HPV16 Genomes: In Silico Analysis of E6 and E7 Oncoproteins in 20 South American Variants.

Background: Human papillomavirus (HPV) is the main risk factor for the development of squamous cell cervical cancer, and E6 oncoprotein and E7 oncoprotein are important components of the viral genome and its oncogenic potential. It is known that different viral variants of HPV16 have different pathology and impact on the development of neoplasia, although few studies have been performed on South American variants. Objective: Therefore, the present study aimed to analyze in silico the genomic diversity of HPV16 in 20 complete genome variants of South America in the National Center for Biotechnology Information (NCBI) database. Methods: We performed a descriptive study to characterize the polymorphic regions of the E6 and E7 genes in HPV16 variants, using software for genomic data and single nucleotide polymorphism (SNP) analysis and others for phylogenetic analysis. Results: The variants analyzed included six SNPs linked to cancer (A131G, G145T, C335T, T350G, C712A, and T732C) and significant variation (798 nucleotide substitutions). Despite this, the variants showed low genetic diversity. Eighteen variants of unclear significance (VUS) were identified, 10 of which were in the coding E6 regions and 8 in the coding E7 regions. The prevalence of lineage D variants is of concern due to their pathology in cervical cancer and requires more research and epidemiological vigilance regarding their prevalence in the population. Conclusion: The data obtained in this study may contribute to future research on South American variants of HPV16, their pathogenicity, and the development of treatments.

Two independent and primitive envelopes of the bilobate nucleus of comet 67P.

The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary and primordial processes. The peculiar bilobed shape of comet 67P/Churyumov-Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the interface between the two lobes. Here we report that the comet's major lobe is enveloped by a nearly continuous set of strata, up to 650 metres thick, which are independent of an analogous stratified envelope on the minor lobe. Gravity vectors computed for the two lobes separately are closer to perpendicular to the strata than those calculated for the entire nucleus and adjacent to the neck separating the two lobes. Therefore comet 67P/Churyumov-Gerasimenko is an accreted body of two distinct objects with 'onion-like' stratification, which formed before they merged. We conclude that gentle, low-velocity collisions occurred between two fully formed kilometre-sized cometesimals in the early stages of the Solar System. The notable structural similarities between the two lobes of comet 67P/Churyumov-Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.

Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

Human-Wildlife Interaction-A Social Survey.

With the results of a survey presented in this paper, we provide insight into public attitudes towards dealing with wildlife. Based on 1569 data sets derived from participating stakeholders, we inquired about the individual experience the participants had made with wild animals, and asked about their personal engagement, attitude towards management, and emotions involved and tried to evaluate basic contextual knowledge. As a result, we discovered a positive effect showing that a strong opinion about dealing with wildlife is associated with increasing contextual knowledge. People that are experienced in and engaged in wildlife conservation expressed significantly stronger positive emotions in this context. We conclude that education is essential in dealing with wildlife responsibly and that positive emotions are a main trigger for such engagement. The results of the survey underline that a combination of contextual knowledge and a positive attitude towards wildlife leads to a higher awareness of possible conflicts between humans and wildlife. Furthermore, these criteria are crucial when developing strategies that strive for a sustainable coexistence.

Validation of Fecal Glucocorticoid Metabolites as Non-Invasive Markers for Monitoring Stress in Common Buzzards (Buteo buteo).

For wild animals, being in captivity in wildlife centers can cause considerable stress. Therefore, it is necessary to establish and validate non-invasive tools to measure chronic stress during rehabilitation. Eight Common Buzzards which lived in permanent husbandry were placed individually into prepared aviaries and their feces were collected before, during and after a stress event for biological validation over a period of seven days. The extracted fecal glucocorticoid metabolites (fGCMs) were analyzed with three different enzyme immune assays (EIA) to find the most suitable one. Additionally, we aimed to investigate the stability of fGCM levels after defecation because further metabolization by bacterial enzymes can lead to changed results. The Cortisone-EIA performed best in males and females and showed that the stress event led to an fGCM increase of 629% (557% in females and 702% in males) in relation to basal values. We found no significant differences between the sexes, but observed significant differences between different times of day. FGCM concentration significantly changed after eight hours at room temperature. Our study successfully validated the non-invasive measurement of fGCM as a stress indicator in Common Buzzards and could therefore lay the foundation for future studies providing new insights for animal welfare research in Buzzards.

