Worms' Antimicrobial Peptides.

Antimicrobial peptides (AMPs) are natural antibiotics produced by all living organisms. In metazoans, they act as host defense factors by eliminating microbial pathogens. But they also help to select the colonizing bacterial symbionts while coping with specific environmental challenges. Although many AMPs share common structural characteristics, for example having an overall size between 10-100 amino acids, a net positive charge, a γ-core motif, or a high content of cysteines, they greatly differ in coding sequences as a consequence of multiple parallel evolution in the face of pathogens. The majority of AMPs is specific of certain taxa or even typifying species. This is especially the case of annelids (ringed worms). Even in regions with extreme environmental conditions (polar, hydrothermal, abyssal, polluted, etc.), worms have colonized all habitats on Earth and dominated in biomass most of them while co-occurring with a large number and variety of bacteria. This review surveys the different structures and functions of AMPs that have been so far encountered in annelids and nematodes. It highlights the wide diversity of AMP primary structures and their originality that presumably mimics the highly diverse life styles and ecology of worms. From the unique system that represents marine annelids, we have studied the effect of abiotic pressures on the selection of AMPs and demonstrated the promising sources of antibiotics that they could constitute.

Effects of postovipositional hypoxia and hyperoxia on leatherback turtle reproductive success and hatchling performance.

Leatherback egg clutches typically experience lower hatching success (~50%) than those of other sea turtle species (>70%). The majority of embryonic death (>50%) occurs at early stages of development, possibly because embryos fail to break preovipositional embryonic arrest after oviposition. The embryonic arrest is maintained by hypoxia in the oviduct and following oviposition increased availability of oxygen is the trigger that breaks arrest in all turtle species studied to date. We conducted an ex situ incubator experiment and an in situ hatchery experiment to examine the influence of oxygen availability on hatching success and hatchling traits in leatherbacks. After oviposition, eggs (n = 1005) were incubated in either normoxia (21% O2 ), hyperoxia (32%-42% O2 ) for 5 days, or hypoxia (1% O2 ) for 3 or 5 days. As with other turtles, hypoxic incubation maintained embryos in arrest, equivalent to the time spent in hypoxia. However, extending arrest for 5 days resulted in greater early-stage death and a significant decrease in hatching success (4% 5-day hypoxia vs. 72% normoxia). Eggs placed in incubators had greater hatching success than those placed into hatchery nests (67% vs. 47%, respectively). We found no impact of hyperoxia on the stage of embryonic death, hatching success, hatchling phenotype, exercise performance, or early dispersal. Our findings indicate that delayed nesting and the subsequent extension of embryonic arrest may negatively impact embryonic development and therefore the reproductive success of leatherbacks. They also indicate that incubation under hyperoxic conditions is unlikely to be a useful method to improve hatching success in this species.

The diversification of the antimicrobial peptides from marine worms is driven by environmental conditions.

Antimicrobial peptides (AMPs) play a key role in the external immunity of animals, offering an interesting model for studying the influence of the environment on the diversification and evolution of immune effectors. Alvinellacin (ALV), arenicin (ARE) and polaricin (POL, a novel AMP identified here), characterized from three marine worms inhabiting contrasted habitats ('hot' vents, temperate and polar respectively), possess a well conserved BRICHOS domain in their precursor molecule despite a profound amino acid and structural diversification of the C-terminal part containing the core peptide. Data not only showed that ARE, ALV and POL display an optimal bactericidal activity against the bacteria typical of the habitat where each worm species lives but also that this killing efficacy is optimal under the thermochemical conditions encountered by their producers in their environment. Moreover, the correlation between species habitat and the cysteine contents of POL, ARE and ALV led us to investigate the importance of disulfide bridges in their biological efficacy as a function of abiotic pressures (pH and temperature). The construction of variants using non-proteinogenic residues instead of cysteines (α-aminobutyric acid variants) leading to AMPs devoid of disulfide bridges, provided evidence that the disulfide pattern of the three AMPs allows for a better bactericidal activity and suggests an adaptive way to sustain the fluctuations of the worm's environment. This work shows that the external immune effectors exemplified here by BRICHOS AMPs are evolving under strong diversifying environmental pressures to be structurally shaped and more efficient/specific under the ecological niche of their producer.

