Search Results (177)

Background/Objectives: Single-domain antibodies (sdAbs) are derived from camelid heavy-chain antibodies (HCAb). Their small size, high stability, and ease of production, among other properties, makes them highly valuable in biomedical research and therapeutic development. Several sdAb-based molecules are currently progressing through clinical trials, highlighting their translational relevance. As sdAbs originate from HCAb of Camelidae family, they can originate from multiple species including Vicugna pacos, Lama glama, Camelus dromedarius and Camelus bactrianus. Although several reports and databases analyze the structure of sdAbs, comprehensive evaluations on species-dependent structural differences remain scarce. Methods: We assembled MO-IISA, an open-access curated database of sdAbs with known antigen targets by integrating six public resources (iCAN, INDI, SAbDab-nano, sdAb-DB, PLabDab-nano, NbThermo) under harmonized eligibility criteria. Results: The final dataset comprises 2053 sdAbs derived from llamas (Lama glama, n = 1316); alpacas (Vicugna pacos, n = 325), dromedary camels (Camelus dromedarius, n = 377) and Bactrian camels (Camelus bactrianus, n = 35). We quantified region lengths, amino acid frequency, and conservation/entropy across frameworks (FR1–FR4). The average length of all sdAbs was about 124 ± 8 amino acids, with minor interspecies differences. We observed a consistent enrichment of lysines in FR3 (and secondarily FR2) and cysteines primarily in FR1 and FR3, with non-canonical cysteines more frequent in Bactrian and dromedary sdAbs CDRs. CDR2 and, particularly CDR3, contributed most to inter- and intra-species variability, whereas FRs were highly conserved. Conclusions: Species-neutral framework constraints and species-tuned loop adaptations have practical implications for sdAb engineering, species selection, and conjugation strategies. These features are captured in MO-IISA, an open-access database of known-target sdAbs from different species. Full article

Limited accessibility, mountainous geography, and seismic conditions have posed challenges to both the preservation and the transmission of knowledge inherited from the Incas. Therefore, this research aims to analyze the ancestral Inca construction systems and their relationship with the Inca worldview through an architectural and structural study of the archaeological site of Choquequirao, located in Cusco, Peru. The research integrates geographic, climatic, spatial, functional, and constructive dimensions, applying digital 3D modeling tools (AutoCAD 2025, SketchUp 2024, and Sun-Path 2024) to assess the orientation, stability, and symbolic configuration of the main sectors. The results of the functional and constructive analysis reveal that Choquequirao incorporates adaptive principles in response to seismic and microclimatic conditions, as well as constructive typologies planned from an integral architectural perspective. These elements allow a clearer understanding of the spatial organization of the site and its cultural significance. Moreover, the study covers ten sectors distributed across 1800 hectares. The upper sector (4 ha) stands out for its architecture and political–ceremonial function; the lower sector (4 ha) includes ritual, administrative, residential, and storage areas for camelids; the southern sector (5 ha) contains the ushnu and priestly enclosures on terraces; and the eastern (7 ha) and western (2 ha) slopes integrate agricultural and residential uses. The study of Choquequirao highlights its complex organization and addresses contemporary challenges in terms of conservation and development. These findings provide essential insights for future restoration and conservation strategies that respect traditional construction systems and their environmental adaptation. Full article

The Middle East Respiratory Syndrome coronavirus (MERS-CoV) remains a highly significant threat to global public health. Dromedary camels are the zoonotic source of human infection. All cases of zoonotic Middle East Respiratory Syndrome (MERS) have occurred in Middle Eastern countries despite MERS-CoV infection of camels being widespread in Africa. This disparity in the geographic burden of the disease may be due to genomic differences between MERS-CoV circulating in Middle Eastern countries (clades A and B) versus those infecting camels in Africa (clade C), although the precise genetic determinants of virulence remain to be elucidated. The objective of the studies reported here was to evaluate differences in the magnitude of virus shedding and in transmissibility of clades A/B and C viruses using alpacas as a surrogate for dromedary camels. We found that two of three African-origin, clade C strains of MERS-CoV induced very reduced levels of virus shedding and were transmitted inefficiently to contact control animals as compared to one other clade C virus and representative viruses from clade A and B. Lower virus titers in the nasopharynx may be associated with lower zoonotic transmission and human disease severity and may explain the observed epidemiology of MERS-CoV in Africa where zoonotic disease appears rare. These results add to our understanding of the transmission of different lineages of MERS CoV in camelids and zoonotic transmission. Full article

