Shell Disease Syndrome Is Associated with Reduced and Shifted Epibacterial Diversity on the Carapace of the Crustacean Cancer pagurus.

Cancer pagurus is highly susceptible to shell disease syndrome. However, little is known about concomitant changes in the epibacterial community. We compared the bacterial communities of black spot affected and nonaffected areas of the carapace by amplicon sequencing of 16S rRNA genes and 16S rRNA. Within each spot, bacterial communities of affected areas were less diverse compared to communities from nonaffected areas. Communities of different affected spots were, however, more divergent from each other, compared to those of different nonaffected areas. This indicates a reduced and shifted microbial community composition caused by the black spot disease. Different communities found in black spots likely indicate different stages of the disease. In affected areas, Flavobacteriaceae rose to one of the most abundant and active families due to the increase of Aquimarina spp., suggesting a significant role in shell disease syndrome. We isolated 75 bacterial strains from diseased and healthy areas, which are primarily affiliated with Proteobacteria and Bacteroidetes, reflecting the dominant phyla detected by amplicon sequencing. The ability to degrade chitin was mainly found for Gammaproteobacteria and Aquimarina spp. within the Flavobacteriia, while the ability to use N-acetylglucosamine, the monomer of the polysaccharide chitin, was observed for most isolates, including many Alphaproteobacteria. One-third of the isolates, including most Aquimarina spp., showed antagonistic properties, indicating a high potential for interactions between the bacterial populations. The combination of bacterial community analysis and the physiological properties of the isolates provided insights into a functional complex epibacterial community on the carapace of C. pagurus. IMPORTANCE In recent years, shell disease syndrome has been detected for several ecologically and economically important crustacean species. Large proportions of populations are affected, e.g., >60% of the widely distributed species Cancer pagurus in different North Sea areas. Bacteria play a significant role in the development of different forms of shell disease, all characterized by microbial chitinolytic degradation of the outer shell. By comparing the bacterial communities of healthy and diseased areas of the shell of C. pagurus, we demonstrated that the disease causes a reduced bacterial diversity within affected areas, a phenomenon co-occurring also with many other diseases. Furthermore, the community composition dramatically changed with some taxa rising to high relative abundances and showing increased activity, indicating strong participation in shell disease. Characterization of bacterial isolates obtained from affected and nonaffected spots provided deeper insights into their physiological properties and thus the possible role within the microbiome.

Olfactory imprinting is triggered by MHC peptide ligands.

Olfactory imprinting on environmental, population- and kin-specific cues is a specific form of life-long memory promoting homing of salmon to their natal rivers and the return of coral reef fish to natal sites. Despite its ecological significance, natural chemicals for olfactory imprinting have not been identified yet. Here, we show that MHC peptides function as chemical signals for olfactory imprinting in zebrafish. We found that MHC peptides consisting of nine amino acids elicit olfactory imprinting and subsequent kin recognition depending on the MHC genotype of the fish. In vivo calcium imaging shows that some olfactory bulb neurons are highly sensitive to MHC peptides with a detection threshold at 1 pM or lower, indicating that MHC peptides are potent olfactory stimuli. Responses to MHC peptides overlapped spatially with responses to kin odour but not food odour, consistent with the hypothesis that MHC peptides are natural signals for olfactory imprinting.

[Screening for distress in women with breast cancer diagnosed for the first time: employment of HADS-D and PO-Bado]. / Screening von psychischen Belastungen bei erst erkrankten Brustkrebspatientinnen: Einsatz von HADS-D und PO-Bado.

OBJECTIVES: In the context of an intensification of efforts to ensure sufficient psychooncological care for breast-cancer patients, the discussion concerning valid psychometric screening instruments gains a special relevance. METHODS: The discriminant and diagnostic validity of HADS-D and PO-Bado were investigated in a sample of 123 women with breast cancer diagnosed for the first time. RESULTS: An ROC analysis revealed a cut-off score of greater than 9 for the subscale anxiety (sensitivity: 50%; specificity: 90%) for the use of HADS-D among breast cancer patients, whereas the recommended cut-off value was greater than 7 (sensitivity: 56%; specificity: 80%) for the subscale depression. Based on the anxiety and depression scores measured by HADS-D, 74% of the clinical cases could be classified correctly. Scores for physical and mental distress measured with PO-Bado were significantly lower in the investigated sample than in the control sample. CONCLUSIONS: HADS-D has only a moderate sensitivity for the group at hand. PO-Bado is a comprehensive basic documentation for specific psychooncological distress, though without cut-off values it is not useful as a screening instrument.