Diversity of Entamoeba spp. in African great apes and humans: an insight from Illumina MiSeq high-throughput sequencing

Understanding the complex Entamoeba communities in the mammalian intestine has been, to date, complicated by the lack of a suitable approach for molecular detection of multiple variants co-occurring in mixed infections. Here, we report on the application of a high throughput sequencing approach based on partial 18S rDNA using the Illumina MiSeq platform. We describe, to our knowledge, for the first time, the Entamoeba communities in humans, free-ranging western lowland gorillas and central chimpanzees living in the Dja Faunal Reserve in Cameroon. We detected 36 Entamoeba haplotypes belonging to six haplotype clusters, containing haplotypes possessing high and low host specificity. Most of the detected haplotypes belonged to commensal Entamoeba, however, the pathogenic species (Entamoeba histolytica and Entamoeba nuttalli) were also detected. We observed that some Entamoeba haplotypes are shared between humans and other hosts, indicating their zoonotic potential. The findings are important not only for understanding the epidemiology of amoebiasis in humans in rural African localities, but also in the context of wild great ape conservation.     

Production and cleavage of a fusion protein of porcine trypsinogen and enhanced green fluorescent protein (EGFP) in <Emphasis Type="Italic">Pichia pastoris</Emphasis>

Pharmaceutical grade trypsin is in ever-increasing demand for medical and industrial applications. Improving the efficiency of existing biotechnological manufacturing processes is therefore paramount. When produced biotechnologically, trypsinogen—the inactive precursor of trypsin—is advantageous, since active trypsin would impair cell viability. To study factors affecting cell physiology and the production of trypsinogen in fed-batch cultures, we built a fusion protein of porcine trypsinogen and enhanced green fluorescent protein (EGFP) in Pichia pastoris. The experiments were performed with two different pH values (5.0 and 5.9) and two constant specific growth rates (0.02 and 0.04 1/h), maintained using exponential addition of methanol. All the productivity data presented rely on an active determination of trypsin obtained by proteolysis of the trypsinogen produced. The pH of the medium did not affect cell growth, but significantly influenced specific production of trypsinogen: A 1.7-fold higher concentration of trypsinogen was achieved at pH 5.9 (64 mg/L at 0.02 1/h) compared to pH 5.0. EGFP was primarily used to facilitate detection of intracellular protein over the biosynthetic time course. Using flow cytometry with fluorescence detection, cell disruption was avoided, and protein extraction and purification prior to analysis were unnecessary. However, Western blot and SDS-PAGE showed that cleavage of EGFP-trypsinogen fusion protein occurred, probably caused by Pichia-endogenous proteases. The fluorescence analysis did therefore not accurately represent the actual trypsinogen concentration. However, we gained new experimentally-relevant insights, which can be used to avoid misinterpretation of tracking and quantifying as well as online-monitoring of proteins with the frequently used fluorescent tags.     

Removal of PCBs by various white rot fungi in liquid cultures

The ability ofPhanerochœte chrysosporium, Trametes versicolor, Coriolopsis polyzona, andPleurotus ostreatus growing in a nitrogen-limited mineral medium (NMM) to degrade PCBs in a commercial, Delor 106 mixture at a concentration of 0.9 ppm was compared. The respective amounts of PCBs removed from the fungal cultures within 3 weeks were 25, 50, 41, and 0%. The capacities of the individual fungal species to remove PCBs correlated to some extent with their capabilities of decolorization of NMM agar containing both Poly R-478 or Remazol Brilliant Blue R dyes. Enzyme estimations indicated that both high and relatively stable activities of Mn-dependent peroxidase, Mn-independent peroxidase, lignin peroxidase, and laccase characterized efficient PCB degraders. The work was supported by a grant of theAcademy of Sciences of the Zech Republic no. A6301501 and a grant of theAgency of the Zech Republic no. 204/94/1190.     

Effects of Sewage Sludge Application on Biomass Production and Concentrations of Cd,Pb and Zn in Shoots of <Emphasis Type="Italic">Salix</Emphasis> and <Emphasis Type="Italic">Populus</Emphasis> Clones: Improvement of Phytoremediation Efficiency in Contaminated Soils

