Species diversity of xerophilic Aspergillus and Penicillium in marine surface waters revealed by isolation using osmophilic medium.

The species diversity of xerophilic and halophilic fungi distributed in marine surface water was studied at four local sites located in two geographically distant regions in Japan. At each site, 5-10 samples were collected and isolated using an osmophilic medium. Species identification was conducted based on nucleotide sequence of calmodulin or ß -tubulin and morphological characteristics for Aspergillus, Penicillium, and Talaromyces, and on the sequences of rRNA internal transcribed spacer for the other taxa. Overall, 231 strains were isolated from all sites and classified into 85 species belonged to 12 orders and 33 genera. The isolates that showed better mycelial growth than the control（no NaCl added) in the halotolerance test were defined as halophilic fungi, and only 22 species（10 Aspergillus species and 12 Penicillium species) were halophilic. Comparison of the halophilic fungal flora of the two regions revealed that four species common to both regions were isolated for Aspergillus, but no such species were isolated for Penicillium. Given that 15 halophilic species（10 Aspergillus and 5 Penicillium species) are known to be xerophilic species distributed in indoor environments, it can be inferred that indoor xerophilic species are likely to be widely distributed in marine surface water.

Ethanolic extract from fruiting bodies of Cordyceps militaris HL8 exhibits cytotoxic activities against cancer cells, skin pathogenic yeasts, and postharvest pathogen Penicillium digitatum.

Cordyceps militaris is a well-known medicinal mushroom in Asian countries. This edible fungus has been widely exploited for traditional medicine and functional food production. C. militaris is a heterothallic fungus that requires both the mating-type loci, MAT1-1 and MAT1-2, for fruiting body formation. However, recent studies also indicated two groups of C. militaris, including monokaryotic strains carrying only MAT1-1 in their genomes and heterokaryotic strains harboring both MAT1-1 and MAT1-2. These strain groups are able to produce fruiting bodies under suitable cultivating conditions. In previous work, we showed that monokaryotic strains are more stable than heterokaryotic strains in fruiting body formation through successive culturing generations. In this study, we report a high cordycepin-producing monokaryotic C. militaris strain (HL8) collected in Vietnam. This strain could form normal fruiting bodies with high biological efficiency and contain a cordycepin content of 14.43 mg/g lyophilized fruiting body biomass. The ethanol extraction of the HL8 fruiting bodies resulted in a crude extract with a cordycepin content of 69.15 mg/g. Assays of cytotoxic activity on six human cancer cell lines showed that the extract inhibited the growth of all these cell lines with the IC50 values of 6.41-11.51 µg/mL. Notably, the extract significantly reduced cell proliferation and promoted apoptosis of breast cancer cells. Furthermore, the extract also exhibited strong antifungal activity against Malassezia skin yeasts and the citrus postharvest pathogen Penicillium digitatum. Our work provides a promising monokaryotic C. militaris strain as a bioresource for medicine, cosmetics, and fruit preservation.

The complete mitochondrial genome of Penicillium expansum: Insights into the fungal evolution and phylogeny.

Penicillium expansum is an important phytopathogenic fungus that causes blue mold disease. In this study, the novel mitochondrial genome of P. expansum was sequenced, assembled, annotated, and compared with the previously published Penicillium mitogenomes. P. expansum mitogenome is composed of circular DNA molecules with a genome size of 25,496 bp. It encodes 16 protein-encoding genes (PCGs), two rRNA genes, and 25 tRNA genes. Comparative analysis with six other Penicillium species revealed that gene length, GC content, AT skew, and GC skew were variable among the core protein-coding genes. The Penicillium species' gene synteny analysis identified several gene rearrangements. Among the core 15 PCGs, atp8 had the lowest K2P genetic distance, which shows that this gene is highly conserved. The Ka/Ks value of most PCGs was less than 1, which shows that these genes have undergone purifying selection. Phylogenetic analysis based on 14 concatenated core mitochondrial genes revealed that P. expansum shares a close relationship with P. solitum. This study served as a first report on the complete mitochondrial genome of P. expansum and its comparative analysis that will contribute to population genetics and rapid evolutionary studies among Penicillium species.

Genomic, transcriptomic, and ecological diversity of Penicillium species in cheese rind microbiomes.

