Dispersal of Aphanoascus keratinophilus by the rook Corvus frugilegus during breeding in East Poland.

The process of dispersal of the potentially disease-causing, geophilic and keratinolytic fungal strain Aphanoascus keratinophilus (the perfect, sexual stage of Chrysosporium keratinophilum) by the rook Corvus frugilegus was studied. The source of A. keratinophilus strains was pellets of the rook, thus far not considered a carrier of this particular opportunistic pathogen. Pellets collected from breeding colonies of rooks were analysed in terms of the occurrence of keratinolytic fungi with the application of the native keratin bait method. Among the 83 rook pellets analysed, 24 (29%) were infected by keratinophilic fungi. Pure cultures of the fungi were identified to species based on traditional morphological features. Traditional mycological identification was verified by the PCR-RFLP molecular identification method as well as DNA sequencing. The obtained results showed the presence of 90 Aphanoascus keratinophilus strains, 6 Chrysosporium tropicum strains, and 3 Chrysosporium pannicola strains. The PCR melting profile (PCR-MP) method was used to identify intraspecies variations of the 90 analysed A. keratinophilus strains. The dispersal of genotypes and possible pathways of A. keratinophilus dispersal and infection via rook pellets were analysed.

Virulence and community dynamics of fungal species with vertical and horizontal transmission on a plant with multiple infections.

The virulence evolution of multiple infections of parasites from the same species has been modeled widely in evolution theory. However, experimental studies on this topic remain scarce, particularly regarding multiple infections by different parasite species. Here, we characterized the virulence and community dynamics of fungal pathogens on the invasive plant Ageratina adenophora to verify the predictions made by the model. We observed that A. adenophora was highly susceptible to diverse foliar pathogens with mixed vertical and horizontal transmission within leaf spots. The transmission mode mainly determined the pathogen community structure at the leaf spot level. Over time, the pathogen community within a leaf spot showed decreased Shannon diversity; moreover, the vertically transmitted pathogens exhibited decreased virulence to the host A. adenophora, but the horizontally transmitted pathogens exhibited increased virulence to the host. Our results demonstrate that the predictions of classical models for the virulence evolution of multiple infections are still valid in a complex realistic environment and highlight the impact of transmission mode on disease epidemics of foliar fungal pathogens. We also propose that seedborne fungi play an important role in structuring the foliar pathogen community from multiple infections within a leaf spot.

A pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, United Kingdom.

Outbreaks of fungal infections due to emerging and rare species are increasingly reported in healthcare settings. We investigated a pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, UK. We aimed to determine route of healthcare-associated transmission and prevent additional infections. From July 2018 through February 2019, we detected a pseudo-outbreak of R. similis isolated from bronchoalveolar lavage (BAL) fluid samples collected from nine patients who had undergone bronchoscopy in a multispecialty teaching hospital, during a period of 8 months. Isolates were identified by MALDI-TOF mass spectrometry. Antifungal susceptibility testing was performed by EUCAST broth microdilution. To determine genetic relatedness among R. similis isolates, we undertook amplified fragment length polymorphism analysis. To determine the potential source of contamination, an epidemiological investigation was carried out. We reviewed patient records retrospectively and audited steps taken during bronchoscopy as well as the subsequent cleaning and decontamination procedures. Fungal cultures were performed on samples collected from bronchoscopes and automated endoscope washer-disinfector systems. No patient was found to have an infection due to R. similis either before or after bronchoscopy. One bronchoscope was identified to be used among all affected patients with positive fungal cultures. Physical damage was found in the index bronchoscope; however, no fungus was recovered after sampling of the affected scope or the rinse water of automated endoscope washer-disinfectors. Use of the scope was halted, and, during the following 12-month period, Rhinocladiella species were not isolated from any BAL specimen. All pseudo-outbreak isolates were identified as R. similis with high genetic relatedness (>90% similarity) on ALFP analysis. The study emphasises the emergence of a rare and uncommon black yeast R. similis, with reduced susceptibility to echinocandins, in a bronchoscope-related pseudo-outbreak with a potential water-related reservoir. Our findings highlight the importance of prolonged fungal culture and species-level identification of melanised yeasts isolated from bronchoscopy samples. Possibility of healthcare-associated transmission should be considered when R. similis is involved in clinical microbiology samples.

