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Background: Fungal keratitis is a severe eye infection that can result in blindness and visual impairment, particularly in developing countries. Fusarium spp. are the primary causative agents of this condition. Diagnosis of Fusarium keratitis (FK) is challenging, and delayed treatment can lead to serious complications. However, there is limited epidemiological data on FK, especially in tropical areas. Objectives: This study aimed to describe the clinical, laboratorial and epidemiological characteristics of FK in a tropical semi‐arid region of Brazil. Patients/Methods: Adult patients with laboratory‐confirmed FK diagnosed between October 2019 and March 2022 were evaluated. Fusarium isolates were characterized at molecular level and evaluated regarding antifungal susceptibility. Results: A total of 226 clinical samples from patients suspected of keratitis were evaluated; fungal growth was detected in 50 samples (22.12%); out of which 42 were suggestive of Fusarium spp. (84%). Molecular analysis of a randomly selected set of 27 isolates identified F. solani species complex (n = 14); F. fujikuroi sensu lato (n = 6) and F. dimerum sensu lato (n = 7); a total of 10 haplotypes were identified among the strains. All but one Fusarium strains were inhibited by amphotericin B, natamycin and fluconazole. Most patients were male (71.42%; 30 out of 42), aged from 27 to 73 years old. Trauma was the most important risk factor for FK (40.47%; 17 out of 42). Patients were treated with antifungals, corticoids and antibiotics; keratoplasty and eye enucleation were also performed. Conclusions: The study provided insights into the characteristics of FK in tropical regions and emphasized the importance of enhanced surveillance and management strategies. [ABSTRACT FROM AUTHOR]

Abstract Background The Fusarium solani species complex (FSSC) comprises fungal pathogens responsible for mortality in a diverse range of animals and plants, but their genome diversity and transcriptome responses in animal pathogenicity remain to be elucidated. We sequenced, assembled and annotated six chromosome-level FSSC clade 3 genomes of aquatic animal and plant host origins. We established a pathosystem and investigated the expression data of F. falciforme and F. keratoplasticum in Chinese softshell turtle (Pelodiscus sinensis) host. Results Comparative analyses between the FSSC genomes revealed a spectrum of conservation patterns in chromosomes categorised into three compartments: core, fast-core (FC), and lineage-specific (LS). LS chromosomes contribute to variations in genomes size, with up to 42.2% of variations between F. vanettenii strains. Each chromosome compartment varied in structural architectures, with FC and LS chromosomes contain higher proportions of repetitive elements with genes enriched in functions related to pathogenicity and niche expansion. We identified differences in both selection in the coding sequences and DNA methylation levels between genome features and chromosome compartments which suggest a multi-speed evolution that can be traced back to the last common ancestor of Fusarium. We further demonstrated that F. falciforme and F. keratoplasticum are opportunistic pathogens by inoculating P. sinensis eggs and identified differentially expressed genes also associated with plant pathogenicity. These included the most upregulated genes encoding the CFEM (Common in Fungal Extracellular Membrane) domain. Conclusions The high-quality genome assemblies provided new insights into the evolution of FSSC chromosomes, which also serve as a resource for studies of fungal genome evolution and pathogenesis. This study also establishes an animal model for fungal pathogens of trans-kingdom hosts.

The north‐east of Brazil is one of the most important melon‐producing regions in the world. Crop yield is often reduced by the occurrence of a root rot disease, caused by Fusarium species. The present study aimed to characterize a collection of 31 isolates with morphological markers of F. solani obtained from melon plants with symptoms of root rot by phylogenetic analysis of the barcode regions EF‐1α and RPB2, and to verify their pathogenicity to melon plantlets. Phylogenetic analysis showed that 29 isolates grouped with reference material of Fusarium falciforme (FSSC 3 + 4) and two with F. suttonianum (FSSC 20). The pathogenicity test showed that isolates of both species cause root rot in melon plants, with no significant difference of virulence between isolates and species with both methodologies used (infested toothpick and infested rice). Melon plants expressed first symptoms 15 days after inoculation, showing yellowing and wilting, with later tipping and rot. To our knowledge, this is the first report of the occurrence of these species causing root rot in muskmelon in Brazil. Our results support monitoring of causal agents of melon fusarioses and will be useful for breeding programmes in the search for plant material with resistance to Fusarium rot. [ABSTRACT FROM AUTHOR]

Cocoa is a commercially important beverage crop that faces new challenges in the context of climate change, which can alter pest and disease dynamics in cocoa plantations. In the Dakshina Kannada district of Karnataka, India, an abrupt increase in cocoa wilt was observed during the 2017–18 and 2018–19 seasons. Systematic examination of affected trees revealed consistent attacks of Euwallacea perbrevis (Schedl, 1951; Coleoptera: Curculionidae: Scolytinae). In-depth studies of the wilted trees revealed the association of the plant pathogenic fungus Fusarium sp. with Euwallacea perbrevis. The identity of the obtained pure culture from the insect and infected tree was confirmed as Fusarium sp. using amplification of ribosomal DNA, RNA polymerase II largest subunit (RPB1) and translation elongation factor 1 (Tef1) genes. Notably, this study reports a remarkable case of mutualistic association between ambrosia beetles and Fusarium sp., belonging to the Fusarium solani species complex (FSSC), rather than the Ambrosia Fusarium clade (AFC). This finding highlights the intriguing diversity of mutualistic relationships in nature and sheds new light on the complex interactions between organisms. The present study also investigated the impact of rainfall on the colonization and spread of the Euwallacea-Fusarium complex. The findings revealed that rainfall was identified as a predisposing factor for the incidence and spread of attacks. Additionally, the study conducted a comprehensive analysis of the modeling of Euwallacea-Fusarium complex spread over a specific period of time. • An abrupt increase in cocoa wilt was documented in Karnataka, India during the periods 2017–2019. • Investigation unveiled incidence of Euwallacea fornicates , an ambrosia beetle, and Fusarium sp. fungus, belonging to the Fusarium solani species complex. • The study identified rainfall as a predisposing factor for the incidence and spread of Euwallacea - Fusarium complex. • This is the first report of Euwallacea - Fusarium complex causing wilt disease of cocoa in India. [ABSTRACT FROM AUTHOR]