Although Penicillium molds can have significant impacts on agricultural, industrial, and biomedical systems, the ecological roles of Penicillium species in many microbiomes are not well characterized. Here we utilized a collection of 35 Penicillium strains isolated from cheese rinds to broadly investigate the genomic potential for secondary metabolism in cheese-associated Penicillium species, the impact of Penicillium on bacterial community assembly, and mechanisms of Penicillium-bacteria interactions. Using antiSMASH, we identified 1558 biosynthetic gene clusters, 406 of which were mapped to known pathways, including several mycotoxins and antimicrobial compounds. By measuring bacterial abundance and fungal mRNA expression when culturing representative Penicillium strains with a cheese rind bacterial community, we observed divergent impacts of different Penicillium strains, from strong inhibitors of bacterial growth to those with no impact on bacterial growth or community composition. Through differential mRNA expression analyses, Penicillium strains demonstrated limited differential gene expression in response to the bacterial community. We identified a few shared responses between the eight tested Penicillium strains, primarily upregulation of nutrient metabolic pathways, but we did not identify a conserved fungal response to growth in a multispecies community. These results in tandem suggest high variation among cheese-associated Penicillium species in their ability to shape bacterial community development and highlight important ecological diversity within this iconic genus.

Structure of the prenyltransferase in bifunctional copalyl diphosphate synthase from Penicillium fellutanum reveals an open hexamer conformation.

Copalyl diphosphate synthase from Penicillium fellutanum (PfCPS) is an assembly-line terpene synthase that contains both prenyltransferase and class II cyclase activities. The prenyltransferase catalyzes processive chain elongation reactions using dimethylallyl diphosphate and three equivalents of isopentenyl diphosphate to yield geranylgeranyl diphosphate, which is then utilized as a substrate by the class II cyclase domain to generate copalyl diphosphate. Here, we report the 2.81 Å-resolution cryo-EM structure of the hexameric prenyltransferase of full-length PfCPS, which is surrounded by randomly splayed-out class II cyclase domains connected by disordered polypeptide linkers. The hexamer can be described as a trimer of dimers; surprisingly, one of the three dimer-dimer interfaces is separated to yield an open hexamer conformation, thus breaking the D3 symmetry typically observed in crystal structures of other prenyltransferase hexamers such as wild-type human GGPP synthase (hGGPPS). Interestingly, however, an open hexamer conformation was previously observed in the crystal structure of D188Y hGGPPS, apparently facilitated by hexamer-hexamer packing in the crystal lattice. The cryo-EM structure of the PfCPS prenyltransferase hexamer is the first to reveal that an open conformation can be achieved even in the absence of a point mutation or interaction with another hexamer. Even though PfCPS octamers are not detected, we suggest that the open hexamer conformation represents an intermediate in the hexamer-octamer equilibrium for those prenyltransferases that do exhibit oligomeric heterogeneity.

Diversity and characterization of culturable fungi associated with the marine sea cucumber Holothuria scabra.

Fungi associated with the marine echinoderm, Holothuria scabra, produces extracellular enzymes and bioactive metabolites, and mycoviruses that could be used for biotechnological and pharmaceutical applications. The species identification based on molecular and morphological characteristics classified the culturable fungi into twenty-three genera belonging to eight orders, Chaetothyriales, Eurotiales, Hypocreales, Mucorales, Mycosphaerellales, Onygenales, Pleosporales and Venturiales, from four classes, Eurotiomycetes, Dothideomycetes, Mucoromycetes and Sordariomycetes of the two phyla Ascomycota and Mucoromycota. The most frequent genera were Aspergillus (relative frequency, 45.30%) and Penicillium (relative frequency, 22.68%). The Menhinick species richness and Shannon species diversity indices were 1.64 and 2.36, respectively, indicating a high diversity of fungi. An enzymatic production test revealed that sixteen isolates could produce proteases and amylases at different levels. The presence of mycoviruses was detected in eight isolates with different genomic profiles. Thirty-two of the 55 isolates produced antimicrobial metabolites which had an inhibitory effect on various microbial pathogens. Most of these active isolates were identified as Aspergillus, Penicillium and Trichoderma. Notably, Aspergillus terreus F10M7, Trichoderma harzianum F31M4 and T. harzianum F31M5 showed the most potent activity against both Gram-positive and Gram-negative bacteria and human pathogenic fungi. Our study represents the first report of the mycobiota associated with the marine echinoderm Holothuria scabra.

WSC1 Regulates the Growth, Development, Patulin Production, and Pathogenicity of Penicillium expansum Infecting Pear Fruits.

