Browsing by Author "Kazimierczak, Waldemar"
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- ItemAddenum to the description of Steinernema jollieti Spiridonov, Krasomil-Osterfeld & Moens, 2004(The Russian Society of Nematologists, 2012-11-14) Skrzypek, Henryk; Kazimierczak, Waldemar; Kreft, Anna; Spiridonov, Sergei; Mráček, ZdeněkAdditonal morphological data are provided for Steinernema jollieti Spiridonov, KrasomilOsterfeld, Moens, 2004. A light and scanning electron microscopy were used to particularize taxonomically important characters missing in the first decsription. The GS% and SW% indices are provided for males. The distribution of genital papillae on male tail is illustrated with SEM images. Structure of female tail and vulvar area are decsribed for females of the first and second generation. The relationships of S. jollieti with other steinernematid feltiae/kraussei group species are discussed.
- ItemBacteria from the midgut of common cockchafer (Melolontha melolontha L.) larvae exhibiting antagonistic activity against bacterial symbionts of entomopathogenic nematodes: isolation and molecular identification(MDPI, 2020-01-16) Skowronek, Marcin; Sajnaga, Ewa; Pleszczyńska, Małgorzata; Kazimierczak, Waldemar; Lis, Magdalena; Wiater, AdrianThe mechanisms of action of the complex including entomopathogenic nematodes of the genera Steinernema and Heterorhabditis and their mutualistic partners, i.e., bacteria Xenorhabdus and Photorhabdus, have been well explained, and the nematodes have been commercialized as biological control agents against many soil insect pests. However, little is known regarding the nature of the relationships between these bacteria and the gut microbiota of infected insects. In the present study, 900 bacterial isolates that were obtained from the midgut samples of Melolontha melolontha larvae were screened for their antagonistic activity against the selected species of the genera Xenorhabdus and Photorhabdus. Twelve strains exhibited significant antibacterial activity in the applied tests. They were identified based on 16S rRNA and rpoB, rpoD, or recA gene sequences as Pseudomonas chlororaphis, Citrobacter murliniae, Acinetobacter calcoaceticus, Chryseobacterium lathyri, Chryseobacterium sp., Serratia liquefaciens, and Serratia sp. The culture filtrate of the isolate P. chlororaphis MMC3 L3 04 exerted the strongest inhibitory effect on the tested bacteria. The results of the preliminary study that are presented here, which focused on interactions between the insect gut microbiota and mutualistic bacteria of entomopathogenic nematodes, show that bacteria inhabiting the gut of insects might play a key role in insect resistance to entomopathogenic nematode pressure.
- ItemCharakterystyka nicieni wyizolowanych z pędraków chrabąszcza Melolontha sp. (Coleoptera: Scarabaeidae)(Instytut Ochrony Roślin - Państwowy Instytut Badawczy, Polskie Towarzystwo Ochrony Roślin, 2012-06-15) Kreft, Anna; Kazimierczak, Waldemar; Sierpińska, Alicja; Skrzypek, Henryk; Skrabucha, Anna; Dybała, Magdalena; Dźwierzyńska, MonikaCelem badań była charakterystyka nicieni porażających pędraki chrabąszcza Melolontha sp. w warunkach naturalnych. Pędraki chrabąszcza były zebrane na terenie nadleśnictw Krasnystaw, Kozienice, Opoczno i Brzeziny, na powierzchniach różniących się warunkami świetlnymi, wilgotnościowymi i temperaturowymi. Identyfikację gatunków przeprowadzono metodą sekwencjonowania fragmentów DNA (deoxyribonucleic acid) oraz metodami morfologicznymi przy zastosowaniu skaningowego mikroskopu elektronowego i mikroskopu optycznego z kontrastem interferencyjno-różnicowym. Uzyskane wyniki wykazały, że pędraki były porażone przez Diplogasteroides magnus oraz Koerneria sp. i Rhabditis sp. Większość zainfekowanych przez nicienie pędraków została zebrana na powierzchniach zadrzewionych, czyli tam, gdzie powierzchnia gleby była dobrze ocieniona, a wilgotność najwyższa.
