Animal Species Research Articles

Development of Machine Learning-Based Quantitative Structure-Activity Relationship Models for Predicting Plasma Half-Lives of Drugs in Six Common Food Animal Species

Abstract Plasma half-life is a crucial pharmacokinetic parameter for estimating extralabel withdrawal intervals of drugs to ensure the safety of food products derived from animals. This study focuses on developing a quantitative structure−activity relationship (QSAR) model incorporating multiple machine learning and artificial intelligence algorithms, and aims to predict the plasma half-lives of drugs in six food animals, including cattle, chickens, goats, sheep, swine, and turkeys. By integrating four machine learning algorithms with five molecular descriptor types, 20 QSAR models were developed using data from the Food Animal Residue Avoidance Databank (FARAD) Comparative Pharmacokinetic Database. The deep neural network (DNN) algorithm demonstrated the best prediction ability of plasma half-lives. The DNN model with all descriptors achieved superior performance with a high coefficient of determination (R 2) of 0.82±0.19 in 5-fold cross-validation on the training sets and a R 2 of 0.67 on the independent test set, indicating accurate predictions and good generalizability. The final model was converted to a user-friendly web dashboard to facilitate its wide application by the scientific community. This machine learning-based QSAR model serves as a valuable tool for predicting drug plasma half-lives and extralabel withdrawal intervals in six common food animals based on physicochemical properties. It also provides a foundation to develop more advanced models to predict the tissue half-life of drugs in food animals.

Trait-based study predicts glycerol/diol dehydratases as a key function of the gut microbiota of hindgut-fermenting carnivores

BackgroundMicrobial pdu and cob-cbi-hem gene clusters encode the key enzyme glycerol/diol dehydratase (PduCDE), which mediates the transformation of dietary nutrients glycerol and 1,2-propanediol (1,2-PD) to a variety of metabolites, and enzymes for cobalamin synthesis, a co-factor and shared good of microbial communities. It was the aim of this study to relate pdu as a multipurpose functional trait to environmental conditions and microbial community composition. We collected fecal samples from wild animal species living in captivity with different gut physiology and diet (n = 55, in total 104 samples), determined occurrence and diversity of pdu and cob-cbi-hem using a novel approach combining metagenomics with quantification of metabolic and genetic biomarkers, and conducted in vitro fermentations to test for trait-based activity.ResultsFecal levels of the glycerol transformation product 1,3-propanediol (1,3-PD) were higher in hindgut than foregut fermenters. Gene-based analyses indicated that pduC harboring taxa are common feature of captive wild animal fecal microbiota that occur more frequently and at higher abundance in hindgut fermenters. Phylogenetic analysis of genomes reconstructed from metagenomic sequences identified captive wild animal fecal microbiota as taxonomically rich with a total of 4150 species and > 1800 novel species but pointed at only 56 species that at least partially harbored pdu and cbi-cob-hem. While taxonomic diversity was highest in fecal samples of foregut-fermenting herbivores, higher pduC abundance and higher diversity of pdu/cbi-cob-hem related to higher potential for glycerol and 1,2-PD utilization of the less diverse microbiota of hindgut-fermenting carnivores in vitro.ConclusionOur approach combining metabolite and gene biomarker analysis with metagenomics and phenotypic characterization identified Pdu as a common function of fecal microbiota of captive wild animals shared by few taxa and stratified the potential of fecal microbiota for glycerol/1,2-PD utilization and cobalamin synthesis depending on diet and physiology of the host. This trait-based study suggests that the ability to utilize glycerol/1,2-PD is a key function of hindgut-fermenting carnivores, which does not relate to overall community diversity but links to the potential for cobalamin formation.5QUW1NVLR3PN1Ur7W1hKTuVideo

Assessment of Species-Based Ecosystem Services and Its Usefulness in Forest-Savanna Ecological Zone

