Bacteriological contamination of egg products after thermal preservation processes

Research was carried out to define the hygienic propriety of thermally treated eggs, i.e. eggs treated at pasteurization temperatures and those stored frozen. The average values of the number of the bacteria in the pasteurized yolk and egg white were log 4.9 and 5.1, respectively, those in the frozen-pasteurized yolk and egg white were log 5.5 and 4.8 and in the frozen yolk and white were log 7.0 and 5.9. The contaminants Salmonella spp., Proteus spp., Staphylococcus aureus, Escherichia coli, Clostridium spp., Clostridium perfringens, Pseudomonas spp., Campylobacter jejuni and Yersinia enterocolitica were tested for 306 samples of pasteurized, frozen and pasteurized and frozen products of eggs, egg-yolks and egg-whites. Presence of Salmonella spp. in the pasteurized yolk was 12%, Clostridium spp. 16%, E. coli 16% and Proteus spp. 14%, but in the pasteurized egg white those bacteria were present in 10.8%, 15.3%, 13.8% and 10.0%. Staphylococcus aureus was isolated in yolk at 4.6 and in white 4.0% and Clostridium perfringens 4.0 and 1.5%, respectively. The bacteriological flora indicated that the degree of contamination of egg-products depends directly on the degree of initial contamination and correlates with the technological egg-treatment processes applied

Data publication with the structural biology data grid supports live analysis

Access to experimental X-ray diffraction image data is fundamental for validation and reproduction of macromolecular models and indispensable for development of structural biology processing methods. Here, we established a diffraction data publication and dissemination system, Structural Biology Data Grid (SBDG; data. sbgrid. org), to preserve primary experimental data sets that support scientific publications. Data sets are accessible to researchers through a community driven data grid, which facilitates global data access. Our analysis of a pilot collection of crystallographic data sets demonstrates that the information archived by SBDG is sufficient to reprocess data to statistics that meet or exceed the quality of the original published structures. SBDG has extended its services to the entire community and is used to develop support for other types of biomedical data sets. It is anticipated that access to the experimental data sets will enhance the paradigm shift in the community towards a much more dynamic body of continuously improving data analysis

Penton blooming, a conserved mechanism of genome delivery used by disparate microviruses

Microviruses are single-stranded DNA viruses infecting bacteria, characterized by T = 1 shells made of single jelly-roll capsid proteins. To understand how microviruses infect their host cells, we have isolated and studied an unusually large microvirus, Ebor. Ebor belongs to the proposed “Tainavirinae” subfamily of Microviridae and infects the model Alphaproteobacterium Rhodobacter capsulatus. Using cryogenic electron microscopy, we show that the enlarged capsid of Ebor is the result of an extended C-terminus of the major capsid protein. The extra packaging space accommodates genes encoding a lytic enzyme and putative methylase, both absent in microviruses with shorter genomes. The capsid is decorated with protrusions at its 3-fold axes, which we show to recognize lipopolysaccharides on the host surface. Cryogenic electron tomography shows that during infection, Ebor attaches to the host cell via five such protrusions. This attachment brings a single pentameric capsomer into close contact with the cell membrane, creating a special vertex through which the genome is ejected. Both subtomogram averaging and single particle analysis identified two intermediates of capsid opening, showing that the interacting penton opens from its center via the separation of individual capsomer subunits. Structural comparison with the model Bullavirinae phage phiX174 suggests that this genome delivery mechanism may be widely present across Microviridae

The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage

BackgroundWe describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing.ResultsOur phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented.ConclusionsOur comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders

Whole genome analysis of a schistosomiasis-transmitting freshwater snail

Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis

Corrigendum: Whole genome analysis of a schistosomiasis-transmitting freshwater snail

This corrects the article DOI: 10.1038/ncomms15451