- ItemComparative nanopore sequencing-based evaluation of the midgut microbiota of the summer chafer (Amphimallon solstitiale L.) associated with possible resistance to entomopathogenic nematodes(MDPI, 2022-03-15) Sajnaga, Ewa; Skowronek, Marcin; Kalwasińska, Agnieszka; Kazimierczak, Waldemar; Lis, Magdalena; Jach, Monika Elżbieta; Wiater, AdrianRoot-feeding Amphimallon solstitiale larvae and certain other scarab beetles are the main soil-dwelling pests found in Europe, while entomopathogenic nematodes (EPN) have been used as a biocontrol agent against these species. Our study provides the first detailed characterization of the bacterial community of the midgut in wild A. solstitiale larvae, based on the nanopore sequencing of the 16S rRNA gene. In the whole dataset, we detected 2586 different genera and 11,641 species, with only 83 diverse bacterial genera shared by all studied individuals, which may represent members of the core midgut microbiota of A. solstitiale larvae. Subsequently, we compared the midgut microbiota of EPN-resistant and T0 (prior to EPN exposure) individuals, hypothesizing that resistance to this parasitic infection may be linked to the altered gut community. Compared to the control, the resistant insect microbiota demonstrated lower Shannon and Evenness indices and significant differences in the community structure. Our studies confirmed that the gut microbiota alternation is associated with resistant insects; however, there are many processes involved that can affect the bacterial community. Further research on the role of gut microbiota in insect-parasitic nematode interaction may ultimately lead to the improvement of biological control strategies in insect pest management.
- ItemEfektywność porażania larw chrabąszcza majowego (Melolontha melolontha L.) przez entomopatogeniczne nicienie(Instytut Ochrony Roślin - Państwowy Instytut Badawczy, Polskie Towarzystwo Ochrony Roślin, 2011-06-15) Kreft, Anna; Skrzypek, Henryk; Kazimierczak, Waldemar; Lech-Pituch, Ewelina; Skrabucha, AnnaExperiments done and presented below aimed at proving that applied species and Polish strains of entomopathogenic nematodes (EPNs) can be used to reduce the number of Melolontha melolontha. Invasive larvae of Steinernema arenarium Bys, S. arenarium Lub, S. feltiae Rap, Heterorhabditis bacteriophora Sie, H. megidis Pla, H. megidis Lub i H. megidis Pla, H. megidis C3 were used in the experiments as biocontrol agents against the larvae L1, L2 and L3 of M. melolontha. The experiments were done at 20°C, in 25 ml boxes filled with pasteurized (3 h at 70°) and air-dried soil. Pathogen doses were 100 IJ/insect. The result showed that susceptibility of M. melolontha to EPNs depends on the insect's developmental stage. Larvae L1 were the most susceptible. S. arenarium Bys and H. megidis strains were more effective in infecting M. melolontha larvae than S. feltiae Rap and H. bacteriohora Sie.
- ItemEffectiveness of infection of Cameraria ohridella (Lepidoptera: Gracillariidae) larvae by entomopathogenic nematodes Steinernema sp. and Heterorhabditis sp. (Nematoda: Rhabditida)(Wydawnictwo UMCS, 2004-06-15) Kreft, Anna; Skrzypek, Henryk; Kazimierczak, WaldemarThe purpose of the present studies was to evaluate the susceptibility of Cameraria ohridella larvae to infection by entomopathogenic nematodes Steinernema sp. and Heterorhabditis sp. in laboratory conditions. The experiments were done at the temperatures 20 ◦C and 25 ◦C with the use of three doses of the pathogen, namely 5, 25 and 50 nematodes/insect. The results showed that Cameraria ohridella larvae were susceptible to infection by entomopathogenic nematodes. Out of two strains of entomopathogenic nematodes used in the studies, the one that was more effective in infecting Cameraria ohridella at the temperature 20 ◦C was Steinernema sp., while at the temperature of 25 ◦C Heterorhabditis sp. infected the insects more intensively. Results of the experiments showed that with lower doses of invasive larvae of nematodes (5 larvae/insect, 25 larvae/insect) Steinernema sp. PIS81 was a more pathogenic strain towards Cameraria ohridella as compared to Heterorhabditis sp. PIH81.