Male fertility is important to ensure herd health and productivity. The camelid male breeding soundness examination (BSE) is strongly recommended because natural mating remains the primary breeding method due to the challenges in semen cryopreservation and artificial insemination. Guidelines for the BSE have been proposed but not adopted in practice. The investigation of male reproductive failure includes history, general health examination, examination of the genitalia, semen evaluation, and testing for contagious diseases. Difficulties in ejaculate collection and semen viscosity are challenges in camelid male fertility investigation. This review summarizes the outcomes of BSE in our practice on South American camelids (SACs) and camels. The results and discussion are presented under four main categories: congenital defects, impotentia coeundi, impotentia generandi, and male reproductive emergencies. There is a difference between camels and SACs in the incidence of various disorders. Congenital defects are common in SACs in particular cryptorchidism, testicular hypoplasia and rete testis cysts. Orchitis is more common in camels, particularly in areas where brucellosis is prevalent. Testicular degeneration occurs in all camelids and has been associated with heat stress, aging, systemic diseases and overuse of anabolic steroids. Precise diagnosis of fertility impairment may require disease testing, testicular biopsy, cytogenetics and endocrine evaluation. A significant proportion of males are referred because of reproductive emergencies, due to poor management, which results in loss of genetic potential. Implementation of regular BSE is possible in SACs but can be difficult in dromedaries because of the large variation in breed characteristics and management systems. Full article

Camelids are increasingly recognized as important livestock species. They are valuable sources of meat, fiber, and milk. Despite their growing popularity, many aspects of their reproductive physiology and pathology remain unclear. Their reproductive performance is reported to be low in many countries. Advances in camelid veterinary care have identified several disorders, some of which are species-specific. This article describes an approach to and the diagnosis of infertility and subfertility cases in alpacas, llamas, and camels referred to the authors over the past 35 years. Ultrasonography, endometrial cytology, and biopsy are the primary diagnostic tools for practitioners. However, laparoscopy, hysteroscopy, and cytogenetics are indicated for cases referred to theriogenologists. The incidence of congenital and acquired reproductive disorders is presented. A high incidence of congenital defects of the reproductive tract is found in South American camelids, which raises concerns about animal welfare. Acquired disorders are similar to those described in other species. Endometritis and endometrosis are major disorders contributing to infertility and early pregnancy loss. However, studies on uterine defense mechanisms and the pathogenesis of these disorders are lacking. Hydrobursitis, a common cause of infertility in dromedary camels, warrants further research. The implications of some contagious diseases (tuberculosis, campylobacteriosis, and brucellosis) in female infertility are discussed. These findings emphasize the importance of including camelid medicine in veterinary education to ensure a high standard of care for this species. Full article