Instant killing of pathogenic chytrid fungi by disposable nitrile gloves prevents disease transmission between amphibians.

To prevent transmission of the pathogenic chytrid fungi Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal), hygiene protocols prescribe the single use of disposable gloves for handling amphibians. We discovered that rinse water from nitrile gloves instantly kills 99% of Bd and Bsal zoospores. Transmission experiments using midwife toads (Alytes obstetricans) and Bd, and Alpine newts (Ichthyosaura alpestris) and Bsal, show that the use of the same pair of gloves for 2 subsequent individuals does not result in significant transmission of any chytrid fungus. In contrast, handling infected amphibians bare-handed caused transmission of Bsal in 4 out of 10 replicates, but did not result in transmission of Bd. Based on the manufacturer's information, high resolution mass spectrometry (HRMS) and colorimetric tests, calcium lactate and calcium nitrate were identified as compounds with antifungal activity against both Bd and Bsal. These findings corroborate the importance of wearing gloves as an important sanitary measure in amphibian disease prevention. If the highly recommended single use of gloves is not possible, handling multiple post-metamorphic amphibians with the same pair of nitrile gloves should still be preferred above bare-handed manipulation.

The endangered Hastings River mouse (Pseudomys oralis) as a disperser of ectomycorrhizal fungi in eastern Australia.

Rodents are the most widespread and diverse order of vertebrate mycophagists and are key to the dispersal of mycorrhizal fungi. Rodents consume and subsequently disperse fungi through their feces on every continent except Antarctica. This study examines the fungal taxa consumed by the Hastings River mouse (Pseudomys oralis), an endangered Australian endemic rodent from the family Muridae. We analyzed 251 fecal samples collected over a 19-year period between 1993 and 2012 at sites throughout the distribution of the animal in New South Wales and Queensland. We show that at least 16 genera of mycorrhizal fungi are eaten by this species and that it is therefore playing an important role as a vector of ectomycorrhizal truffle-like fungi in eastern Australia. Similar to the fungal diets of other mammals in eastern Australia, seasonal fungal consumption was greatest in autumn and winter. The dietary diversity of P. oralis also appeared to follow a geographic trend from south to north; samples collected at sites in the southern part of the species' range had greater diversity than those from sites in the northern part of the range, and overall, diets from southern sites yielded more fungal taxa than did northern sites. This study provides novel insights into the diet of P. oralis and highlights the importance of previously overlooked ecosystem services this species provides through its dispersal of mycorrhizal fungi.

Crossing the kingdom border: Human diseases caused by plant pathogens.

Interactions between pathogenic microorganisms and their hosts are varied and complex, encompassing open-field scale interactions to interactions at the molecular level. The capacity of plant pathogenic bacteria and fungi to cause diseases in human and animal systems was, until recently, considered of minor importance. However, recent evidence suggests that animal and human infections caused by plant pathogenic fungi, bacteria and viruses may have critical impacts on human and animal health and safety. This review analyses previous research on plant pathogens as causal factors of animal illness. In addition, a case study involving disruption of type III effector-mediated phagocytosis in a human cell line upon infection with an opportunistic phytopathogen, Pseudomonas syringae pv. tomato, is discussed. Further knowledge regarding the molecular interactions between plant pathogens and human and animal hosts is needed to understand the extent of disease incidence and determine mechanisms for disease prevention.

Laboulbeniomycetes: Evolution, natural history, and Thaxter's final word.

