Pavel Hyrsl

• Masaryk University

Photorhabdus laumondii is a well-known bacterium with a complex life cycle involving mutualism with nematodes of the genus Heterorhabditis and pathogenicity towards insect hosts. It provides an excellent model for studying the diverse roles of lectins, saccharide-binding proteins, in both symbiosis and pathogenicity. This study focuses on the seven...

Host-specific Lactobacillus and Bifidobacterium species constitute the core microbiota of the honey bee digestive tract and are recognized for their probiotic properties. One of the properties of these bacteria is the inhibition of bacterial pathogens such as Paenibacillus larvae and Melissococcus plutonius, the causative agents of American and Eur...

Intensive agricultural practices impact the health and nutrition of pollinators like honey bees (Apis mellifera). Rapeseed (Brassica napus L.) is widely cultivated, providing diverse nutrients and phytochemicals, including S-methyl-L-cysteine sulfoxide (SMCSO). While the nutritional impact of rapeseed on bees is known, SMCSO’s effects remain unexpl...

The honey bee, Apis mellifera L., is one of the main pollinators worldwide. In a temperate climate, seasonality affects the life span, behavior, physiology, and immunity of honey bees. In consequence, it impacts their interaction with pathogens and parasites. In this study, we used Bayesian statistics and modeling to examine the immune response dyn...

Introduction: The fungal pathogen Aspergillus fumigatus can induce prolonged colonisation of the lungs of susceptible patients, resulting in conditions such as allergic bronchopulmonary aspergillosis and chronic pulmonary aspergillosis. Methodology; Galleria mellonella larvae were infected with A. fumigatus and the metabolism of host carbohydrate...

Reactive oxygen species (ROS) are generated as products of normal cellular metabolic activities; however, the use of pesticides to control leafcutter ants leads to unbalanced ROS production. We evaluated the effects of two insecticides (fipronil, sulfluramid) and metallic insecticide complex (magnesium complex [Mg(hesp)2(phen)] (1)) on the superoxi...

In the present study, we describe a natural outbreak of carp edema virus disease (CEVD) in koi carp, concentrating on clinical manifestation, gross and microscopic pathology, immunological parameters, viral diagnostics, and phylogenetic analysis. Examination of white blood cell parameters showed increased monocyte and decreased lymphocyte counts in...

The extensive annual loss of honey bees (Apis mellifera L.) represents a global problem affecting agriculture and biodiversity. The parasitic mite Varroa destructor, associated with viral co-infections, plays a key role in this loss. Despite years of intensive research, the complex mechanisms of Varroa – honey bee interaction are still not fully de...

Simple Summary The European honey bee, Apis mellifera, is well-known to have two distinct populations in temperate climate zone: short-living summer bees and long-living winter bees. Several biological factors related to the different lifespans of the two populations have been studied. However, the link between the metabolic changes and basic physi...

In the temperate climates of middle Europe and North America, two distinct honeybee (Apis mellifera) populations are found in colonies: short-living summer bees emerge in spring and survive until summer, whereas long-living winter bees emerge in late August and overwinter. Besides the difference in their life spans, each of these populations fulfil...

Hybrid advantage, described as the superiority of hybrids in some traits over their parents and termed the “heterosis effect,” is widely documented in the case of reciprocal crosses of parental species (i.e., hybrids representing the F1 generation). In fish, high survival, fast growth and better health status have been widely documented in F1 hybri...

The aim of this study was to investigate the effects of three commercial diets, standard, immunostimulant-supplemented (β-glucan, vitamins C and E) and plant-based, on the degree of oxidative stress in tissues of rainbow trout ( Oncorhynchus mykiss ). Selected immune and haematological indices were measured and challenge with Aeromonas salmonicida...

Individuals reared in captivity are exposed to distinct selection pressures and evolutionary processes causing genetic and phenotypic divergence from wild populations. Consequently, restocking with farmed individuals may represent a considerable risk for the fitness of free-living populations. Supportive breeding on a massive scale has been establi...