Gastro-intestinal nematodes (GINs) are still of great concern in grazing ruminants, such as camelids, ovines and caprines, affecting animal health and productivity. This is mainly due to the development of anthelmintic resistance (AR) to the compounds used long term, without much evaluation on their efficacy, including ivermectin (IVM), the most used anthelmintic drug in livestock. The aims of this study were to determine the efficacy of IVM and identify which GIN species are affecting different ruminant farms in Quebec (QC), Canada. Firstly, we collected fecal samples from six farms with different ruminant species (camelids, goats and sheep) before and after IVM treatment when applicable, analyzing them by Fecal Egg Count (FEC) and further assessments on IVM efficacy through the Fecal Egg Count Reduction Test (FECRT). In addition, molecular analyses were conducted using PCR, targeting the ITS-2 and COX-1 genes to identify GIN species. FECRT was applied only for three farms, showing that variable results with optimal efficacy (ranging from 95.5–100%) were obtained in only one farm, whereas on the other two farms, FECRT exhibited reduced efficacy, suggesting the development of IVM resistance. Among the GIN species found, Haemonchus contortus and Trichostrongylus vitrinus were identified in most of the farms, being present in sheep, goat, llama and alpaca farms, whereas Teladorsagia circumcincta was identified only in sheep and llama samples from four farms but not in alpaca samples. Trichostrongylus axei and Chabertia ovina were present in two farms (sheep and sheep and llamas). Oesophagostomum venulosum was detected in one sheep and one alpaca farm. Only one sheep farm was positive for Trichostrongylus colubriformis and Cooperia curticei. Also, Nematodirus spp. and Trichuris spp. were found in four farms, including sheep and camelids. In addition, three other species were found in camelids, including Camelostrongylus mentulatus (only in the llama samples), whereas Lamanema chavezi and Marshallagia marshalli were identified in one alpaca farm. Therefore, our work reports evidence of an uneven efficacy of IVM against GINs from ruminant farms, including the most likely emergence of IVM resistance. The diversity of GIN species found in ruminant farms in QC along with the inconsistent IVM efficacy are helpful information for veterinarians and animal producers in setting an optimal parasite management programs, including the proper use of IVM and alternative anthelmintic drugs to control these pathogens in grazing livestock. Full article

Host phylogeny can imprint the gut microbiota, but it is often masked by diet and environment. Leveraging the standardized husbandry of a zoological collection, we profiled fecal microbiota from 55 captive artiodactyls representing 12 species in Bovidae, Cervidae, and Camelidae using 16S rRNA amplicon sequencing targeting the V3–V4 region on the Illumina MiSeq platform. Community composition differed significantly among host families (Bray–Curtis PERMANOVA, R² = 0.1075, p = 0.001). A host–microbiota tanglegram, which juxtaposes the host phylogeny with a dendrogram of microbiota similarity, recovered a topology congruent with the host phylogeny, with camelids forming a distinct branch separate from true ruminants in both trees. The linear discriminant analysis effect size (LEfSe; LDA ≥ 3.5) identified family-specific biomarkers, including enrichment of Acinetobacter/Moraxellaceae in Bovidae, Rikenellaceae (the Rikenellaceae_RC9_gut_group) in Cervidae, and Rummeliibacillus together with the Christensenellaceae_R-7_group in Camelidae. Functional inference with PICRUSt2 revealed significant differences in KEGG level-2 pathways (e.g., carbohydrate metabolism and xenobiotics biodegradation), consistent with taxonomic shifts. Altogether, these findings show that—even under uniform captive conditions—host evolutionary history remains a primary determinant of both the structure and the predicted functions of the artiodactyl gut microbiota, refining the scope of phylosymbiosis and providing actionable baselines for veterinary monitoring and conservation management in zoo settings. Full article

This study aimed to determine herd prevalence of tail alterations (deviated and shortened tails) on farms in Germany. In total, 86,355 cows on 765 dairy farms in three regions (North, South, East) were assessed for presence or absence of deviated and shortened tails. Mean herd prevalence of deviated tails was 10.00% with a median of 7.89%. The mean herd prevalence of shortened tails was 1.07% with a median of 0%. Herd size, energy-corrected milk yield (ECM), and husbandry system were associated with herd prevalence rates of tail deviations and shortened tails. Herd prevalence increased with herd size (Spearman’s ρ = 0.586) and median ECM (ρ = 0.404). 28.10% farms had a herd prevalence <5% tail alterations, while 26.41% had a herd prevalence of >15%. Our findings plead for including monitoring of tail alterations in animal welfare assessments of dairy farms. The National Dairy FARM Program in New Zealand aims to achieve a herd prevalence of less than 5%. A herd prevalence of >15% tail alterations is regarded as the critical threshold requiring clarification and elimination of causes. It is imperative that all dairy farms strive to achieve a herd prevalence of less than 5% and welfare protocols are duly adjusted. Full article