The width of riparian habitats for understory birds in an Amazonian forest.

Riparian habitats are important for the maintenance of regional biodiversity. Many studies have compared bird distributions between riparian and non-riparian habitats but have not established how wide riparian habitats used by birds are, as measured by distance from the nearest stream. We investigated the distribution of understory birds along gradients of distance from streams, soil clay content, and slope in a central Amazonian forest, by mist-netting birds three times in 45 plots. We used nonmetric multidimensional scaling (NMDS) to reduce the dimensionality of species quantitative (abundance) and qualitative (presence-absence) composition to one multivariate axis. Estimates of the width of riparian habitats as indicated by understory birds depended on the community attribute considered, measuring 90 m for species quantitative composition and 140 m for species qualitative composition. Species distributions were correlated with clay content but were independent of slope, while distance from streams was positively correlated with clay content but independent of slope. Clay content affects plant species composition, which in turn, may influence bird species composition. However, distribution patterns of birds in relation to distance from streams are consistent among studies carried out in many different temperate and tropical regions, indicating an effect of distance from streams itself. Protection of riparian habitats is one of the most widely used conservation strategies, and Brazilian environmental legislation mandates the protection of a 30 m wide strip of riparian vegetation on either side of small streams. We show that the protected strip should be much wider and recommend strategies to place other forms of land protection contiguous with riparian areas so that Brazilian environmental legislation better fulfills its role of protecting biodiversity associated with riparian habitats.

Translation, cross-cultural adaptation, and validation of the Munro Scale in Italian.

BACKGROUND: The Munro Pressure Ulcer Risk Assessment Scale for Perioperative Patients - Adult (Munro scale) is a pressure ulcer/injury risk assessment scale for adult surgical patients. It consists of 3 sections relating to the preoperative, intraoperative, and postoperative periods. It is not available in Italian. PURPOSE: The aim of this study was to translate the Munro scale into Italian and assess its cross-cultural content and face validity. METHODS: The translation and cross-cultural adaptation process adhered to World Health Organization guidelines including forward translation, expert review, and back translation. Health care professionals with a minimum of 5 years of experience working in the operating rooms of different hospitals in northern Italy were invited to participate in a content and face validation of the translated instrument. Content validity was evaluated by rating the relevance of each scale item using a 4-point Likert scale, ranging from 1 (not relevant) to 4 (very relevant). Face validity (comprehensibility and clarity) was also measured using a 4-point rating scale. RESULTS: Expert agreement of the translated instrument reached a Fleiss' kappa of 0.95. The content validity index was 0.91, and all items had a score ≥ 3 for clarity and comprehensibility. CONCLUSION: The Italian version of the Munro scale can be used safely to assess patient risk of injuries during the perioperative period in Italy. The translation and validation study results confirmed that the Italian version was consistent with the original version. Further testing, including prospective validation, is needed.

Biomarkers of reproduction in endangered green sea turtles (Chelonia mydas) nesting at Tortuguero, Costa Rica.

Understanding the timing of vitellogenesis is essential for identifying threats to the reproductive success of endangered oviparous vertebrate species, such as sea turtles. We measured concentrations of testosterone (T) and vitellogenin (VTG) in green sea turtles (Chelonia mydas) nesting at Tortuguero, Costa Rica, as biomarkers of ovarian development. Testosterone concentration increased from the first to second month and VTG concentration increased at the third week of sampling. These results show that Tortuguero green sea turtles were still producing both biomarkers early into the nesting season. VTG concentration was negatively correlated with female weight, suggesting that larger females start nesting earlier at Tortuguero and that we may have sampled larger females further into their reproductive cycle.

Investigation of Capitella spp. symbionts in the context of varying anthropic pressures: First occurrence of a transient advantageous epibiosis with the giant bacteria Thiomargarita sp. to survive seasonal increases of sulfides in sediments.