Exploring the biological activities and potential therapeutic applications of agro-industrial waste products through non-clinical studies: A systematic review.

The latent potential of active ingredients derived from agro-industrial waste remains largely untapped and offers a wealth of unexplored resources. While these types of materials have applications in various fields, their ability to benefit human health needs to be further explored and investigated. This systematic review was conducted to systematically evaluate non-clinical studies that have investigated the biological effects of fractions, extracts and bioactive compounds from agro-industrial wastes and their potential therapeutic applications. Articles were selected via PubMed, Embase and Medline using the descriptors (by-products[title/abstract]) AND (agro-industrial[title/abstract]). The systematic review was registered in the International Prospective Register of Systematic Reviews (Prospero) under the number CRD42024491021. After a detailed analysis based on inclusion and exclusion criteria, a total of 38 articles were used for data extraction and discussion of the results. Information was found from in vitro and in vivo experiments investigating a variety of residues from the agro-industry. The studies investigated peels, pomace/bagasse, pulp, seeds, aerial parts, cereals/grains and other types of waste. The most studied activities include mainly antioxidant and anti-inflammatory effects, but other activities such as antimicrobial, cytotoxic, antiproliferative, antinociceptive, hypoglycemic, antihyperglycemic and anticoagulant effects have also been described. Finally, the studies included in this review demonstrate the potential of agro-industrial waste and can drive future research with a focus on clinical application.

The Comet Interceptor Mission.

Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA's F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum ΔV capability of 600 ms-1. Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes - B1, provided by the Japanese space agency, JAXA, and B2 - that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission's science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.

[Critical Evaluation of Permanently Listed Psychosocial Digital Health Applications into the Directory for Reimbursable Digital Health Applications of the BfArM]. / Kritische Prüfung der Evidenz dauerhaft aufgenommener psychosozialer digitaler Gesundheitsanwendungen in das Verzeichnis für erstattungsfähige digitale Gesundheitsanwendungen des BfArM.

Digital health applications (DiGA) delivered as psychosocial therapeutic interventions entail a huge potential through their proven medical benefit or patient-relevant structure and process improvements. Their usage as first-line or concomitant therapy is refunded by the German health insurances. Therefore, the digital health applications have to pass a complex evidence process as requested by the Federal Institute for Drugs and Medical Services. The present article aimed at critically evaluating the available evidence of the permanently registered DiGA using the Critically Appraised Topic method. In conclusion, all studies fulfil at least two thirds of the evaluation criteria, implying that the overall evidence is of sufficient quality.

Neonicotinoid insecticides in global agricultural surface waters - Exposure, risks and regulatory challenges.

Neonicotinoids are the most widely used insecticides worldwide. However, the widespread usage of neonicotinoids has sparked concerns over their effects on non-target ecosystems including surface waters. We present here a comprehensive meta-analysis of 173 peer-reviewed studies (1998-2022) reporting measured insecticide concentrations (MICs; n = 3983) for neonicotinoids in global surface waters resulting from agricultural nonpoint source pollution. We used compound-specific regulatory threshold levels for water (RTLSW) and sediment (RTLSED) defined for pesticide authorization in Canada, the EU and the US, and multispecies endpoints (MSESW) to assess acute and chronic risks of global neonicotinoid water-phase (MICSW; n = 3790) and sediment (MICSED; n = 193) concentrations. Results show a complete lack of exposure information for surface waters in >90 % of agricultural areas globally. However, available data indicates for MICSW overall acute risks to be low (6.7 % RTLSW_acute exceedances), but chronic risks to be of concern (20.7 % RTLSW_chronic exceedances); exceedance frequencies were particularly high for chronic MSESW (63.3 %). We found RTLSW exceedances to be highest for imidacloprid and in less regulated countries. Linear model analysis revealed risks for global agricultural surface waters to decrease significantly over time, potentially biased by the lack of sensitive analytical methods in early years of neonicotinoid monitoring. The Canadian, EU and US RTLSW differ considerably (up to factors of 223 for RTLSW_acute and 13,889 for RTLSW_chronic) for individual neonicotinoids, indicating large uncertainties and regulatory challenges in defining robust and protective RTLs. We conclude that protective threshold levels, in concert with increasing monitoring efforts targeting agricultural surface waters worldwide, are essential to further assess the ecological consequences from anticipated increases of agricultural neonicotinoid uses.