Forest ecosystems are the main species rich ecosystem on earth, having a significant role in the provision of massive benefits to the populace who depended on them for sustenance. This study aimed at assessing the forest provisioning ecosystem service and use in Ihiala Local Government Area of Anambra State, Nigeria. The objectives of this study include the identification of forest provisioning ecosystem services and their uses, people’s dependence for livelihood and quantity of ecosystem services supplied by community forests. Stratified sampling technique was used to select 8 sampled communities while Nikolopoulou convenience sampling technique was adopted for selecting sampling size of 200 persons. Also, 31 key informants were interviewed across the study area. The responses from the entire sampled questionnaire and interview were analyzed using Microsoft excel and statistical package for social sciences. The study revealed that a good number of the forest resources such as Elaeis guineensis, Garcinia kola, Bambusa vulgaris, Azadirachta indica and Brophyllum pinnatum have multiple uses. The result also revealed that the nature of forest determines the quantity of ecosystem service benefits supplied. Hence, those community forests with weak policies supply less than 40% of resources because their traditional laws of entering and harvesting forest resources are no longer effective, while those with strong policies like restriction into their sacred groves, forest reserves and swampy forests supply above 40%. The chi-square value of 352.873 with 28 degrees of freedom (DF) proved that there is strong relationship between the nature of forest and the quantity of ecosystem services provided. This research concludes that forest ecosystem in Ihiala L.G.A, supplies a wide variety of plant and animal species to the populace, which they basically use for timber, firewood, food and medicine. Nonetheless, without alternative and diversified livelihood, the supply is becoming unsustainable. It recommends that since palm tree and its resources are averagely abundant in the study area, there is need to support the establishment of basket making training centre in various communities and as such, make it an attractive skill acquisition programme.

A Case of Epicardial Epidermoid Cyst in a Crested Porcupine

The crested porcupine (Hystrix cristata) is present in central Italy with an estimated population of 1800 individuals. Despite the local abundance, little data are available on the diseases affecting free-ranging individuals. We describe a case of an epidermoid cyst (EC) in a male adult porcupine found in the municipality of Sovicille, province of Siena (Tuscany). At necropsy, a firm rounded nodule was noted on the left ventricle wall. Histological examination revealed a cystic formation lined by stratified squamous epithelium. The cyst was filled with lamellar keratin, while hair shafts were not present. The adjacent epicardium was infiltrated by lymphoplasmacytic cells in reaction to the rupture of the cyst with the spilling of keratinaceous debris. The lesion was diagnosed as a ruptured epicardial epidermoid cyst. EC are most commonly found in the skin, both in human and animal patients, though infrequently, they can occur in any internal organ. Cardiac EC has not been reported in domestic animals, and this is the first report of EC in a wild animal species. Clinical veterinarians should consider the possibility of similar cardiac lesions in captive subjects since the long lifespan of these rodents could allow the growth of the cyst with the compression of the adjacent tissues.

Parasites Diversity, Abundance, Prevalence, and Richness Infecting Didelphis aurita (Didelphimorphia: Didelphidae) in the Atlantic Rainforest, Brazil

Parasites are key players in ecosystems, influencing population sizes and food webs, yet the impact of environmental factors on their diversity is not well understood. The Atlantic rainforest in Brazil, particularly the Parque Estadual das Fontes do Ipiranga (PEFI), exemplifies a biodiversity hotspot facing significant deforestation, housing diverse animal species such as the synanthropic Brazilian common opossum (Didelphis aurita), which serves as a reservoir for multiple zoonotic pathogens. In this study, we investigated parasite diversity, abundance, prevalence, and richness in free-living D. aurita in the PEFI, São Paulo, Brazil. From January 2015 to January 2017, 101 fecal samples of D. aurita were collected in two areas of PEFI, at the Instituto de Pesquisas Ambientais (IPA) and the Parque de Ciência e Tecnologia (Cientec), and analyzed using three different parasitological methods. In total, 99% of the samples were positive for at least one parasite. The most prevalent parasite belonged to the order Strongylida (82%), followed by Cruzia sp. (77%), the latter having a significantly higher prevalence at IPA. In contrast, Acanthocephala showed greater prevalence at Cientec. Co-infections were common, with some individuals harboring up to seven different parasites. Our findings reveal significant parasite diversity in the D. aurita population at PEFI, including both helminths and protozoan trophozoites, some of which are reported for the first time in this host species. Further research is essential for accurate species identification of the observed parasites.

Cumulative human impacts on global marine fauna highlight risk to biological and functional diversity.