In this study, the role of WSC1 in the infection of pear fruit by Penicillium expansum was investigated. The WSC1 gene was knocked out and complemented by Agrobacterium-mediated homologous recombination technology. Then, the changes in growth, development, and pathogenic processes of the knockout mutant and the complement mutant were analyzed. The results indicated that deletion of WSC1 slowed the growth rate, reduced the mycelial and spore yield, and reduced the ability to produce toxins and pathogenicity of P. expansum in pear fruits. At the same time, the deletion of WSC1 reduced the tolerance of P. expansum to cell wall stress factors, enhanced antioxidant capacity, decreased hypertonic sensitivity, decreased salt stress resistance, and was more sensitive to most metal ions. Our results confirmed that WSC1 plays an important role in maintaining cell wall integrity and responding to stress, toxin production, and the pathogenicity of P. expansum.

Chitosan inhibits Penicillium expansum possibly by binding to DNA and triggering apoptosis.

Chitosan is a natural polysaccharide that is abundant, biocompatible and exhibits effective antifungal activity against various pathogenic fungi. However, the potential intracellular targets of chitosan in pathogenic fungi and the way of activity of chitosan are far from well known. The present work demonstrated that chitosan could inhibit Penicillium expansum, the principal causal agent of postharvest blue mold decay on apple fruits, by binding to DNA and triggering apoptosis. UV-visible spectroscopy, fluorescence spectroscopy and electrophoretic mobility assay proved the interaction between chitosan and DNA, while atomic force microscope (AFM) observation revealed the binding morphology of chitosan to DNA. Chitosan could inhibit in vitro DNA replication, and cell cycle analysis employing flow cytometry demonstrated that cell cycle was retarded by chitosan treatment. Furthermore, the reactive oxygen species (ROS) assay and membrane potential analysis showed that apoptosis was induced in P. expansum cells after exposure to chitosan. In conclusion, our results confirmed that chitosan interacts with DNA and induces apoptosis. These findings are expected to provide a feasible theoretical basis and practical direction for the promoting and implementing of chitosan in plant protection and further illuminate the possible antifungal mechanisms of chitosan against fungal pathogens.

Exploring the Biocontrol Capability of Non-Mycotoxigenic Strains of Penicillium expansum.

Penicillium expansum is one the major postharvest pathogens of pome fruit during postharvest handling and storage. This fungus also produces patulin, which is a highly toxic mycotoxin that can contaminate infected fruits and their derived products and whose levels are regulated in many countries. In this study, we investigated the biocontrol potential of non-mycotoxigenic strains of Penicillium expansum against a mycotoxigenic strain. We analyzed the competitive behavior of two knockout mutants that were unable to produce patulin. The first mutant (∆patK) involved the deletion of the patK gene, which is the initial gene in patulin biosynthesis. The second mutant (∆veA) involved the deletion of veA, which is a global regulator of primary and secondary metabolism. At the phenotypic level, the ∆patK mutant exhibited similar phenotypic characteristics to the wild-type strain. In contrast, the ∆veA mutant displayed altered growth characteristics compared with the wild type, including reduced conidiation and abnormal conidiophores. Neither mutant produced patulin under the tested conditions. Under various stress conditions, the ∆veA mutants exhibited reduced growth and conidiation when exposed to stressors, including cell membrane stress, oxidative stress, osmotic stress, and different pH values. However, no significant changes were observed in the ∆patK mutant. In competitive growth experiments, the presence of non-mycotoxigenic strains reduced the population of the wild-type strain during in vitro growth. Furthermore, the addition of either of the non-mycotoxigenic strains resulted in a significant decrease in patulin levels. Overall, our results suggest the potential use of non-mycotoxigenic mutants, particularly ∆patK mutants, as biocontrol agents to reduce patulin contamination in food and feed.

Determination of mycobiota and aflatoxin contamination in commercial bee pollen from eight provinces and one autonomous region of China.

The co-occurrence of fungi and mycotoxins in various foods has been frequently reported in many countries, posing a serious threat to the health and safety of consumers. In this study, the mycobiota in five types of commercial bee pollen samples from China were first revealed by DNA metabarcoding. Meanwhile, the content of total aflatoxins in each sample was investigated by high-performance liquid chromatography with fluorescence detection. The results demonstrated that Cladosporium (0.16 %-89.29 %) was the most prevalent genus in bee pollen, followed by Metschnikowia (0-81.12 %), unclassified genus in the phylum Ascomycota (0-81.13 %), Kodamaea (0-73.57 %), and Penicillium (0-36.13 %). Meanwhile, none of the assayed aflatoxins were determined in the 18 batches of bee pollen samples. In addition, the fungal diversity, community composition, and trophic mode varied significantly among five groups. This study provides comprehensive information for better understanding the fungal communities and aflatoxin residues in bee pollen from different floral origins in China.

