Where microbes colonizing skin surface may help maintain organism homeostasis, those that invade living skin layers cause disease. In bats, white-nose syndrome is a fungal skin infection that affects animals during hibernation and may lead to mortality in severe cases. Here, we inferred the amount of fungus that had invaded skin tissue of diseased animals. We used simulations to estimate the unobserved disease severity in a non-lethal wing punch biopsy and to relate the simulated pathology to the measured fungal load in paired biopsies. We found that a single white-nose syndrome skin lesion packed with spores and hyphae of the causative agent, Pseudogymnoascus destructans, contains 48.93 pg of the pathogen DNA, which amounts to about 1560 P destructans genomes in one skin lesion. Relating the information to the known UV fluorescence in Nearctic and Palearctic bats shows that Nearctic bats carry about 1.7 µg of fungal DNA per cm2, whereas Palearctic bats have 0.04 µg cm-2 of P. destructans DNA. With the information on the fungal load that had invaded the host skin, the researchers can now calculate disease severity as a function of invasive fungal growth using non-destructive UV light transillumination of each bat's wing membranes. Our results will enable and promote thorough disease severity assessment in protected bat species without the need for extensive animal and laboratory labor sacrifices.

• MeSH
• Ascomycota * metabolismus   patogenita   MeSH
• Chiroptera mikrobiologie   MeSH
• dermatomykózy * mikrobiologie   prevence a kontrola   terapie   veterinární   MeSH
• hibernace * MeSH
• křídla zvířecí mikrobiologie   MeSH
• kůže mikrobiologie   MeSH
• ultrafialové záření * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In underground hibernacula temperate northern hemisphere bats are exposed to Pseudogymnoascus destructans, the fungal agent of white-nose syndrome. While pathological and epidemiological data suggest that Palearctic bats tolerate this infection, we lack knowledge about bat health under pathogen pressure. Here we report blood profiles, along with body mass index (BMI), infection intensity and hibernation temperature, in greater mouse-eared bats (Myotis myotis). We sampled three European hibernacula that differ in geomorphology and microclimatic conditions. Skin lesion counts differed between contralateral wings of a bat, suggesting variable exposure to the fungus. Analysis of blood parameters suggests a threshold of ca. 300 skin lesions on both wings, combined with poor hibernation conditions, may distinguish healthy bats from those with homeostatic disruption. Physiological effects manifested as mild metabolic acidosis, decreased glucose and peripheral blood eosinophilia which were strongly locality-dependent. Hibernating bats displaying blood homeostasis disruption had 2 °C lower body surface temperatures. A shallow BMI loss slope with increasing pathogen load suggested a high degree of infection tolerance. European greater mouse-eared bats generally survive P. destructans invasion, despite some health deterioration at higher infection intensities (dependant on hibernation conditions). Conservation measures should minimise additional stressors to conserve constrained body reserves of bats during hibernation.

• MeSH
• Ascomycota fyziologie   MeSH
• Chiroptera krev   mikrobiologie   fyziologie   MeSH
• hibernace * MeSH
• index tělesné hmotnosti MeSH
• interakce hostitele a patogenu * MeSH
• kožní nemoci krev   mikrobiologie   patologie   veterinární   MeSH
• mykózy krev   mikrobiologie   patologie   veterinární   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Phagocytosis by hemocytes, Drosophila macrophages, is essential for resistance to Streptococcus pneumoniae in adult flies. Activated macrophages require an increased supply of energy and we show here that a systemic metabolic switch, involving the release of glucose from glycogen, is required for effective resistance to S. pneumoniae. This metabolic switch is mediated by extracellular adenosine, as evidenced by the fact that blocking adenosine signaling in the adoR mutant suppresses the systemic metabolic switch and decreases resistance to infection, while enhancing adenosine effects by lowering adenosine deaminase ADGF-A increases resistance to S. pneumoniae. Further, that ADGF-A is later expressed by immune cells during infection to regulate these effects of adenosine on the systemic metabolism and immune response. Such regulation proved to be important during chronic infection caused by Listeria monocytogenes. Lowering ADGF-A specifically in immune cells prolonged the systemic metabolic effects, leading to lower glycogen stores, and increased the intracellular load of L. monocytogenes, possibly by feeding the bacteria. An adenosine-mediated systemic metabolic switch is thus essential for effective resistance but must be regulated by ADGF-A expression from immune cells to prevent the loss of energy reserves and possibly to avoid the exploitation of energy by the pathogen.