Anthropogenic stressors to marine ecosystems from climate change and human activities increase extinction risk of species, disrupt ecosystem integrity, and threaten important ecosystem services. Addressing these stressors requires understanding where and to what extent they are impacting marine biological and functional diversity. We model cumulative risk of human impact upon 21,159 marine animal species by combining information on species-level vulnerability and spatial exposure to a range of anthropogenic stressors. We apply this species-level assessment of human impacts to examine patterns of species-stressor interactions within taxonomic groups. We then spatially map impacts across the global ocean, identifying locations where climate-driven impacts overlap with fishing, shipping, and land-based stressors to help inform conservation needs and opportunities. Comparing species-level modeled impacts to those based on marine habitats that represent important marine ecosystems, we find that even relatively untouched habitats may still be home to species at elevated risk, and that many species-rich coastal regions may be at greater risk than indicated from habitat-based methods alone. Finally, we incorporate a trait-based metric of functional diversity to identify where impacts to functionally unique species might pose greater risk to community structure and ecosystem integrity. These complementary lenses of species, function, and habitat provide a richer understanding of threats to marine biodiversity to help inform efforts to meet conservation targets and ensure sustainability of nature's contributions to people.

Population differences in putty-nosed monkey (Cercopithecus nictitans) call order.

Non-human primates generally lack the ability to learn new call structures or to substantially modify existing ones, suggesting that callers need alternative mechanisms to convey information. One way to escape the constraints of limited vocal control is by assembling calls into variable sequences, as has been documented in various animal species. Here, we were interested in the flexibility with which different calls might be assembled in a species known for its meaningful call order, putty-nosed monkeys (Cercopithecus nictitans). Since most information comes from studies conducted at Gashaka Gumti National Park (Nigeria), we tested two further populations in the Nouabalé-Ndoki National Park (Republic of the Congo) and Taï National Park (Côte d'Ivoire) in how males responded to common threats, leopards, and crowned eagles. As predicted, callers produced the same basic call types as seen elsewhere-long 'pyow', short 'pyow' ('kek'), 'hack'-but populations differed in how males assembled calls. To leopards, males from both populations started with 'pyows' and 'keks', with occasional hacks later, as already reported from Gashaka. To crowned eagle, however, Nouabalé-Ndoki males consistently initiated their responses with 'pyows', whereas neither Taï nor Gashaka males ever did, demonstrating that nonhuman primates have some control over sequence production. We discuss possible mechanisms to account for the population differences, predation pressure, and male-male competition, and address implications for linguistic theories of animal call order, notably the Urgency and Informativity Principles.

Conservation threats from tourism land grabs and greenwash

We report a new threat to conservation, namely land grabs by large tourism developers inside public protected areas. Locally, these tourism land grabs damage national parks through building footprints and access corridors, bringing habitat fragmentation, noise, light, roadkill, fire risk, and invasive plant and animal species and pathogens. They also create negative impacts on social equity and regional economies. The global tourism industry now perceives private development in public national parks as a mechanism to profit from land speculation, rather than merely monopoly provision of visitor services. Investment funds now use tourism, often with socialwashing components, as a political lever for land grabs. International “nature positive” marketing by tourism industry associations and multilateral tourism advocacy organisations is greenwash: it lacks substance, and aims to coopt conservation organisations.

Mixed effects of honey bees on pollination function in the Tibetan alpine grasslands

The global expansion of domesticated plant and animal species has profoundly impacted biodiversity and ecosystem functions. However, the spillover effect of non-native honey bees from mass-flowering crops into adjacent natural vegetation on pollination function within plant communities remains unclear. To address this, we conduct field experiments to investigate the ecological impacts of honey bees (Apis mellifera) and a mass-flowering crop (Brassica rapa var. oleifera) on pollinator communities, plant-pollinator interactions, and reproductive performance of wild plants in 48 pollinator-limited alpine grasslands. Our findings indicate that the transition of dominant pollinators from flies to honey bees enhances visitation fidelity of pollinator species and reconfigures pollination interactions due to an increase in competition between honey bees and native pollinator species. Additionally, honey bees increase, decrease or do not alter plant reproductive success, depending on the plant species. Here, we report the mixed effects of honey bees on pollination function in pollinator-limited alpine grasslands.

