and outcomes are typically poor. Infections typically occur following traumatic skin inoculation; however, a long refractory period may occur before symptoms develop. Early diagnosis and combination antimicrobial therapy are essential to optimize visual outcomes.

Age and Gender Affect the Composition of Fungal Population of the Human Gastrointestinal Tract

The fungal component of the human gut microbiota has been neglected for long time due to the low relative abundance of fungi with respect to bacteria, and only recently few reports have explored its composition and dynamics in health or disease. The application of metagenomics methods to the full understanding of fungal communities is currently limited by the under representation of fungal DNA with respect to the bacterial one, as well as by the limited ability to discriminate passengers from colonizers. Here, we investigated the gut mycobiota of a cohort of healthy subjects in order to reduce the gap of knowledge concerning fungal intestinal communities in the healthy status further screening for phenotypical traits that could reflect fungi adaptation to the host. We studied the fecal fungal populations of 111 healthy subjects by means of cultivation on fungal selective media and by amplicon-based ITS1 metagenomics analysis on a subset of 57 individuals. We then characterized the isolated fungi for their tolerance to gastrointestinal (GI) tract-like challenges and their susceptibility to antifungals. A total of 34 different fungal species were isolated showing several phenotypic characteristics associated with intestinal environment such as tolerance to body temperature (37°C), to acidic and oxidative stress, and to bile salts exposure. We found a high frequency of azoles resistance in fungal isolates, with potential and significant clinical impact. Analyses of fungal communities revealed that the human gut mycobiota differs in function of individuals' life stage in a gender-related fashion. The combination of metagenomics and fungal cultivation allowed an in-depth understanding of the fungal intestinal community structure associated to the healthy status and the commensalism-related traits of isolated fungi. We further discussed comparatively the results of sequencing and cultivation to critically evaluate the application of metagenomics-based approaches to fungal gut populations.