First report of Babesia bigemina in Lama glama in a zoological garden of Veracruz, Mexico

Zoological gardens represent specialised centres for the preservation of biological inventories and genetic diversity, allowing the recognition of multiple species in critical conservation categories. However, the close coexistence of multiple species of vertebrates that may be associated with various species of ectoparasites may be the cause of the transmission of multiple infectious agents, among which tick-borne pathogens stand out. In these areas, several animal species usually live in a small space and proximity to other wildlife, visitors and keepers. In Mexico, little is known about the disease agents transmitted by arthropods in zoological gardens. For this reason, the aim of this study was to identify the presence of Babesia/Theileria in animals maintained in captivity. As a part of a project identifying vector-borne pathogens in wildlife, 24 animals were sampled in the Miguel Angel de Quevedo zoo. Molecular identification of Babesia/Theileria was realised through amplification of a fragment of the mitochondrial cytB gene and the ribosomal 18S-rDNA. Two neotropical camelids (Lama glama) tested positive (2/3 = 66.6%) to Babesia bigemina. Our results represent the first record of B. bigemina in animals in captivity in a zoological garden in Mexico and the first finding of this haemoparasite in neotropical camelids in Mexico.

Development of High affinity Nanobodies Specific for NaV1.4 and NaV1.5 Voltage-Gated Sodium Channel Isoforms

Voltage-gated sodium channels, Na_Vs, are responsible for the rapid rise of action potentials in excitable tissues. Na_V channel mutations have been implicated in several human genetic diseases, such as hypokalemic periodic paralysis, myotonia, and long-QT and Brugada syndromes. Here, we generated high-affinity anti-Na_V nanobodies (Nbs), Nb17 and Nb82, that recognize the Na_V1.4 (skeletal muscle) and Na_V1.5 (cardiac muscle) channel isoforms. These Nbs were raised in llama (Lama glama) and selected from a phage display library for high affinity to the C-terminal (CT) region of Na_V1.4. The Nbs were expressed in Escherichia coli, purified, and biophysically characterized. Development of high-affinity Nbs specifically targeting a given human Na_V isoform has been challenging because they usually show undesired crossreactivity for different Na_V isoforms. Our results show, however, that Nb17 and Nb82 recognize the CTNa_V1.4 or CTNa_V1.5 over other CTNav isoforms. Kinetic experiments by biolayer interferometry determined that Nb17 and Nb82 bind to the CTNa_V1.4 and CTNa_V1.5 with high affinity (K_D ∼ 40–60 nM). In addition, as proof of concept, we show that Nb82 could detect Na_V1.4 and Na_V1.5 channels in mammalian cells and tissues by Western blot. Furthermore, human embryonic kidney cells expressing holo Na_V1.5 channels demonstrated a robust FRET-binding efficiency for Nb17 and Nb82. Our work lays the foundation for developing Nbs as anti-Na_V reagents to capture Na_Vs from cell lysates and as molecular visualization agents for Na_Vs.

From the Andes to the Apennines: Rise and Fall of a Free-Ranging Population of Feral Llamas

Simple Summary

Domestic mammals may become invasive alien species when introduced within natural environments and when they establish reproductive populations. One of the most common pathways of species introduction is represented by intentional or accidental escapes from confined environments, including zoos, farms and enclosures. A feral population of llama Lama glama has been present in Central Italy since 2016 after escaping from a zoological garden. In 2020, only three individuals were confirmed to be still present within a 40-hectare area, following a field survey. We carried out questionnaires with the resident human population to determine the local perception and the acceptance of two possible management actions, i.e., direct killing and surgical sterilization. Llamas are quite docile domestic animals, thus local perception was, in general, very positive and also linked to the exotic origin of the species, making llamas a welcome observation and a pleasant surprise. The observed decline of this population may be due to predation by wolves and poaching, together with the lack of suitability of natural environment, which may have prevented llamas establishing an invasive population. In this context, however, individual removal action should be conducted before the population shows a demographic rebound.

Abstract

Since 2016, a feral population of llama Lama glama has been present in Central Italy after escaping from a zoological garden and starting to reproduce. We updated demographic status and distribution of this population and investigated societal perception towards the llama presence and management in the area through a standard questionnaire. Field data were collected through direct (transects traveled by car and on foot) and indirect (newspapers, social networks and online platforms) research. The feral population appears to be declining. In July 2020, the population was represented by three individuals (one male and two females), identified also through photoidentification, most likely located within a 40-hectare area. The majority of citizens are aware of the presence of feral llamas and show a positive attitude toward them and a negative one toward management actions. The case of feral llamas in Italy is an evident example of unsafe management of a species which should have kept in a zoo and which, once set free, was able to catalyze the attention of the general public. The decline of this population limits the need of drastic management actions that, given the appreciation expressed by people and press toward these animals, would have been at risk of conflict with the public opinion. Removal action should be rapidly taken, i.e., before any demographic rebound and before the population becomes a stable feature of the local landscape.