Effect of multicomponent rehabilitation on independence and functioning in elderly patients with common age-associated diseases: protocol for a scoping review (REHOLD).

INTRODUCTION: Elderly patients after hospitalisation for acute events on account of age-related diseases (eg, joint or heart valve replacement surgery) are often characterised by a remarkably reduced functional health. Multicomponent rehabilitation (MR) is considered an appropriate approach to restore the functioning of these patients. However, its efficacy in improving functioning-related outcomes such as care dependency, activities of daily living (ADL), physical function and health-related quality of life (HRQL) remains unclarified. We outline the research framework of a scoping review designed to map the available evidence of the effects of MR on the independence and functional capacity of elderly patients hospitalised for age-related diseases in four main medical specialties beyond geriatrics. METHODS AND ANALYSIS: The biomedical databases (PubMed, Cochrane Library, ICTRP Search Platform, ClinicalTrials) and additionally Google Scholar will be systematically searched for studies comparing centre-based MR with usual care in patients ≥75 years of age, hospitalised for common acute events due to age-related diseases (eg, joint replacement, stroke) in one of the specialties of orthopaedics, oncology, cardiology or neurology. MR is defined as exercise training and at least one additional component (eg, nutritional counselling), starting within 3 months after hospital discharge. Randomised controlled trials as well as prospective and retrospective controlled cohort studies will be included from inception and without language restriction. Studies investigating patients <75 years, other specialties (eg, geriatrics), rehabilitation definition or differently designed will be excluded. Care dependency after at least a 6-month follow-up is set as the primary outcome. Physical function, HRQL, ADL, rehospitalisation and mortality will be additionally considered. Data for each outcome will be summarised, stratified by specialty, study design and type of assessment. Furthermore, quality assessment of the included studies will be performed. ETHICS AND DISSEMINATION: Ethical approval is not required. Findings will be published in a peer-reviewed journal and presented at national and/or international congresses. TRIAL REGISTRATION NUMBER: https://doi.org/10.17605/OSF.IO/GFK5C.

Rodent models for anticancer toxicity studies: Contributions to drug development and future perspectives.

Antineoplastic treatment induces a type of gastrointestinal toxicity known as mucositis. Findings in animal models are usually easily reproducible, and standardized treatment regimens are often used, thus supporting translational science. Essential characteristics of mucositis, including intestinal permeability, inflammation, immune and oxidative responses, and tissue repair mechanisms, can be easily investigated in these models. Given the effects of mucositis on the quality of life of patients with cancer, and the importance of experimental models in the development of more effective new therapeutic alternatives, this review discusses progress and current challenges in using experimental models of mucositis in translational pharmacology research.

Polysaccharides from Passion Fruit Peels: From an Agroindustrial By-Product to a Viable Option for 5-FU-Induced Intestinal Damage.

Gastrointestinal mucositis is a serious and dose-limiting toxic side effect of oncologic treatment. Interruption of cancer treatment due to gastrointestinal mucositis leads to a significant decrease in cure rates and consequently to the deterioration of a patient's quality of life. Natural polysaccharides show a variety of beneficial effects, including a gastroprotective effect. Treatment with soluble dietary fiber (SDF) from yellow passion fruit (Passiflora edulis) biomass residues protected the gastric and intestinal mucosa in models of gastrointestinal injury. In this study, we investigated the protective therapeutic effect of SDF on 5-FU-induced mucositis in male and female mice. Oral treatment of the animals with SDF did not prevent weight loss but reduced the disease activity index and preserved normal intestinal function by alleviating diarrhea and altered gastrointestinal transit. SDF preserved the length of the colon and histological damage caused by 5-FU. SDF significantly restored the oxidative stress and inflammation in the intestine and the enlargement and swelling of the spleen induced by 5-FU. In conclusion, SDF may be a promising adjuvant strategy for the prevention and treatment of intestinal mucositis induced by 5-FU.