Onychomycosis, a nail fungal infection, is normally caused by dermatophytes. However, yeasts and non‐dermatophyte moulds (NDM) are among pathogens that cause nail disease. Regarding, this study aimed to describe the molecular epidemiology of Fusarium onychomycosis in the North of Iran. Two hundred and fifty seven nail samples collected from the patients clinically suspected of onychomycosis were subjected to direct microscopy, calcofluor white staining and culture. Fusarium isolates were identified at a species level through determination of multi‐locus sequences for internal transcribed spacer and translation elongation factor 1 alpha. Based on the findings, Fusarium species were isolated from onychomycosis patients (n = 27). According to a previous partial genes analysis, the species in the recent study belonged to the members of F. fujikuroi species complex (n = 14), Fusarium incarnatum‐equiseti species complex (n = 1) and F. solani species complex (n = 12). In this study, F. proliferatum was the dominant Fusarium species collected from the samples. The correct identification of Fusarium species is essential regarding the increased prevalence of Fusarium onychomycosis and the inherent resistance of these agents to a wide spectrum of antifungals. The obtained results indicated variation in the epidemiology of Fusarium species isolated from onychomycosis. Moreover, the minimum inhibitory concentration (MIC) of luliconazole and lanoconazole was in the range of 0.001–1 μg/ml, with the geometric mean of MICs obtained at 0.0103 and 0.0343 μg/ml against Fusarium species, respectively. These findings can increase researchers' knowledge regarding diversity of species, distribution of onychomycosis and the choice of a proper treatment. [ABSTRACT FROM AUTHOR]

Background: The Fusarium solani species complex (FSSC) comprises fungal pathogens responsible for mortality in a diverse range of animals and plants, but their genome diversity and transcriptome responses in animal pathogenicity remain to be elucidated. We sequenced, assembled and annotated six chromosome-level FSSC clade 3 genomes of aquatic animal and plant host origins. We established a pathosystem and investigated the expression data of F. falciforme and F. keratoplasticum in Chinese softshell turtle (Pelodiscus sinensis) host. Results: Comparative analyses between the FSSC genomes revealed a spectrum of conservation patterns in chromosomes categorised into three compartments: core, fast-core (FC), and lineage-specific (LS). LS chromosomes contribute to variations in genomes size, with up to 42.2% of variations between F. vanettenii strains. Each chromosome compartment varied in structural architectures, with FC and LS chromosomes contain higher proportions of repetitive elements with genes enriched in functions related to pathogenicity and niche expansion. We identified differences in both selection in the coding sequences and DNA methylation levels between genome features and chromosome compartments which suggest a multi-speed evolution that can be traced back to the last common ancestor of Fusarium. We further demonstrated that F. falciforme and F. keratoplasticum are opportunistic pathogens by inoculating P. sinensis eggs and identified differentially expressed genes also associated with plant pathogenicity. These included the most upregulated genes encoding the CFEM (Common in Fungal Extracellular Membrane) domain. Conclusions: The high-quality genome assemblies provided new insights into the evolution of FSSC chromosomes, which also serve as a resource for studies of fungal genome evolution and pathogenesis. This study also establishes an animal model for fungal pathogens of trans-kingdom hosts. [ABSTRACT FROM AUTHOR]

Fungal-infections are mostly due to fungi in an adhering, biofilm-mode of growth and not due to planktonically growing, suspended-fungi. 1, 8-cineole is a natural product, which has been shown to possess antifungal effect. However, the anti-biofilm effect and mechanism of 1,8-cineole against Fusarium solani species complex has not reported previously. In this study, we found that 1,8-cineole has a good antifungal activity against F. solani with an MIC value of 46.1 μg/ml. Notably, 1,8-cineole showed good anti-biofilm formation activity against F. solani via inhibiting cell adhesion, hypha formation and decreasing the secretion of extracellular matrix at the concentration of ≥5.76 μg/ml. In addition, transcriptome sequencing analysis results showed that F. solani species complex genes related to ECM, protein synthesis and energy metabolism were down-expressed in the biofilms formation process treated with 1,8-cineole. In conclusion, these results show that 1,8-cineole has good anti-biofilm formation activity against F. solani species complex, and it exerts its anti-biofilm formation activity by downregulating of ergosterol biosynthetic genes, inhibiting adhesion, hindering the synthesis of ECM and interfering mitochondrial activity. This study suggests that 1,8-cineole is a promising anti-biofilm agent against F. solani species complex.

Ambrosia beetles bore into host trees, and live with fungi symbiotically that serve as a food source. However, it is challenging to directly observe these beetles in the wild. In this study, Euwallacea interjectus (Blandford) (Coleoptera: Curculionidae: Scolytinae), a pest of fig trees in Japan, were reared under artificial conditions to emulate the behavior of ambrosia beetle. Fungi were isolated from the adult females of E. interjectus to identify the species associated with secondary symbiosis. In total, nine filamentous fungi and one yeast were identified using morphological characteristics and DNA sequence data. Neocosmospora metavorans (Hypocreales: Nectriaceae), Fusarium sp. (Hypocreales: Nectriaceae), that is undescribed, and Meyerozyma guilliermondii (Saccharomycetes: Saccharomycetales) (yeast) were isolated more frequently from the head (including from mycangia, the fungus-carrying organ) than from the thorax and abdomen of adult beetles. Neocosmospora metavorans was the dominant species isolated from 12 out of 16 heads at 200 to 3300 CFUs/head, compared to the primary mycangia fungus from wild beetles, i.e., Fusarium kuroshium (Hypocreales: Nectriaceae). Temperature had a marked effect on fungal growth in the three symbiont species. Our results represent a major paradigm shift in understanding beetle–fungal interactions, as they show specific symbiont switching can occur in different nesting places. [ABSTRACT FROM AUTHOR]