This special issue contains articles that add to the ever-expanding toolbox of insect pathogenic nematodes (entomopathogenic nematodes; EPNs) as well articles that provide new insights into the mutualistic interaction between EPNs and their hosts. The study of natural infection models such as EPNs allows detailed insight into micro- and macro-evolu...

O‐methylation is an unusual sugar modification with a function that is not fully understood. Given its occurrence and recognition by lectins involved in the immune response, methylated sugars were proposed to represent a conserved pathogen‐associated molecular pattern. We describe the interaction of O‐methylated saccharides with two β‐propeller lec...

Entomopathogenic nematodes (EPNs) are efficient insect parasites, that are known for their mutualistic relationship with entomopathogenic bacteria and their use in biocontrol. EPNs produce bioactive molecules referred to as excreted/secreted products (ESPs), which have come to the forefront in recent years because of their role in the process of ho...

The aim of this study was to assess the effects of T-2 toxin–contaminated feed (at concentrations of 1.0 and 1.8 mg/kg) on the rainbow trout immune system by studying non-specific cellular and humoral immune responses and its effect on red and white blood cells. Consumption of T-2 toxin at both concentrations resulted in significantly increased ery...

Bumble bees are important pollinators broadly used by farmers in greenhouses and under conditions in which honeybee pollination is limited. As such, bumble bees are increasingly being reared for commercial purposes, which brings into question whether individuals reared under laboratory conditions are fully capable of physiological adaptation to fie...

Entomopatogenní hlístice (EPN) jsou přirození parazité hmyzu. Mezi jejich významné zástupce patří rody Heterorhabditis a Steinernema, kteří žijí v mutualistickém vztahu s entomopatogenními bakteriemi. Naše studie se zaměřuje na virulenci a její změny v závislosti na stáří hlístic. Testovali jsme nákazy H. bacteriophora u larev zavíječe voskového, G...

It has been known for many years that in temperate climates the European honey bee, Apis mellifera, exists in the form of two distinct populations within the year, short-living summer bees and long-living winter bees. However, there is only limited knowledge about the basic biochemical markers of winter and summer populations as yet. Nevertheless,...

Entomopathogenic nematodes (EPNs) are the obligate parasites of insects. In the fight against the immune system of the host, nematodes use their excreted/secreted products (ESPs). These products are a mixture of molecules with distinct functions. We identified several functions of the ESPs and examined them in detail - specifically their influence...

Drosophila melanogaster and Galleria mellonella are among the most widespread model organisms used in various fields of research. For behaviour research a new method called FIMTrack was developed to simplify the collection and processing of locomotor data. It is based on frustrated total internal reflection and allows us to observe groups of larvae...

Bacteria of the genus Photorhabdus are known as potent entomopathogens that produce a variety of toxins, proteases and other virulence factors to overcome host immune system and successfully establish the infection. Although lectins with their carbohydrate-binding abilities are not the typical example of molecules causing direct damage to host orga...

Již dlouho dobu je známo, že se během roku uvnitř populace včely medonosné (Apis mellifera) vyvíjejí dvě rozdílné generace. Krátce žijící letní včely zajišťující sběr zásob a dlouho žijící zimní včely přežívající nepříznivé období roku. Vědomosti umožňující rozlišení těchto dvou generací včel jsou velice důležité pro včelaře, kteří by na jejich zák...

Drosophila melanogaster is one of the most widespread model organisms. It is used in various fields of research including genetics, immunology, developmental studies, behaviour and others. For behaviour research a new method called FIMTrack was developed to simplify the collection and processing of locomotor data of Drosophila larvae. The method ca...

Photorhabdus is a genus of gram-negative bacteria which is known for its symbiotic relationship with entomopathogenic nematodes of the genus Heterorhabditis. Both bacteria and nematodes produce variety of toxins, proteases and other compounds which make them highly pathogenic for a wide range of insects. In our work we focused on lectins produced b...

This study examined how adipokinetic hormone (AKH) and adenosine affect defense responses in Drosophila melanogaster larvae infected with entomopathogenic nematodes (EPN, Steinernema carpocapsae and Heterorhabditis bacteriophora). Three loss-of-function mutant larvae were tested: Akh1, AdoR1(adenosine receptor), and Akh1AdoR1. Mortality decreased i...