CPW partially attenuates DSS-induced ulcerative colitis in mice.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) of the gastrointestinal tract. The etiology is not fully understood, but environmental, microbial, and immunologic factors, as well as a genetic predisposition, play a role. UC is characterized by episodes of abdominal pain, diarrhea, bloody stools, weight loss, severe colonic inflammation, and ulceration. Despite the increase in the frequency of UC and the deterioration of the quality of life, there are still patients who do not respond well to available treatment options. Against this background, natural products such as polysaccharides are becoming increasingly important as they protect the intestinal mucosa, promote wound healing, relieve inflammation and pain, and restore intestinal motility. In this study, we investigated the effect of a polysaccharide isolated from the biomass of Campomanesia adamantium and Campomanesia pubescens (here referred to as CPW) in an experimental model of acute and chronic ulcerative colitis induced by dextran sulfate sodium (DSS). CPW reversed weight loss, increased disease activity index (DAI), bloody diarrhea, and colon shortening. In addition, CPW reduced visceral mechanical hypersensitivity, controlled oxidative stress and inflammation, and protected the mucosal barrier. CPW is not absorbed in the intestine, does not inhibit cytochrome P450 proteins, and does not exhibit AMES toxicity. These results suggest that CPW attenuates DSS-induced acute and chronic colitis in mice and may be a potential alternative treatment for UC.

Jupiter Science Enabled by ESA's Jupiter Icy Moons Explorer.

ESA's Jupiter Icy Moons Explorer (JUICE) will provide a detailed investigation of the Jovian system in the 2030s, combining a suite of state-of-the-art instruments with an orbital tour tailored to maximise observing opportunities. We review the Jupiter science enabled by the JUICE mission, building on the legacy of discoveries from the Galileo, Cassini, and Juno missions, alongside ground- and space-based observatories. We focus on remote sensing of the climate, meteorology, and chemistry of the atmosphere and auroras from the cloud-forming weather layer, through the upper troposphere, into the stratosphere and ionosphere. The Jupiter orbital tour provides a wealth of opportunities for atmospheric and auroral science: global perspectives with its near-equatorial and inclined phases, sampling all phase angles from dayside to nightside, and investigating phenomena evolving on timescales from minutes to months. The remote sensing payload spans far-UV spectroscopy (50-210 nm), visible imaging (340-1080 nm), visible/near-infrared spectroscopy (0.49-5.56 µm), and sub-millimetre sounding (near 530-625 GHz and 1067-1275 GHz). This is coupled to radio, stellar, and solar occultation opportunities to explore the atmosphere at high vertical resolution; and radio and plasma wave measurements of electric discharges in the Jovian atmosphere and auroras. Cross-disciplinary scientific investigations enable JUICE to explore coupling processes in giant planet atmospheres, to show how the atmosphere is connected to (i) the deep circulation and composition of the hydrogen-dominated interior; and (ii) to the currents and charged particle environments of the external magnetosphere. JUICE will provide a comprehensive characterisation of the atmosphere and auroras of this archetypal giant planet.

Self-endangering: A qualitative study on psychological mechanisms underlying nurses' burnout in long-term care.

