Actinomucor elegans as an emerging cause of Mucormycosis

Isolation of Main Pathogens Causing Postharvest Disease in Fresh Codonopsis pilosula during Different Storage Stages and Ozone Control against Disease and Mycotoxin Accumulation

Codonopsis pilosula is an important Chinese herbal medicine. However, fresh C. pilosula is prone to decay during storage due to microorganism infections, seriously affecting the medicinal value and even causing mycotoxin accumulation. Therefore, it is necessary to study the pathogens present and develop efficient control strategies to mitigate their detrimental effects on the herbs during storage. In this study, fresh C. pilosula was collected from Min County in Gansu Province, China. The natural disease symptoms were observed during different storage stages, and the pathogens causing C. pilosula postharvest decay were isolated from the infected fresh C. pilosula. Morphological and molecular identification were performed, and pathogenicity was tested using Koch's postulates. In addition, the control of ozone was examined against the isolates and mycotoxin accumulation. The results indicated that the naturally occurring symptom increased progressively with the extension of storage time. The mucor rot caused by Mucor was first observed on day 7, followed by root rot caused by Fusarium on day 14. Blue mold disease caused by Penicillum expansum was detected as the most serious postharvest disease on day 28. Pink rot disease caused by Trichothecium roseum was observed on day 56. Moreover, ozone treatment significantly decreased the development of postharvest disease and inhibited the accumulations of patulin, deoxynivalenol, 15-Acetyl-deoxynivalenol, and HT-2 toxin.

Emerging mould infections: Get prepared to meet unexpected fungi in your patient

Invasive fungal diseases are increasing issues in modern medicine, where the human immunodeficiency virus (HIV) pandemic and the wider use of immunosuppressive drugs generate an ever-growing number of immunocompromised patients with an increased susceptibility to uncommon fungal pathogens. In the past decade, new species have been reported as being responsible for disseminated and invasive fungal diseases in humans. Among them, the following genera are rare but seem emerging issues: Scopulariopsis, Hormographiella, Emergomyces, Westerdykella, Trametes, Actinomucor, Saksenaea, Apophysomyces, and Rhytidhysteron. Delay in diagnosis, which is often the case in these infections, jeopardizes patients' prognosis and leads to increased mortality. Here we summarize the clinical and biological presentation and the key features to identify these emerging pathogens and we discuss the available antifungal classes to treat them. We focused on Pubmed to recover extensively reported human invasive cases and articles regarding the nine previously cited fungal organisms. Information concerning patient background, macroscopic and microscopic description and pictures of these fungal organisms, histological features in tissues, findings with commonly used antigen tests in practice, and hints on potential efficient antifungal classes were gathered. This review's purpose is to help clinical microbiologists and physicians to suspect, identify, diagnose, and treat newly encountered fungi in hospital settings.

An Unusual Case of Actinomucor elegans: A Challenging Diagnosis

Patient: Male, 70-year-old

Final Diagnosis: Actinomucor elegans

Symptoms: Bleeding • dizziness • eschar

Medication: —

Clinical Procedure: Culture • MALDI • sequencing • tooth extraction

Specialty: Infectious Diseases

Updates on the Taxonomy of Mucorales with an Emphasis on Clinically Important Taxa

Fungi of the order Mucorales colonize all kinds of wet, organic materials and represent a permanent part of the human environment. They are economically important as fermenting agents of soybean products and producers of enzymes, but also as plant parasites and spoilage organisms. Several taxa cause life-threatening infections, predominantly in patients with impaired immunity. The order Mucorales has now been assigned to the phylum Mucoromycota and is comprised of 261 species in 55 genera. Of these accepted species, 38 have been reported to cause infections in humans, as a clinical entity known as mucormycosis. Due to molecular phylogenetic studies, the taxonomy of the order has changed widely during the last years. Characteristics such as homothallism, the shape of the suspensors, or the formation of sporangiola are shown to be not taxonomically relevant. Several genera including Absidia, Backusella, Circinella, Mucor, and Rhizomucor have been amended and their revisions are summarized in this review. Medically important species that have been affected by recent changes include Lichtheimia corymbifera, Mucor circinelloides, and Rhizopus microsporus. The species concept of Rhizopus arrhizus (syn. R. oryzae) is still a matter of debate. Currently, species identification of the Mucorales is best performed by sequencing of the internal transcribed spacer (ITS) region. Ecologically, the Mucorales represent a diverse group but for the majority of taxa, the ecological role and the geographic distribution remain unknown. Understanding the biology of these opportunistic fungal pathogens is a prerequisite for the prevention of infections, and, consequently, studies on the ecology of the Mucorales are urgently needed.