DNA Metabarcoding Approach as a Potential Tool for Supporting Official Food Control Programs: A Case Study

Food authentication significantly impacts consumer health and the credibility of Food Business Operators (FBOs). As European regulations mandate the verification of food authenticity and supply chain integrity, competent authorities require access to innovative analytical methods to identify and prevent food fraud. This study utilizes the DNA metabarcoding approach on meat preparations, sampled during an official control activity. It assesses animal and plant composition by amplifying DNA fragments of the 12S rRNA and trnL (UAA) genes, respectively. The results not only confirmed the declared species but also revealed undeclared and unexpected taxa in products labelled as containing a single animal species and various unspecified plant species. Notable findings such as the presence of Murinae, Sus scrofa, Ovis aries, and Pisum sativum could raise public health concerns, compromise consumer choices made for ethical or religious reasons, and reflect the hygienic conditions of the processing plant. This study demonstrates that the DNA metabarcoding approach looks to be a promising support tool for official control authorities to ensure food authenticity and safety, and to develop risk profiles along the supply chain.

Homeopathy, Acupuncture and Phytotherapy in the Veterinary Treatment or Prophylaxis of Diseases in Animals: An Overview of Systematic Reviews.

Complementary and alternative veterinary medicine (CAVM) has been intensively used, and there is currently an increasing demand for a more rigorous approach regarding its clinical effectiveness. The objectives of this overview were: first, to identify systematic reviews on homeopathy, acupuncture and phytotherapy in veterinary medicine and assess their methodological quality; and second, to map interventions and findings in the treatment or prophylaxis of any medical conditions in any animal species for which high-quality systematic reviews had identified reliable evidence of efficacy or effectiveness in randomized controlled trials (RCTs) or controlled clinical trials (CCTs). The study was an overview of systematic reviews published in the years 2000 to 2022 inclusive. The following databases were used: CAB Abstracts, PubMed and Vet Index, from which the abstracts of 173 articles were extracted, 22 of which were initially included for complete analysis. After excluding 15 studies according to the exclusion/inclusion criteria, 7 review papers were comprehensively analyzed. The review quality was assessed by the Measurement Tool to Assess Systematic Reviews (AMSTAR 2) method. The reported RCTs/CCTs in these reviews were analyzed for their reliability, and the results were classified according to statistical significance and risk of bias. Seven eligible systematic reviews reported studies on dogs, horses, cats, cattle, sheep, goats, swine, rabbits and poultry. The number of primary RCTs/CCTs was 38 for homeopathy, 35 for acupuncture, and 171 for phytotherapy. The AMSTAR 2 evaluation ranked two reviews of veterinary homeopathy as high-quality, in which two placebo-controlled RCTs comprised reliable evidence, one of which reported efficacy of homeopathy as prophylaxis for diarrhea in pigs. The systematic reviews of acupuncture and phytotherapy were all of low quality, preventing formal assessment of their reviewed RCTs/CCTs. Only the systematic reviews of homeopathy were rated of sufficient quality to enable the assessment of reliable evidence within their reviewed RCTs. Contemporary high-quality systematic reviews of clinical trials in each of the three areas of CAVM are required.

FRUGIVORY CAMTRAP: A dataset of plant-animal interactions recorded with camera traps.