Background: Bispecific antibodies have emerged as a promising class of therapeutics, enabling simultaneous targeting of two distinct antigens. Single-domain antibodies (sdAbs) comprising camelid variable heavy chains (VHHs) provide a compact and adaptable platform for bispecific antibody design due to their small size and ease of linkage. Methods: Here we investigate structure-activity relationship of VHH-based cytokine surrogates by combining cell signaling and functional assays with x-ray crystallography and other biophysical techniques. Results: We describe crystal structures of four unique bispecific VHHs that engage and activate the cytokine receptor pairs IL-18Rα/IL-18Rβ and IL-2Rβ/IL-2Rγ. These bispecific VHH molecules, referred to as surrogate cytokine agonists (SCAs), create unique cytokine signals that can be tuned by linker engineering. Our structural analysis reveals multiple dimeric conformations for these bispecific SCAs, where the two VHH domains can interact to form a compact structure. We demonstrate that the dimeric conformation can be enforced via engineering of a non-native disulfide bond between the VHH subunits, thus enhancing molecular thermostability. Conclusion: Our findings have important implications for the design and engineering of bispecific VHHs or sdAbs, offering a novel strategy for tuning their activity and increasing their stability. Full article

Background. We are developing cytotoxic anti-HIV immunoconjugates to attack the reservoir of infected cells that persist after years of fully suppressive anti-retroviral therapy. Methods. We have produced a chimeric fusion protein, J3ExoA, consisting of J3VHH, a broadly reactive anti-gp120 camelid nanobody, joined to the de-immunized PE38 fragment of Pseudomonas exotoxin A. The efficacy of J3ExoA was compared to that of a well-studied anti-gp41 immunotoxin (IT), 7B2-dgA, in cytotoxicity assays and for inhibition of infectivity. Immunogenicity of the ITs was tested in mice. Results. J3ExoA killed cells expressing the HIV envelope with specificity in concentrations in the ng/mL range. Of all anti-HIV ITs we have tested, only J3ExoA compared to 7B2-dgA in cytotoxic efficacy, although there were differences between the two ITs on different target cells. J3ExoA suppressed the spread of HIV infection in tissue culture. J3ExoA was less immunogenic than 7B2-dgA, but mice made antibodies to both portions of the fusion protein. Conclusions. J3ExoA represents a novel IT that may be used to eliminate infected cells in the persistent HIV reservoir of infection, the barrier to an HIV “cure.” Additional approaches for addressing IT immunogenicity are discussed. Full article

Australian alpacas contribute to a developing alternative fibre industry with an increasing number of larger-scale enterprises requiring real-time management options. This study aimed to investigate the ability of GNSS real-time tracking tags to monitor alpaca herd behaviour in an extensive production system and assess their suitability as a future management tool. A total of 32 alpacas were fitted with collar-mounted GNSS tracking livestock tags, and an additional 32 alpacas were used as a control group without tags. Both Huacaya (n = 32) and Suri (n = 32) breeds were included. There was no effect of treatment on body condition score change (p = 0. 3648). Breed had a significant effect on distance travelled (p < 0.0184), with Suri alpacas travelling 1.03 (±0.058) km and Huacayas 0.9 (±0.058) km per day. Season significantly impacted the distance travelled each day (p< 0.0001), with alpacas moving a greater distance in winter and spring compared to summer and autumn. The alpacas displayed an increase in activity between 0600 and 1600, with the majority (60%) of their activity occurring during daylight hours. This study outlines normal paddock behaviour for extensively raised alpacas in Australia and showcases the potential for GNSS remote monitoring technology to be utilised as a management tool. Full article