Fast-growing clones of Salix and Populus species have been studied for phytoremediation of soils contaminated by risk elements (REs) using short-rotation coppice plantations. Biomass yield, accumulation and removal of RE (Cd, Pb and Zn) by highly productive willow (S1—(Salix schwerinii × Salix viminalis) × S. viminalis, S2—Salix × smithiana) and poplar (P1—Populus maximowiczii × Populus nigra, P2—P. nigra) clones were investigated with and without sewage sludge (SS) application. The precise field experiment was established in April 2008 on moderately Cd-, Pb- and Zn-contaminated soil. Initially, shoots were harvested after four seasons in February 2012 and then after two more seasons in February 2014. The application of SS limited plant growth during the first years of the experiment in the majority of treatments, mainly due to weed competition and higher concentrations of available soil nutrients causing lower yields than those of control (C) treatments. Well-developed roots were able to take advantage of SS applications, and shoot yield was mainly higher in SS treatments in the second harvest, reaching up to 15 t dry matter (DM)?ha^?1. Willows performed better than poplars. Application of SS reduced RE shoot concentrations compared to the C treatment. The removal of RE was significantly higher in the second harvest for all clones and elements (except the P2 clone), and the biomass yield was the major driving force for the amount of RE removed by shoots. Well-developed plantations of fast-growing trees showed better suitability for the phytoextraction of moderately contaminated soils for Cd and partly for Zn but not for Pb, which was less available to plants. From the four tested clones, S2 showed the best removal of Cd (up to 0.94 %) and Zn (up to 0.34 %) of the total soil element content, respectively, and this clone is a good candidate for phytoextraction. SS can be a suitable source of nutrients for Salix clones without any threat to the food chain in terms of biomass contamination, but its application to the soil can result in an increased incidence of some weeds during the first years of plantation.     

The effect of maleic hydrazide and exogenous DNA on chromosomes ofVicia faba

The mitotic activity of merstematic cells ofVicia faba, the frequency of chromosomal abnormalities and their interchromosomal distribution are evaluated in dependence on the concentration of maleic hydrazide (MH) and on the recovery period. The influence of exogenous DNA of different genetic origin on the course of repair of primary root cells damaged by MH was also studied. Isologous DNA which exhibited a strong repair effect in authors' previous experiments was quite ineffective in the case of maleic hydrazide. Heterologous DNA, on the other hand, had to some extent a parallel effect with MH in breaking down the structural integrity of chromosomes and increased the frequency of aberrations induced by maleic hydrazide in meristematic cells ofVicia faba.     

The effect of length of incubation on adherence of group B streptococci to epithelial cells

Adhesion of group B streptococci to human epithelial vaginal and buccal cells proceeded in three phases which differed qualitatively. Maximum adhesion took place within 10 min of interaction, during the second phase (10–15 min), the percentage of adherent cells decreased significantly (P<0.05) whereas during the last phase the decrease became stabilized at a value which differed significantly from the maximum (P<0.01). The cause of variability in the number of positively reacting cells in relation to the exposure time is discussed.     

Immobilization of yeast cells on polyphenyleneoxide

Summary The potential of a polymeric product of 2, 6-dimethylphenol as a support for immobilized intact yeast cells was investigated. The procedure used is based on modification of the polymeric adsorbent by adsorption of glutaraldehyde, and the immobilization of cells is probably accomplished by their adsorption and covalent linkage.     

Ecological gradients on the contact of xerothermic grassland and woodland in the Bohemian karst

The gradients of floristic composition and environmental factors (temperature, soil moisture, pH, light intensity) were followed on three transects delimited in the contact zone between woodland and xerothermic grassland on the NW. slope of the Velká hora Hill in the Bohemian Karst. The densities of the more frequent plants and corresponding values of environmental factors are presented in graph form. Three different ecotopes, e.g. woodland, thermophilous grassland, contact between woodland and grassland, could be traced. The values of temperature, soil moisture, light intensity grouped according to the three ecotopes show significant differences in the respective mean. Furthemore, the association between species has been calculated and thechi-square matrix for the 11 most frequent species is given. On the basis of these calculations, a diagram of assumed relations between species was constructed. On the ground of data obtained, a significant regression of the density of thermophilous herbaceous plants on the temperature of the soil surface was found. The type of gradient on this experimental site is discussed and noticeable step-like, discontinuous character of both the floristic and environmental gradient is shown.     

A case of IgD plasmacytoma with unusual neurological symptoms]

A disease in an IgD (lambda) plasmocytoma is described, where after therapy with Alkeran and prednisone a disappearance of all clinical and laboratory findings indicating an activity could be observed. However, there was a progressive development of a picture of encephalomyelitic and polyradicular neuritic syndrome in the female patient with all signs of a recidivous temporary intracranial hypertension which could not be cured. The aetiology of these processes could only be found by the autopsy which revealed an isolated massive infiltration of the meninges and the sheaths of the spinal cord nerves with atypical plasma cells. No signs of the tumour could be identified in other organs. Such localization of the disease, as it is described here, is the first observation of its king. Problems of clinical diagnosis and treatment are discussed.