Historically, thallus-forming Laboulbeniomycetes, including the orders Laboulbeniales and Herpomycetales, were set apart because of their distinctive morphology and ecology. Although some biologists correctly interpreted these arthropod ectoparasites as fungi, even ascomycetes, others thought they were worms, red algae, or members of taxa described especially for them. Speculation on the evolution of the group involving red algae, the morphology-based Floridean Hypothesis, persisted deep into the 20th century, in part because valid alternatives were not presented. Although the distinctive features of Laboulbeniales clearly set them apart from other fungi, the difficulty was in the absence of characters grouping them among the fungi. Thaxter considered the Laboulbeniales to be ascomycetes, but he avoided phylogenetic discussions involved in the Floridean Hypothesis all of his life. Eventually, developmental studies of the life history of Pyxidiophora species, hyphal perithecial ascomycetes with 2-celled ascospores, revealed characters connecting Laboulbeniales to other ascomycetes. The distinctive morphological features of Laboulbeniales (absence of mycelium, a thallus developed from 2-celled ascospores by cell divisions in several planes, arthropod parasitism) can be best understood by comparison with Pyxidiophora. The development of a 3-dimensional thallus composed of true parenchyma occurs not only in Laboulbeniales, but also in Pyxidiophora species. The life history of arthropod ectoparasitism of Laboulbeniales as well as mycoparasitism and phoretic dispersal by arthropods of Pyxidiophora species can be explained by Tranzschel's Law, originally applied to rust fungi. Molecular analyses including other arthropod-associated fungi have contributed to a better understanding of an enlarged class, Laboulbeniomycetes, which now includes a clade comprising Chantransiopsis, Tetrameronycha, and Subbaromyces. A two-locus phylogenetic tree highlights evolutionary and life history questions with regard to the placement of Herpomycetales as the first diverging lineage of the Laboulbeniomycetes. The sister group for all the Laboulbeniomycetes remains to be discovered.

Clinical Impacts and Outcomes With Possible Donor-Derived Infection in Infected Donor Liver Transplantation: A Single-Center Retrospective Study in China.

BACKGROUND: Information on possible donor-derived transmission events in China is limited. We evaluated the impacts of liver transplantation from infected deceased-donors, analyzed possible donor-derived bacterial or fungal infection events in recipients, and evaluated the etiologic agents' characteristics and cases outcomes. METHODS: A single-center observational study was performed from January 2015 to March 2017 to retrospectively collect data from deceased-donors diagnosed with infection. Clinical data were recorded for each culture-positive donor and the matched liver recipient. The microorganisms were isolated and identified, and antibiotic sensitivity testing was performed. The pathogens distribution and incidence of possible donor-derived infection (P-DDI) events were analyzed and evaluated. RESULTS: Information from 211 donors was collected. Of these, 82 donors were infected and classified as the donation after brain death category. Overall, 149 and 138 pathogens were isolated from 82 infected donors and 82 matched liver recipients, respectively. Gram-positive bacteria, Gram-negative bacteria, and fungi accounted for 42.3% (63 of 149), 46.3% (69 of 149), and 11.4% (17 of 149) of pathogens in infected donors. The incidence of multidrug-resistant bacteria was high and Acinetobacter baumannii was the most concerning species. Infections occurred within the first 2 weeks after liver transplantation with an organ from an infected donor. Compared with the noninfection recipient group, the infection recipient group experienced a longer mechanical ventilation time (P = .004) and intensive care unit stay (P = .003), a higher incidence of renal dysfunction (P = .026) and renal replacement therapy (P = .001), and higher hospital mortality (P = .015). Possible donor-derived infection was observed in 14.6% of cases. Recipients with acute-on-chronic liver failure were more prone to have P-DDI than recipients with other diseases (P = .007; odds ratio = 0.114; 95% confidence interval, .025-.529). CONCLUSIONS: When a liver recipient receives a graft from an infected deceased-donor, the postoperative incidence of infection is high and the infection interval is short. In addition, when a possible donor-derived, drug-resistant bacterial infection occurs, recipients may have serious complications and poor outcomes.

Host density and habitat structure influence host contact rates and Batrachochytrium salamandrivorans transmission.