Avidin is key egg white antimicrobial protein with strong binding capacity for biotin, an essential growth and immune cell precursor. As such, it is assumed to have a pronounced, though still poorly explored, effect on hatchling phenotype. We tested the effect of experimentally increased egg white avidin concentration (AVIDIN+) on hatching success,...

Entomopatogenní hlístice (EPN) jsou přirození parazité hmyzu. Mezi jejich významné zástupce patří rody Heterorhabditis a Steinernema. Při boji proti imunitnímu systému hmyzu využívají hlístice kromě svých symbiotických bakterií také exkretované/sekretované produkty (ESP). Funkce zmíněných ESP byla detailně zkoumána v této studii – konkrétně jejich...

Reflex bleeding is one of the many anti-predation behavioural tactics used by insects. This behaviour is recorded widely in several insect taxa and provides scientists with an interesting opportunity for easily obtaining samples of haemolymph for physiological experiments. However, there is no good evidence that haemolymph and reflex blood have the...

The effect of feeding caffeine on the behaviour and neural proteome of Galleria mellonella larvae was assessed. Caffeine was administered to larvae by force feeding and the metabolites theobromine and theophylline were subsequently detected by RP-HPLC analysis. Administration of caffeine to larvae resulted in reduced movement and a reduction in the...

The harlequin ladybird is considered to be one of the most successful invasive insect species. Among other traits, its invasive success is considered to be caused by a powerful immune system. In the present study, we investigate the ontogenetic profile of protein concentration, concentration of circulating haemocytes and constitutive antimicrobial...

Photorhabdus asymbiotica is one of the three recognized species of the Photorhabdus genus, which consists of gram-negative bioluminescent bacteria belonging to the family Morganellaceae. These bacteria live in a symbiotic relationship with nematodes from the genus Heterorhabditis, together forming a complex that is highly pathogenic for insects. Un...

Glycan array—Raw data. (XLSX)

Dose-dependence of PHL effect on antimicrobial activity against E. coli K12 in human serum. Serum was incubated with different doses of PHL and mixed with bioluminescent bacteria E. coli K12. The bioluminescence was measured and evaluated as described in Experimental procedure. The results are expressed as difference between total measurement time...

Dose-dependence of PHL effect on ROS production. Whole blood was incubated with different doses of PHL and the subsequent production of ROS was measured luminometrically in the absence (without activator; white columns) or presence of the activator zymosan A (black columns). The presented data show the integral of ROS production in blood with PHL n...

Glycan array results. Screening of glycans printed on a microarray chip (Semiotik, Moscow; Slide number 10085636) via a standard manufacturer’s procedure. Results were calculated from hexaplicates. (XLSX)

Entomopathogenic nematodes (EPNs) are obligate insect parasites symbiotically associated with entomopathogenic bacteria. They can be used as a natural infection model combining bacterial infection with infection by multicellular parasite and as such, can be used in biological control and also offer a powerful tool to study insect immunity. Both mix...

Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematol...

One of the key factors that determine the interaction between hosts and their parasites is the frequency of their interactions, which depends on the locomotory behavior of both parts. To address host behavior we used natural infections involving insect pathogenic nematodes and Drosophila melanogaster larvae as hosts. Using a modified version of a r...

Potassium nitrate (E252) is widely used as a food preservative and has applications in the treatment of high blood pressure however high doses are carcinogenic. Larvae of Galleria mellonella were administered potassium nitrate to establish whether the acute effects in larvae correlated with those evident in mammals. Intra-haemocoel injection of pot...

In-situ formed hyaluronan/silver (HA/Ag) nanoparticles (NPs) were used to prepare composite fibers/fabrics for the first time. Different concentrations of silver nitrate (1, 2mg/100ml) were added at ambient temperature to sodium hyaluronate solution (40mg/ml), then the pH was increased to 8 by adding sodium hydroxide. The in-situ formed HA/Ag-NPs w...