Effect of Cooling and Freezing on Llama (Lama glama) Sperm Ultrastructure

Semen cryopreservation in South American camelids has a low efficiency. Post-thaw viability of sperm is low, and poor results are obtained when artificial insemination is performed with cryopreserved semen, impeding advances both in accelerated genetic progress and selection. This study aimed to describe the effect of a conventional method of camelid semen cryopreservation on the llama sperm ultrastructure during cooling and freezing, using transmission and scanning electron microscopy (TEM, SEM). Sperm motility, vigor, viability, and DNA integrity during those steps were also examined. Ejaculates from five fertile adult llama males were obtained by electroejaculation. For cooling, semen samples were washed with Hepes-balanced salt solution (HBSS), diluted in Tris-citric acid-fructose egg yolk extender (TCF-EY), and then cooled until 5°C for 24 h. For freezing, sperm samples were washed with HBSS, diluted in TCF-EY and cooled until 5°C for 2.5 h. Samples were equilibrated with TCF-EY, supplemented with 6% glycerol at 5°C for 20 min, and then stored in liquid nitrogen for a month before thawing. TEM and SEM analyses were carried out on sperm samples prior to cryopreservation, after cooling down until 5°C for 2.5 and 24 h, and after the freeze-thaw process. Ultrastructural injury was noticed during cooling, even though sperm motility, vigor, viability, and DNA integrity were not significantly affected. Analysis revealed plasma membrane and acrosome damage, loss of mitochondria, and axoneme and periaxonemal structure disorganization after 2.5 h of cooling. During freezing, a significant decrease in sperm motility and viability was observed after thawing. TEM and SEM revealed prominent signs of post-thawing damage. The plasma membrane was lost or exhibited various degrees of swelling, undulation, and perforations. Besides, the sperm presented vacuoles in the nucleus and broken acrosomes. Mitochondria in the midpiece showed vacuolization and structural disorganization. In conclusion, SEM and TEM revealed that cryopreservation induced ultrastructural damages in llama sperm that initiated during cooling and intensified during freezing. These details provide valuable data for further studies to minimize cryodamage in camelid sperm.

South American Camelids: their values and contributions to people

South American Camelids (SACs) make several material and non-material contributions to people and are a key component of the Andean biocultural heritage. From the perspective of the IPBES' Conceptual Framework, SACs constitute the "nature" component in the complex system of interactions between human societies and the Andean mountain environment. There are four SAC living species today, two of which are wild, or Salqa, in the indigenous cosmovision: guanaco (Lama guanicoe) and vicuña (Vicugna vicugna). Llama (Lama glama) and alpaca (Vicugna pacos) were domesticated 5000 years ago, and are therefore Uywa, in the indigenous cosmovision. Both wild and domestic camelids were, and in several cases still are, the most highly appreciated resource for Andean livelihoods. Historically, camelids and their contributions have been used by Andean people since the peopling of the Americas over 11,000 years ago. In this paper, we present three case studies (chakus for vicuña management, llama caravans, and llama nanobodies) to bring attention to the essential role of vicuñas and llamas for Andean communities today, their intercultural linkages with the Western world, and telecoupling interactions.

Effect of mating on mRNA and protein expression of beta nerve growth factor and its receptor, TrKA, in the oviduct of llama (Lama glama)

Copulation produces different stimuli in the female reproductive tract in camelids, which lead to ovulation. Expression of β-nerve growth factor (β-NGF) and its specific receptor, tropomyosin receptor kinase A (TrKA), was studied comparing the oviductal microenvironment of mated and nonmated llamas. β-NGF and TrKA were expressed in the llama ampulla, isthmus, and utero-tubal-junction (UTJ), and they were mainly colocalized in the apical region of the oviductal mucosa. A TrKA immunosignal was also found in muscle cells and blood vessels, with the highest mark in UTJ muscle cells of copulated females. Both β-NGF and TrKA transcripts were expressed in the three oviductal segments. Relative TrKA abundance did not differ between mated and nonmated females, but relative β-NGF abundance was higher in the UTJ of copulated females (p < .05). β-NGF might not be secreted into the oviductal fluid (OF) since the protein was not found in the OF of mated or nonmated females. Therefore, it can be concluded that the llama oviduct expresses the β-NGF/TrKA system and that an increase in β-NGF gene expression in the UTJ 24 h after copulation along with an increase in TrKA protein expression may indicate an important role in the gamete transport and fertilization process in llamas.