ABSTRACT Sweetpotato (Ipomoea batatas) is the eighth most important crop globally. However, the production and quality of sweetpotatoes are threatened by Fusarium diseases that are prevalent around the world. In this study, a Fusarium species that causes root and stem rot in sweetpotatoes was studied. The pathogenic fungus CRI 24-3 was isolated and sequenced using third- and next-generation sequencing techniques and a 49.6 Mb chromosome-level draft genome containing 15,374 putative coding genes were obtained. Molecular phylogenetic analysis showed that CRI 24-3 was an F. solani-melongenae strain within clade 3 of the F. solani species complex (FSSC). CRI 24-3 showed a relatively high number of virulence factors, such as carbohydrate-active enzymes (CAZymes), pathogen-host interaction (PHI) proteins, and terpene synthases (TSs), compared with the number of those identified in other sequenced FSSC members. Comparative genome analysis revealed considerable conservation and unique characteristics between CRI 24-3 and other FSSC species. In conclusion, the findings in the current study provide important genetic information about F. solani-melongenae and should be useful in the exploration of pathogenicity mechanisms and the development of Fusarium disease management strategies. IMPORTANCE Fusarium root and stem rot in sweetpotato are prevalent in the main sweetpotato-growing areas in China, and fungal isolation, morphological characteristics, and molecular phylogenetic analysis of the disease causal agent (F. solani-melongenae isolate CRI 24-3) were systematically studied. The genome sequence of F. solani-melongenae isolates CRI 24-3 was first reported, which should provide a basis for genome assembly of other closely related Fusarium species. Carbohydrate-active enzymes predicted in CRI 24-3 may be important to convert the substantial polysaccharides to sustainable and renewable energy. Moreover, other virulence factors facilitating Fusarium diseases, including effectors and toxic secondary metabolites, are ideal objects for pathogenicity mechanism research and molecular targets for fungicide development. The findings of comparative genome analysis of CRI 24-3 and 15 sequenced members of the F. solani species complex help promote an integral understanding of genomic features and evolutionary relationships in Fusarium.

Background and Objectives: Fusarium species are known to be one of the common causes of keratitis. This study was conducted to identify Fusarium spp. causing keratitis and to investigate their genetic diversity using TEF1 and RPB2 gene sequences. Materials and Methods: Twenty-four clinical isolates of Fusarium were isolated from the patient with keratitis. Phylogenetic analysis of two-locus of the 24 clinical isolates and three reference strains was carried out using the maximum parsimony and RAxML methods. Results: Based on gene sequences of the 24 clinical isolates, 17, 4, and 3 isolates were identified as Fusarium solani species complex (FSSC), Fusarium fujikuroi species complex (FFSC), and Fusarium oxysporum, respectively. FFSC include F. proliferatum (n=1), F. globosum (n=1), F. verticillioides (n=1), and F. brevicatenulatum (n=1), respectively. Conclusion: Given that sequence of a sole gene can be challenging and on the other hand, due to the high resistance to antifungal drugs, identification of Fusarium species is of substantial significance. In this study, by designing a novel set of primers for the RPB2 area and using TEF1 primer, we were able to differentiate 24 Fusarium spp. isolated from patients with keratitis. [ABSTRACT FROM AUTHOR]

During 2018 summer season (April–May), several young (1–3-year-old) arecanut seedlings exhibited yellowing, drying, drooping and wilting symptoms in farmer's gardens located in Dakshina Kannada district of Karnataka, India. The longitudinal section of the infected seedlings showed extensive decaying of fibrous roots which extended up to the collar region and ultimately resulted in the death of young seedlings. A series of cultural, morphological, molecular characterization using multi-gene phylogeny and pathogenicity assays with Koch's postulates confirmed the association of Fusarium falciforme (FSSC 3 + 4) as the causal organism of arecanut root decay disease. To the best of our knowledge, the present study confirms the first report of root decay disease caused by F. falciforme in arecanut. [ABSTRACT FROM AUTHOR]

Abstract Background The transition to a biobased economy involving the depolymerization and fermentation of renewable agro-industrial sources is a challenge that can only be met by achieving the efficient hydrolysis of biomass to monosaccharides. In nature, lignocellulosic biomass is mainly decomposed by fungi. We recently identified six efficient cellulose degraders by screening fungi from Vietnam. Results We characterized a high-performance cellulase-producing strain, with an activity of 0.06 U/mg, which was identified as a member of the Fusarium solani species complex linkage 6 (Fusarium metavorans), isolated from mangrove wood (FW16.1, deposited as DSM105788). The genome, representing nine potential chromosomes, was sequenced using PacBio and Illumina technology. In-depth secretome analysis using six different synthetic and artificial cellulose substrates and two agro-industrial waste products identified 500 proteins, including 135 enzymes assigned to five different carbohydrate-active enzyme (CAZyme) classes. The F. metavorans enzyme cocktail was tested for saccharification activity on pre-treated sugarcane bagasse, as well as untreated sugarcane bagasse and maize leaves, where it was complemented with the commercial enzyme mixture Accellerase 1500. In the untreated sugarcane bagasse and maize leaves, initial cell wall degradation was observed in the presence of at least 196 µg/mL of the in-house cocktail. Increasing the dose to 336 µg/mL facilitated the saccharification of untreated sugarcane biomass, but had no further effect on the pre-treated biomass. Conclusion Our results show that F. metavorans DSM105788 is a promising alternative pre-treatment for the degradation of agro-industrial lignocellulosic materials. The enzyme cocktail promotes the debranching of biopolymers surrounding the cellulose fibers and releases reduced sugars without process disadvantages or loss of carbohydrates.

Background and Objectives: Fusarium species are known to be one of the common causes of keratitis. This study was conducted to identify Fusarium spp. causing keratitis and to investigate their genetic diversity using TEF1 and RPB2 gene sequences. Materials and Methods: Twenty-four clinical isolates of Fusarium were isolated from the patient with keratitis. Phylogenetic analysis of two-locus of the 24 clinical isolates and three reference strains was carried out using the maximum parsimony and RAxML methods. Results: Based on gene sequences of the 24 clinical isolates, 17, 4, and 3 isolates were identified as Fusarium solani species complex (FSSC), Fusarium fujikuroi species complex (FFSC), and Fusarium oxysporum, respectively. FFSC include F. proliferatum (n=1), F. globosum (n=1), F. verticillioides (n=1), and F. brevicatenulatum (n=1), respectively. Conclusion: Given that sequence of a sole gene can be challenging and on the other hand, due to the high resistance to antifungal drugs, identification of Fusarium species is of substantial significance. In this study, by designing a novel set of primers for the RPB2 area and using TEF1 primer, we were able to differentiate 24 Fusarium spp. isolated from patients with keratitis.