Invasive mucormycosis during treatment for acute lymphoblastic leukaemia-successful management of two life-threatening diseases

A 5-year-old patient treated for acute lymphoblastic leukaemia (ALL) developed proven pulmonary invasive fungal disease (IFD) due to Actinomucor elegans. While completing ALL treatment according to AIEOP ALL protocol 2009 for further 15 months, antifungal treatment with liposomal amphotericin B and intermittent additional posaconazole was continued until immune reconstitution 7 months after the end of ALL treatment. Repeated imaging guided treatment decisions. Twenty-six and 19 months after the end of ALL treatment and antifungal treatment, respectively, the patient is still in the first complete remission and shows no signs of active invasive fungal disease (IFD).

Phylogenetic Status of Two Undescribed Zygomycete Species from Korea: Actinomucor elegans and Mucor minutus

During a survey of fungal diversity of the order Mucorales, three zygomycete isolates, CNUFC-YR113-1, CNUFC-KNU16-7, and CNUFC-BS1-1 were isolated from freshwater and soil samples in Korea. The strains were analyzed both morphologically and phylogenetically based on internal transcribed spacer and 28S rDNA gene sequences. Based on their morphology and phylogeny, the CNUFC-YR113-1 and CNUFC-KNU16-7 isolates were identified as Actinomucor elegans, and CNUFC-BS1-1 was identified as Mucor minutus. To the best of our knowledge, the species A. elegans and M. minutus, belonging to an undiscovered taxon, have not been previously described in Korea.

Update on Actinomucor elegans, a mucormycete infrequently detected in human specimens: how combined microbiological tools contribute efficiently to a more accurate medical care

Actinomucor elegans is a fungus belonging to mucormycetes and is still probably underdiagnosed due to misidentification. Based on a recent first case of Actinomucor elegans sinusitis in Europe, in an immunocompromised patient under voriconazole treatment, this paper aims to summarize knowledge about A. elegans mucormycoses. Even if the diagnosis of mucormycosis was made using traditional mycology techniques, precise identification of the fungus could only be achieved using molecular tools. In this observation, the galactomannan dosage was positive until the introduction of treatment and surgical debridement. The patient experienced no relapse after one year. By reviewing the four previous A. elegans reported cases and describing the mycological characteristics of this species, we highlight the need to use a combination of tools to improve the diagnostic strategy in such rare and life-threatening clinical situations.

A High-Level Fungal Diversity in the Intertidal Sediment of Chinese Seas Presents the Spatial Variation of Community Composition

The intertidal region is one of the most dynamic environments in the biosphere, which potentially supports vast biodiversity. Fungi have been found to play important roles in marine ecosystems, e.g., as parasites or symbionts of plants and animals, and as decomposers of organic materials. The fungal diversity in intertidal region, however, remains poorly understood. In this study, sediment samples from various intertidal habitats of Chinese seas were collected and investigated for determination of fungal community and spatial distribution. Through ribosomal RNA internal transcribed spacer-2 (ITS2) metabarcoding, a high-level fungal diversity was revealed, as represented by 6,013 OTUs that spanned six phyla, 23 classes, 84 orders and 526 genera. The presence of typical decomposers (e.g., Corollospora in Ascomycota and Lepiota in Basidiomycota) and pathogens (e.g., Olpidium in Chytriomycota, Actinomucor in Zygomycota and unidentified Rozellomycota spp.), and even mycorrhizal fungi (e.g., Glomus in Glomeromycota) indicated a complicated origin of intertidal fungi. Interestingly, a small proportion of sequences were classified to obligate marine fungi (e.g., Corollospora, Lignincola, Remispora, Sigmoidea). Our data also showed that the East China Sea significantly differed from other regions in terms of species richness and community composition, indicating a profound effect of the huge discharge of the Yangtze River. No significant difference in fungal communities was detected, however, among habitat types (i.e., aquaculture, dock, plant, river mouth and tourism). These observations raise further questions on adaptation of these members to environments and the ecological functions they probably perform.