OBJECTIVES: To develop a more specific understanding of psychological mechanisms in the development of burnout in long-term care as a basis for potential new intervention strategies aiming at improving nurses' mental health. METHODS: Two qualitative studies with thematic analysis were conducted. In Study 1, we conducted eight group interviews with 110 nurses from May-July 2019 in the context of workshops at eight nursing homes in Germany. In Study 2, we supplemented these with semi-structured interviews with 14 executives at German nursing homes in December 2019. RESULTS: The thematic analysis in Study 1 identified three main themes: causes of challenges, employees' opportunities for change, and organisational opportunities for change. Thematic analysis in Study 2 identified three main themes: job motives, reasons for filling in for others, and employee self-care. Further, our results show that the need to stand in for colleagues, in particular, is one of the greatest challenges for geriatric caregivers. In dealing with these challenges we found that self-endangering behaviour-a diminished ability to say no when asked to fill in or to do work overtime-was an important antecedent of nurses' burnout. Further, high levels of altruistic motivation and identification with the team or organisation were associated with self-endangering behaviour in the presence of adverse working conditions. Low levels of self-worth are a further risk factor for self-endangering. CONCLUSIONS: Our findings are at odds with some core tenets of classic models of job demands and burnout that construe motivation and identification as resources. Our results show the need of a holistic intervention program in nursing including individual coaching, team-based interventions and organisational development processes. Employees themselves should be sensitized to this issue and supported in the long term, and politicians should create structures that do not encourage this behaviour any further.

A large dust/ice ratio in the nucleus of comet 9P/Tempel 1.

Comets spend most of their life in a low-temperature environment far from the Sun. They are therefore relatively unprocessed and maintain information about the formation conditions of the planetary system, but the structure and composition of their nuclei are poorly understood. Although in situ and remote measurements have derived the global properties of some cometary nuclei, little is known about their interiors. The Deep Impact mission shot a projectile into comet 9P/Tempel 1 in order to investigate its interior. Here we report the water vapour content (1.5 10(32) water molecules or 4.5 10(6) kg) and the cross-section of the dust (330 km2 assuming an albedo of 0.1) created by the impact. The corresponding dust/ice mass ratio is probably larger than one, suggesting that comets are 'icy dirtballs' rather than 'dirty snowballs' as commonly believed. High dust velocities (between 110 m s(-1) and 300 m s(-1)) imply acceleration in the comet's coma, probably by water molecules sublimated by solar radiation. We did not find evidence of enhanced activity of 9P/Tempel 1 in the days after the impact, suggesting that in general impacts of meteoroids are not the cause of cometary outbursts.

Adaptations to haematophagy: Investigations on how male and female Culex quinquefasciatus (Diptera: Culicidae) deal with human complement activation after a blood meal.

Culex quinquefasciatus is a mosquito species with an anthropophilic habit, often associated with areas with poor sanitation in tropical and urban regions. Adult males and females feed on sugars but only females feed on blood in natural conditions for egg maturation. During haematophagy, female C. quinquefasciatus transmit pathogens such as the West Nile virus, Oropouche virus, various encephalitis viruses, and Wuchereria bancrofti to human hosts. It has been observed in laboratory conditions that male C. quinquefasciatus may feed on blood during an artificial feed. Experiments were carried out to understand how males and females of this species deal with human complement activation. Our results showed that female C. quinquefasciatus, but not males, withstand the stress caused by the ingestion of normal human serum. It was observed that the salivary gland extracts from female mosquitoes were able to inhibit the classical and lectin pathways, whereas male salivary gland extracts only inhibited the lectin pathway. The male and female intestinal contents inhibited the classical and lectin pathways. Neither the salivary glands nor the intestinal contents from males and females showed inhibitory activity towards the alternative pathway. However, the guts of male and female C. quinquefasciatus captured factor H from the human serum, permitting C3b inactivation to its inactive form iC3b, and preventing the formation of the C3 convertase. The activity of the antioxidant enzyme catalase is similar in C. quinquefasciatus females and males. This article shows for the first time that males from a haematophagous arthropod species present human anti-complement activity in their salivary gland extracts and gut contents. The finding of an activity that helps to protect the damage caused by blood ingestion in sugar-feeding male mosquitoes suggests that this may be a pre-adaptation to blood-feeding.

An overview of the gut side of the SARS-CoV-2 infection.