Batrachochytrium salamandrivorans (Bsal) is an emerging invasive pathogen that is highly pathogenic to salamander species. Modeling infection dynamics in this system can facilitate proactive efforts to mitigate this pathogen's impact on North American species. Given its widespread distribution and high abundance, the eastern newt (Notophthalmus viridescens) has the potential to significantly influence Bsal epidemiology. We designed experiments to 1) estimate contact rates given different host densities and habitat structure and 2) estimate the probability of transmission from infected to susceptible individuals. Using parameter estimates from data generated during these experiments, we modeled infection and disease outcomes for a population of newts using a system of differential equations. We found that host contact rates were density-dependent, and that adding habitat structure reduced contacts. The probability of Bsal transmission given contact between newts was very high (>90%) even at early stages of infection. Our simulations show rapid transmission of Bsal among individuals following pathogen introduction, with infection prevalence exceeding 90% within one month and >80% mortality of newts in three months. Estimates of basic reproductive rate (R0) of Bsal for eastern newts were 1.9 and 3.2 for complex and simple habitats, respectively. Although reducing host density and increasing habitat complexity might decrease transmission, these management strategies may be ineffective at stopping Bsal invasion in eastern newt populations due to this species' hyper-susceptibility.

The Mycobiome in Health and Disease: Emerging Concepts, Methodologies and Challenges.

Fungal disease is an increasingly recognised global clinical challenge associated with high mortality. Early diagnosis of fungal infection remains problematic due to the poor sensitivity and specificity of current diagnostic modalities. Advances in sequencing technologies hold promise in addressing these shortcomings and for improved fungal detection and identification. To translate such emerging approaches into mainstream clinical care will require refinement of current sequencing and analytical platforms, ensuring standardisation and consistency through robust clinical benchmarking and its validation across a range of patient populations. In this state-of-the-art review, we discuss current diagnostic and therapeutic challenges associated with fungal disease and provide key examples where the application of sequencing technologies has potential diagnostic application in assessing the human 'mycobiome'. We assess how ready access to fungal sequencing may be exploited in broadening our insight into host-fungal interaction, providing scope for clinical diagnostics and the translation of emerging mycobiome research into clinical practice.

Rastreio de leveduras patogênicas isoladas de fezes de pombos no Distrito Federal-Pombos: propagadores de fungos patogênicos? / Screening for pathogenic yeasts isolated from pigeon droppings in the Federal District-Pigeons: propagators of pathogenic fungi? / Detección de levaduras patógenas aisladas de excrementos de paloma en el Distrito Federal-Palomas: ¿propagadores de hongos patógenos?

Objetivo: Investigar a presença de fungos patogênicos isolados a partir de amostras de fezes de pombos, em locais de atenção a pacientes imunocomprometidos no DF. Método: As amostras foram coletadas em hospitais onde se oferta atendimento a pacientes HIV/AIDS e que tenha uma presença massiva de pombos. Colônias de leveduras foram previamente selecionados em meio Ágar Sabouraud Dextrose acrescido de cloranfenicol, seguindo-se com análise microscópica das estruturas leveduriformes. Colônias de leveduras com suspeita de pertencerem ao gênero Candida spp. ou Cryptococcus sp., foram inoculadas no meio Ágar Cromogênico para identificação das espécies de Candida e em meio Ágar quimicamente definido para indução dos fenótipos de virulência característicos de Cryptococcus sp. Resultados: 100% das amostras analisadas apresentaram crescimento de leveduras do gênero Candida spp. e Rhodotorula sp. No meio Ágar Cromogênico foram identificadas nas amostras C. krusei em 75%; C. tropicalis em 50% e C. glabrata em 15%. Em 15% das amostras foi identificado leveduras do gênero Cryptococcus sp. Conclusão: Dados deste estudo sugerem que fezes de pombo podem estar dispersando leveduras patogênicas e contribuindo com a incidência de infecções fúngicas no DF.

Objective: To investigate the presence of pathogenic fungi isolated from pigeon stool samples, in places of care for immunocompromised patients in the Federal District. Method: The samples were collected in hospitals where care is offered to HIV / AIDS patients and which has a massive presence of pigeons. Yeast colonies were previously selected on Sabouraud Dextrose Agar plus chloramphenicol, followed by microscopic analysis of the yeast structures. Yeast colonies suspected of belonging to the genus Candida spp. or Cryptococcus sp., were inoculated in the Chromogenic Agar medium to identify Candida species and in chemically defined Agar medium to induce the virulence phenotypes characteristic of Cryptococcus sp. Results: 100% of the analyzed samples showed growth of yeasts of the genus Candida spp. and Rhodotorula sp. In the chromogenic agar medium, 75% were identified in C. krusei samples; C. tropicalis in 50% and C. glabrata in 15%. In 15% of the samples, yeasts of the genus Cryptococcus sp. Conclusion: Data from this study suggest that pigeon feces may be dispersing pathogenic yeasts and contributing to the incidence of fungal infections in DF