Ecological interactions are a key component of biodiversity, essential for understanding ecosystem services and functioning. Recording and quantifying ecological interactions is challenging, frequently requiring complex logistics and substantial effort in the field. Camera traps are routinely used in ecology for various applications, and have proven to be an excellent method for passive and non-invasive sampling of plant-animal interactions. We implemented a standardized camera trap protocol to document vertebrate frugivores-fleshy fruitedplants interactions in Doñana National Park, SW Spain, with the central objective of inventorying the diversity of plant-animal ecological interactions providing seed dispersal services. From 2018 to 2023 we recorded pairwise interactions from which we obtained qualitative (presence-absence) and quantitative (frequency of visits) information. Each record in the dataset contains information of a visit by an individual animal to an individual plant, resulting in any form of fleshy-fruit use and provides information on visitation phenology, visit length, and feeding behavior. The dataset presented here includes 10,659 frugivory interaction events for 59 vertebrate species (46 birds, 13 mammals) recorded on 339 plant individuals from 13 different plant species which dominate the fleshy-fruited plant assemblage in the Doñana National Park. The most recorded animal species consuming fruits and playing a legitimate seed dispersal role was Curruca melanocephala (1678 records) among birds and Vulpes vulpes among mammals (751 records). Cervus elaphus, a fruit consumer with a marginal role as legitimate seed disperser, was the most recorded mammal species (1508 records). Avian frugivores, particularly those from the Sylviidae and Turdidae families, are widespread in the region and play a crucial role in maintaining the dispersal service for the fleshy-fruited plant populations in the area. The dataset offers highly versatile quantitative information that can be used to investigate frugivory from the highest resolution scale, the interaction event between pairs of individuals. In addition, other information that can be extracted includes the timing of interactions of animals and plants (their phenological couplings), activity periods of the animals, behavior during the events and preferences for individual plants within populations. There are no copyright restrictions on the data. When using the data from this data paper in publications, we kindly request that you cite the paper accordingly. Additionally, we encourage researchers and educators to inform us about how they are using this data, as we value feedback and would like to be aware of its various applications.

Of popsicles and crackers: when spatio-temporal memory is not integrated into children's decision-making.

Prior research has used innovative paradigms to show that some non-human animal species demonstrate behavioural choices (i.e. foraging for a food item at a specific location, and at a time that guarantees it has not yet decayed), reflecting episodic-like or 'WWW' memory (memory for 'what' happened, 'where' and 'when'). These results raised the question of whether similar approaches could be used to examine memory in young children in order to reduce verbal demands. The present research examines the extent to which children's WWW memory aligns with memory-based choices in 3- to 5-year-olds (n = 95; study 1) and in 7- to 11-year-olds and adults (n = 168; study 2). Results indicate that preschoolers' struggle with choice-based tasks probably reflects difficulty integrating their WWW memory with an understanding that certain items decay over time. Moreover, a convergence between verbal recall measures and choice-based measures is observable in 7-year-olds and beyond, reflecting a stronger integration of memory signals, understanding of state transformation, and decision-making. This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.

PSLBI-25 Students’ perceptions of an artificial intelligence photo generation tool in upper-level animal science curriculum

Abstract Domesticated livestock behavior (DLB) is an advanced animal science lecture course that emphasizes behavior associated with domestication of various animal species such as livestock, equine, companion animals and exotic species. Meat Science (MS) is an introductory dual lecture and laboratory course that focuses on muscle biology, food-borne illnesses, humane livestock harvesting, and fabrication techniques. With the emerging usage of artificial intelligence (AI) generative technologies, an assignment was developed utilizing the free AI photo generation tool, Craiyon. Students in DLB and MS were tasked with completing an AI assignment, generating images relevant to either DLB or MS concepts, to expose students to AI technologies. Therefore, the objective of this study was to determine students’ perceptions, knowledge, concerns, and willingness to use AI generative tools and evaluate differences relative to course enrolled (DLB compared with MS). Students (n = 60) enrolled in DLB and MS completed a post-completion survey instrument that consisted of demographic and 5-point Likert-scale questions to gauge student perceptions of the AI assignment. Student survey responses were compiled online using Qualtrics and subsequent respondent data was analyzed using JMP. To give some demographic information relative to the population of students enrolled in DLB and MS, 81 and 76% of the students were female while 19 and 24% were male, respectively. Both courses contained students further along in their degree-seeking program (> 80% Junior or Senior classification). Approximately, 43% of respondents were first generation college students and 66% commute over 14 km daily. When asked about their previous experience using AI generative technologies, 75% of respondents reported no previous experience using AI generative programs. Students enrolled in MS showed a greater concern (P ≤ 0.03) of AI technologies limiting their opportunity to interact and socialize with others as compared with DLB students. Student experience, knowledge, and willingness to use AI tools was not impacted by course enrolled (P ≥ 0.14). Most students reported that they had a positive experience with the AI assignment and felt the experience would be useful in their future (53 and 73%, respectively). Additionally, a majority of students reported that the AI assignment allowed them to visualize concepts and offered a unique learning experience. Participants seemed to have a solid understanding of AI technologies reporting knowledge in tool limitations and inaccurate output. Students were neutral regarding concerns in becoming over-reliant on AI tools and AI use hindering the development of transferable skills. Students felt that AI image generation tools boosted creativity and could be useful in the realm of DLB and MS. Overall, students possessed a general knowledge of AI generative technologies and saw value in using AI image generation tools as it relates to domesticated animal behavior and meat science principles.