- ItemEvolution and taxonomy of nematode-associated entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus: an overview(Springer Nature, 2020-01-10) Sajnaga, Ewa; Kazimierczak, WaldemarEntomopathogenic bacteria from the genera Photorhabdus and Xenorhabdus are closely related Gram-negative bacilli from the family Enterobacteriaceae (γ-Proteobacteria). They establish obligate mutualistic associations with soil nematodes from the genera Steinernema and Heterorhabditis to facilitate insect pathogenesis. The research of these two bacterial genera is focused mainly on their unique interactions with two different animal hosts, i.e. nematodes and insects. So far, studies of the mutualistic bacteria of nematodes collected from around the world have contributed to an increase in the number of the described Xenorhabdus and Photorhabdus species. Recently, the classification system of entomopatogenic nematode microsymbionts has undergone profound revision and now 26 species of the genus Xenorhabdus and 19 species of the genus Photorhabdus have been identified. Despite their similar life style and close phylogenetic origin, Photorhabdus and Xenorhabdus bacterial species differ significantly in e.g. the nematode host range, symbiotic strategies for parasite success, and arrays of released antibiotics and insecticidal toxins. As the knowledge of the diversity of entomopathogenic nematode microsymbionts helps to enable the use thereof, assessment of the phylogenetic relationships of these astounding bacterial genera is now a major challenge for researchers. The present article summarizes the main information on the taxonomy and evolutionary history of Xenorhabdus and Photorhabdus, entomopathogenic nematode symbionts.
- ItemFunctional traits of Lactobacillus plantarum from fermented Brassica oleracea var. capitata L. in view of multivariate statistical analysis(Springer, 2018-05-04) Polak-Berecka, Magdalena; Kubik-Komar, Agnieszka; Gustaw, Klaudia; Michalak, Magdalena; Kazimierczak, Waldemar; Waśko, AdamIn the present study, Lactobacillus plantarum strain was isolated and identifid from spontaneous fermentation of Brassica oleracea var. capitata L. We used the Unweighted Pair Group Method with Arithmetic Mean Analysis (UPGMA) and Principal Component Analysis (PCA) to examine the variations in the functional properties of the isolates. Six functional traits were analyzed, i.e., viability at low pH, resistance to lysozyme and to SIF, auto- and coaggregation, and ß-glucosidase activity. The present work is the fist study in which the PCA and UPGMA statistical methods were used together to analyze data obtained from the same microbiological experiments. This provided information about the similarity of the examined isolates in terms of their functional traits. Additionally, the level of the analyzed functional traits within the particular groups of isolates was shown. The presented approach is the basis for choosing isolates that are most closely related to the reference strain isolated from pickled cabbage.