The Australian alpaca industry is continuing to develop as an alternative fibre industry to the traditional merino or angora industries. This study aimed to investigate herd behaviour in an extensive system in south eastern Australia. Healthy adult female alpacas (Huacaya n = 32, Suri n = 32) over two years old were inducted into the trial and kept together across a 10 month period. A total of 5 animals were removed during the study due to illthrift or death unrelated to the study. GoPro cameras were set up at 5 locations in the paddock for 3 days in the middle of every season (Summer, Autumn, Winter, Spring) to record alpaca behaviour without a human observer present. Visual observations were taken at 0800, 1000, 1100, 1300, 1500 for 60 min. Behaviour observations were taken every 5 min from the videos according to a prepared ethogram. A count of animals exhibiting each behaviour was recorded at each time point within each of the designated 60-minute periods. A generalised linear mixed-effects model (GLMM) was run on binary data for each behaviour. Behaviours that returned a predicted proportion of over 0.10 for all seasons were used in an ordinal logistic regression that was then utilised to determine the effect of the season, time of day, and weather conditions on the number of animals. Season significantly impacted the number of alpacas grazing, resting, and standing (p < 0.0001). Alpacas were more likely to be grazing throughout the day in cooler seasons (autumn, winter) and resting in the warmer parts of the day in summer and spring. The time of day impacted the proportion of alpacas resting and grazing (p < 0.05) but not standing (p = 0.4432). This study highlights that alpacas spend the majority of the daylight hours grazing, with some variability across different seasons, which may impact ideal management practices to optimise production in an extensive system. Full article

ET is used in camel reproduction to increase the reproductive potential of elite females selected for production and show. This retrospective study analyzed the association between factors related to embryo flushing (flushing fluid turbidity and debris), embryo quality (grades 1–4), recipient uterine status (tone and endometrial microcalcifications (EM)), farm and its locations (Qassim and Hail), as well high and low temperature on the likelihood of establishment of the 2-month pregnancy rate (PR) in dromedary camels. A total of 4360 embryos were transferred to 2947 recipients in this study. Logistic regression analysis (binary) was applied to evaluate the association between the selected factors and PR in month two. The likelihood of PR was affected by embryo quality (p < 0.01), EMs (p < 0.01), and farm (p < 0.05) and its location (p < 0.01). Transferring embryos to low (p < 0.01) or medium (p < 0.05) EM recipients decreased the likelihood of PR by ~1.3 times compared to uteri without EM. Grade 3 or 4 embryo transfer decreased the likelihood of PR by ~1.9 and 2.6 times, respectively, compared to grade 1 embryos (p< 0.01). In Saudi Arabia, applying an ET program in dromedaries in the Hail region raised the prediction of PR over the Qassim region by 1.2 times. Temperature changes had no effect on PR; however, higher temperature only affected the PR when grade 4 embryos were transferred. In conclusion, the likelihood of PR was higher with the transfer of grade 1 or 2 embryos in an EM-free uterus in the Hail region (Saudi Arabia). PR was only affected by higher temperature in the case of transferring grade 4 embryos. Full article

This study aimed to perform ultrasonography of the tympanic bulla in healthy, non-sedated camelids for the first time. In the first step, dissection and sonography in cadaver specimens allowed the essential identification of the anatomical structures of the region of interest. Ultrasonography of the tympanic bulla was then performed on 71 healthy llamas and alpacas, and the length of the visible lateral bulla wall was measured sonographically. The reproducibility of measuring was determined between two examiners. Differences in length and the influences of gender, age, and body condition scores were monitored. A 10 MHz linear probe was positioned in the rostrocaudal and dorsoventral directions caudal to the mandibular ramus and ventral to the base of the ear using a lateral approach. The equipment used proved to be appropriate to visualize the tympanic bulla, the zygomatic bone, the paracondylar process, the external ear canal, and the parotid gland in the cadaver specimens and all live animals. Llamas revealed a significantly longer visible lateral bulla wall than alpacas, but its length was not influenced by gender, body condition score, or age. In alpacas, older females showed a significantly shorter tympanic bulla wall. The intra- and inter-observer reliability yielded a significant agreement. Based on this study’s results, ultrasonography may serve as a non-invasive diagnostic tool for detecting osseous and soft-tissue changes in camelids with otitis media. Full article