Ficus carica plantations in Japan were first reported to be infested by an ambrosia beetle species, identified as Euwallacea interjectus, in 1996. The purpose of this study was to determine the symbiotic fungi of female adults of E. interjectus emerging from F. carica trees infected with fig wilt disease (FWD). Dispersal adults (51 females) of E. interjectus, which were collected from logs of an infested fig tree in Hiroshima Prefecture, Western Japan, were separated into three respective body parts (head, thorax, and abdomen) and used for fungal isolation. Isolated fungi were identified based on the morphological characteristics and DNA sequence data. Over 13 species of associated fungi were detected, of which a specific fungus, Fusarium kuroshium, was dominant in female head (including oral mycangia). The plant-pathogenic fungus of FWD, Ceratocystis ficicola, was not observed within any body parts of E. interjectus. We further discussed the relationship among E. interjectus and its associated fungi in fig tree.

Ficus carica plantations in Japan were first reported to be infested by an ambrosia beetle species, identified as Euwallacea interjectus , in 1996. The purpose of this study was to determine the symbiotic fungi of female adults of E. interjectus emerging from F. carica trees infected with fig wilt disease (FWD). Dispersal adults (51 females) of E. interjectus , which were collected from logs of an infested fig tree in Hiroshima Prefecture, Western Japan, were separated into three respective body parts (head, thorax, and abdomen) and used for fungal isolation. Isolated fungi were identified based on the morphological characteristics and DNA sequence data. Over 13 species of associated fungi were detected, of which a specific fungus, Fusarium kuroshium , was dominant in female head (including oral mycangia). The plant-pathogenic fungus of FWD, Ceratocystis ficicola , was not observed within any body parts of E. interjectus. We further discussed the relationship among E. interjectus and its associated fungi in fig tree. [ABSTRACT FROM AUTHOR]

Background: Invasive fusariosis is associated with marked morbidity and mortality in immunocompromised hosts, and clinical outcomes are poor with conventional therapy. Olorofim (F901318) is an investigational antifungal in the orotomide class that selectively targets fungal dihydroorotate dehydrogenase (DHODH) causing inhibition of pyrimidine biosynthesis. Objective: We evaluated the in vitro activity of olorofim against 61 clinical isolates of the Fusarium oxysporum and F solani species complexes (FOSC and FSSC, respectively), the most prevalent causes of invasive fusariosis. Methods: Clinical isolates of FOSC (n = 45) and FSSC (n = 16) were identified using DNA sequence analysis of the translation elongation factor 1‐alpha (TEF1α) and RNA polymerase II second largest subunit (RPB2). Antifungal susceptibility testing was performed by CLSI M38 broth microdilution for olorofim, amphotericin B, isavuconazole, posaconazole, voriconazole and micafungin. Results: Olorofim demonstrated good in vitro activity against both FOSC and FSSC. Against the 45 FOSC isolates, olorofim MICs ranged between 0.03‐0.5 mg/L and 0.06‐>4 mg/L at the 50% and 100% inhibition endpoints, respectively. Against FSSC isolates, olorofim MIC ranged between 0.25‐1 mg/L and 1‐>4 mg/L at 50% and 100% inhibition, respectively. While amphotericin B also demonstrated similar in vitro activity (MIC ranges 1‐4 and 0.25‐4 mg/L against FOSC and FSSC, respectively), neither the triazoles nor micafungin demonstrated consistent in vitro activity against Fusarium isolates at clinically relevant concentrations. Conclusions: The investigational agent olorofim demonstrated good in vitro activity against FOSC and FSSC clinical isolates. Further studies are warranted to determine how well this in vitro activity translates into in vivo efficacy. [ABSTRACT FROM AUTHOR]

Ambrosia beetles bore into host trees, and live with fungi symbiotically that serve as a food source. However, it is challenging to directly observe these beetles in the wild. In this study, Euwallacea interjectus (Blandford) (Coleoptera: Curculionidae: Scolytinae), a pest of fig trees in Japan, were reared under artificial conditions to emulate the behavior of ambrosia beetle. Fungi were isolated from the adult females of E. interjectus to identify the species associated with secondary symbiosis. In total, nine filamentous fungi and one yeast were identified using morphological characteristics and DNA sequence data. Neocosmospora metavorans (Hypocreales: Nectriaceae), Fusarium sp. (Hypocreales: Nectriaceae), that is undescribed, and Meyerozyma guilliermondii (Saccharomycetes: Saccharomycetales) (yeast) were isolated more frequently from the head (including from mycangia, the fungus-carrying organ) than from the thorax and abdomen of adult beetles. Neocosmospora metavorans was the dominant species isolated from 12 out of 16 heads at 200 to 3300 CFUs/head, compared to the primary mycangia fungus from wild beetles, i.e., Fusarium kuroshium (Hypocreales: Nectriaceae). Temperature had a marked effect on fungal growth in the three symbiont species. Our results represent a major paradigm shift in understanding beetle–fungal interactions, as they show specific symbiont switching can occur in different nesting places.

Background: The transition to a biobased economy involving the depolymerization and fermentation of renewable agro-industrial sources is a challenge that can only be met by achieving the efficient hydrolysis of biomass to monosaccharides. In nature, lignocellulosic biomass is mainly decomposed by fungi. We recently identified six efficient cellulose degraders by screening fungi from Vietnam. Results: We characterized a high-performance cellulase-producing strain, with an activity of 0.06 U/mg, which was identified as a member of the Fusarium solani species complex linkage 6 (Fusarium metavorans), isolated from mangrove wood (FW16.1, deposited as DSM105788). The genome, representing nine potential chromosomes, was sequenced using PacBio and Illumina technology. In-depth secretome analysis using six different synthetic and artificial cellulose substrates and two agro-industrial waste products identified 500 proteins, including 135 enzymes assigned to five different carbohydrate-active enzyme (CAZyme) classes. The F. metavorans enzyme cocktail was tested for saccharification activity on pre-treated sugarcane bagasse, as well as untreated sugarcane bagasse and maize leaves, where it was complemented with the commercial enzyme mixture Accellerase 1500. In the untreated sugarcane bagasse and maize leaves, initial cell wall degradation was observed in the presence of at least 196 µg/mL of the in-house cocktail. Increasing the dose to 336 µg/mL facilitated the saccharification of untreated sugarcane biomass, but had no further effect on the pre-treated biomass. Conclusion: Our results show that F. metavorans DSM105788 is a promising alternative pre-treatment for the degradation of agro-industrial lignocellulosic materials. The enzyme cocktail promotes the debranching of biopolymers surrounding the cellulose fibers and releases reduced sugars without process disadvantages or loss of carbohydrates. [ABSTRACT FROM AUTHOR]