Teleost fish include many different species, having a large economic and environmental impact. Glucose is a key source of energy for most vertebrate organisms. Fish as well as mammals maintain a specific level of blood sugar – glycaemia, which is influenced by multiple factors such as hormone production, diet, and temperature. Therefore, it is a us...

Photorhabdus luminescens is known for its symbiosis with the entomopathogenic nematode Heterorhabditis bacteriophora and its pathogenicity towards insect larvae. A hypothetical protein from P. luminescens was identified, purified from the native source and characterized as an L-fucose-binding lectin, named PLL. Glycan array and biochemical characte...

The present invention provides a relates to a composition for the preparation of gelatinous nanofibers containing oxidized cellulose, which comprises gelatin and oxidized cellulose sodium salt, wherein the weight ratio of the oxidized cellulose to gelatin is in the range of 0.1 to 2, and optionally further contains a solvent being selected from the...

Despite the high number of studies concerning seasonality of immune response in fish, information for some fish species is still scarce. Here, we assess seasonal changes in leukocyte counts and several immune parameters in three groups of farmed salmonids, i.e. brook trout (Salvelinus fontinalis), brook trout x Arctic charr hybrids (Salvelinus font...

The harlequin ladybird, Harmonia axyridis, is considered to be one of the world’s most important invasive insects. It has been spread over substantial part of Europe and North America in last decades and its invasion is potentially detrimental for native ladybird species. The powerful immune system makes harlequin ladybird highly resistant to disea...

Honey bees are important pollinators that are used by human for several thousand years. The immune system of honey bees can be divided to cellular and humoral branch that are complemented by highly developed social behaviour of bees. The activity of some immune factors is low in honey bees compared to other insects which is supposed to be caused ju...

According to the viability indicator hypothesis, ornaments of many bird species honestly signal individual quality and health status. In this study, we investigated the health- and stress-indicating capacity of both feather- and skin-based ornamental traits in the grey partridge (Perdix perdix), a vulnerable avian species of the European agricultur...

Novel hydrolytically stable gelatin nanofibers modified with sodium or calcium salt of oxycellulose were prepared by electrospinning method. The unique inhibitory effect of these nanofibers against Escherichia coli bacteria was examined by luminometric method. Biocompatibility of these gelatin/oxycellulose nanofibers with eukaryotic cells was teste...

Carassius auratus complex is an extraordinary species complex including the diploid and polyploid forms exhibiting asexual and sexual reproduction modes. The coexistence of both forms in the same habitats is currently reported. The stable coexistence of asexual and sexual forms assumes some disadvantages for asexuals that balance the costs of sex....

In birds, spectrum of egg white proteins deposited into the egg during its formation are thought to be essential maternal effects. Particularly, egg white lysozyme (LSM), exhibiting great between and within species variability, is considered to be essential for developing avian embryos due to its physiological, antimicrobial, and innate immune defe...

A 6-carboxycellulose (in medicine known as “oxidized cellulose” or “oxycellulose”) is one of the cellulose derivatives popular in the field of surgery. Health products based on oxidized cellulose are great local hemostatics with unique bactericidal and fully bioabsorbable effects. Traditional process of native cellulose oxidation is described as a...

The study analysed the effect of fish ploidy level and seasonality on haematological parameters and innate immune response of tench (Tinca tinca, Cyprinidae), fish species extensively bred in European aquaculture. Fish samples were collected from a breeding pond in Vodňany (Czech Republic) during four sampling periods (September, December, March an...

We describe an antibacterial assay based on bioluminescence of two Gram negative bacteria, Photorhabdus luminescens and transformed Escherichia coli, which can be used as a real-time measurement of antibacterial activity in insect haemolymph. This method is based on the production of the bioluminescence signal depending on the viability of bacteria...

Over the years, researchers have used presumptively neutral molecular variation to infer the origins of current species' distributions in northern latitudes (especially Europe). However, several reported examples of genic and chromosomal replacements suggest that end-glacial colonizations of particular northern areas may have involved genetic input...