Objetivo: Investigar la presencia de hongos patógenos aislados de muestras de heces de palomas, en los lugares de atención a pacientes inmunodeprimidos del Distrito Federal. Método: Las muestras se recolectaron en hospitales donde se brinda atención a pacientes con VIH / SIDA y que tiene una presencia masiva de palomas. Las colonias de levadura se seleccionaron previamente en Sabouraud Dextrose Agar más cloranfenicol, seguido de un análisis microscópico de las estructuras de la levadura. Las colonias de levaduras sospechosas de pertenecer al género Candida spp. o Cryptococcus sp., se inocularon en medio de agar cromogénico para identificar especies de Candida y en medio de agar químicamente definido para inducir los fenotipos de virulencia característicos de Cryptococcus sp. Resultados: el 100% de las muestras analizadas presentó crecimiento de levaduras del género Candida spp. y Rhodotorula sp. En el medio agar cromogénico, el 75% se identificó en muestras de C. krusei; C. tropicalis en 50% y C. glabrata en 15%. En el 15% de las muestras, levaduras del género Cryptococcus sp. Conclusión: Los datos de este estudio sugieren que las heces de las palomas pueden estar dispersando levaduras patógenas y contribuyendo a la incidencia de infecciones fúngicas en el DF.

Talaromycosis (Penicilliosis) Due to Talaromyces (Penicillium) marneffei: Insights into the Clinical Trends of a Major Fungal Disease 60 Years After the Discovery of the Pathogen.

Talaromycosis (penicilliosis) is a major fungal disease endemic across a narrow band of tropical countries of South and Southeast Asia. The etiologic agent is a thermally dimorphic fungus Talaromyces (Penicillium) marneffei, which was first isolated from a bamboo rat in Vietnam in 1956, but no formal description was published. In 1959, Professor Gabriel Segretain formally described it as a novel species Talaromyces (Penicillium) marneffei, and the human pathogenic potential of the fungus in Mycopathologia. The first natural human case of talaromycosis (penicillosis) was reported in 1973 and involved an American minister with Hodgkin's disease who lived in Southeast Asia. Sixty years after the discovery of the pathogen, talaromycosis caused by T. marneffei is recognized as an important human disease with the potential to cause high mortality in the absence of proper diagnosis and prompt treatment. Talaromycosis remains a significant infectious complication in HIV/AIDS patients and in patients with other immune defects. The disease is being recognized with an increasing frequency well beyond the traditional endemic areas. The natural reservoirs of T. marneffei in wild rodents are well-defined, which links the ecology with the epidemiology of talaromycosis in endemic areas. There is an urgent unmet need for rapid and affordable point-of-care diagnostic tests. We also need more clinical studies to define the best therapeutic options for the management of talaromycosis patients.

Bullfrog farms release virulent zoospores of the frog-killing fungus into the natural environment.

Bullfrog farming and trade practices are well-established, globally distributed, and economically valuable, but pose risks for biodiversity conservation. Besides their negative impacts on native amphibian populations as an invasive species, bullfrogs play a key role in spreading the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in the natural environment. Bullfrogs are tolerant to Bd, meaning that they can carry high infection loads without developing chytridiomycosis. To test the potential of bullfrog farms as reservoirs for diverse and virulent chytrid genotypes, we quantified Bd presence, prevalence and infection loads across approximately 1,500 farmed bullfrogs and in the water that is released from farms into the environment. We also described Bd genotypic diversity within frog farms by isolating Bd from dozens of infected tadpoles. We observed individuals infected with Bd in all sampled farms, with high prevalence (reaching 100%) and high infection loads (average 71,029 zoospore genomic equivalents). Average outflow water volume from farms was high (60,000 L/day), with Bd zoospore concentration reaching approximately 50 million zoospores/L. Because virulent pathogen strains are often selected when growing in tolerant hosts, we experimentally tested whether Bd genotypes isolated from bullfrogs are more virulent in native anuran hosts compared to genotypes isolated from native host species. We genotyped 36 Bd isolates from two genetic lineages and found that Bd genotypes cultured from bullfrogs showed similar virulence in native toads when compared to genotypes isolated from native hosts. Our results indicate that bullfrog farms can harbor high Bd genotypic diversity and virulence and may be contributing to the spread of virulent genotypes in the natural environment. We highlight the urgent need to implement Bd monitoring and mitigation strategies in bullfrog farms to aid in the conservation of native amphibians.