• MeSH
• adenosin farmakologie   MeSH
• Drosophila melanogaster růst a vývoj   imunologie   metabolismus   mikrobiologie   MeSH
• energetický metabolismus MeSH
• extracelulární prostor metabolismus   MeSH
• fagocytóza účinky léků   imunologie   MeSH
• hemocyty účinky léků   imunologie   metabolismus   MeSH
• interakce hostitele a patogenu účinky léků   MeSH
• Listeria monocytogenes účinky léků   imunologie   metabolismus   MeSH
• listeriové infekce imunologie   metabolismus   mikrobiologie   MeSH
• makrofágy účinky léků   imunologie   metabolismus   MeSH
• mutace MeSH
• pneumokokové infekce imunologie   metabolismus   mikrobiologie   MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• signální transdukce účinky léků   imunologie   MeSH
• Streptococcus pneumoniae účinky léků   imunologie   metabolismus   MeSH
• vazodilatancia farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A total of 7778 host-seeking adult Dermacentor reticulatus (Ixodida: Ixodidae) ticks were examined for the prevalence of Francisella tularensis holarctica (Thiotrichales: Francisellaceae) in a natural focus of tularaemia in the floodplain forest-meadow ecosystem along the lower reaches of the Dyje (Thaya) river in South Moravia (Czech Republic) between 1995 and 2013. Ticks were pooled (10 specimens per pool) and their homogenates inoculated subcutaneously in 4-week-old specific pathogen-free mice. Dead mice were sectioned, their spleens cultivated on thioglycollate-glucose-blood agar and impression smears from the spleen, liver and heart blood were Giemsa-stained. Sixty-four pools were positive for F. tularensis: the overall minimum infection rate (MIR) was 0.82%. Overall MIRs for the 4714 female and 3064 male D. reticulatus examined were 0.89 and 0.72%, respectively; MIRs fluctuated across years between 0.0 and 2.43%. The estimated bacterial load in infected ticks varied from 0.84 to 5.34 log10 infectious F. tularensis cells per tick (i.e. from about seven to 220 000 cells). Ticks with low loads were more prevalent; more than 1000 infectious cells were detected in 24 ticks (0.3% of all ticks and 37.5% of infected ticks). Monitoring of D. reticulatus for the presence and cell numbers of F. tularensis may be a valuable tool in the surveillance of tularaemia.

• MeSH
• bakteriální nálož * MeSH
• Dermacentor mikrobiologie   MeSH
• Francisella tularensis fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Vermicomposting is a process of degradation of biowaste which involves complex interactions between earthworms and microorganisms. This process lacks a thermophilic stage and thus, the possible presence of pathogens poses a potential health hazard. To assess the contribution of earthworms during the selective reduction of various pathogens, apple pomace substrate was artificially inoculated with Escherichia coli, Salmonella spp., thermotolerant coliform bacteria, and Enterococci. The artificial bacterial load did not influence the weight, reproduction, or intestinal enzymatic activity of the earthworms, but it caused reversible histological changes to the epithelial layer and chloragogen tissue of their intestines. The reduction of pathogenic Enterococci and E. coli from the substrate was accelerated by earthworms (63-fold, 77-fold, and 840-fold for Enterococci and 6-fold, 36-fold, and 7-fold for E. coli inoculated substrates after 2, 4, and 6 weeks, respectively). Moreover, the rapid elimination of Salmonella spp. was supported by the upregulated expression of two pattern recognition receptors which bind lipopolysaccharide, coelomic cytolytic factor, and lipopolysaccharide-binding protein. Further, the microbiomes of the intestine and the composting substrate differed significantly. Graphical abstract.