- ItemGradual disapperance of vacuolated enterocytes in the small intestine of neonatal piglets(Kraków: Polish Physiological Society, 2007) Skrzypek, Tomasz; Valverde Piedra, Jose Luis; Skrzypek, Henryk; Kazimierczak, Waldemar; Biernat, Marzena; Zabielski, RomualdThe unique feature of enterocytes in newborn mammals is the presence of an apical canalicular system (ACS) leading to production of large vacuoles, important for colostral macromolecule uptake. The vacuolated fetal-type enterocytes (VFE) enable transfer of colostral and milk proteins from the intestinal lumen across the epithelium without loosing their biological activity. First VFE are observed in the pig and lamb fetuses in the second trimester of pregnancy, located at the upper part of villi in the proximal region of the fetal small intestine and subsequently in the middle and distal regions. After birth the VFE are replaced with enterocytes lacking ACS. The present study aimed to investigate the depletion of VFE in the small intestine in the sow reared pig neonates during the first postnatal weeks using scanning electron microscopy (SEM). The SEM analysis demonstrated the gradual disappearance of vacuolated enterocytes in time. VFE remained in the jejunum for a few days after birth, whereas in the duodenum single VFE were present only at birth. In the proximal jejunum, the VFE were localized in the upper part of the villi, and disappeared until the day 3 of life. VFE were present in the mid and distal jejunum, and diminished gradually until day 14 of life. By the day 21 of life, the vacuolated cells were not observed neither in the jejunum nor ileum. In conclusion, morphology analysis of pig small intestinal mucosa suggests that replacement of fetal type vacuolated enterocytes is resumed within 21 days after birth.
- ItemGum arabic/gelatin and water-soluble soy polysaccharide/gelatin blend films as carriers of astaxanthin - a comparative study of the kinetics of release and antioxidant properties(MDPI, 2021-03-28) Kowalczyk, Dariusz; Łupina, Katarzyna; Kazimierczak, WaldemarPolymer blending and incorporation of active substances offer a possibility of generation of novel packaging materials with interesting features. Astaxanthin is one of the most powerful antioxidants. Hence, in this study, water-soluble AstaSana astaxanthin (AST) was incorporated into 75/25 gum arabic/gelatin (GAR75/GEL25) and water-soluble soy polysaccharides/gelatin (WSSP75/GEL25) blend films in different concentrations (0, 0.25%, 0.5%, 1%). Microscope images showed good compatibility between the polysaccharides and GEL. Basing on time required for 50% release, the WSSP-based film exhibited an approximately four-fold slower release rate (t50% = 65.16–142.80 min) than the GAR-based film (t50% = 14.64–34.02 min). This result was mainly ascribed to the slower dissolution of the WSSP-based carrier. The faster release rate of the GAR-based films resulted in stronger antioxidant activity (quarter-scavenging time (t25%ABTS) = 0.22–7.51 min) in comparison to the WSSP-based films (t25%ABTS = 0.91–12.94 min). The increase in the AST concentration was accompanied by gradually reduced solubility and the release rate. It is possible that the increasing number of starch granules (from the AST formulation) acted as a dissolution blocking agent. In general, the WSSP75/GEL25 film displayed the most linear (the Zero-order similar) release profile. So, this carrier has potential for release of AST at a quasi-constant speed.
- ItemIntestinal MMC-related electric fields and pancreatic juice control the adhesion of Gram-positive and Gram-negative bacteria to the gut epithelium - in vitro study(2008) Jankowska, Alicja; Wrzesiński, Michał; Laubitz, Daniel; Kazimierczak, Waldemar; Skrzypek, Henryk; Bardowski, Jacek; Zabielski, Romuald; Grzesiuk, ElżbietaThe adhesion of six different Lactobacillus and Lactococcus and three pathogenic Escherichia and Salmonella strains was studied using Caco-2 cell line. In this in vitro model system the influence of weak electric field (EF) on bacterial adhesion was tested. The EF source was the in vitro reconstruction of spiking potentials recorded in the duodenum of a healthy calf during one myoelectrical migration complex (MMC) cycle. The ability to adhere to Caco-2 cells of bacteria belonging to two groups, Gram-positive lactobacilli and lactococci, and Gram-negative Escherichia and Salmonella differed considerably. The pathogenic bacteria adhered better to well-differentiated Caco-2 cells whereas lactobacilli and lactococci displayed better adhesion to non-differentiated Caco-2 cells. In the presence of MMC-related EF an increased adhesion of Lactobacillus and Lactococcus but not of Salmonella enterica s. Enteritidis and E. coli 269 to Caco-2 cells was observed. Two later strains adhered even less in the presence of EF. The same tendency was found in the presence of pancreatic juice in a cell medium. In conclusion, the myoelectric component of the small intestinal motility, the MMC-related EF, and pancreatic juice may increase the ability of lactic acid bacteria to adhere to GI epithelial cells, creating better environmental conditions for colonization of the intestine and competition with Gram-negative pathogens.