Preparation of ß-galacto-oligosaccharides using a novel endo-1,4-ß-galactanase from Penicillium oxalicum.

Endo-1,4-ß-galactanase is an indispensable tool for preparing prebiotic ß-galacto-oligosaccharides (ß-GOS) from pectic galactan resources. In the present study, a novel endo-1,4-ß-galactanase (PoßGal53) belonging to glycoside hydrolase family 53 from Penicillium oxalicum sp. 68 was cloned and expressed in Pichia pastoris GS115. Upon purification by affinity chromatography, recombinant PoßGal53 exhibited a single band on SDS-PAGE with a molecular weight of 45.0 kDa. Using potato galactan as substrate, PoßGal53 showed optimal reaction conditions of pH 4.0, 40 °C, and was thermostable, retaining >80 % activity after incubating below 45 °C for 12 h. Significantly, PoßGal53 exhibited relatively conserved substrate specificity for (1 â†’ 4)-ß-D-galactan with an activity of 6244 ± 282 U/mg. In this regard, the enzyme is in effect the most efficient endo-1,4-ß-galactanase identified to date. By using PoßGal53, ß-GOS monomers were prepared from potato galactan and separated using medium pressure liquid chromatography. HPAEC-PAD, MALDI-TOF-MS and ESI-MS/MS analyses demonstrated that these ß-GOS species ranged from 1,4-ß-D-galactobiose to 1,4-ß-D-galactooctaose (DP 2-8) with high purity. This work provides not only a highly active tool for enzymatic degradation of pectic galactan, but an efficient protocol for preparing ß-GOS.

Heterologous Naringenin Production in the Filamentous Fungus Penicillium rubens.

Naringenin is a natural product with several reported bioactivities and is the key intermediate for the entire class of plant flavonoids. The translation of flavonoids into modern medicine as pure compounds is often hampered by their low abundance in nature and their difficult chemical synthesis. Here, we investigated the possibility to use the filamentous fungus Penicillium rubens as a host for flavonoid production. P. rubens is a well-characterized, highly engineered, traditional "workhorse" for the production of ß-lactam antibiotics. We integrated two plant genes encoding enzymes in the naringenin biosynthesis pathway into the genome of the secondary metabolite-deficient P. rubens 4xKO strain. After optimization of the fermentation conditions, we obtained an excellent molar yield of naringenin from fed p-coumaric acid (88%) with a titer of 0.88 mM. Along with product accumulation over 36 h, however, we also observed rapid degradation of naringenin. Based on high-resolution mass spectrometry analysis, we propose a naringenin degradation pathway in P. rubens 4xKO, which is distinct from other flavonoid-converting pathways reported in fungi. Our work demonstrates that P. rubens is a promising host for recombinant flavonoid production, and it represents an interesting starting point for further investigation into the utilization of plant biomass by filamentous fungi.

Draft genome sequence and comparative genomic analysis of Penicillium pancosmium MUM 23.27 isolated from raw honey.

The draft genome sequence and main genomic features of Penicillium pancosmium MUM 23.27, isolated from Portuguese raw honey are reported. The genome size is 34.82 Mb, containing a 48.99% GC content, 11,394 genes, with 39 rRNAs and 147 tRNAs/tmRNAs. Twenty-six BGCs were predicted with four exhibiting significant similarities with YWA1, chaetoglobosin A/chaetoglobosin C, squalestatin S1, and nidulanin A. Moreover, the whole-genome sequencing and in silico genomic analysis, allowed to further understand some aspects of this species habitat, resistance, and evolutionary genomic events. Altogether, the results obtained also allow to dwell deeper on particular Penicillia biological characteristics and genomic traits, permitting them to thrive in these honey substrates. In addition, this resource represents the first genome for the species and one of the first for raw honeys filamentous fungi.

Construction of RNA silencing system of Penicillium brevicompactum and genetic manipulation of the regulator pbpcz in mycophenolic acid production.