Global Catastrophic Threats from the Fungal Kingdom : Fungal Catastrophic Threats.

The fungal kingdom poses major catastrophic threats to humanity but these are often unappreciated and minimized, in biological threat assessments. The causes for this blind spot are complex and include the remarkable natural resistance of humans to pathogenic fungi, the lack of contagiousness of human fungal diseases, and the indirectness of fungal threats, which are more likely to mediate their destructive effects on crops and ecosystems. A review of historical events reveals that the fungal kingdom includes major threats to humanity through their effects on human health, agriculture, and destruction of materiel. A major concern going forward is the likelihood that physiological adaptations by fungal species to global warming will bring new fungal threats. Fungal threats pose significant challenges specific to this group of organisms including the potential for intercontinental spread by air currents, capacity for rapid evolution, a paucity of effective drugs, the absence of vaccines, and increasing drug resistance. Preparedness against bio-catastrophic risks must include consideration of the threats posed by fungi, which in turn requires a greater investment in mycology-related research.

Horizontal transmission of Metarhizium anisopliae between Spoladea recurvalis (Lepidoptera: Crambidae) adults and compatibility of the fungus with the attractant phenylacetaldehyde.

The compatibility of the entomopathogenic fungus Metarhizium anisopliae ICIPE 30 which was proved to be pathogenic to adult Spoladea recurvalis, and phenylacetaldehyde (PAA) floral attractant for lepidopteran moths, was investigated under laboratory and field conditions through spatial and temporal separations. Horizontal transmission of M. anisopliae ICIPE 30 between adult S. recurvalis and the number of conidia picked up by a single moth from the autoinoculation device were also determined under laboratory tests. When freshly emerged moths were inoculated with fungal conidia ("donors") and maintained together with an equal number of untreated freshly emerged moths ("recipients") in the laboratory, they were able to transmit infection to untreated moths resulting to 76.9% mortality with an LT50 value of 6.9 days. The quantity of conidia a moth could acquire and retain from the autoinoculation device in the laboratory was assessed at 0, 24, 48, and 72 h post-inoculation. The overall mean number of conidia acquired by a single moth was significantly higher immediately after exposure (0 h) (14.3 ±â€¯2.5 × 105) than at 24, 48, and 72 h after inoculation (F = 10.26, Df = 3,8, P = 0.003), though a single moth still retained 4.6 ±â€¯0.9 × 105 conidia 72 h post inoculation. Laboratory results showed that PAA completely inhibited the germination of the conidia 8 days post exposure, while the conidial viability was not affected in the control treatment without PAA. Under field conditions, the inhibitory effects of PAA on conidial germination was minimized by placing it at a distance of 5-10 cm from M. anisopliae isolate ICIPE 30 conidia. There was no significant difference in conidial germination in the control treatment and in treatments where PAA was placed at 5 cm and 10 cm away from M. anisopliae isolate ICIPE 30. Conidial germination was low in the autoinoculation device that had PAA directly exposed to the fungus. PAA is therefore compatible with M. anisopliae ICIPE 30 for use in integrated management of S. recurvalis, if spatially separated 5 cm away from the fungus and could thus be combined in an autocontamination devices for the control of S. recurvalis.

Honey bee-collected pollen is a potential source of Ascosphaera apis infection in managed bumble bees.