The present study provides a comprehensive data on the antioxidant, antimicrobial and neutrophil-modulating activities of extracts from six medicinal plants - blackberry (Rubus fruticosus) leaves, chokeberry (Aronia melanocarpa) leaves, hawthorn (Crataegus monogyna) leaves, lady's mantle (Alchemilla glabra) aerial parts, meadowsweet (Filipendula ul...

Heterorhabditis bacteriophora is an entomopathogenic nematode (EPN) which infects its host by accessing the hemolymph where it releases endosymbiotic bacteria of the species Photorhabdus luminescens. We performed a genome-wide transcriptional analysis of the Drosophila response to EPN infection at the time point at which the nematodes reached the h...

The infective juveniles (IJs) of entomopathogenic nematodes (EPNs) seek out host insects and release their symbiotic bacteria into their body cavity causing septicaemia, which eventually leads to host death. The interaction between EPNs and their hosts are only partially understood, in particular the host immune responses appears to involve pathway...

Eicosanoids mediate insects cellular and humoral immune reactions and stress responses. Function of these mediators can be specifically blocked using different eicosanoid biosynthesis inhibitors (EBIs). Effects of EBIs on total haemolymph protein composition have not been extensively studied in insects. We posed the hypothesis that eicosanoids also...

The innate immune response in fishes includes both cellular (phagocytes) and humoral (complement system mainly) components. In fish, as in mammals, reactive oxygen metabolites (ROM) are involved in the respiratory burst of phagocytes and three pathways of complement activation can be discerned. The aim of this study was to analyze the innate immune...

The aim of this study was to investigate whether haemocytes of Galleria mellonella (Lepidoptera: Pyralidae) larvae produce reactive oxygen species (ROS) like human blood phagocytes. The production of ROS was measured first using luminol-enhanced chemiluminescence of un-stimulated and stimulated (four activators with different modes of action) haemo...

Entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema are obligate and lethal insect parasites. In last decade they are widely used as biological control agents for pest insects of commercial crops, therefore research in this area is directly linked to agriculture. In this study, the pathogenicity of four nematode species...

The basic function of the immune system is to protect an organism against infection in order to minimize the fitness costs of being infected. According to life-history theory, energy resources are in a trade-off between the costly demands of immunity and other physiological demands. Concerning fish, both physiology and immunity are influenced by se...

Eicosanoids mediate insects cellular and humoral immune reactions and stress responses. Function of these mediators can be specifically blocked using different eicosanoid biosynthesis inhibitors (EBIs). Effects of EBIs on total haemolymph protein composition have not been extensively studied in insects. We posed the hypothesis that eicosanoids also...

We show that hemolymph clotting protects Drosophila melanogaster against infections with an entomopathogenic nematode and its symbiotic bacterium. We also provide biochemical and genetic evidence for an involvement of eicosanoids in the same infection model. Taken together, our results confirm the conserved nature of the immune function of clot for...

Hemocytes from eater mutants but not from TG-RNAi larvae show reduced phagocytosis of P. luminescens. The percentage of hemocytes that had taken up bacteria was counted essentially as described [22] after mixing with GFP-expressing P. luminescens and incubation for 30 minutes. Note that in contrast to eater mutants (p = 8.1×10−8 compared to control...

Zymosan particles are sequestered by the clot matrix. A drawout (A and [16] was performed in the presence of zymosan and the resulting fibers analyzed under fluorescence microscopy (B) and phase contrast (C). Zymosan beads visible due to autofluorescence are indicated by arrowheads, fat body debris released during wounding is also incorporated (*)....

Humoral procoagulants bind to E. coli (A) and P. luminescens (B) surfaces. Bacterial lysates were incubated in the presence of hemolymph (Hl), B-cad or the combination of both or with B-cad alone (in the case of E. coli) and analyzed using polyacrylamide gel electrophoresis. The additional band in the samples with Hl and B-cad (asterisks) represent...