Since the early 2000s, over 5000 hectares of guava orchards have been decimated in Brazil by guava decline. The disease has caused tens of millions of dollars in yield losses, the loss of thousands of jobs, and the closing of many fruit pulp-processing plants. Guava decline has been described as a synergistic interaction between the nematode Meloidogyne enterolobii and the fungus Fusarium solani. Nonetheless, the etiology of the disease has had to be reappraised because recent molecular studies have reassigned the whole 'F. solani species complex' to the genus Neocosmospora, with several plant-parasitic species being reclassified or synonymized. Hence, from a collection of 'F. solani' isolates associated with guava decline, we chose four of the most aggressive isolates, from which we sequenced RNA polymerase II subunit 1 (RPB1), RNA polymerase II subunit 2 (RPB2), and translation elongation factor 1-alpha (TEF1) genes. A GenBank® BLASTn search showed that the isolates belonged to Neocosmospora sp. Phylogenetic analyses using the maximum likelihood (ML) and Bayesian inference (BI) methods, with individual and combined datasets for TEF1, RPB1 and RPB2 genes, clustered all isolates within the N. falciformis clade, with maximum support in the ML and BI multilocus analyses. This and previous studies show that N. falciformis is the causal agent of guava decline and soybean sudden death syndrome, as well as of crown and root rots in other annual and perennial crops. [ABSTRACT FROM AUTHOR]

Some taxa of the Fusarium solani species complex (FSSC) have been associated with clinical infections in humans and plant diseases. Among the several fusaria that cause relevant mycoses in cucurbits in Spain, Neocosmospora keratoplastica is described for the first time as responsible for wilt and root rot in both watermelon and melon crops in producing areas of Valencia and Alicante provinces. Due to the ecological and systematic complexity of the group, with described clinical forms and plant pathogens practically indistinguishable from each other, both pathological evidences (including artificial inoculation bioassays) and molecular methods (multilocus phylogeny based on ITS, TEF-1α, and RPB2 regions) are provided to confirm this finding, since the presence of this soil-borne pathogen could have been probably underestimated in cucurbits-producing areas of Spain. [ABSTRACT FROM AUTHOR]

The genus Fusarium is noted for including important plant pathogens and mycotoxin producers. Furthermore, many Fusarium lineages have been reported to be efficient in controlling insects and to exhibit promising characteristics for agricultural pest control such as causing high mortality rates and having fast action and abundant sporulation. In this review we present a survey of peer-reviewed papers published from 2000 to 2019, demonstrating the widespread pathogenicity of Fusarium to insects. This survey was made using search strings in a number of databases. We list the major complexes and species of Fusarium reported as entomopathogenic and highlight the features of interest for insect control as well as the advantages and implications of this practice. Out of a total of forty papers, at least 30 species and 273 isolates of Fusarium were reported as pathogenic to at least one species of insect. Ten complexes of Fusarium species harbor entomopathogenic fungi, of which F. incarnatum-equiseti , F. fujikuroi , F. oxysporum and F. solani (= Neocosmospora solani) species complexes represented the most abundant number of entomopathogenic strains. The entomopathogenic interactions of these fungi have received greater attention in recent years, but much remains to be explored, especially regarding the specificity of these fungi for the host insect, the production of undesirable secondary metabolites, and side-effect and safety tests organisms not targets. Detailed investigations in this regard will be crucial if we are to fully exploit the potential of Fusarium for controlling insect pests. • Fusarium isolates can be effective insect pest control agents. • At least ten Fusarium species complexes harbor entomopathogenic fungi. • A better characterization of these strains will enable their effective application as biocontrol agents. [ABSTRACT FROM AUTHOR]

To clarify the cause of castor bean bud rot, pathogenic strains were isolated by tissue isolation and tested for pathogenicity. Classification status of the pathogens were determined by ITS-PCR combined with morphological identification. Results showed that RFR1-4 isolated from the disease samples, was confirmed to be the pathogen according to Koch's rule. It was identified as Fusarium solani by morphological characteristics. By ITS analysis, EF1-α and β-tubulin sequences revealed a 100% identity with F. solani species complex by polyphasic identification of FUSARIUM-ID database. Therefor, the pathogenic strain (RFR1-4) was identified to be a member of F. solani species complex which caused castor bean bud rot. [ABSTRACT FROM AUTHOR]

Members of the Fusarium solani species complex (FSSC) are the most frequently isolated fusaria from soil. Moreover, this complex solely affects more than 100 plant genera, and is also one of the major opportunistic human pathogenic filamentous fungi, being responsible for approximately two-third of fusariosis cases. Mycotic keratitis due to Fusarium species is among the leading causes of visual impairment and blindness in South India, but its management is still challenging due to the poor susceptibility of the isolates to conventional antifungal drugs. Aims of the present study were to isolate South Indian clinical and environmental FSSC strains and identify them to species level, to determine the actual trends in their susceptibilities to antifungal therapeutic drugs and to compare the virulence of clinical and environmental FSSC members. Based on the partial sequences of the translation elongation factor 1α gene, the majority of the isolates—both from keratomycosis and environment—were confirmed as F. falciforme, followed by F. keratoplasticum and F. solani sensu stricto. In vitro antifungal susceptibilities to commonly used azole, allylamine and polyene antifungals were determined by the CLSI M38-A2 broth microdilution method. The first generation triazoles, fluconazole and itraconazole proved to be ineffective against all isolates tested. This phenomenon has already been described before, as fusaria are intrinsically resistant to them. However, our results indicated that despite the intensive agricultural use of azole compounds, fusaria have not developed resistance against the imidazole class of antifungals. In order to compare the virulence of different FSSC species from clinical and environmental sources, a Drosophila melanogaster model was used. MyD88 mutant flies having impaired immune responses were highly susceptible to all the examined fusaria. In wild-type flies, one F. falciforme and two F. keratoplasticum strains also reduced the survival significantly. Pathogenicity seemed to be independent from the origin of the isolates.

