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In the few past decades, genetic approaches for analysis of soil microbiome, e.g pyrosequencing, gained major attention and cultivation techniques were pushed into the background. The combination of several techniques could be useful and cheap approach for analysis of changes in soil microbiome. In our study of effect of silver nanoparticles on soil microbiome we exploited classical microbiological and biochemical methods for assessment of microbial structure. Effect caused by addition of silver nanoparticles was concentration dependent, the highest concentration of silver nanoparticles caused, besides the others, significant decrease in dehydrogenase activity of soil microorganisms. Concentration dependent changes in soil microbiome were also detected, e.g. in total numbers of cultivable microorganisms, cellulolytic or peroxidase. CLPP indicated significant shift in microbial diversity in all levels of substrate utilization.

Majority of terrestrial soils are used primarily for agricultural production. The main factor of soil fertility is mediated by soil microorganisms and invertebrates. Soil microorganisms plays crutial role in ecosystems nutrient cycling and therefore any change in their diversity could have serious consequences on soil fertility and agricultural yields. Silver nanoparticles as novel potentialy nontoxic compounds are nowadays used in many daily use products and also as pesticides. But based on their antimicrobial activity, they can adversely influence structure of soil microbiome. Our work is focused on qPCR analysis of soil microbiome diversity with and without silver nanoparticles treatment. Phylogenetic analysis revealed concentration dependent shifts in microbial diversity, usually in the favor of one phylogenetic group of bacteria or fungi and analysis of melting curves showed changes inside individual phylogenetic groups.

Silver and silver nanoparticles (AgNPs) are extensively used as antimicrobial agents in various products and consequently enter the soil ecosystem, in which they accumulate and can have adverse effects on above and belowground organisms. Since the composition of the soil microbiome could have a significant impact on soil fertility, we focused, in this study, on the effect of AgNPs on soil microbial communities. We evaluated the biomass, plant growth-promoting activities, and microbial genetic (taxonomical) and functional diversity in the soil and the “soil-plant” system using chemical, microbiological, and molecular biological methods, especially qPCR, RFLP, and REP-PCR. By compiling the results of the applied assays, we were able to correlate the changes in genetic diversity with the changes in functional diversity and their impact on the composition of soil organic matter. The effect of AgNPs was predominantly dose-dependent, whereas the concentration 100 mg kgdw−1 had the highest effect on all followed parameters. From the taxonomical point of view, AgNPs had the most significant impact on the relative abundance of Bacteroidetes, which increased in a dose-dependent manner, and Firmicutes, which decreased in a dose-dependent manner, and they caused the predominance of Ascomycota among Fungi. These changes in taxonomic diversity result in a significant decrease in the functional diversity of the microbial communities. Especially for the concentration 100 mg kgdw−1, we detected a significant decrease in the ability of the microbial community to utilize simple carbon substrates, determined by Biolog EcoPlates. We detected also a significant alteration in enzyme activity. The activity of enzymes responsible for depolymerization of complex organic matter was in a dose-dependent manner increased, whereas the highest activity reach samples amended with AgNPs at 100 mg kgdw−1. All these changes result in the accumulation of simple organic matter, which could increase osmotic pressure and have severe consequences on soil fertility. In amended soils, we detected alterations of activity of plant growth-promoting bacteria, specifically in the production of indole-3-acetic acid, 1-aminocyclopropane-1-carboxylic acid deaminase, and siderophores. All these activities are related to mitigating abiotic stress. The presence of plants in experimental soil had both a mitigating and deepening effect on the toxicity of AgNPs. Both effects probably relate to the influence of AgNPs on the selection of different microbial communities in the soil and the “soil-plant” system.

A case report of the pregnancy complicated by the presence of vein of Galen aneurysmal malformation in fetus.The case report.Department of Obstetrics and Gynaecology, Masaryks Hospital, Jilemnice; Obstetrics and Gynecology Clinic, University Hospital in Hradec Králové.The description of the pregnancy complicated by the presence of vein of Galen aneurysmal malformation in a fetus 32 weeks gestation which led to a progressive heart failure and the development of the hydrocephalus.The vein of Galen aneurysmal malformation is a rare cerebrovascular malformation of the fetus, the diagnosis of this malformation is usually detectable during prenatal ultrasound examination possibly also by magnetic resonance imaging.

