Lecanicillium and Verticillium species from Indonesia and Japan including three new species

Lecanicillium psalliotae (Hypocreales: Cordycipitaceae) Exerts Ovicidal and Larvicidal Effects against the Sheep Blood-Feeding Nematode Haemonchus contortus through Its Liquid Culture Filtrates

Nematophagous fungi (NF) form part of the soil microbiota and are natural enemies of nematodes, helping to regulate nematode populations. A verticillate NF isolated from soil from Tepalcingo, Mexico, was morphologically and molecularly characterised. This fungus was cultured in two different liquid media-Czapek-Dox broth (CzDoxB) and sweet potato dextrose broth (SPDB)-for 21 days. The ovicidal (OA) and larvicidal (LA) activities of fungal liquid culture filtrates (LCFs) were assessed in 96-well microtitre plates at different concentrations against Haemonchus contortus after 48 h. The morphological and molecular identification revealed the presence of Lecanicillium psalliotae. Additionally, the groups of compounds associated with nematocidal activity were determined from a qualitative chemical profile (QCP) using different reagents. The highest OA of the LCFs was obtained at 25 mg/mL from SPDB and CzDoxB and amounted to 97.2 and 99.06%, respectively. Meanwhile, the highest LA recorded with these LCFs at 100 mg/mL was 54.27% and 96.8%, respectively. The QCP revealed the presence of alkaloids and tannins in both LCFs that have previously been associated with nematocidal activity. Lecanicillium psalliotae exerted an important effect on H. contortus and could be of significance in future studies focused on the control and prevention of haemonchosis in small ruminants.

Morpho-molecular study of entomopathogenic fungi associated with citrus orchard pests in Northern Iran

Entomopathogenic fungi play a significant role in regulating insect populations in nature and have potential applications in pest management strategies in different regions. Citrus spp. are among the important horticultural products in northern Iran, and the orchards are affected by different insect pests, especially mealybugs. This study aimed to isolate and identify entomopathogenic fungi associated with citrus orchard pests in northern Iran, focusing on Akanthomyces and Lecanicillium species on mealybugs. Through the samples collected from different regions within Guilan province, 12 fungal isolates were collected and identified based on the combination of morphological characteristics and molecular data. Akanthomyces lecanii, A. muscarius, Engyodontium rectidentatum, Lecanicillium aphanocladii and Lecanicillium rasoulzarei sp. nov. were identified. Of these, A. muscarius on Lepidosaphes sp., E. rectidentatum on Coccidae, and L. aphanocladii on Tetranychus urticae are reported as new fungal-host records from Iran. Moreover, a new species, Lecanicillium rasoulzarei, is illustrated, described, and compared with closely related species.

Characterization of insecticidal metabolite oosporein in Lecanicillium saksenae (Kushwaha) Kurihara and Sukarno, a geographically distinct isolate from Kerala, India

Lecanicillium saksenae, an indigenous isolate from Kerala, India is a potent entomopathogen against hemipteran pests. The wine-red pigmentation produced by this isolate distinguishes it from many other isolates of L. saksenae reported across the globe. This study, therefore, sought to isolate and characterize the pigment molecule. The wine-red pigment extracted through liquid - liquid partition of the fungal culture was subjected to structural characterization and identification through UV spectrometry, Fourier Transform Infrared Spectrometry (FTIR), High Resolution Liquid Chromatography, Mass Spectrometry (HR-LCMS) and Nuclear Magnetic Resonance Spectrometry (NMR). It was unambiguously identified as a dibenzoquinone compound, oosporein, a known bioactive insecticidal metabolite. The empirical formula of which was confirmed as C₁₄H₁₀O₈ and molecular weight, m/z 306.22. The dose dependent bioefficacy of oosporein with 1000 ppm at 96 h recorded a mortality of 60.25 per cent in nymphs of brinjal mealybug, Coccidohystrix insolita, while it was still lower (51.00%) in adults. In this study, we could identify that L. saksenae reported from Kerala, India was geographically distinct. Sequence analysis based on 18srDNA and phylogenetic analysis confirmed the species identity of this indigenous isolate with that of L. saksenae documented in NCBI. This finding paves the way for the possibilities of tapping the potential of bioactive metabolites for pest management and uplifting the species as a potent bioagent in insect pest management programmes.