Sequestration of bacteria is inhibited by the TG inhibitor monodansylcadaverine (MDC). Clots were prepared as described (see Fig. 3B) in the presence and absence of MDC alone or in the presence of either E. coli or S. aureus SH1000. The scale bar corresponds to 10 µm. (3.75 MB TIF)

Identification of microaggregate proteins. (0.05 MB DOC)

Hexamerin binding to microbes is reduced in TG-RNAi larvae. Proteins binding to zymosan in the presence of biotincadaverine were analyzed using polyacrylamide-gelelectrophoresis. Both complete zymosan beads (−) as well as beads after pullout [5] on peanut agglutinin (PNA, +) are shown for a control cross (TG-contr) and a TG-knockdown (TG-RNAi). Not...

Clotting systems are required in almost all animals to prevent loss of body fluids after injury. Here, we show that despite the risks associated with its systemic activation, clotting is a hitherto little appreciated branch of the immune system. We compared clotting of human blood and insect hemolymph to study the best-conserved component of clotti...

Antioxidant enzymes play a major role in the defense against pro-oxidative effects of xenobiotics and pro-oxidant plant allelochemicals in insects. We posed the hypothesis that eicosanoids also mediate antioxidant enzymatic defense reactions to pro-oxidant challenge. To test this idea, we reared first-instar larvae of Galleria mellonella (L.) with...

Multiple stressor scenarios, as they are relevant in many watersheds, call for approaches extending beyond conventional chemical-focused approaches. The present study, investigated the fish population, represented by chub (Leuciscus cephalus), in the Bílina River (Czech Republic), which is impacted by various pollution sources and might pose a risk...

Relationships between immunocompetence, somatic condition, parasitism and water temperature in a wild population of chub Leuciscus cephalus were investigated. The effects of a rapid temperature increase in early spring were studied for both sexes as water temperature affects immunocompetence. Investment in gonads and activity of mucus lysozyme were...

The paper is devoted to the results of biophysical experiments by which the existence of the field of so called pulse vector magnetic potential was successfully proved. The decision to carry out these tests was motivated by a favorable coincidence of pieces of knowledge obtained in the solution of other biophysical-research projects. The aim of the...

Activity of enzymes oxidizing phenolic substrates commonly termed phenoloxidases (POs) was investigated during normal de-velopment of Galleria mellonella L. in haemolymph, intact cuticle and homogenized cuticle. PO activities were determined col-orimetrically following chemical activation of prophenoloxidase with acetone or methanol using hydroquin...

The dietary effects of boric acid (BA) on the protein profiles of greater wax moth, Galleria mellonella (L.), were investigated in hemolymph and fat body of final instar (VIIth) and pupae. The insects were reared from first-instar larvae on an artificial diets containing 156, 620, 1250 or 2500 ppm of BA. We detected many undetermined protein fracti...

Larvae of the wax moth, Galleria mellonella (L.), were reared from first instar on a diet supplemented with 156, 620, 1,250, or 2,500 ppm boric acid (BA). The content of malondialdehyde (MDA, an oxidative stress indicator), and activities of the antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and gl...

Nitric oxide production by the hemocytes of the last instar larvae and sessile pharate prepupa of Galleria mellonella (Lepidoptera: Pyralidae) was demonstrated in vitro in response to preparations of bacterial lipopolysaccharide (LPS) from Escherichia coli using the Griess reaction. Augmented, dose dependent nitric oxide production was observed in...

Sodium dodecyl sulphate polyacrylamide gradient gel electrophoresis (SDS-PAGGE) was used to determine the hemolymph protein profiles of the silkworm Bombyx mori during the development of the final instar, prepupa and pupa. Using this technique it was possible to distinguish approximately 16-23 protein fractions in the final instar larva, in the pre...

The aim of the study was to test the effect of experimental conditions such as light radiation and temperature on chemiluminescence (CL) of 10(-2)-10(-5) mol/L lucigenin dissolved in various types of solvents. Irradiation by UV light (280, 297, 313 or 400 nm) induced a significant increase in CL of lucigenin dissolved in borate buffer. This effect...

Natural bioluminescence of all recently accepted Photorhabdus species and subspecies type strains (bacterial symbionts of entomopathogenic nematodes) was measured using a commercial luminometer; optimum conditions for the measurement were described. Cultures emitted reliably measurable bioluminescence with characteristic level and kinetics for each...