The trade of bumble bees started in the early nineties for pollinator-dependent greenhouse plants. Nowadays, its rearing and transport have received public attention, since managed bees can transfer pathogens to wild bee populations. Therefore, guaranteeing pathogen-free bumble bees is fundamental. The major protein source used in rearing facilities is honey bee-collected pollen. This can carry pathogens, however to date, solid data on the risk of this food source to the health of bumble bees is lacking. Here we performed a large pathogen screening of non-irradiated honey bee-collected pollen to discover particles infective to Bombus terrestris. We identified seven parasites (Apicystis bombi, Ascosphaera apis, Crithidia mellificae, Nosema ceranae, Paenibacillus larvae and two parasites resembling Nosema thomsoni and Microsporidium sp. Oise) and four viruses (CBPV, DWV, IAPV and SBV) in 17 pollen batches from two major European pollen source regions (Spain and Romania). Ascosphaera apis was capable of infecting bumble bees; the larvae showed similar symptoms to chalkbrood disease reported in honey bees. Bumble bee breeding facilities need to be cautious about the potential presence of this disease, which was originally reported in honey bees. Thorough diagnostic and control methods are needed, as risk of spillover to wild bee species is possible.

Which came first: The disease or the pest? Is there a host mediated spread of Beauveria bassiana (Ascomycota: Hypocreales) by invasive palm pests?

The red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) is threatening the palm family worldwide, causing important economic losses. Current tactics to manage the weevil are largely based on chemical control, although the use of pesticides is hampered by several environmental constraints. Since the first introduction of RPW in Spain in 1996 and during its progressive spread around the Mediterranean basin, the number of reports of natural infection of RPW populations by entomopathogenic fungi (EPF) has been rising for 15 years, and this rise could support a pest-mediated EPF spread. To challenge this hypothesis, we assessed the usefulness of the region of elongation factor 1-alpha (EF1-α), Bloc nuclear intergenic region (Bloc) and inter simple sequence repeat (ISSR) markers, alone or in combination, to infer the relationships among Mediterranean Beauveria and Metarhizium strains isolated from the RPW. Second, the effect of abiotic factors, such as temperature, humidity and UV-B radiation, on the germination and growth of these EPFs strains as a function of their genealogy and geographic origin were determined. Finally, the pathogenicity of strains from different genetic clades was evaluated against larvae and adults of R. ferrugineus. The phylogenetic analysis based on the EF-1α gene identified eight different sequences among 24 fungal isolates of four fungal species. Similar clades were clustered when Bloc and ISSR analyses were performed. The results showed that strains of different origins were clustered in the same clade, and this outcome could be explained by an RPW-mediated EPF spread that was also influenced by time, geographical and other RPW related factors. Neither the response to abiotic factors nor virulence to RPW larvae and adults were related to the sequence type, with all B. bassiana strains well adapted to Mediterraneam climatic conditions. Taken together, these findings may help to select the best strain for RPW management.

Cryptic connections illuminate pathogen transmission within community networks.

Understanding host interactions that lead to pathogen transmission is fundamental to the prediction and control of epidemics1-5. Although the majority of transmissions often occurs within social groups6-9, the contribution of connections that bridge groups and species to pathogen dynamics is poorly understood10-12. These cryptic connections-which are often indirect or infrequent-provide transmission routes between otherwise disconnected individuals and may have a key role in large-scale outbreaks that span multiple populations or species. Here we quantify the importance of cryptic connections in disease dynamics by simultaneously characterizing social networks and tracing transmission dynamics of surrogate-pathogen epidemics through eight communities of bats. We then compared these data to the invasion of the fungal pathogen that causes white-nose syndrome, a recently emerged disease that is devastating North American bat populations13-15. We found that cryptic connections increased links between individuals and between species by an order of magnitude. Individuals were connected, on average, to less than two per cent of the population through direct contact and to only six per cent through shared groups. However, tracing surrogate-pathogen dynamics showed that each individual was connected to nearly fifteen per cent of the population, and revealed widespread transmission between solitarily roosting individuals as well as extensive contacts among species. Connections estimated from surrogate-pathogen epidemics, which include cryptic connections, explained three times as much variation in the transmission of the fungus that causes white-nose syndrome as did connections based on shared groups. These findings show how cryptic connections facilitate the community-wide spread of pathogens and can lead to explosive epidemics.