Metagenomic analysis of the gut microbiota of hooded cranes (Grus monacha) on the Izumi plain in Japan.

Recent advances in DNA sequencing technology have dramatically improved our understanding of the gut microbiota of various animal species. However, research on the gut microbiota of birds lags behind that of many other vertebrates, and information about the gut microbiota of wild birds such as migratory waterfowl is particularly lacking. Because the ecology of migratory waterfowl (e.g., lifestyle, diet, physiological characteristics) differs from that of other birds, the gut microbiota of migratory waterfowl likely also differs, but much is still unknown. The hooded crane (Grus monacha) is an important representative migratory waterbird species and is listed as endangered on the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species. In this study, we analyzed the bacterial and viral microbiota in the gut of hooded cranes by using deep sequencing data from fecal samples of hooded cranes that winter on the Izumi plain in Japan, and found that Cetobacterium, Clupeiformes, and Pbunavirus were clearly present in the fecal samples of hooded cranes. These findings advance our understanding of the ecology of hooded cranes.

PSLBI-30 SARS-CoV-2 Screening and Detection: Assessment of surrogate virus neutralization test (svNT) diagnostic appropriateness in multispecies SARS-CoV-2 virus screening and detection

Abstract The National Veterinary Services Laboratories (NVSL) have been testing animal samples since the 2020 SARS-CoV-2 outbreak. The current “gold standard” for serodetection of SARS-CoV-2 is the virus neutralization (VN) test. This method requires specialized training, more time to complete, and specialized facilities (BSL 3). Therefore, the SARS-CoV-2 VN test is not widely run outside of NVSL. To facilitate increased testing capacity during the outbreak, the surrogate virus neutralization test (sVNT) was selected mid-2020. This commercially available kit uses an ELISA format, giving a percent inhibition (%I) cut-off value to indicate “negative” or “positive,” allowing for faster testing turnaround. Despite its widespread use in many species, an in-depth, multispecies analysis of the data comparing sVNT to VN results has not been reported. Such an analysis is useful to assess the diagnostic appropriateness of the sVNT test for SARS-CoV-2 virus screening and detection across multiple species. Results were considered from all serological samples submitted to NVSL from March 2020 to May 2023 for routine SARS-CoV-2 diagnostic testing. Of these, samples with results for both VN and sVNT testing were considered for further analysis (n = 942). Samples were sorted by the species and family levels, and were assessed for rates of “true positive,” “false positive,” “true negative,” and “false negative” by sVNT, using paired VN results as the indicator of the true status of the sample. Additionally, the increased sVNT cut-off threshold for %I (20%I to 30%I for “positive”) was assessed for appropriateness by species using mean %I values for VN-positive samples. Increasing sVNT %I cut-off threshold for “positive” results from 20%I to 30%I resulted in 58 samples being correctly re-classified as “negative” by sVNT, rather than “positive” at the 20%I cut-off threshold. The mean %I values for most species fell between 40 to 80%I, except for Felidae, which had a mean %I of 93%I, and a minimum %I of 40.6%I for VN-positive samples. The true negative (sVNT/VN-NEG) rates for most species fell between 97to 100%, with 0 to 3% being false negatives (svNT-NEG, VN-POS), with very few exceptions. However, the least false positive (sVNT-POS;VN-NEG) rate was 8.8%, ranging up to 100% false positives for Equidae and one species of Cervidae. While the mean %I for most species indicates the cut-off value is appropriate (for those species where sVNT is an appropriate diagnostic), overall, the results highlight a lack of precision and specificity of the sVNT for many animal species. This indicates a lack of diagnostic appropriateness of the sVNT as a SARS-CoV-2 screening tool for certain species and a need for refinement in cut-off values for other species. The sVNT as a screening tool varies considerably by species for serodetection of SARS-CoV-2, results should be interpreted with caution, and use of other confirmatory tests is recommended.