Reinvestigation of vitellogenesis in the caryophyllidean cestode Caryophyllaeus laticeps (Pallas, 1781) has been performed using light microscope (LM) and transmission electron microscopy (TEM), and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for glycogen. Vitellogenesis is generally similar to that reported in the past, however, some new observations were made. The present study reveals the first evidence of: (i) interstitial tissue in the vitelline follicles, (ii) lipid droplets in maturing and mature vitellocytes from vitelline follicles, and (iii) lamellar bodies in vitellocytes from the vitelloduct in C. laticeps. Projections of interstitial tissue surround each vitellocyte and the follicle periphery. The perinuclear cytoplasm of the interstitial tissue contains granular endoplasmic reticulum and vesicles of various size and density. Cytoplasmic osmiophobic lipid droplets and lamellar bodies, previously believed to be absent in most caryophyllid cestodes, are readily apparent in vitellocytes of C. laticeps. The origin and presumed function of these inclusions are discussed. On the other hand, the formation and storage of massive amounts of glycogen in the nucleus and large amounts in the cytoplasm of mature vitelline cells are similar to the condition found in other caryophyllids. Results are compared and contrasted with previous studies on vitellogenesis in other monopleuroid cestodes (Amphilinidea and Gyrocotylidea) as well as polypleuroid cestodes (Spathebothriidea) and the remaining strobilated Eucestoda.

The vitellarium of the invasive caryophyllidean tapeworm Khawia sinensis Hsu, 1935 from carp Cyprinus carpio L. was examined by means of transmission electron microscopy and cytochemical staining for glycogen with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP). A vitellarium consists of numerous follicles of irregular size that are interconnected by a net of vitelline ducts. Vitelline follicles are composed of vitelline cells at various stages of development that are interconnected by interstitial tissue. Vitelline follicles are surrounded by a cytoplasmic sheath associated with an intercellular matrix. Extensive development of the granular endoplasmic reticulum and Golgi complexes are both involved in the production of shell globules/shell globule clusters and characterise cytodifferentiation of vitellocytes. Nuclear and nucleolar transformation lead to the formation and storage of intranuclear glycogen, a feature specific for the Caryophyllidea. Newly observed within the mature vitellocytes of Khawia sp. is the presence of lamellar bodies and a few lipid droplets. These cytoplasmic inclusions first occur in the mature cells within the follicles and persist in the vitelline cells within vitelloducts and intrauterine eggs. Two types of lamellar bodies are detected: regular lamellar-structured body and irregular lamellar-structured body. None of the lamellar bodies are membrane bound. Results of the present study indicate that the formation of lamellar bodies may be closely related to the endoplasmic reticulum or shell globule clusters. Some of the shell globule clusters are transformed into lamellar body clusters. Ultrastructural features of vitellocytes in K. sinensis are compared with those of other monopleuroid, polypleuroid, and strobilated cestodes.

SUMMARYA strain of Bacillus larvae which formed orange pigmented colonies was isolated and described from regions in the Czech and Slovak Republics. Analysis of fatty acids by gas chromatography revealed no differences between isolates of pigment-forming (pigmenting) and standard (without any ability to form pigment) B. larvae. A close relationship with B. pulvifaciens and substantial differences from B. alvei and B. laterosporus were found. Phage sensitivity, plasmid DNA presence and spore morphology supported the conclusion that the two types of B. larvae should be considered as one species.

Vitellogenesis in two caryophyllidean cestodes Caryophyllaeus laticeps and Khawia sinensis, parasitizing cyprinid fishes, were examined using light(LM)and transmission electron microscopy(TEM)and cytochemical staining for glycogen. Mature vitelline folicles consist of vitelline cells at various stages of development and an interstitial tissue. Maturing and mature vitellocytes contain vitelline material in the form of single small shell globules, which fuse and give rise to the large shell globule clusters.Glycogen was present in the cytoplasm and in the nucleus of the mature vitellocytes. Small lipid droplets were found in the cytoplasm of C. laticeps. "Lamellar granules" were observed in the cytoplasm of the mature vitellocytes in K. sinensis.

Vitellogenesis in the parthenogenetic caryophyllidean tapeworm Atractolytocestus huronensis Anthony, 1958, parasitizing the carp Cyprinus carpio L., has been examined using light (LM) and transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. It was found that formation of vitellocytes shares the same basic patterns in lower tapeworms with parthenogenetic and normal reproduction. Each vitelline follicle of A. huronensis consists of vitellocytes at various stages of development and an interstitial tissue. Projections of the interstitial tissue surround each vitellocyte and extend as a cytoplasmic sheath on the follicular periphery. In contrary to other Eucestoda, interstitial tissue of A. huronensis includes numerous electron-dense vesicles of various sizes. Maturing and mature vitellocytes contain vitelline material in the form of single small shell globules, which may gradually fuse and give rise to the large shell globule clusters. Shell globule clusters are of two types in A. huronensis. Additional vitelline material is represented by single "lamellar" granules and glycogen in the cytoplasm of mature vitellocytes. The ultrastructural features of vitellogenesis and/or vitellocyte in A. huronensis are compared with that in other caryophyllideans and/or Neodermata.