Occurrence of entomopathogenic hypocrealean fungi in mosquitoes and their larval habitats in Central Brazil, and activity against Aedes aegypti

Collecting entomopathogenic fungi associated with mosquitoes and studies on their activity against mosquito developmental stages will improve the understanding of their potential as agents to control important mosquito vectors. Twenty one strains of entomopathogenic fungi affecting mosquitoes in Central Brazil were studied: 7 of Beauveria bassiana, 7 of Metarhizium humberi, 3 of M. anisopliae, 2 of Cordyceps sp. and one each of Akanthomyces saksenae and Simplicillium lamellicola. These fungi were isolated from field-collected mosquito adults (3 strains) or larvae (a single strain); the other 17 strains were isolated from laboratory-reared Aedes aegypti sentinel larvae set out in partially immersed cages placed in diverse small- to middle-sized aquatic mosquito habitats in or close to areas with secondary tropical forest. The frequent recovery of normally soil-borne Metarhizium spp. and B. bassiana from aquatic habitats is notable. Our laboratory findings indicated that M. anisopliae IP 429 and IP 438 and M. humberi IP 421 and IP 478 were highly active against immature stages and, together with M. anisopliae IP 432, also against adults. These strains appear to be the most promising candidates to develop effective control strategies targeting the different developmental stages of A. aegypti, the most important vector of viral diseases in humans in the tropics.

Estimated Divergence Times of Lecanicillium in the Family Cordycipitaceae Provide Insights Into the Attribution of Lecanicillium

Background

The genus Lecanicillium W.Gams & Zare is a recognized insect pathogen but members of the genus have been found parasitizing various hosts including arthropods, nematodes, plants, and fungi. The new classification system for fungi proposed to reject Lecanicillium and transfer some of the species to the genus Akanthomyces. However, the attribution problem of most species in the original genus Lecanicillium remains unsolved. The current study aimed to improve understanding of the pivotal internal phylogeny in Lecanicillium by estimating the divergence times of Lecanicillium to provide additional insights into the status of this genus within the family Cordycipitaceae.

Results

Dating analyses support the supposition that the ancestor of Lecanicillium was in the Cretaceous period (84.36 Mya, 95% HPD: 72.12–94.74 Mya). After originating from a common ancestor, eight clades of Lecanicillium were derived and evolved independently in parallel with other genera of Cordycipitaceae. Based on the clear divergence age estimates, Lecanicillium clade 8 originated earlier as an independent group in the Cretaceous period (75.61 Mya, 95% HPD: 63.31–87.54 Mya), while Lecanicillium clades 1–7 originated later as an independent group in the boundary of the Cretaceous and Paleogene periods (64.66 Mya, 95% HPD: 52.75–76.74 Mya). Lecanicillium huhutii formed an independent branch in a polytomy together with a clade containing Lecanicillium tenuipes (BI posterior probabilities 1, ML bootstrap 100%).

Conclusion

The pivotal internal phylogeny, origin, and evolutionary history of Lecanicillium in the family Cordycipitaceae were investigated. Phylogenetic and morphological analyses indicated that there are eight representative clades (four representative branches of evolutionary history), including clade 1 (members have a relatively uniform sporulation structure comprising globose heads with a higher number of conidia), clade 8 (including all members of Gamszarea), clades 2–5 (the differences of the divergence time estimations were smaller compared with other clades), and clade 6–7 (members are close to Gibellula, Hevansia, and Ascopolyporus). Based on the above findings, a novel spider-pathogenic fungus, Lecanicillium huhutii, is described. All other species in Lecanicillium clade 1 (Lecanicillium araneogemum, L. nodulosum, L. pissodis, and L. uredinophilum) should be transferred to the genus Akanthomyces. Furthermore, the monotypic genus Parengyodontium should be merged with the genus Gamszarea. More novel species need to be discovered to thoroughly resolve the attribution problem of Lecanicillium. Finally, no major lineages of Lecanicillium were correlated with the nearby Cretaceous-Tertiary extinction event, indicating that the diversity of Lecanicillium is more likely to be caused by long-term environmental adaptation and coevolution with insects rather than by dramatic extinction events.