Exposure patterns and the risk factors of Crimean Congo hemorrhagic fever virus amongst humans, livestock and selected wild animals at the human/livestock/wildlife interface in Isiolo County, upper eastern Kenya.

Crimean Congo hemorrhagic fever (CCHF) is a tick-borne zoonotic disease caused by CCHF virus (CCHFV). The disease has a complex transmission cycle that involves a wide range of hosts including mammalian and some species of birds. We implemented a sero-epidemiological study in Isiolo County, Kenya, to determine relative seroprevalences of CCHFV in humans, livestock and in wild animals. A seropositive herd was defined as having at least one seropositive animal. In addition, we identified subject and environment level factors that could promote exposure to CCHFV. Humans (n = 580) and livestock species (n = 2,137) were recruited into the study through a multistage random sampling technique, and in addition, various species of wild animals (n = 87) were also sampled conveniently. Serum samples from all recruited humans and animals were collected and screened for CCHFV antibodies using ID Screen multispecies, double-antigen IgG enzyme-linked immunosorbent assay (ELISA). The overall anti-CCHFV IgG seroprevalences in humans, cattle, goats, sheep and camels were 7.2% [95% CI: 3.1-15.8%], 53.9% [95% CI: 30.7-50.9%], 11.6% [95% CI: 7.2-22.5%], 8.6% [95% CI: 3-14%] and 89.7% [95% CI: 78-94%], respectively. On average, the sampled wild animals had CCHFV seroprevalence of 41.0% [95% CI: 29.1-49.4%]; giraffes had the highest mean CCHF seroprevalence followed by buffaloes, while impala had very low exposure levels. Statistical analyses using mixed effects logistic regression models showed that CCHFV exposure in humans was significantly associated with male gender, being over 30 years of age and belonging to a household with a seropositive herd. In livestock, a combination of animal- and environment level factors including older animals, high normalized difference vegetation indices (NDVI) and high vapour pressure deficit were significantly associated with CCHFV infection. Age, sex and species of wild animals were considered the key risk factors in the analysis, but none of these variables was significant (P-value = 0.891, 0.401 and 0.664, respectively). Additionally, RT-qPCR analysis revealed the presence of CCHFV RNA in camels (30%), cattle (14.3%), and goats (3.8%), but not in humans, sheep, or wild animals. This study demonstrates that environmental factors, such as NDVI and vapor pressure deficit, affect CCHFV exposure in livestock, while the presence of infected livestock is the key determinant of human exposure at the household level. These findings underscore the importance of using One Health approaches to control the disease in human-livestock-wildlife interfaces. For instance, the existing CCHF surveillance measures could be enhanced by incorporating algorithms that simulate disease risk based on the environmental factors identified in the study. Additionally, tick control in livestock, such as the use of acaricides, could reduce CCHFV exposure in livestock and, consequently, in humans.

166 Development of non-model organoids in animal research: A paradigm shift in in vitro models

Abstract For decades, two-dimensional (2D) cell cultures have been used as the gold standard in vitro models for basic research, drug discovery and preclinical screening applications. However, since 2009, the field has quickly shifted towards the use of three-dimensional (3D) stem cell-derived organoids. Organoids offer a variety of advantages compared with conventional 2D models, including being self-organized, retaining their cellular polarity, and being simplified versions of organs in vitro. Adult stem cells can self-renew, differentiate into multiple cell types, and are genomically stable over multiple passage lines, providing a variety of technical benefits and offering the closest recapitulation of the in vivo environment. Our laboratory has focused on expanding, characterizing, and utilizing animal-derived 3D organoid models, specifically focusing on canines; but also including other animals such as swine, turtles, snakes, and squirrels to study their unique adaptations. Practically, we can use 3D canine colonoids for the screening of anti-inflammatory candidates using our tumor necrosis factor (TNF)-α stimulation model. Additionally, we have grown and used swine lung organoids as a model for studying H1N1 viral uptake. Furthermore, we have grown and bio-banked tumor organoids/spheroids from a variety of canine cancers, including urothelial carcinoma (derived from urine and biopsies) and nasal carcinoma, among others, with future applications in precision veterinary medicine and comparative oncology. To accomplish this goal, we have carried out in vitro screening of a variety of chemotherapies and combination therapies at different concentrations across patients to predict in vivo responses and demonstrate the predictive ability of the organoid model. Finally, our laboratory has derived and characterized a variety of healthy organoid lines from canines including the pancreas, lung, liver, bladder, colon, and pituitary to act as healthy controls in mechanistic studies looking at disease pathogenesis and for uses in basic biology. In summary, in vitro organoid models from various animal species and tissues can be used in a variety of basic and applied research fields, including virology, toxicology, and oncology, with the potential to broaden our scientific understanding of disease and overall improve human and veterinary medicine.