Two Fusarium strains, isolated from Asparagus in Italy and Musa in Vietnam respectively, proved to be members of an undescribed clade within the Fusarium solani species complex based on phylogenetic species recognition on ITS, partial RPB2 and EF-1α gene fragments. Macro- and micro-morphological investigations followed with physiological studies done on this new species: Fusarium ershadii sp. nov can be distinguished by its conidial morphology. Both isolates of Fusarium ershadii were shown to be pathogenic to the monocot Asparagus officinalis when inoculated on roots and induced hollow root symptoms within two weeks in Asparagus officinalis seedlings. In comparison mild disease symptoms were observed by the same strains on Musa acuminata seedlings. [ABSTRACT FROM AUTHOR]

Members of the Fusariumsolani species complex (FSSC) are themost frequently isolated fusaria from soil. Moreover, this complex solely affects more than 100 plant genera, and is also one of the major opportunistic human pathogenic filamentous fungi, being responsible for approximately two-third of fusariosis cases. Mycotic keratitis due to Fusarium species is among the leading causes of visual impairment and blindness in South India, but its management is still challenging due to the poor susceptibility of the isolates to conventional antifungal drugs. Aims of the present study were to isolate South Indian clinical and environmental FSSC strains and identify them to species level, to determine the actual trends in their susceptibilities to antifungal therapeutic drugs and to compare the virulence of clinical and environmental FSSC members. Based on the partial sequences of the translation elongation factor 1a gene, the majority of the isolates--both from keratomycosis and environment--were confirmed as F. falciforme, followed by F. keratoplasticum and F. solani sensu stricto. In vitro antifungal susceptibilities to commonly used azole, allylamine and polyene antifungals were determined by the CLSI M38-A2 broth microdilution method. The first generation triazoles, fluconazole and itraconazole proved to be ineffective against all isolates tested. This phenomenon has already been described before, as fusaria are intrinsically resistant to them. However, our results indicated that despite the intensive agricultural use of azole compounds, fusaria have not developed resistance against the imidazole class of antifungals. In order to compare the virulence of different FSSC species from clinical and environmental sources, a Drosophila melanogaster model was used. MyD88 mutant flies having impaired immune responses were highly susceptible to all the examined fusaria. In wild-type flies, one F. falciforme and two F. keratoplasticumstrains also reduced the survival significantly. Pathogenicity seemed to be independent from the origin of the isolates. [ABSTRACT FROM AUTHOR]

Although Fusarium spp. rarely cause infections in healthy people, they can cause fusariosis, particularly in neutropenic hematological malignancies, bone marrow transplant patients, and immunocompromised patients, such as those with acquired immune deficiency syndrome (AIDS), and rarely in solid organ transplant recipients. Here, we present a case of a liver transplant recipient with F. solani species complex (FSSC) infection treated with posaconazole. A 61-year-old man presented with multiple itchy, painful, palpable, irregular, subcutaneous nodules on the right leg and total dystrophic onychomycosis in the right toenails. Incisional skin biopsies of the lesions were performed, and the samples were sent to the pathology and mycology laboratories for analysis. The clinical isolate was identified as FSSC using phenotypic, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and genotypic methods. Liposomal amphotericin B could not be administered owing to the development of side effects; hence, the patient was treated with posaconazole for 4 months. While some nodular lesions disappeared completely under this treatment, the others showed dimensional regression. This is the first case of FSSC infection with skin and nail involvement in a non-neutropenic, liver transplant patient in Turkey. Fusariosis may develop with rare species, such as FSSC, as first reported in this case of a liver transplant patient. Regardless of the species, amphotericin B is the first choice for treating fusariosis; however, posaconazole is an effective and safe alternative to amphotericin B. [ABSTRACT FROM AUTHOR]

Fungal keratitis (FK) is a site-threatening infection of the cornea associated with ocular trauma and contact lens wear. Members of the Fusarium solani species complex (FSSC) are predominant agents of FK worldwide, but genes that support their corneal virulence are poorly understood. As a means to bolster genetic analysis in FSSC pathogens, we sought to employ a CRISPR/Cas9 system in an FK isolate identified as Fusarium petroliphilum. Briefly, this approach involves the introduction of two components into fungal protoplasts: (1) A purified Cas9 protein complexed with guide RNAs that will direct the ribonuclease to cut on either side of the gene of interest, and (2) a “repair template” comprised of a hygromycin resistance cassette flanked by 40 bp of homology outside of the Cas9 cuts. In this way, Cas9-induced double strand breaks should potentiate double homologous replacement of the repair template at the desired locus. We targeted a putative ura3 ortholog since its deletion would result in an easily discernable uracil auxotrophy. Indeed, 10% of hygromycin-resistant transformants displayed the auxotrophic phenotype, all of which harbored the expected ura3 gene deletion. By contrast, none of the transformants from the repair template control (i.e., no Cas9) displayed the auxotrophic phenotype, indicating that Cas9 cutting was indeed required to promote homologous integration. Taken together, these data demonstrate that the in vitro Cas9 system is an easy and efficient approach for reverse genetics in FSSC organisms, including clinical isolates, which should enhance virulence research in these important but understudied ocular pathogens.

The defoliation and mortality of Erythrina spp. are increasing on the southern islands of Japan as well as in Taiwan. Although infestation by the gall wasp Quadrastichus erythrinae has been accepted as the cause of Erythrina decline, its role in the death of hosts has never been investigated. We thus studied the cause of the decline, focusing on physiological changes and any contributions by microorganisms. From declining and defoliated trees, Fusarium sp. within F. solani species complex (FSSC) clade 3 was primarily detected, especially from discolored xylem and necrotic phloem that had an odor. This fungus belongs to the Ambrosia Fusarium clade, a group of symbionts of ambrosia beetles that includes the causal agent of Fusarium dieback on avocado. No specific fungi were detected from twigs and leaves with Q. erythrinae galls. According to histological observations, the internal symptoms of declining E. variegata are similar to those of sudden death syndrome in soybeans, which is caused by F. virguliforme, a member of FSSC clade 2. One of the isolates of the Fusarium sp. isolated from E. variegata induced wilt and necrosis of cortex and phloem in the seedlings after artificial inoculation, and the inoculated strain was reisolated. The present results demonstrated that the isolate was pathogenic to E. variegata and may be a causal agent of Erythrina decline. [ABSTRACT FROM AUTHOR]

