Morphologic and phylogenetic characterization of Conidiobolus lamprauges recovered from infected sheep

 Azygosporus gen. nov., a synapmorphic clade in the family Ancylistaceae

The fungal genus Conidiobolus sensu lato was delimited into four genera based on morphology and phylogeny. However, the taxonomic placement of C.parvus has not been determined until now. Here, we show that C.parvus belongs to a distinct lineage based on mitochondrial (mtSSU) and nuclear (TEF1 and nrLSU) phylogenetic analyses. Phylogenetic analyses further revealed a new species as sister to C.parvus. We identified a synapomorphy uniting these lineages (azygospore production) that was not observed in other allied genera of the family Ancylistaceae, and erected a new genus Azygosporusgen. nov. for this monophyletic group, with a new combination, A.parvuscomb. nov. as the type species. Within Azygosporus, the novel species A.macropapillatussp. nov. was introduced from China based on morphological characteristics and molecular evidence, which is characterized by its prominent basal papilla, in comparison to other closely related species, measuring 7.5–10.0×5.0–10.0 µm. Our study resolved the phylogenetic placement of C.parvus and improved the taxonomic system of the Ancylistaceae family.

The Gene Rearrangement, Loss, Transfer, and Deep Intronic Variation in Mitochondrial Genomes of Conidiobolus

The genus Conidiobolus s.s. was newly delimited from Conidiobolus s.l. In order to gain insight into its mitochondrial genetic background, this study sequenced six mitochondrial genomes of the genus Conidiobolus s.s. These mitogenomes were all composed of circular DNA molecules, ranging from 29,253 to 48,417 bp in size and from 26.61 to 27.90% in GC content. The order and direction for 14 core protein-coding genes (PCGs) were identical, except for the atp8 gene lost in Conidiobolus chlamydosporus, Conidiobolus polyspermus, and Conidiobolus polytocus, and rearranged in the other Conidiobolus s.s. species. Besides, the atp8 gene split the cox1 gene in Conidiobolus taihushanensis. Phylogenomic analysis based on the 14 core PCGs confirmed that all Conidiobolus s.s. species formed a monophyly in the Entomophthoromycotina lineage. The number and length of introns were the main factors contributing to mitogenomic size, and deep variations and potential transfer were detected in introns. In addition, gene transfer occurred between the mitochondrial and nuclear genomes. This study promoted the understanding of the evolution and phylogeny of the Conidiobolus s.s. genus.

Brazilian fungal diversity represented by DNA markers generated over 20 years

Molecular techniques using fungal DNA barcoding (ITS) and other markers have been key to identifying the biodiversity of different geographic areas, mainly in megadiverse countries. Here, we provide an overview of the fungal diversity in Brazil based on DNA markers of phylogenetic importance generated since 1996. We retrieved fungal sequences of ITS, LSU, SSU, tef1-α, β-tubulin, rpb1, rpb2, actin, chitin synthase, and ATP6 from GenBank using different field keywords that indicated their origin in Brazil. A total of 19,440 sequences were recovered. ITS is the most representative marker (11,209 sequences), with 70.1% belonging to Ascomycota, 18.6% Basidiomycota, 10.2% unidentified, 1.1% Mucoromycota, two sequences of Olpidium bornovanus (Fungi incertae sedis), one sequence of Blastocladiomycota (Allomyces arbusculus), and one sequence of Chytridiomycota (Batrachochytrium dendrobatidis). Considering the sequences of all selected markers, only the phyla Cryptomycota and Entorrhizomycota were not represented. Based on ITS, using a cutoff of 98%, all sequences comprise 3047 OTUs, with the majority being Ascomycota (2088 OTUs) and Basidiomycota (681 OTUs). Previous numbers based mainly on morphological and bibliographical data revealed 5264 fungal species from Brazil, with a predominance of Basidiomycota (2741 spp.) and Ascomycota (1881 spp.). The unidentified ITS sequences not assigned to a higher taxonomic level represent 1.61% of all ITS sequences sampled and correspond to 38 unknown class-level lineages (75% cutoff). A maximum likelihood phylogeny based on LSU illustrates the fungal classes occurring in Brazil.