The bacterial and fungal nest microbiomes in populations of the social spider Stegodyphus dumicola

Social spiders of the species Stegodyphus dumicola live in communal nests with hundreds of individuals and are characterized by extremely low species-wide genetic diversity. The lack of genetic diversity in combination with group living imposes a potential threat for infection by pathogens. We therefore proposed that specific microbial symbionts inhabiting the spider nests may provide antimicrobial defense. To compare the bacterial and fungal diversity in 17 nests from three different locations in Namibia, we used 16S rRNA gene and internal transcribed spacer (ITS2) sequencing. The nest microbiomes differed between geographically distinct spider populations and appeared largely determined by the local environment. Nevertheless, we identified a core microbiome consisting of four bacterial genera (Curtobacterium, Modestobacter, Sphingomonas, Massilia) and four fungal genera (Aureobasidium, Didymella, Alternaria, Ascochyta), which likely are selected from surrounding soil and plants by the nest environment. We did not find indications for a strain- or species-specific symbiosis in the nests. Isolation of bacteria and fungi from nest material retrieved a few bacterial strains with antimicrobial activity but a number of antimicrobial fungi, including members of the fungal core microbiome. The significance of antimicrobial taxa in the nest microbiome for host protection remains to be shown.

Multigene phylogeny of the family Cordycipitaceae (Hypocreales): new taxa and the new systematic position of the Chinese cordycipitoid fungus Paecilomyces hepiali

The phylogeny and systematics of cordycipitoid fungi have been extensively studied in the last two decades. However, systematic positions of some taxa in the family Cordycipitaceae have not yet been thoroughly resolved. In this study, a new phylogenetic framework of Cordycipitaceae is reconstructed using multigene (nrSSU, nrLSU, tef-1α, rpb1 and rpb2) sequence data with large-scale taxon sampling. In addition, ITS sequence data of species belonging to the Lecanicillium lineage in the family Cordycipitaceae are used to further determine their phylogenetic placements. Based on molecular phylogenetic data together with morphological evidence, two new genera (Flavocillium and Liangia), 16 new species and four new combinations are introduced. In the new genus Flavocillium, one new species F. bifurcatum and three new combinations previously described as Lecanicillium, namely F. acerosium, F. primulinium and F. subprimulinium, are proposed. The genus Liangia is built by the new species Lia. sinensis with Lecanicillium-like asexual morph, isolated from an entomopathogenic fungus Beauveria yunnanensis. Due to the absence of Paecilomyces hepiali, an economically and medically significant fungus, in the earlier phylogenetic analyses, its systematic position has been puzzling in both business and academic communities for a long time. Here, P. hepiali is recharacterized using the holotype material along with seven additional samples. It is assigned to the genus Samsoniella (Cordycipitaceae, Hypocreales) possessing Cordyceps-like sexual morph and Isaria-like asexual morph, and thus a new combination, namely S. hepiali is proposed. An additional nine new species in Samsoniella are described: S. alpina, S. antleroides, S. cardinalis, S. cristata, S. lanmaoa, S. kunmingensis, S. ramosa, S. tortricidae and S. yunnanensis. Four new species in Cordyceps are described: C. chaetoclavata, C. cocoonihabita, C. shuifuensis and C. subtenuipes. Simplicillium yunnanense, isolated from synnemata of Akanthomyces waltergamsii, is described as a new species.

Diversity of Akanthomyces on moths (Lepidoptera) in Thailand

Akanthomyces is a genus of invertebrate-pathogenic fungi from the family Cordycipitaceae (Ascomycota, Hypocreales). Its species occurs on two different types of hosts, spiders and insects, and in the latter case specifically Lepidoptera adults. Three new species of Akanthomyces, A. noctuidarum, A. pyralidarum, and A. tortricidarum occurring on adult moths from Thailand are proposed based on the differences of their morphological characteristics and molecular data. Phylogenetic analyses using a combined dataset, including the internal transcribed spacer regions, the large subunit of the ribosomal DNA, translation elongation factor 1-α, the largest subunit of RNA polymerase II, and the second largest subunit of RNA polymerase II, support the delimitation of these new species in Akanthomyces.

The complete mitochondrial genome of the Chan-hua fungus Isaria cicadae: a tale of intron evolution in Cordycipitaceae

Isaria cicadae is an entomogenous fungus of great medicinal value. Its nuclear genome has been reported, while its mitogenome remains unknown. Herein, we first described its mitogenome and then inferred intron evolution from both intraspecific and interspecific perspectives. The fungus represented the largest mitogenome (56.6 kb in strain CCAD02) known in Cordycipitaceae due to the presence of 25 introns interrupting nine genes. Comparison of three I. cicadae strains revealed intron presence/absence dynamics at six intron loci plus a few indels and single nucleotide polymorphisms. Phylogenetic analyses confirmed the placement of I. cicadae in Cordycipitaceae. Comparison of 10 Cordycipitaceae species revealed a high degree of synteny and conserved genetic content. They, however, varied in intron numbers (1-25 per species) with overall 34 intron loci identified, which resulted in more than twofold variations in mitogenome sizes (24.5-56.6 kb). An rnl intron encoding ribosomal protein S3 was present in all species, suggesting its early invasion in Cordycipitaceae, while further divergence occurred for this intron. The other introns identified in this study were present in some, but not all of the species and have undergone multiple gains and losses in Cordycipitaceae. This study greatly enhanced our understanding of intron evolution in Cordycipitaceae.