Penicillium brevicompactum is a critical industrial strain for the production of mycophenolic acid (MPA). However, the genetic background of Penicillium brevicompactum is unclear, and there are few tools available for genetic manipulation. To investigate its gene function, we first verified the feasibility of a pair of citrate synthase promoter (Pcit) and terminator (Tcit) from P. brevicompactum by constructing a fluorescent expression cassette. Based on this, an RNAi vector was designed and constructed with reverse promoters. This study focused on the functional investigation of the pbpcz gene in P. brevicompactum, a regulator belonging to the Zn(II)2Cys6 family. RNAi was used to silence the pbpcz gene, providing a valuable tool for genetic studies in P. brevicompactum. After seven days, we observed differences in the number of spores between different phenotypes strains of pbpcz gene. Compared to the wild-type strain (WT), the spore yield of the pbpcz gene silencing mutant (M2) was only 51.4 %, while that of the pbpcz gene overexpressed mutant (SE4) was increased by 50 %. Expression levels of the three genes (brlA, abaA, and wetA) comprising conidia's central regulatory pathway were significantly reduced in the pbpcz gene silencing mutant, while fluorescence localization showed that PbPCZ protein was mainly distributed in spores. The results indicated that the pbpcz gene is critical for conidia and asexual development of P. brevicompactum. In addition, overexpressing the pbpcz gene resulted in a 30.3 % increase in MPA production compared to the wild type, with a final yield of 3.57 g/L. These results provide evidence that PbPCZ acts as a positive regulator in P. brevicompactum, controlling MPA production and regulating conidia and asexual development.

Novel genetic tools improve Penicillium expansum patulin synthase production in Aspergillus niger.

Since the first CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) system was developed for creating double-stranded DNA breaks, it has been adapted and improved for different biotechnological applications. In this issue of The FEBS Journal, Arentshorst et al. developed a novel approach to enhance transgene expression of a specific protein, patulin synthase (PatE) from Penicillium expansum, in the important industrial filamentous fungus Aspergillus niger. Their technique involved the disruption of selected genes with counter-effects on targeted protein production and simultaneous integration of glucoamylase landing sites into the disrupted gene locus such as protease regulator (prtT) in an ATP-dependent DNA helicase II subunit 1 (kusA or ku70)-deletion strain. Multiple copies of the PatE transgene expression cassette were introduced by CRISPR-Cas9-mediated insertion. The purified PatE was further used for structural and functional studies, and the technique laid the foundation for elevating the overall production of various proteins or chemicals in those industrially important fungi.

Characterization and regulation of salt upregulated cyclophilin from a halotolerant strain of Penicillium oxalicum.

Penicillium species are an industrially important group of fungi. Cyclophilins are ubiquitous proteins and several members of this family exhibit peptidyl-prolyl cis-trans isomerase (PPIase) activity. We had earlier demonstrated that the salt-induced PPIase activity in a halotolerant strain of P. oxalicum was associated with enhanced expression of a cyclophilin gene, PoxCYP18. Cloning and characterization of PoxCYP18 revealed that its cDNA consists of 522 bp encoding a protein of 173 amino acid residues, with predicted molecular mass and pI values of 18.91 kDa and 8.87, respectively. The recombinant PoxCYP18 can catalyze cis-trans isomerization of peptidyl-prolyl bond with a catalytic efficiency of 1.46 × 107 M-1 s-1 and is inhibited specifically only by cyclosporin A, with an inhibition constant of 5.04 ± 1.13 nM. PoxCYP18 consists of two cysteine residues at positions - 45 and - 170, and loses its activity under oxidizing conditions. Substitution of these residues alone or together by site-directed mutagenesis revealed that the PPIase activity of PoxCYP18 is regulated through a redox mechanism involving the formation of disulfide linkages. Heterologous expression of PoxCYP18 conferred enhanced tolerance to salt stress in transgenic E. coli cells, implying that this protein imparts protection to cellular processes against salt-induced damage.

Penicillium rhizophilum, a novel species in the section Exilicaulis isolated from the rhizosphere of sugarcane in Southwest Iran.

During a survey of species diversity of Penicillium and Talaromyces in sugarcane (Saccharum officinarum) rhizosphere in the Khuzestan province of Iran [1], 195 strains were examined, from which 187 belonged to Penicillium (11 species) and eight to Talaromyces (one species). In the present study, three strains of Penicillium belonging to section Exilicaulis series Restricta, identified as P. restrictum by Ansari et al. [1], were subjected to a phylogenetic study. The multilocus phylogeny of partial ß-tubulin, calmodulin and RNA polymerase II second largest subunit genes enabled the recognition of one new phylogenetic species that is here formally described as Penicillium rhizophilum sp. nov. This species is phylogenetically distinct in series Restricta, but it does not show significant morphological differences from other species previously classified in the series. Therefore, we here placed bias on the phylogenetic species concept. The holotype of Penicillium rhizophilum sp. nov. is IRAN 18169F and the ex-type culture is LA30T (=IRAN 4042CT=CBS 149737T).