In vitro assessment of antifungal, antibacterial, and antiprotozoal drugs against clinical isolates of Conidiobolus lamprauges

We have determined the in vitro activity of antifungal, antibacterial, and antiprotozoal drugs alone and in combination against seven Conidiobolus lamprauges clinical isolates. The assays were based on the M38-A2 protocol and the checkerboard microdilution method. The lowest inhibitory concentrations were observed for amphotericin B, miconazole (MCZ), terbinafine, and miltefosine (MTF) (MIC range 0.25-1; 2-8; 0.25-2; 2-16 μg/ml, respectively). The main synergism observed was through the combination of azithromycin (AZI)+MTF and dapsone (DAP)+MTF (100%), AZI+DAP (85.7%), AZI+MCZ (57.1%) as well as MCZ plus CTX and DAP (42.9%). The in vitro activities suggest that the combination of MTF and AZI or DAP are promising candidate therapies for conidiobolomycosis.

Mitochondrial genome of the entomophthoroid fungus Conidiobolus heterosporus provides insights into evolution of basal fungi

Entomophthoroid fungi represent an ecologically important group of fungal pathogens on insects. Here, the whole mitogenome of Conidiobolus heterosporus, one of the entomophthoroid fungi, was described and compared to those early branching fungi with available mitogenomes. The 53,364-bp circular mitogenome of C. heterosporus contained two rRNA genes, 14 standard protein-coding genes, 26 tRNA genes, and three free-standing ORFs. Thirty introns interrupted nine mitochondrial genes. Phylogenetic analysis based on mitochondrion-encoded proteins revealed that C. heterosporus was most close to Zancudomyces culisetae in the Zoopagomycota of basal fungi. Comparison on mitogenomes of 23 basal fungi revealed great variabilities in terms of mitogenome conformation (circular or linear), genetic code (codes 1, 4, or 16), AT contents (53.3-85.5%), etc. These mitogenomes varied from 12.0 to 97.3 kb in sizes, mainly due to different numbers of genes and introns. They showed frequent DNA rearrangement events and a high variability of gene order, although high synteny and conserved gene order were also present between closely related species. By reporting the first mitogenome in Entomophthoromycotina and the second in Zoopagomycota, this study greatly enhanced our understanding on evolution of basal fungi.

Human Pathogenic Entomophthorales

The pathogenic entomophthoralean fungi cause infection in insects and mammalian hosts. Basidiobolus and Conidiobolus species can be found in soil and insect, reptile, and amphibian droppings in tropical and subtropical areas. The life cycles of these fungi occur in these environments where infecting sticky conidia are developed. The infection is acquired by insect bite or contact with contaminated environments through open skin. Conidiobolus coronatus typically causes chronic rhinofacial disease in immunocompetent hosts, whereas some Conidiobolus species can be found in immunocompromised patients. Basidiobolus ranarum infection is restricted to subcutaneous tissues but may be involved in intestinal and disseminated infections. Its early diagnosis remains challenging due to clinical similarities to other intestinal diseases. Infected tissues characteristically display eosinophilic granulomas with the Splendore-Höeppli phenomenon. However, in immunocompromised patients, the above-mentioned inflammatory reaction is absent. Laboratory diagnosis includes wet mount, culture serological assays, and molecular methodologies. The management of entomophthoralean fungi relies on traditional antifungal therapies, such as potassium iodide (KI), amphotericin B, itraconazole, and ketoconazole, and surgery. These species are intrinsically resistant to some antifungals, prompting physicians to experiment with combinations of therapies. Research is needed to investigate the immunology of entomophthoralean fungi in infected hosts. The absence of an animal model and lack of funding severely limit research on these fungi.