In recent years, turtle eggs incubated in situ or in protected hatcheries in Malaysia have been reported to show symptoms and signs of fungal colonisation. However, there are no studies addressing this problem and potential relationship with frequent hatching failures. We identified Fusarium species from nesting sites of green turtle (Chelonia mydas) and hawksbill turtle (Eretmochelys imbricata) situated in Terengganu and Melaka, as well as the environments surrounding those sites. The eggs were incubated on the nesting beach (in situ) or relocated to the beach hatchery and styrofoam boxes (ex situ) in Peninsular Malaysia. Samples were collected from infected eggs, sand, plant roots and debris around the egg chambers. One-hundred and six strains of Fusarium spp. were isolated. They were identified morphologically as member of the Fusarium solani species complex (FSSC, 101 strains), F. oxysporum (four strains) and F. proliferatum (one strain). We conducted phylogenetic analysis based on nucleotide sequences of translation elongation factor 1-alpha gene (TEF-1α). The strains of the FSSC were further separated into three lineages, F. falciforme, F. lichenicola and F. keratoplasticum. This is the first report on Fusarium species isolated from symptomatic green and hawksbill turtle eggs in Peninsular Malaysia. Fusarium colonisation in sea turtle nests poses a serious risk to the survival of endangered sea turtles in Malaysia. It is, therefore, important to examine the nature of such colonisation and their relationship to hatching failures of the turtles in Malaysia or elsewhere in the region to mitigate pathogenic fungi impact. [ABSTRACT FROM AUTHOR]

Fusarium spp. are recognized as the second most frequently filamentous fungi causing opportunistic infections and particularly important due to the increasing number of immunocompromised patients. F. keratoplasticum (a member of F. solani species complex) is one of the Fusarium species commonly associated with human infection, and therefore, studies on the virulence of this fungus are needed. This study aimed to confirm the presence of melanin in F. keratoplasticum from a patient with systemic fusariosis. Immunofluorescence labeling with anti-melanin monoclonal antibody (MAb) was used to examine an expression of melanin in F. keratoplasticum in vitro and during infection. Electron spin resonance identified the particles extracted from F. keratoplasticum as stable free radical consistent with melanin. Lesional skin from the sites with fusariosis contained hyphal structures that could be labeled by melanin-binding MAb, while digestion of the tissue yielded dark particles that were reactive. These findings suggest that F. keratoplasticum hyphae and chlamydospores can produce melanin in vitro and that hyphae can synthesize pigment in vivo. Given the potential role of melanin in virulence of other fungi, this pigment in F. keratoplasticum may play a role in the pathogenesis of fusariosis. [ABSTRACT FROM AUTHOR]

In Japan, Fusarium species are known etiological agents of human fungal infection; however, there has been no report of a large-scale epidemiological study on the etiological agents of fusariosis. A total of 73 Fusarium isolates from patients with invasive fusariosis（IF, n = 36）or superficial fusariosis（SF, n = 37）, which were obtained at hospitals located in 28 prefectures in Japan between 1998 and 2015, were used for this study. Fusarium isolates were identified using Fusarium- and Fusarium solani species complex （FSSC）-specific real-time PCR and partial DNA sequences of the elongation factor-1 alpha（EF-1α） gene and the nuclear ribosomal internal transcribed spacer（ITS）region. FSSC was predominately isolated from both patients with IF and SF（IF, 77.8% and SF, 67.6%）. Distribution of the phylogenetic species of FSSC isolates from patients with IF and SF exhibited different spectra; specifically, F. keratoplasticum（FSSC 2）（25.0%）was the most frequent isolate from patients with IF, whereas F. falciforme（FSSC 3+ 4）（32.4%）was the most frequent isolate from patients with SF. Fusarium sp.（FSSC 5）was the second most frequent isolate from both patients with IF and SF（IF, 22.2% and SF, 24.3%）. Notably, F. petroliphilum（FSSC 1）was isolated only from patients with IF. Each species was isolated from a broad geographic area, and an epidemic was not observed. This is the first epidemiological study of Fusarium species causing IF and SF in Japan. [ABSTRACT FROM AUTHOR]

Fungal infection in sea turtle nests has become a potential threat to sea turtle embryos. We screened the hatchery nest sand, eggshells of failed eggs, and stillbirths of green turtles and hawksbills collected from hatcheries in Malacca, Pahang, Perak and Terengganu for the presence of fungi. The DNA sequence of the ITS region of the three highest occurring isolated fungi confirmed that these species were Pseudallescheria ellipsoidea (35.4%), Scedosporium aurantiacum (27.2%), and Fusarium solani (22.0%). Morphological characteristics of these fungi were recorded. Although the total fungi abundance had no significant effect on hatching success (p > 0.05), the abundance of P. ellipsoidea significantly increased mortality in the nests (r = 0.70, p < 0.05). Future research should focus on understanding the biological aspects of this species to establish a more effective mitigation technique for the prevention of fungal infection of sea turtle eggs and hatchery employees. • Pseudallescheria ellipsoidea was the most frequently isolated fungal species. • Fungal abundance had no significant effect on hatching success. • Abundance of P. ellipsoidea significantly increase mortality of the nests. • Fungal abundance was significantly higher on failed eggs than in nest sand. [ABSTRACT FROM AUTHOR]

Clinically relevant members of the fungal genus, Fusarium, exhibit an extraordinary genetic diversity and cause a wide spectrum of infections in both healthy individuals and immunocompromised patients. Generally, Fusarium species are intrinsically resistant to all systemic antifungals. We investigated whether the presence or absence of the ability to produce biofilms across and within Fusarium species complexes is linked to higher resistance against antifungals. A collection of 41 Fusarium strains, obtained from 38 patients with superficial and systemic infections, and three infected crops, were tested, including 25 species within the Fusarium fujikuroi species complex, 14 from the Fusarium solani species complex (FSSC), one Fusarium dimerum species complex, and one Fusarium oxysporum species complex isolate. Of all isolates tested, only seven strains from two species of FSSC, five F. petroliphilum and two F. keratoplasticum strains, recovered from blood, nail scrapings, and nasal biopsy samples, could produce biofilms under the tested conditions. In the liquid culture tested, sessile biofilm-forming Fusarium strains exhibited elevated minimum inhibitory concentrations (MICs) for amphotericin B, voriconazole, and posaconazole, compared to their planktonic counterparts, indicating that the ability to form biofilm may significantly increase resistance. Collectively, this suggests that once a surface adherent biofilm has been established, therapies designed to kill planktonic cells of Fusarium are ineffective.