Capitella spp. is considered as an important ecological indicator of eutrophication due to its high densities in organic-rich, reduced, and sometimes polluted coastal ecosystems. We investigated whether such ability to cope with adverse ecological contexts might be a response to the microorganisms these worms are associated with. In populations from the French Atlantic coast (Roscoff, Brittany), we observed an epibiotic association covering the tegument of 20-30% specimens from an anthropized site while individuals from a reference, non-anthropized site were devoid of any visible epibionts. Using RNAseq, molecular and microscopic analyses, we described and compared the microbial communities associated with the epibiotic versus the non-epibiotic specimens at both locations. Interestingly, data showed that the epibiosis is characterized by sulfur-oxidizing bacteria among which the giant bacterium Thiomargarita sp., to date only described in deep sea habitats. Survey of Capitella combined with the geochemical analysis of their sediment revealed that epibiotic specimens are always found in muds with the highest concentration of sulfides, mostly during the summer. Concomitantly, tolerance tests demonstrated that the acquisition of epibionts increased survival against toxic level of sulfides. Overall, the present data highlight for the first time a peculiar plastic adaptation to seasonal variations of the habitat based on a transcient epibiosis allowing a coastal species to survive temporary harsher conditions.

Changes in haptoglobin, C-reactive protein and pig-MAP during a housing period following long distance transport in swine.

The aim of this study was to investigate the effects of a housing period following long distance transport on haptoglobin (Hp), C-reactive protein (CRP) and pig major acute phase protein (pig-MAP) in swine. After transportation, 80 gilts were allotted to group A, B, C, or D. Blood samples were collected on arrival and 28 days later; additional samples were collected from Group C on day 14, and from Group D on days 3, 5 and 14. Acute phase proteins (APPs) in Group A were significantly lower on day 28 than on day 1; the opposite occurred in Group B because of a tail biting episode. In Group C, values remained elevated on day 14 and showed a reduction on day 28; in Group D elevated levels detected on day 14 were preceded by a decrease from days 1 to 5. The results indicate that stressors associated with transportation and new accommodation can cause an increase in APPs that could be useful indicators of welfare during transport and routine management.

A combination of behavioral and physiological indicators for assessing pig welfare on the farm.

The purpose of this research was to identify pig welfare indicators that could help in recognizing stressful practices on farm. The study evaluated behavioral and physiological indicators (cortisol and negative acute phase proteins) in 2 groups of 20 female pigs 4 months old after a 48-hr transport. The first group (A) was transported at the end of May, the second (B) in June. Behavioral observations and blood collection occurred at arrival (D1) and 28 days later (D28). Compared with within-animal control samples obtained 28 days later, pigs of Group A had increased cortisol levels and decreased albumin concentrations after arrival. As demonstrated by lesion and behavior observations, the effect on cortisol and albumin was higher in Group B pigs after a tail-biting episode occurred. The study has reported no evidence of Retinol Binding Protein (RBP) in pigs. A method developed for swine RBP quantification found RBP strongly reduced in D28 samples of Group B, confirming it to be a negative protein in pigs. The suggested combination of physiological and behavioral indicators could provide useful information on the welfare state of an animal.

Enhanced expression of interferon-gamma-induced antigen-processing machinery components in a spontaneously occurring cancer.

In human tumors, changes in the surface expression and/or function of major histocompatibility complex (MHC) class I antigens are frequently found and may provide malignant cells with a mechanism to escape control of the immune system. This altered human lymphocyte antigen (HLA) class I phenotype can be caused by either structural alterations or dysregulation of genes encoding subunits of HLA class I antigens and/or components of the MHC class I antigen-processing machinery (APM). Herein we analyze the expression of several proteins involved in the generation of MHC class I epitopes in feline injection site sarcoma, a spontaneously occurring tumor in cats that is an informative model for the study of tumor biology in other species, including humans. Eighteen surgically removed primary fibrosarcoma lesions were analyzed, and an enhanced expression of two catalytic subunits of immunoproteasomes, PA28 and leucine aminopeptidase, was found in tumors compared to matched normal tissues. As a functional counterpart of these changes in protein levels, proteasomal activities were increased in tissue extracts from fibrosarcomas. Taken together, these results suggest that alterations in the APM system may account for reduced processing of selected tumor antigens and may potentially provide neoplastic fibroblasts with a mechanism for escape from T-cell recognition and destruction.