In late 2019, an outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) initiated in Wuhan, Hubei province, China. The major clinical symptoms described for coronavirus disease (COVID-19) include respiratory distress and pneumonia in severe cases, and some patients may experience gastrointestinal impairments. In accordance, viral RNA or live infectious virus have been detected in feces of patients with COVID-19. Binding of SARS-CoV-2 to the angiotensin-converting enzyme 2 (ACE2) is a vital pathway for the virus entry into human cells, including those of the respiratory mucosa, esophageal epithelium as well as the absorptive enterocytes from ileum and colon. The interaction between SARS-CoV-2 and ACE2 receptor may decrease the receptor expression and disrupt the function of B0AT1 transporter influencing the diarrhea observed in COVID-19 patients. In this context, a fecal-oral transmission route has been considered and points out a role for the digestive tract in disease transmission and severity. Here, in order to further understand the impact of COVID-19 in human physiology, the cellular and molecular mechanisms of SARS-CoV-2 infection and disease severity are discussed in the context of gastrointestinal disturbances.

Aquatic pesticide exposure in the U.S. as a result of non-agricultural uses.

Non-agricultural uses of pesticides are common in the U.S. and may thus lead to exposure of non-target ecosystems such as urban waterways. However, surface water exposure resulting from agricultural pesticide uses has received substantially more attention during the last decades. Here we conducted a literature review and meta-analysis of peer-reviewed studies to identify measured environmental concentrations (MEC) of pesticides in perennial surface water bodies due to non-agricultural uses in the U.S. Acute and chronic Aquatic Life Benchmarks (ALBacute, ALBchronic) for water-phase concentrations and regulatory threshold levels (RTLSED) for sediment concentrations were used for risk evaluations. Based on 10,755 MECs retrieved from 70 scientific studies, results show that a multitude of pesticide compounds (approx. 150) have been detected at 609 urban surface water sites. Particularly herbicides and insecticides were among the most frequently detected compounds in the water phase, whereas insecticides dominated detections in sediments. While overall acute (5.64% ALBacute exceedances; n = 9034 MEC) and chronic (9.31% ALBchronic exceedances; n = 9036 MEC) risks were comparably low in the water phase, 35% of sediment concentrations (n = 1621 MEC) exceeded RTLSED. Insecticides and particularly pyrethroids were identified as the main drivers of benchmark exceedances in both the water phase and sediments. In addition to pesticide type, a linear model analysis identified further drivers important for risks such as sampling methods. Overall insecticide risks in non-agricultural surface waters were significantly (by a factor of 1.9) lower than those already known from agricultural surface waters in the U.S. However, substantially higher risks in sediments were identified for urban compared with agricultural waterbodies. The present study provides the first comprehensive assessment of pesticides in urban surface waters in the U.S. with overall results indicating common occurrence and non-negligible risks particularly due to urban insecticide uses.

Trypanosomes Modify the Behavior of Their Insect Hosts: Effects on Locomotion and on the Expression of a Related Gene.

BACKGROUND: As a result of evolution, the biology of triatomines must have been significantly adapted to accommodate trypanosome infection in a complex network of vector-vertebrate-parasite interactions. Arthropod-borne parasites have probably developed mechanisms, largely still unknown, to exploit the vector-vertebrate host interactions to ensure their transmission to suitable hosts. Triatomines exhibit a strong negative phototaxis and nocturnal activity, believed to be important for insect survival against its predators. METHODOLOGY/PRINCIPAL FINDINGS: In this study we quantified phototaxis and locomotion in starved fifth instar nymphs of Rhodnius prolixus infected with Trypanosoma cruzi or Trypanosoma rangeli. T. cruzi infection did not alter insect phototaxis, but induced an overall 20% decrease in the number of bug locomotory events. Furthermore, the significant differences induced by this parasite were concentrated at the beginning of the scotophase. Conversely, T. rangeli modified both behaviors, as it significantly decreased bug negative phototaxis, while it induced a 23% increase in the number of locomotory events in infected bugs. In this case, the significant effects were observed during the photophase. We also investigated the expression of Rpfor, the triatomine ortholog of the foraging gene known to modulate locomotion in other insects, and found a 4.8 fold increase for T. rangeli infected insects. CONCLUSIONS/SIGNIFICANCE: We demonstrated for the first time that trypanosome infection modulates the locomotory activity of the invertebrate host. T. rangeli infection seems to be more broadly effective, as besides affecting the intensity of locomotion this parasite also diminished negative phototaxis and the expression of a behavior-associated gene in the triatomine vector.