The Fusarium solani species complex (FSSC) includes important root pathogens of soybean in the United States, but the evolutionary lineages associated with soybean root rot are unknown. A multilocus phylogeny based on 93 isolates from soybean and pea roots from North Dakota and Minnesota revealed that root rot was associated with three known phylogenetic species, FSSC 3 + 4 (= Fusarium falciforme) (3 % of isolates), FSSC 5 (60 %), FSSC 11 (34 %), and one unknown species, FSSC X (2 %). Of these species FSSC 5 and FSSC 3 + 4 are clinically important while FSSC 11 is a plant pathogen. Isolates from FSSC 11 were pathogenic on soybean, dry bean, pea and lentil, and did not grow at 37 °C. However, isolates from FSSC 5 were weakly to non-pathogenic, but grew at 37 °C. Isolates from both FSSC 5 and FSSC 11 were highly resistant to fludioxonil in vitro. This is the first study revealing the pathogenic robustness of FSSC 11 in causing root rot among Fabaceae crops and also the association of clinically important members of the FSSC with roots of a widely grown field crop in the United States. [ABSTRACT FROM AUTHOR]

Fungal peritonitis is a rare serious complication most commonly observed in immunocompromised patients under peritoneal dialysis. Nevertheless, this clinical condition is more difficult to treat than bacterial peritonitis. Bacterial peritonitis followed by the use of antibiotics is the main risk factor for developing fungal peritonitis. Candida spp. are more frequently isolated, and the isolation of filamentous fungi is only occasional. Here we describe a case of Fusarium solani species complex peritonitis associated with bacterial peritonitis in a female kidney transplant recipient with previous history of nephrotic syndrome. The patient has had Enterobacter sp. endocarditis and was hypertensive and diabetic. Two sequential isolates of F. solani were recovered from cultures and identified with different molecular techniques. She was successfully treated with 50 mg daily amphotericin B for 4 weeks. [ABSTRACT FROM AUTHOR]

Members of the Fusarium solani species complex (FSSC) are causing the majority of the fusariosis in humans. Disseminated fusariosis has a high mortality and is predominantly observed in patients with leukemia. Here, we present the case of a fatal infection by a Fusarium strain with a degenerated phenotype, in a patient with acute lymphatic leukemia. Multiple nasal and skin biopsies as well as blood cultures yielded fungal growth, while in direct and histopathological examination of biopsy material septate hyphae were visible. Initial colonies were white with slimy masses with microconidia reminiscent of Fusarium/ Acremonium, but with conidiospore production directly on the hyphae. Multi-locus sequence typing discerned a pionnotal-morphologically degenerated-colony of the recently recognized F. petroliphilum as etiological agent. The culture returned to a typical F. solani species complex morphology only after several weeks of growth in culture. Antifungal susceptibility tests indicate amphotericin B as best drug for this FSSC member rather than any of the azoles or echinocandins. [ABSTRACT FROM AUTHOR]

Members of Fusarium solani species complex (FSSC) are frequently isolated from soils, food, feeds, trees, and to some extent from humans and other animals. The taxonomic status of these fungi is being revised but no attempt has been made to identify those isolated in Iran, a mountainous country with a high biodiversity. The objective of the present research was to study the phylogenetic diversity of FSSC strains recovered from soils in Iran by analyzing morphological characteristics and DNA sequences. A total of 65 strains belonging to the FSSC were recovered from agricultural soils in western Iran. Based on differences in their morphological characters, 25 strains were selected for phylogenetic analysis employing translation elongation factor-1α ( tef1) and internal transcribed spacer (ITS) region sequences. Comparisons of DNA sequence data revealed that all isolates belonged to Fusarium falciforme, Fusarium keratoplasticum, Fusarium petroliphilum, the unnamed species FSSC 5, and unknown species of Fusarium, which represents a new lineage within members of Clade 3. Based on morphological features and phylogenetic study, F. keratoplasticum and F. petroliphilum were reported for the first time in Iran. [ABSTRACT FROM AUTHOR]

Fusarium tucumaniae is the only known sexually reproducing species among the seven closely related fusaria that cause soybean sudden death syndrome (SDS) or bean root rot (BRR). In a previous study, laboratory mating of F. tucumaniae yielded recombinant ascospore progeny but required two mating-compatible strains, indicating that it is heterothallic. To assess the reproductive mode of the other SDS and BRR fusaria, and their potential for mating, whole-genome sequences of two SDS and one BRR pathogen were analyzed to characterize their mating type (MAT) loci. This bioinformatic approach identified a MAT1-1 idiomorph in F. virguliforme NRRL 22292 and MAT1-2 idiomorphs in F. tucumaniae NRRL 34546 and F. azukicola NRRL 54364. Alignments of the MATloci were used to design PCR primers within the conserved regions of the flanking genes APN1 and SLA2, which enabled primer walking to obtain nearly complete sequences of the MAT region for six MAT1-1 and five MAT1-2 SDS/BRR fusaria. As expected, sequences of the highly divergent 4.7 kb MAT1-1 and 3.7 kb MAT1-2 idiomorphs were unalignable. However, sequences of the respective idiomorphs and those that flank MAT1-1 and MAT1-2 were highly conserved. In addition to three genes at MAT1-1 (MATl-1-1, MAT1-1-2, MAT1-1-3) and two at MAT1-2 (MAT1-2-1, MAT1-2-3), the MAT loci of the SDS/BRR fusaria also include a putative gene predicted to encode for a 252 amino acid protein of unknown function. Alignments of the MAT1-1-3 and MAT1-2-1 sequences were used to design a multiplex PCR assay for the MA T loci. This assay was used to screen DNA from 439 SDS/BRR isolates, which revealed that each isolate possessed MAT1-1 or MAT1-2, consistent with heterothallism. Both idiomorphs were represented among isolates of F. azukicola, F. brasiliense, F. phaseoli and F. tucumaniae, whereas isolates of F. virguliforme and F. cuneirostrum were only MAT1-1 and F. crassistipi-tatum were only MAT1-2. Finally, nucleotide sequence data from the RPB1 and RPB2 genes were used to date the origin of the SDS/BRR group, which was estimated to have occurred about 0.75 Mya (95% HPD interval; 0.27, 1.68) in the mid-Pleistocene, long before the domestication of the common bean or soybean. [ABSTRACT FROM AUTHOR]