• MeSH
• Escherichia coli MeSH
• kompostování metody   MeSH
• Oligochaeta mikrobiologie   fyziologie   MeSH
• půdní mikrobiologie * MeSH
• střevní mikroflóra * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH

Pathogen adaptations during host-pathogen co-evolution can cause the host balance between immunity and immunopathology to rapidly shift. However, little is known in natural disease systems about the immunological pathways optimised through the trade-off between immunity and self-damage. The evolutionary interaction between the conjunctival bacterial infection Mycoplasma gallisepticum (MG) and its avian host, the house finch (Haemorhous mexicanus), can provide insights into such adaptations in immune regulation. Here we use experimental infections to reveal immune variation in conjunctival tissue for house finches captured from four distinct populations differing in the length of their co-evolutionary histories with MG and their disease tolerance (defined as disease severity per pathogen load) in controlled infection studies. To differentiate contributions of host versus pathogen evolution, we compared house finch responses to one of two MG isolates: the original VA1994 isolate and a more evolutionarily derived one, VA2013. To identify differential gene expression involved in initiation of the immune response to MG, we performed 3'-end transcriptomic sequencing (QuantSeq) of samples from the infection site, conjunctiva, collected 3-days post-infection. In response to MG, we observed an increase in general pro-inflammatory signalling, as well as T-cell activation and IL17 pathway differentiation, associated with a decrease in the IL12/IL23 pathway signalling. The immune response was stronger in response to the evolutionarily derived MG isolate compared to the original one, consistent with known increases in MG virulence over time. The host populations differed namely in pre-activation immune gene expression, suggesting population-specific adaptations. Compared to other populations, finches from Virginia, which have the longest co-evolutionary history with MG, showed significantly higher expression of anti-inflammatory genes and Th1 mediators. This may explain the evolution of disease tolerance to MG infection in VA birds. We also show a potential modulating role of BCL10, a positive B- and T-cell regulator activating the NFKB signalling. Our results illuminate potential mechanisms of house finch adaptation to MG-induced immunopathology, contributing to understanding of the host evolutionary responses to pathogen-driven shifts in immunity-immunopathology trade-offs.

• MeSH
• imunita MeSH
• konjunktiva MeSH
• mykoplazmové infekce * veterinární   mikrobiologie   MeSH
• pěnkavovití * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Some viroids-single-stranded, non-coding, circular RNA parasites of plants-are not transmissible through pollen to seeds and to next generation. We analyzed the cause for the elimination of apple fruit crinkle viroid (AFCVd) and citrus bark cracking viroid (CBCVd) from male gametophyte cells of Nicotiana tabacum by RNA deep sequencing and molecular methods using infected and transformed tobacco pollen tissues at different developmental stages. AFCVd was not transferable from pollen to seeds in reciprocal pollinations, due to a complete viroid eradication during the last steps of pollen development and fertilization. In pollen, the viroid replication pathway proceeds with detectable replication intermediates, but is dramatically depressed in comparison to leaves. Specific and unspecific viroid degradation with some preference for (-) chains occurred in pollen, as detected by analysis of viroid-derived small RNAs, by quantification of viroid levels and by detection of viroid degradation products forming "comets" on Northern blots. The decrease of viroid levels during pollen development correlated with mRNA accumulation of several RNA-degrading factors, such as AGO5 nuclease, DICER-like and TUDOR S-like nuclease. In addition, the functional status of pollen, as a tissue with high ribosome content, could play a role during suppression of AFCVd replication involving transcription factors IIIA and ribosomal protein L5.