Vitellogenesis in caryophyllidean cestode Atractolytocestus huronensis, parasitizing cyprinid fish Cyprinus carpio was examined using light (LM) and transmission electron microscopy (TEM). Vitelline folicules contain vitelline cells at various stages of development: immature, maturing and mature cells. Maturing and mature vitellocytes contain vitelline material in the form of single small shell globules that gradually fuse and give rise to the large shell globule clusters. Glycogen is present in the cytoplasm and in the nucleus of the mature vitellocytes.

SummaryTwelve Bacillus larvae strains were searched for the presence of extrachromosomal DNA by agarose gel electrophoretic methods. Small plasmid molecules of a uniform size were detected in three of them. The molecular mass was determined at 5·72 ± SD 0·25 Mdal by electron microscopy. The bacterial cells harbouring plasmid molecules were then tested for resistance to sulphonamides, antibiotics, mercury chloride and cadmium nitrate. No specific resistance or any other function connected with the presence of the plasmid molecules in B. larvae strains was found. The plasmid DNA, however, has a high stability in B. larvae cells, because the DNA isolates did not change their electrophoretic pattern during a 2-year cultivation of the cells on solid nutrient agar. The plasmid was denoted pBL423 according to the B. larvae strain in which it was first detected.

SummaryWorker honeybees in cages, fed on honey and pollen treated with ethylene oxide at 900 g/m3 without subsequent ventilation, did not show a higher mortality than controls. Mice fed on honey similarly treated showed neither pathological alterations in liver and kidneys, nor higher mortality, than controls. On the other hand, the addition of ethylene glycol to honey, at a concentration as low as 1·25% by weight, had a toxic action in bees, and in mice a concentration of 0·78% caused toxic damage to the liver (steatosis). The effectiveness of the ethylene oxide treatment on vegetative forms and spores of Bacillus larvae (except in dry scales), and on other micro-organisms, was confirmed.

Summary Oxidation of cytosine and uracil was studied and the number of bacteria capable of utilizing these substrates as a single source of electrons and nitrogen was estimated. Four cultivated and two virgin soils were compared. The Warburg technique was used for measurement of oxygen consumption and the decrease of substrate concentration was determined by chromatography and spectrophotometry. Both substrates were oxidized to a greater extent in the cultivated soils. A correlation was found between the oxidation of substrates and the number of specific bacteria. Added substrates could not be detected in these soils after one mole of oxygen had been used per mole of substrate.

SummaryThe bacteriophage of Bacillus larvae was isolated in Czechoslovakia for the first time. Most strains of B. larvae were found to contain a temperate non-virulent phage which could be detected by a cross-test. This bacteriophage is polyvalent and may become virulent, forming plaques with various strains of B. larvae. The morphology and ultrastructure of the phage are described for the first time. This bacteriophage of B. larvae has been designated BLA.

(1) The method of the enzymatic hydrolysing of organic phosphorus compounds in soil was used, on the basis of determination of the release of inorganic phosphate after extraction by Truog's solution. (2) Glycerophosphate was hydrolysed much more intensively than nucleic acid. Both substrates were hydrolysed very well by sandy-loam soils (C and K), but relatively poorly by loam field soil (U) and forest soil (D). (3) The optimal temperature for glycerophosphatase activity was 55°C, except in soil K, while the optimal temperature for nuclease activity was about 42°C. (4) The percentual decomposition of both substrates was greatest up to a 500 μM substrate concentration. (5) Glycerophosphatase and nuclease activity increased up to the fifteenth hour of incubation. (6) In all soils hydrolysis of glycerophosphate and nucleic acid was highest at a neutral or mildly alkaline pH, with the exception of soil U, in which activity continued to rise with the pH. (7) Maximum sorption of phosphorus was found in humus-carbonate soil K. The test soils differed mainly in relation to the time course of sorption. The author therefore considers it important to correct every determination of phosphatases based on the release of phosphorus by the results of phosphorus sorption.

The authoress studied the growth of Bacillus larvae on different nutrient media and its ability of decomposing hydrogen peroxide and reducing nitrates. There are also instructions for rapid cultivation and biochemical diagnosis of Bacillus larvae. It can be performed in any microbiological laboratory, the culture medium can be prepared from available commercially produced preparations, and B. larvae can be detected in suspected material even out of the season, if the method of selective cultivation and repeated pasteurizing is used. Catalase test is proposed to be added to the examination; the result of this test was negative in all 96 strains studied. Photographic documentation of different developmental stages of B. larvae can serve as an aid in microbiological examination.

New bacteriophage (BL2) was isolated from plaques ofBacillus larvae cultures. Its morphology is distinct from the earlier bacteriophage BLA.