Experimental infection in gerbils by Conidiobolus lamprauges

Conidiobolomycosis is an emerging entomophthoramycosis caused by fungi Conidiobolus spp. Animal models are essential for the study of infectious disease in various areas such as pathogenesis, diagnostic methods, treatment and prevention. There is not currently an animal model for conidiobolomycosis. The aim of this study was to create an experimental infection protocol for Conidiobolus lamprauges in gerbils (Meriones unguiculatus). The study animals were randomly divided into four groups of four animals: immunosuppressed with cyclophosphamide (CPA) and infected with C. lamprauges (G1), immunocompetent and infected with C. lamprauges (G2), immunosuppressed with CPA (G3), and an immunocompetent control group (G4). Clinical signs were observed only in G1 animals, where the mortality rate reached 75% by day 7 after infection (AI) with a median survival of 2 days. C. lamprauges was detected only in G1, both by PCR and by isolation. Necropsies of the G1 animals showed lesions in the nasal cavity and lung tissue. These lesions were characterized by polymorphonuclear infiltrate cells and by the presence of hyphal structures under silver staining. This animal model will be useful for further investigation of diseases caused by C. lamprauges, particularly of those associated with immunosuppression factors in naturally occurring animal infections.

[A case of rhinofacial entomophthoromycosis in Soudano-Sahelian tropical climate in Burkina Faso]

We describe a rhinofacial entomophthoramycosis case in a sexagenarian (65 years old) housewife. She was immunocompetent and resident of Burkina Faso. She consulted both the service of dermatology and the service of stomatology of the Teaching Hospital of Bobo-Dioulasso in February 2016 for a diffuse facial tumefaction evolving over six months. This tumefaction was associated with headaches and a left nasal obstruction. Histological examination of the lesion showed an important and polymorphic inflammatory reaction. Also, a filamentous fungus with wide non-septated hyphae and right-angled fungal branching, consistent with mucormycosis was isolated. Mycological diagnosis based on fungal culture with Sabouraud medium without any antibiotic and cyclohexemide after incubation at 27°C and at 30°C was negative. Furthermore, it was not possible to amplify the DNA extracted from biopsy. Antifungal therapy based on the administration of fluconazole per os at 800mg/day was started allowing clinical improvement. This is the first case of a rhinofacial entomophtharomycosis documented in Bobo-Dioulasso. Rhinofacial entomophthoromycosis is largely unknown, even in tropical regions such as Burkina Faso. This lack of knowledge results in a delay in the diagnosis, and subsequently a bad prognosis. It is therefore urgent to improve knowledge on this disease to guide diagnostic steps, prognosis of outcome, and antifungal therapy.

Classification of Rhinoentomophthoromycosis into Atypical, Early, Intermediate, and Late Disease: A Proposal

BACKGROUND

Rhinoentomophthoromycosis, or rhino-facial conidiobolomycosis, is a rare, grossly disfiguring disease due to an infection with entomophthoralean fungi. We report a case of rhinoentomophthoromycosis from Gabon and suggest a staging system, which provides information on the prognosis and duration of antifungal therapy.

METHODS

We present a case of rhinoentomophthoromycosis including the histopathology, mycology, and course of disease. For the suggested staging system, all cases on confirmed rhinoentomophthoromycosis published in the literature without language restriction were eligible. Exclusion criteria were missing data on (i) duration of disease before correct diagnosis, (ii) outcome, and (iii) confirmation of entomophthoralean fungus infection by histopathology and/or mycology. We classified cases into atypical (orbital cellulitis, severe pain, fever, dissemination), early, intermediate, and late disease based on the duration of symptoms before diagnosis. The outcome was evaluated for each stage of disease.

FINDINGS

The literature search of the Medpilot database was conducted on January 13, 2014, (updated on January 18, 2015). The search yielded 8,333 results including 198 cases from 117 papers; of these, 145 met our inclusion criteria and were included in the final analysis. Median duration of treatment was 4, 3, 4, and 5 months in atypical, early, intermediate, and late disease, respectively. Cure rates were clearly associated with stage of disease and were 57%, 100%, 82%, and 43% in atypical, early, intermediate, and late disease, respectively.

CONCLUSION

We suggest a clinical staging system that underlines the benefit of early case detection and may guide the duration of antifungal treatment. The scientific value of this classification is its capacity to structure and harmonize the clinical and research approach towards rhinoentomophthoromycosis.