Variance Partitioning of nest provisioning rates in blue tits: Individual Repeatability, heritability, and partner interactions.

In many animal species, including most birds, parental care is performed by both parents, which has important implications for mate choice (good parent hypothesis) and parental investment strategies. Partitioning the variance in measures of parental care into heritable and non-heritable components is important to understand the evolvability of parental investment and its potential role in mate choice. We employed an automated system to monitor provisioning behavior at 817 blue tit nests over 10 years (totaling ~3 million visits). Daily provisioning rates of males and females were moderately repeatable between years (Radj = 0.16 and 0.15 respectively), which was almost entirely explained by additive genetic effects. While this degree of heritability is sufficient for parental investment to respond to selection, we argue that the modest level of repeatability provides limited potential for a 'provisioning phenotype' to be used as a criterion in mate choice. Daily visit rates were positively correlated between pair members, but after accounting for shared environmental factors this relationship became clearly negative, thereby providing support for models of partial compensation. Visit rates also differed substantially between years, and between days within a year. Thus, it is important to account for these variables when comparing parental investment between individuals. Our results highlight the interplay between genetic, social, and environmental influences on provisioning behavior.

CRISPR-prime editing, a versatile genetic tool to create specific mutations with a single nucleotide resolution in Leptospira.

Leptospirosis, caused by pathogenic bacteria from the genus Leptospira, is a global zoonosis responsible for more than one million human cases and 60,000 deaths annually. The disease also affects many domestic animal species. Historically, genetic manipulation of Leptospira has been difficult to perform, resulting in limited knowledge on pathogenic mechanisms of disease and the identification of virulence factors. The application of CRISPR/Cas9 and its variations have helped fill these gaps but the generation of knockout mutants remains challenging because double-strand breaks (DSBs) inflicted by Cas9 nuclease are lethal to Leptospira cells. The novel CRISPR prime editing (PE) strategy is the first precise genome-editing technology that allows deletions, insertions, and base substitutions without introducing DSBs. This revolutionary technique utilizes a nickase Cas9 that cleaves a single strand of DNA, coupled with an engineered reverse transcriptase and a modified single-guide RNA (termed prime editing guide RNA) containing an extended 3' end with the desired edits. We demonstrate the application of CRISPR-PE in both saprophytic and pathogenic Leptospira from multiple species and serovars by introducing deletions or insertions into target DNA with a remarkable precision of just one nucleotide. Additionally, we demonstrate the ability to genetically manipulate Leptospira borgpetersenii, a prevalent pathogenic species of humans, domestic cattle, and wildlife animals. Rapid plasmid loss by mutated strains in liquid culture allows for the generation of knockout strains without selective markers, which can be readily used to elucidate virulence factors and develop optimized bacterin and/or live vaccines against leptospirosis.IMPORTANCELeptospirosis is a geographically widespread bacterial zoonosis. Genetic manipulation of pathogenic Leptospira spp. has been laborious and difficult to perform, limiting our ability to understand how leptospires cause disease. The application of the CRISPR/Cas9 system to Leptospira enhanced our ability to generate knockdown and knockout mutants; however, the latter remains challenging. Here, we demonstrate the application of the CRISPR prime editing technique in Leptospira, allowing the generation of knockout mutants in several pathogenic species, with mutations comprising just a single nucleotide resolution. Notably, we generated a mutant in the Leptospira borgpetersenii background, a prevalent pathogenic species of humans and cattle. Our application of this method opens new avenues for studying pathogenic mechanisms of Leptospira and the identification of virulence factors across multiple species. These methods can also be used to facilitate the generation of marker-less knockout strains for updated and improved bacterin and/or live vaccines.