Comparative assessment of toxic effects of surfactants using biotesting methods

This study assesses the comparative sensitivity and possibility of obtaining fast results of various methods of biotesting for several surfactants: Tween 85, sodium dodecyl sulfate (SDS), Fairy dishwashing gel, and Mif washing powder. The following test organisms are used for the study: luminescent bacteria Photobacterium phosphoreum (Beijerinck), preparation of Ecolum luminescent bacteria, unicellular algae Scenedesmus quadricauda (G.M. Smith), infusorian Paramecium caudatum (Ehrenberg), and crustacean Daphnia magna (Straus). It has been revealed that Fairy dishwashing gel possesses the strongest toxicity against the studied test objects. Daphnia and algae are most sensitive to the effects of Fairy and SDS, protozoan and luminescent bacteria are most sensitive to SDS, and Ecolum is most sensitive to Mif washing powder. The tested aquatic organisms and Ecolum are most tolerant to the effect of Tween 85.     

Phylogenetic relationships and evolution of pulmonate gastropods (Mollusca): new insights from increased taxon sampling

Phylogenetic relationships among higher clades of pulmonate gastropods are reconstructed based on a data set including one nuclear marker (complete ribosomal 18S) and two mitochondrial markers (partial ribosomal 16S and Cytochrome oxidase I) for a total of 96 species. Sequences for 66 of these species are new to science, with a special emphasis on sampling the Ellobiidae, Onchidiidae, and Veronicellidae. Important results include the monophyly of Systellommatophora (Onchidiidae and Veronicellidae) as well as the monophyly of Ellobiidae (including Trimusculus, Otina, and Smeagol). Relationships within Ellobiidae, Onchidiidae, and Veronicellidae are evaluated here for the first time using molecular data. Present results are compared with those from the recent literature, and the current knowledge of phylogenetic relationships among pulmonate gastropods is reviewed: despite many efforts, deep nodes are still uncertain. Identification uncertainties about early fossils of pulmonates are reviewed. Impacts of those phylogenetic and fossil record uncertainties on our understanding of the macro-evolutionary history of pulmonates, especially transitions between aquatic and terrestrial habitats, are discussed.     

Hepatitis E virus infection in Europe: regional situation regarding laboratory diagnosis and epidemiology

Hepatitis E virus (HEV) was first identified in the excreta of an experimentally infected human volunteer and further confirmed by similar findings in clinical specimens from patients with acute jaundice disease different from hepatitis A and B. The HEV is a 27- to 34-nm spherical non-enveloped virus obviously represented by a single serotype; however, its final taxonomic definition remains to be established. Studies on molecular biology of this virus revealed some peculiar characteristics showing no homologies in its nucleotide sequence to any entries in the Genbank database. The HEV infection was experimentally transmitted to non-human primates producing a disease in many features similar to that occurring in humans. Recently cell lines persistently infected with the HEV have also been obtained. These studies provided valuable virus-specific reagents which were used in diagnostic tests. Currently immune electron microscopy, fluorescent antibody technique, latex agglutination, cDNA hybridization, and Western blotting are employed to prove the etiological involvement of HEV in suspected hepatitis cases; serological tests with synthetic substances analogous to HEV antigens are expected to be available soon. Reliable diagnostic procedures can be carried out in a number of laboratories with the locally produced reagents. The HEV infection is common in many hot climate countries being responsible for more than 50% of jaundice cases among young adults. The European region is considered to be free of natural foci of this infection, however, several sporadic cases of HEV disease were reported to occur in Europeans who developed jaundice shortly after returning from endemic areas. It is suspected that in the Mediterranean countries (Italy and Spain) the cases of HEV infection could be causatively related to the consumption of shell-fish cultivated in sewage-polluted waters.     

Effects of Probiotic Lactobacillus acidophilus Strain INMIA 9602 Er 317/402 and Putative Probiotic Lactobacilli on DNA Damages in the Small Intestine of Wistar Rats In Vivo

Probiotics and Antimicrobial Proteins - Double-strand breaks in the DNA of the small intestine in male Wistar rats were studied using a neutral comet assay after 7 days of feeding with a...     

Combined enzymatic modification of stevioside and rebaudioside A

Cyclodextrin glucanotransferases (CGTases, EC 2.4.1.19) produced by mesophilic, thermophilic, alkaliphilic, and halophilic bacilli were used for transglycosylating stevioside and rebaudiosides A with the use of starch as a donor. CGTases produced by Bacillus stearothermophilus B-5076 B. Macerans BIO-4m were the most effective biocatalysts. This method can be used successfully for direct transglycosylation of stevia extract without purification of its individual components.     

Combined use of eBeam irradiation and the potential probiotic Lactobacillus rhamnosus Vahe for control of foodborne pathogen Klebsiella pneumoniae

The implementation of electron beam radiation coupled with the use of probiotics is one of the newest food processing technologies that may be used to ensure food safety and improve shelf life of food products. The purpose of this study was to evaluate the effect of 50–150-Gy electron beam irradiation on the antimicrobial activity of the putative probiotic strain Lactobacillus rhamnosus Vahe. Low-dose electron beam irradiation of lactobacilli cells was performed using the Advanced Research Electron Accelerator Laboratory’s electron accelerator, and the agar well diffusion method and Verhulst logistic function were used to evaluate the effect of radiation on anti–Klebsiella pneumoniae activity of the cell free supernatant of L. rhamnosus Vahe cells in vitro. Our results suggest that 50–150-Gy electron beam irradiation decreases the viability of the investigated lactobacilli, but does not significantly change the probiotic’s activity against K. pneumoniae. Results indicate that the combined use of irradiation and L. rhamnosus Vahe might be suggested for non-thermal food sterilizing technologies.     

Growth peculiarities of commensal Escherichia coli isolates from the gut microflora in Crohn’s disease patients

Verhulst’s logistic differential equation, popular in mathematical ecology, is used in modeling of population growth, neural networks, statistics, reaction models, Fermi distribution, modeling of tumor growth, etc. We used this function to characterize growth of commensal Escherichia coli isolates from gut microflora in Crohn’s disease patients. The results of our investigations show differences in growth parameters of commensal E. coli, isolated from the gut microflora in Crohn’s disease patients and healthy volunteers; it is most likely explained by the influence of chronic inflammatory processes on growth and reproduction of these bacteria. It has been established that the used mathematical model well characterizes growth of patients’ gut E. coli isolates, and it can be important for the expedient probiotics’ application during the disease.