Lecanicilliumcauligalbarum sp. nov. (Cordycipitaceae, Hypocreales), a novel fungus isolated from a stemborer in the Yao Ren National Forest Mountain Park, Guizhou

A new species of entomopathogenic fungi, Lecanicilliumcauligalbarum, was discovered from a survey of invertebrate-associated fungi in the Yao Ren National Forest Mountain Park in China. The synnemata of this species emerged from the corpse of a stemborer (Lepidoptera), which was hidden amongst pieces of wood on the forest floor. It differs from morphologically similar Lecanicillium species mainly in its short conidiogenous cells and ellipsoid to ovoid and aseptate conidia. Phylogenetic analysis of a combined data set comprising ITS, SSU, LSU, TEF, RPB1 and RPB2 sequence data supported the inclusion of L.cauligalbarum in the Lecanicillium genus and its recognition as a distinct species.

Draft Genome Sequence of the Fungus Lecanicillium psalliotae Strain HWLR35, Isolated from a Wheat Leaf Infected with Leaf Rust (Caused by Puccinia triticina)

Lecanicillium psalliotae is an entomopathogenic, mycoparasitical, and nematophagous fungus known to produce antibiotic and antifungal compounds. Here, we report the first 36-Mb draft genome sequence of L. psalliotae strain HWLR35. The draft genome contains 197 scaffolds and is predicted to have 11,009 protein-coding genes.

A phylogenetically-based nomenclature for Cordycipitaceae (Hypocreales)

The ending of dual nomenclatural systems for pleomorphic fungi in 2011 requires the reconciliation of competing names, ideally linked through culture based or molecular methods. The phylogenetic systematics of Hypocreales and its many genera have received extensive study in the last two decades, however resolution of competing names in Cordycipitaceae has not yet been addressed. Here we present a molecular phylogenetic investigation of Cordycipitaceae that enables identification of competing names in this family, and provides the basis upon which these names can be maintained or suppressed. The taxonomy presented here seeks to harmonize competing names by principles of priority, recognition of monophyletic groups, and the practical usage of affected taxa. In total, we propose maintaining nine generic names, Akanthomyces, Ascopolyporus, Beauveria, Cordyceps, Engyodontium, Gibellula, Hyperdermium, Parengyodontium, and Simplicillium and the rejection of eight generic names, Evlachovaea, Granulomanus, Isaria, Lecanicillium, Microhilum, Phytocordyceps, Synsterigmatocystis, and Torrubiella. Two new generic names, Hevansia and Blackwellomyces, and a new species, Beauveria blattidicola, are described. New combinations are also proposed in the genera Akanthomyces, Beauveria, Blackwellomyces, and Hevansia.

The complete mitochondrial genome of the nematophagous fungus Lecanicillium saksenae

Lecanicillium saksenae CGMCC5329 is a useful biological control agent against plant-parasitic nematodes. The complete mitogenome sequence of L. saksenae is reported for the first time. The mitochondrial genome is 25 919 bp long with 14 typical protein-coding genes, an intronic ORF coding for a putative ribosomal protein (rps3), 2 ribosomal RNA genes and a set of 26 transfer RNA genes. The phylogeny based on 12 protein-coding genes (except the loss of other two genes in Acremonium implicatum) suggests the close phylogenetic relationship between L. saksenae and L. muscarium. Comparative analysis reveals that mitogenome of L. saksenae is 1420 bp larger than L. muscarium, mainly due to the intergenic region between cox2 and trnR. The trnC between cob and cox1 is conserved in the mitogenomes of three nematophagous fungus of Pochonia chlamydosporia, A. implicatum and L. saksenae, but absent in L. muscarium. This study may provide valuable information for further research on mitochondrial evolution of nematophagous fungus and Lecanicillium species.

Pseudo-outbreak of Lecanicillium and Acremonium species in orthopedic surgery patients

Acremonium species cause a variety of human infections, while Lecanicillium species have not been reported as human pathogens. We describe a pseudo-outbreak involving both organisms, highlighting the role and limitations of molecular methods in the characterization of rare fungal isolates. Repeated isolation of these fungi from patient tissue samples raises concerns about exogenous contamination in the hospital environment.