• MeSH
• fenotyp MeSH
• interakce hostitele a patogenu MeSH
• konformace nukleové kyseliny MeSH
• nemoci rostlin virologie   MeSH
• pyl virologie   MeSH
• replikace viru MeSH
• RNA virová MeSH
• tabák virologie   MeSH
• viroidy * MeSH
• virová nálož MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Leishmaniasis is a disease caused by protozoan parasites of genus Leishmania. The frequent involvement of Leishmania tropica in human leishmaniasis has been recognized only recently. Similarly as L. major, L. tropica causes cutaneous leishmaniasis in humans, but can also visceralize and cause systemic illness. The relationship between the host genotype and disease manifestations is poorly understood because there were no suitable animal models. METHODS: We studied susceptibility to L. tropica, using BALB/c-c-STS/A (CcS/Dem) recombinant congenic (RC) strains, which differ greatly in susceptibility to L. major. Mice were infected with L. tropica and skin lesions, cytokine and chemokine levels in serum, and parasite numbers in organs were measured. PRINCIPAL FINDINGS: Females of BALB/c and several RC strains developed skin lesions. In some strains parasites visceralized and were detected in spleen and liver. Importantly, the strain distribution pattern of symptoms caused by L. tropica was different from that observed after L. major infection. Moreover, sex differently influenced infection with L. tropica and L. major. L. major-infected males exhibited either higher or similar skin pathology as females, whereas L. tropica-infected females were more susceptible than males. The majority of L. tropica-infected strains exhibited increased levels of chemokines CCL2, CCL3 and CCL5. CcS-16 females, which developed the largest lesions, exhibited a unique systemic chemokine reaction, characterized by additional transient early peaks of CCL3 and CCL5, which were not present in CcS-16 males nor in any other strain. CONCLUSION: Comparison of L. tropica and L. major infections indicates that the strain patterns of response are species-specific, with different sex effects and largely different host susceptibility genes.

• MeSH
• cytokiny krev   MeSH
• interakce hostitele a patogenu MeSH
• játra parazitologie   MeSH
• kůže parazitologie   patologie   MeSH
• Leishmania major imunologie   patogenita   MeSH
• Leishmania tropica imunologie   patogenita   MeSH
• leishmanióza kožní genetika   imunologie   parazitologie   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• náchylnost k nemoci MeSH
• parazitární zátěž MeSH
• sexuální faktory MeSH
• slezina parazitologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

A striking feature of white-nose syndrome, a fungal infection of hibernating bats, is the difference in infection outcome between North America and Europe. Here we show high WNS prevalence both in Europe and on the West Siberian Plain in Asia. Palearctic bat communities tolerate similar fungal loads of Pseudogymnoascus destructans infection as their Nearctic counterparts and histopathology indicates equal focal skin tissue invasiveness pathognomonic for WNS lesions. Fungal load positively correlates with disease intensity and it reaches highest values at intermediate latitudes. Prevalence and fungal load dynamics in Palearctic bats remained persistent and high between 2012 and 2014. Dominant haplotypes of five genes are widespread in North America, Europe and Asia, expanding the source region of white-nose syndrome to non-European hibernacula. Our data provides evidence for both endemicity and tolerance to this persistent virulent fungus in the Palearctic, suggesting that host-pathogen interaction equilibrium has been established.

• MeSH
• Ascomycota patogenita   MeSH
• Chiroptera mikrobiologie   MeSH
• haplotypy MeSH
• hibernace MeSH
• interakce hostitele a patogenu * MeSH
• kůže mikrobiologie   patologie   MeSH
• lidé MeSH
• mykózy epidemiologie   mikrobiologie   patologie   MeSH
• nos mikrobiologie   patologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Arktida MeSH
• Evropa MeSH
• Rusko MeSH
• Severní Amerika MeSH

• MeSH
• Bacteria růst a vývoj   imunologie   metabolismus   MeSH
• bakteriální nálož MeSH
• bydlení zvířat MeSH
• chov zvířat MeSH
• druhová specificita MeSH
• gnotobiologické modely * MeSH
• interakce hostitele a patogenu MeSH
• lidé MeSH
• mikrobiota * MeSH
• modely nemocí na zvířatech MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH
• úvodní články MeSH
• úvodníky MeSH