- ItemIs soil management system really important? comparison of microbial community diversity and structure in soils managed under organic and conventional regimes with some view on soil properties(PLoS, 2021-09-09) Rachwał, Kamila; Gustaw, Klaudia; Kazimierczak, Waldemar; Waśko, AdamThe fertility and productive value of soil are closely related to the physical and chemical properties of the soil as well as its biological activity. This activity is related to the intensity of microbially catalysed processes of transformation of organic and mineral substances contained in the soil. These processes are closely correlated with the abundance and biodiversity of soil microorganisms, especially bacteria, and the activity of enzymes produced by them. In this article we have compared some physicochemical properties of soil derived from conventional and organic farms and microbial communities inhabiting these ecosystems. We aim to investigate whether the soil management regime affects the abundance and diversity of these environments in terms of bacteria. Some differences in microbial communities were observed, but the rhizosphere of plants from organic and conventional soils does not harbour separate microbiomes. Albeit, the method of fertilization influences the diversity of soil microorganisms. A greater diversity of bacteria was observed in soils from farms where organic fertilizers were applied. Soil pH and activity of some soil enzymes were also shown to differ between organic and conventional soil cropping systems.
- ItemMechanisms involved in the development of the small intestine mucosal layer in postnatal piglets(Kraków: Polish Physiological Society, 2018) Skrzypek, Tomasz; Kazimierczak, Waldemar; Skrzypek, Henryk; Valverde Piedra, Jose Luis; Godlewski, Michał; Zabielski, RomualdThe use of complementary visualization and measurement techniques allowed accurate description and quantification of changes in the intestinal mucosal architecture and provided a comprehensive outlook on the dynamics of remodeling and maturation processes of the mucosal layer taking place in the small intestine of piglets from birth to weaning. The aim of the study was to examine the early postnatal development of the small intestine in pigs. Three techniques were used: scanning electron microscopy (measurements ofvillus density and shape, height ofenterocytes and microvilli, cell exfoliation, and location of extrusion zones), optical microscopy (cross section, measurement of structures: villus length and width; crypt depth; mucosal thickness), and confocal microscopy (cell localization, apoptosis, exfoliation and migration). The postnatal development ofthe mucosal layer ofthe small intestine was reflected in changes in the density, length, width, and shape of villi, crypt depth, replacement of enterocyte population, and arrangement. The presence of deep transverse furrows on villus corpus and vacuolated fetal-type enterocytes in the mucosal layer of the small intestine, which are able to engulf large amounts of colostrum shortly after birth, appears to play an important role in the observed phenomenon of straightening of the villus height and increasing of the villus diameter shortly after birth. We hypothesized that the intestinal mucosal layer is compressed before birth and ready to unfold within a short time after birth.