A biochemical screening approach to putatively differentiate mammalian pathogenic Oomycota species in the clinical laboratory

The report of four novel mammalian pathogenic species of the genus Lagenidium prompted us to study the use of biochemical assays to differentiate the Oomycota mammalian pathogens Pythium insidiosum and Lagenidium spp. We investigated the reaction of 23 Lagenidium and eight Pythium species in various biochemical assays. Because the morphological features of the Oomycota species are similar to those of species in the Entomophthoramycota and Mucormycota, five fungal species with coenocytic hyphae were also included. We found that mammalian and plant isolates of Pythium spp. all hydrolysed sucrose, but Lagenidium species and the fungal strains did not. In addition, both Pythium spp. and Lagenidium spp. were found to be maltose-positive, whereas fungal strains did not hydrolyse this sugar. The fungal species and thermo-sensitive Lagenidium giganteum and Lagenidium humanum were urease-negative, but the mammalian Lagenidium spp. and Pythium spp. hydrolysed urea within 24  h. These findings suggest these assays can be used for the presumptive differentiation of mammalian Oomycota species in the laboratory.

Disseminated Conidiobolus incongruus in a dog: A case report and literature review

Conidiobolomycosis is a rare fungal disease of both humans and animals, occurring mainly in tropical and subtropical climates. We describe a disseminated fungal infection in a young, apparently immunocompetent dog who initially presented for antibiotic resistant pneumonia. Histopathology and mycology identified a Conidiobolus sp., further confirmed as Conidiobolus incongruus through DNA sequencing of D1/D2 regions. This is the first report of this species causing disease in dogs and the fifth reported infection in animals.

Neglected fungal zoonoses: hidden threats to man and animals

Zoonotic fungi can be naturally transmitted between animals and humans, and in some cases cause significant public health problems. A number of mycoses associated with zoonotic transmission are among the group of the most common fungal diseases, worldwide. It is, however, notable that some fungal diseases with zoonotic potential have lacked adequate attention in international public health efforts, leading to insufficient attention on their preventive strategies. This review aims to highlight some mycoses whose zoonotic potential received less attention, including infections caused by Talaromyces (Penicillium) marneffei, Lacazia loboi, Emmonsia spp., Basidiobolus ranarum, Conidiobolus spp. and Paracoccidioides brasiliensis.

Human Fungal Pathogens of Mucorales and Entomophthorales

In recent years, we have seen an increase in the number of immunocompromised cohorts as a result of infections and/or medical conditions, which has resulted in an increased incidence of fungal infections. Although rare, the incidence of infections caused by fungi belonging to basal fungal lineages is also continuously increasing. Basal fungal lineages diverged at an early point during the evolution of the fungal lineage, in which, in a simplified four-phylum fungal kingdom, Zygomycota and Chytridiomycota belong to the basal fungi, distinguishing them from Ascomycota and Basidiomycota. Currently there are no known human infections caused by fungi in Chytridiomycota; only Zygomycotan fungi are known to infect humans. Hence, infections caused by zygomycetes have been called zygomycosis, and the term "zygomycosis" is often used as a synonym for "mucormycosis." In the four-phylum fungal kingdom system, Zygomycota is classified mainly based on morphology, including the ability to form coenocytic (aseptated) hyphae and zygospores (sexual spores). In the Zygomycota, there are 10 known orders, two of which, the Mucorales and Entomophthorales, contain species that can infect humans, and the infection has historically been known as zygomycosis. However, recent multilocus sequence typing analyses (the fungal tree of life [AFTOL] project) revealed that the Zygomycota forms not a monophyletic clade but instead a polyphyletic clade, whereas Ascomycota and Basidiomycota are monophyletic. Thus, the term "zygomycosis" needed to be further specified, resulting in the terms "mucormycosis" and "entomophthoramycosis." This review covers these two different types of fungal infections.