Mucormycosis or extranodal natural killer/T cell lymphoma, similar symptoms but different diagnosis

Facial mucormycosis and extranodal natural killer/T cell lymphoma (NK/TCL) are characterized by facial progressive swelling, ulceration and destruction. Patient one was a 58-year-old woman, who had typical clinical-pathological symptoms of tumor. She was hospitalized in order to remove the tumor. But the diagnosis turned out to be primary mucor infection, which was corrected by positive tissue culture and fungal elements in histology. She was also diagnosed with type 2 diabetes mellitus and acute myelocytic leukemia M2a. With the antifungal therapy, her symptoms, signs and general conditions improved. Regrettably, she gave up the treatment, and died three months later for unknown reason. Patient two was a 60-year-old woman, with the complaints of chronic sinusitis, swelling and necrotic lesion in the right temporal area. Although the mycelium was recovered in biopsy tissues from the necrotic lesion, the diagnosis was revised to extranodal NK/TCL by reviewing the histopathological features and immunophenotypic analysis. The patient also voluntarily abandoned treatment, and died at home for unknown reason. The differential diagnosis of facial mucormycosis and extranodal NK/TCL is usually perplexing.

First Human Case of Fungal Keratitis Caused by a Putatively Novel Species of Lophotrichus

We report an aggressive fungal keratitis caused by a putatively novel species of Lophotrichus in a patient with traumatic injury to the cornea from a dog paw. The organism was isolated from the patient's necrotic cornea, which perforated despite coverage with hourly fortified broad-spectrum topical antibiotic therapy. This report represents the first case of human infection caused by this species.

First report of Westerdykella dispersa as a cause of an angioinvasive fungal infection in a neutropenic host

Angioinvasive fungal infections (AFIs) are an important cause of morbidity and mortality among immunocompromised patients. However, clinicomicrobiological characteristics and treatment of many AFI agents remain poorly defined. We report the first human case of infection with Westerdykella dispersa, an emergent cause of AFI, which was successfully treated in a neutropenic pediatric patient.

Cunninghamella echinulata causing fatally invasive fungal sinusitis

We report a fatal case of invasive fungal sinusitis caused by Cunninghamella echinulata in a febrile, neutropenic 15-year-old male with relapsing acute leukemia. The isolate was recovered from a nasal biopsy from the right middle meatus, and microscopic examination of the tissue revealed angioinvasion and necrosis. Human infection caused by this organism has not been well documented; however, this report alerts us to its life-threatening potential.

Taxonomy and epidemiology of Mucor irregularis, agent of chronic cutaneous mucormycosis

Mucormycosis usually presents as a progressive infection with significant angio-invasion. Mucormycosis due to Mucor irregularis (formerly Rhizomucor variabilis var. variabilis), however, is exceptional in causing chronic cutaneous infection in immunocompetent humans, ultimately leading to severe morbidity if left untreated. More than 90 % of the cases known to date were reported from Asia, mainly from China. The nearest neighbour of M. irregularis is the saprobic species M. hiemalis. The aim of this study was to evaluate the taxonomic position, epidemiology, and intra- and inter-species diversity of M. irregularis based on 21 strains (clinical n = 17) by multilocus analysis using ITS, LSU, RPB1 and RPB2 genes, compared to results of cluster analysis with amplified fragment length polymorphism (AFLP) data. By combining MLST and AFLP analyses, M. irregularis was found to be monophyletic with high bootstrap support, and consisted of five subgroups, which were not concordant in all partitions. It was thus confirmed that M. irregularis is a single species at 96.1–100 % ITS similarity and low recombination rates between populations. Some geographic structuring was noted with some localised populations, which may be explained by limited air-dispersal. The natural habitat of the species is likely to be in soil and decomposing plant material.