- ItemMicrosporidia Nosema spp. – obligate bee parasites are transmitted by air(Nature Research, 2019-10-07) Sulborska, Aneta; Horecka, Beata; Cebrat, Małgorzata; Kowalczyk, Marek; Skrzypek, Tomasz; Kazimierczak, Waldemar; Trytek, Mariusz; Borsuk, GrzegorzMicrosporidia Nosema are transferred among bees via the faecal-oral route. Nosema spp. spores have been detected on fowers and transferred to hives along with the bee pollen. The aim of the present study was to determine whether Nosema microsporidia are transferred by air in an apiary, in a control area (without the presence of bee colonies), and/or in a laboratory during cage experiments with artifcially infected bees. The novel way of transmission by air was investigated by the volumetric method using a Hirst-type aerobiological sampler located on the ground in the apiary, in the Botanical Garden and on the laboratory foor. Concurrently, the mean rate of Nosema infections in the foragers in the apiary was estimated with the Bürker haemocytometer method. Spore-trapping tapes were imaged by means of light microscopy, nomarski interference contrast microscopy and scanning electron microscopy. the highest concentration of Nosema spores per 1m3 of air (4.65) was recorded in August, while the lowest concentration (2.89) was noted in July. This was confrmed by a Real-Time PCR analysis. the presence of N. apis as well as N. ceranae was detected in each of the tested tapes from the apiary. the average copy number of N. apis was estimated at 14.4 × 104 copies per 1 cm2 of the tape; whereas the number of N. ceranae was 2.24 × 104 copies per tape per 1 cm2. the results indicate that Nosema microsporidia were transferred by the wind in the apiary, but not in the Botanical Garden and laboratory by air. This was confrmed by genetic analyses. DNA from immobilised biological material was isolated and subjected to a pcR to detect the Nosema species. A fragment of the 16S rRNA gene, characteristic of Nosema apis and N. ceranae, was detected. our research adds knowledge about the transfer of Nosema spp. microsporidia in the natural environment and indicates the season associated with the greatest risk of a bee colony infection with Nosema spp.
- ItemNanopore-sequencing characterization of the gut microbiota of Melolontha melolontha larvae: contribution to protection against entomopathogenic nematodes?(MDPI, 2021-03-25) Sajnaga, Ewa; Skowronek, Marcin; Kazimierczak, Waldemar; Ferenc, Karolina; Lis, Magdalena; Wiater, AdrianThis study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.
- ItemScanning electron microscopy study of infective juveniles Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae)(Wydawnictwo UMCS, 2004-06-15) Skrzypek, Henryk; Kazimierczak, Waldemar; Kreft, AnnaStudies were conducted on the morphology of infective larvae Heterorhabditis bacteriophora using a scanning electron microscopy. The purpose of the studies was to point to the morphological and morphometric characters of infective larvae of entomogenous nematodes that are useful in taxonomy and species identification. It was found out that the studies using SEM make it possible to analyze the morphological characters unvisible in an optic microscope. Morphometric properties can also be examined in SEM, and since the measurements are very accurate they can be applied in taxonomic studies and in species identification. The preparation of the material for the studies in SEM and their performance is neither more labour-consuming nor more tiresome than in optic microscopy.
- ItemScreening and molecular identification of bacteria from the midgut of Amphimallon solstitiale larvae exhibiting antagonistic activity against bacterial symbionts of entomopathogenic nematodes(MDPI, 2021-11-05) Skowronek, Marcin; Sajnaga, Ewa; Kazimierczak, Waldemar; Lis, Magdalena; Wiater, AdrianEntomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) are a group of organisms capable of infecting larvae of insects living in soil, including representatives of the family Scarabaeidae. Their insecticidal activity is related to the presence of symbiotic bacteria Xenorhabdus spp. or Photorhabdus spp. in the alimentary tract, which are released into the insect body, leading to its death caused by bacterial toxins and septicemia. Although the antibacterial activities of symbionts of entomopathogenic nematodes have been well described, there is insufficient knowledge of the interactions between these bacteria and microorganisms that naturally inhabit the alimentary tract of insects infested by nematodes. In this study, 900 bacterial strains isolated from midgut samples of Amphimallon solstitiale larvae were tested for their antagonistic activity against the selected five Xenorhabdus and Photorhabdus species. Cross-streak tests showed significant antibacterial activity of 20 isolates. These bacteria were identified as Bacillus [Brevibacterium] frigoritolerans, Bacillus toyonensis, Bacillus wiedmannii, Chryseobacterium lathyri, Chryseobacterium sp., Citrobacter murliniae, Enterococcus malodoratus, Paenibacillus sp., Serratia marcescens and Serratia sp. Since some representatives of the intestinal microbiota of A. solstitiale are able to inhibit the growth of Xenorhabdus and Photorhrhabdus bacteria in vitro, it can be assumed that this type of bacterial interaction may occur at certain stages of insect infection by Steinernema or Heterorhabditis nematodes.