Development and application of polymerase chain reaction test for detection of Conidiobolus lamprauges

Conidiobolomycosis is a granulomatous disease caused by the fungus Conidiobolus spp. in humans and animals. Traditional technique for diagnosis of the disease is isolation of the agent associated with the presence of typical clinical signs and pathological conditions. The aim of this study was to describe the development of a specific polymerase chain reaction (PCR) test for Conidiobolus lamprauges to detect the fungus in clinical samples. Samples from suspected animals were collected and submitted to isolation, histopathological analysis and amplification by PCR. DNA from tissues was subjected to PCR with fungi universal primers 18S rDNA gene, and specific primers were designed based on the same gene in C. lamprauges that generated products of about 540 bp and 222 bp respectively. The culture was positive in 26.6% of clinical samples. The PCR technique for C. lamprauges showed amplification of DNA from fresh tissues (80%) and paraffin sections (44.4%). In conclusion, the PCR technique described here demonstrated a high sensitivity and specificity for detection of fungal DNA in tissue samples, providing a tool for the rapid diagnosis of C. lamprauges.

In vitro susceptibility of Conidiobolus lamprauges recovered from sheep to antifungal agents

Data regarding the susceptibility of Conidiobolus lamprauges is limited and there is no consensus about the optimal treatment for infections caused by Conidiobolus spp. In this context, the objective of this study was to evaluate the in vitro susceptibility of six C. lamprauges strains isolated from sheep conidiobolomycosis to amphotericin B, ketoconazole, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, micafungin, flucytosine, and terbinafine using the CLSI M38-A2 microdilution technique. Terbinafine was the most active (MIC range <0.06-0.5 μg/mL). Resistance or reduced susceptibility was observed for amphotericin B and azole and echinocandin antifungals. Additional studies are necessary to determine the therapeutic potential of terbinafine as monotherapy or in combination therapy with other antifungals.

Pathology of nasal infection caused by Conidiobolus lamprauges and Pythium insidiosum in sheep

Conidiobolomycosis and pythiosis are important diseases of sheep in midwestern Brazil. Veterinary practitioners consider it difficult to differentiate between these diseases because they have similar clinical features. In this study, 186 sheep were subjected to necropsy examination over a 6-year period. Thirty (16.1%) cases of rhinitis in sheep that were caused by Conidiobolus lamprauges (n = 15) or Pythium insidiosum (n = 15) were investigated further. The lesions of C. lamprauges infection were mainly rhinopharyngeal (86.7%), localized to the ethmoidal region and associated with exophthalmos. The lesions appear as a white to yellow, firm mass that microscopically appears as a granulomatous inflammatory reaction with numerous giant cells. In contrast, P. insidiosum infection is associated with rhinofacial (93.3%) lesions that mainly involve the frontal region and hard palate and appear as an irregular, friable, yellow to red mass. Microscopically, pythiosis presents as diffuse necrotizing eosinophilic rhinitis. Immunohistochemistry using polyclonal antisera raised specifically against the two organisms was used to confirm the identity of the infectious agent in each disease. This study reports the first immunohistochemical diagnosis of conidiobolomycosis and the first description of a rhinopharyngeal lesion caused by P. insidiosum in sheep.

Disseminated human conidiobolomycosis due to Conidiobolus lamprauges

We describe a disseminated fungal infection by Conidiobolus lamprauges in a patient with malignant lymphoma. Histopathology and mycological studies were performed, along with molecular analyses. This is the first record of this species causing human disease and the fifth reported disseminated infection by a Conidiobolus sp. in humans.

Doenças da cavidade nasal em ruminantes no Brasil

Este trabalho descreve as doenças das fossas nasais diagnosticadas em ruminantes no Hospital Veterinário da Universidade Federal de Campina Grande, em Patos, Paraíba, nos anos de 2003-2009. No período foram registrados três diagnósticos de doenças das fossas nasais de bovinos, três em caprinos e nove em ovinos (de um total de 404 diagnósticos em bovinos, 330 em caprinos e 338 em ovinos). Descrevem-se um caso de rinite atópica em bovinos, sete surtos de conidiobolomicose e dois de pitiose rinofacial em ovinos, dois casos de prototecose e um de aspergilose nasal em caprinos e um mixoma e um fibrossarcoma em bovinos. Adicionalmente, é realizada uma revisão de outras doenças das fossas nasais de ruminantes descritas em outras regiões do Brasil, incluindo oestrose, rinosporidiose, carcinoma epidermóide e tumor etmoidal enzoótico.