The histone demethylase KdmB is part of a trimeric protein complex and mediates virulence and mycotoxin production in Penicillium expansum.

Epigenetic modification of chromosome structure has increasingly been associated with alterations in secondary metabolism and sporulation defects in filamentous fungal pathogens. Recently, the epigenetic reader protein SntB was shown to govern virulence, spore production and mycotoxin synthesis in the fruit pathogen Penicillium expansum. Through immunoprecipitation-coupled mass spectrometry, we found that SntB is a member of a protein complex with KdmB, a histone demethylase and the essential protein RpdA, a histone deacetylase. Deletion of kdmB phenocopied some but not all characteristics of the ΔsntB mutant. KdmB deletion strains exhibited reduced lesion development on Golden Delicious apples and this was accompanied by decreased production of patulin and citrinin in host tissue. In addition, ΔkdmB mutants were sensitive to several cell wall stressors which possibly contributed to the decreased virulence observed on apples. Slight differences in spore production and germination rates of ΔkdmB mutants in vitro did not impact overall diameter growth in culture.

Reconciliation and evolution of Penicillium rubens genome-scale metabolic networks-What about specialised metabolism?

In recent years, genome sequencing of filamentous fungi has revealed a high proportion of specialised metabolites with growing pharmaceutical interest. However, detecting such metabolites through in silico genome analysis does not necessarily guarantee their expression under laboratory conditions. However, one plausible strategy for enabling their production lies in modifying the growth conditions. Devising a comprehensive experimental design testing in different culture environments is time-consuming and expensive. Therefore, using in silico modelling as a preliminary step, such as Genome-Scale Metabolic Network (GSMN), represents a promising approach to predicting and understanding the observed specialised metabolite production in a given organism. To address these questions, we reconstructed a new high-quality GSMN for the Penicillium rubens Wisconsin 54-1255 strain, a commonly used model organism. Our reconstruction, iPrub22, adheres to current convention standards and quality criteria, incorporating updated functional annotations, orthology searches with different GSMN templates, data from previous reconstructions, and manual curation steps targeting primary and specialised metabolites. With a MEMOTE score of 74% and a metabolic coverage of 45%, iPrub22 includes 5,192 unique metabolites interconnected by 5,919 reactions, of which 5,033 are supported by at least one genomic sequence. Of the metabolites present in iPrub22, 13% are categorised as belonging to specialised metabolism. While our high-quality GSMN provides a valuable resource for investigating known phenotypes expressed in P. rubens, our analysis identifies bottlenecks related, in particular, to the definition of what is a specialised metabolite, which requires consensus within the scientific community. It also points out the necessity of accessible, standardised and exhaustive databases of specialised metabolites. These questions must be addressed to fully unlock the potential of natural product production in P. rubens and other filamentous fungi. Our work represents a foundational step towards the objective of rationalising the production of natural products through GSMN modelling.

Penicillium and Talaromyces spp. emerging pathogens in dogs since 1990s.

Penicillium and Talaromyces spp. are environmental saprophytic molds rarely encountered as infectious agents in humans and animals. This article summarizes the clinical features, treatment, and outcomes of proven infections caused by Penicillium or Talaromyces in four dogs in France. Two dogs had disseminated infections, while the other two had a localized form. All dogs had positive histopathological results showing the presence of hyaline septate hyphae and a positive fungal culture with typical Penicillium conidiophores. Talaromyces georgiensis (n = 1), Penicillium labradorum (n = 2), and Penicillium from section Ramosa series Raistrickiorum (n = 1), were identified based on Internal Transcribed Spacer (ITS) Sanger sequencing. The dogs were initially treated with ketoconazole or itraconazole. Second-line treatment was initiated in three dogs, but after several relapses, the prognosis remained poor. Since the 1990s, 18 cases of Penicillium or Talaromyces infections in dogs have been described worldwide. This series of four reports brings new cases to those already reported in the literature, which are probably underestimated in the world.

Penicillium and Talaromyces spp. are molds found in the environment that rarely cause infections in humans and animals. This article summarizes the clinical features and treatment of proven infections caused by Penicillium or Talaromyces species in four dogs in France.