- ItemSteinernema poinari (Nematoda: Steinernematidae): a new symbiotic host of entomopathogenic bacteria Xenorhabdus bovienii(Springer, 2018-06-19) Sajnaga, Ewa; Kazimierczak, Waldemar; Skowronek, Marcin; Lis, Magdalena; Skrzypek, Tomasz; Waśko, AdamThree strains of symbiotic bacteria were isolated from an entomopathogenic nematode Steinernema poinari retrieved from soil in eastern Poland. Using 16S rDNA, recA, gltX, gyrB, and dnaN gene sequences for phylogenetic analysis, these strains were shown to belong to the species Xenorhabdus bovienii. The nucleotide identity between the studied S. poinari microsymbionts and other X. bovienii strains calculated for 16S rDNA and concatenated sequences of four protein-coding genes was 98.7–100% and 97.9–99.5%, respectively. The phenotypic properties of the isolates also supported their close phylogenetic relationship with X. bovienii. All three tested X. bovienii strains of diffrent Steinernema clade origin supported the recovery of infective juveniles and subsequent development of the nematode population. However, the colonization degree of new infective juvenile generations was signifiantly affcted by the bacterial host donor/recipient. The colonization degree of infective juveniles reared on bacterial symbionts deriving from a non-cognate clade of nematodes was extremely low, but proved the possible host-switching between non-related Steinernema species.
- ItemSteinernema sandneri n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Poland(Exeley, 2021-05-21) Lis, Magdalena; Sajnaga, Ewa; Skowronek, Marcin; Wiater, Adrian; Rachwał, Kamila; Kazimierczak, WaldemarA new species of entomopathogenic nematodes, Steinernema sandneri n. sp., was recovered by baiting from Poland. Its morphological traits indicate that the new species is a member of the feltiae-kraussei group. A body length of 843 (708-965) μm., a more anterior position of excretory pore (56 μm), and the lower D% value (40 vs. >46) discriminate this species from most of the other group members. The first-generation males of S. sandneri n. sp. can be distinguished from the other clade members by a 60 μm long spicule, a relatively long gubernaculum (GS%=79), and the position of the excretory pore (80 μm). Phylogenetic analysis of the ITS rDNA, D2D3 of 28S rDNA, and cox1 sequences confirmed that S. sandneri n. sp. is a new species of the feltiae-kraussei group, closely related to S. kraussei and S. silvaticum.
- ItemThe contribution of vacuolated foetal-type enterocytes in the process of maturation of the small intestine in piglets(Kielanowski Institute of Animal Physiology and Nutrition, 2018-08-27) Skrzypek, Tomasz; Szymańczyk, Sylwia; Ferenc, Karolina; Kazimierczak, Waldemar; Szczepaniak, Klaudiusz; Zabielski, RomualdIn neonates the vacuolated foetal-type enterocytes (VFE) play a key role in the transport of intact colostral and milk proteins from the lumen of the small intestine into the circulation and/or in the intracellular digestion of intestinal nutrients. The absorption of intact colostral macromolecules (including immunoglobulins, hormones and bioactive peptides) is important in the development of the immune and digestive systems of newborn piglets. The digestion of the intestinal content inside the VFE supports the luminal digestion of nutrients. The presence of apical canalicular system, which produces both the transport and the digestive vacuoles, is a key feature of VFE. The VFEs are gradually replaced by adult-type enterocytes. VFEs disappear gradually from the proximal part of the small intestine to the ileum. VFEs containing large (also referred to as giant) transport vacuoles disappear within the first 2–3 days after birth. VFEs containing digestive vacuoles are present for up to week 3 of life. In contrast, VFEs of intrauterine growth retarded piglets show abnormalities in their development of the apical area. The loss of VFEs is a good marker of the small intestine epithelium maturation.