New protocol to separate llama sperm without enzymatic treatment using Androcoll-E™

The objective of this study was to design a protocol to separate spermatozoa from seminal plasma of raw llama semen without prior enzymatic treatment using a single-layer centrifugation with Androcoll-E^™ (AE). Two experiments were performed: (a) samples were divided into three aliquots (1 ml) that were deposited on the top of 4, 5 or 6 ml of AE and were centrifuged at 800g for 20 min and (b) samples were divided into two aliquots (1 ml) that were deposited on the top of 4 ml of AE and were centrifuged at 600g or 1,000g for 20 min. Columns of 5 and 6 ml of AE showed a total sperm motility (TM) significantly lower, while in the 4 ml column, this parameter was not different from the TM of samples before the AE treatment. The percentage of spermatozoa with intact and functional membranes, normal morphology and intact acrosomes, as well as the percentages of sperm with highly condensed chromatin, was conserved (p ˃ .05) in the three column heights and in the two centrifugation speeds evaluated. In conclusion, the different column heights of AE (4, 5 and 6 ml) and the different centrifugation speeds used (600, 800 and 1,000g) allow separating spermatozoa of raw llama semen without enzymatic treatment, preserving the evaluated sperm characteristics. However, of all the studied treatments, centrifugation in the 4 ml column of AE at 800g would be the method of choice to process raw llama semen samples destined for reproductive biotechnologies.

Toxoplasma gondii and Neospora caninum infections in South American camelids in Switzerland and assessment of serological tests for diagnosis

Background

Little is known about the epidemiology of Toxoplasma gondii and Neospora caninum infections in alpacas (Vicugna pacos) and llamas (Lama glama) outside South America. The study aimed to estimate the seroprevalence of T. gondii and N. caninum infections in South American camelids (SAC) in Switzerland, to optimize serological tests for SAC and to identify risk factors, which may favour infection.

Methods

A total of 571 sera from 132 Swiss farms (374 alpacas and 197 llamas, mean 4.3 animals/farm) were obtained. Four commercial enzyme-linked immunosorbent assays (ELISA) for detecting antibodies against T. gondii (ID Screen^® Toxoplasmosis Indirect (TOXO-MS)) or N. caninum (i.e. ID Screen^® Neospora caninum Indirect Multi-species (NCS-MS); ID Screen^® Neospora caninum Competition (NCC) and ID Screen^® Neospora caninum Indirect (NCS)) were first assessed for their use on SAC comparing their results with those in immunoblot, and optimizing cut-offs. Subsequently, two kits (TOXO-MS and NCS-MS) were selected for seroprevalence estimation. Additionally, a risk factor analysis for infection was performed on 41 farms, which agreed to participate in a web-based survey.

Results

Three kits (TOXO-MS, NCS-MS and NCC) showed almost perfect agreement (kappa > 0.901) with immunoblot results when the cut-offs were optimized, and one kit (NCS) proved not to be useful for detecting N. caninum seropositive SAC. By TOXO-MS ELISA, 82.3% (308/374) of the alpacas and 84.8% (167/197) of the llamas were seropositive for T. gondii, and 131/132 (99.2%) farms had seropositive animals. By NCS-MS ELISA, 3.5% (13/374) of the alpacas and 2.5% (5/197) of the llamas evidenced antibodies against N. caninum, and 9.1% (12/132) of the farms had seropositive animals. The variables “age” and “female sex” were identified as risk factors for T. gondii infection and “absence of cats in the farm during the last two years” as a protective factor. No risk or protective factors for N. caninum infection could be identified.

Conclusions

This nationwide cross-sectional study demonstrated for the first time the presence of antibodies against T. gondii and N. caninum in the Swiss SAC population, highlighting a high seroprevalence for T. gondii, the presence of cats as a risk factor and suggesting that SAC meat might represent an additional infection source for humans.

Genetic Diversity and Population Structure of Llamas (Lama glama) from the Camelid Germplasm Bank-Quimsachata

Llamas (Lama glama) are invaluable resources of Peru. Despite their importance, their population is decreasing. The Camelid Germplasm Bank-Quimsachata was created as a guardian of this South American camelid (SAC) species and established a bank of llamas from their two types, Ch'aku and Q'ara. However, these populations need to present high genetic diversity to be considered suitable conservation stocks. Thus, in the present study, 13 microsatellites specific for the SAC were used to assess the current genetic variability and differentiation of the llama population from the Bank. The global population showed high genetic diversity with a total of 157 different alleles, with an average of 12.08 alleles per microsatellite, an expected and observed heterozygosity of 0.758 and 0.707, respectively, and an average polymorphic information content (PIC) of 0.723. Although considered as two different breeds and managed separately, the genetic differentiation between Ch'aku and Q'ara was low (FST = 0.01). Accordingly, the gene flow value was high (Nm = 30.5). Overall, our results indicate the existence of high genetic variation among individuals, and thus, this llama population could be considered a suitable genetic stock for their conservation and for sustainability programs. Additionally, the 13 microsatellites can be used to study other Peruvian llama populations and monitor the genetic variability of llamas from the Camelid Germplasm Bank-Quimsachata.

Incubation of frozen-thawed llama sperm with seminal plasma

Seminal plasma is intimately connected to sperm physiology and particularly in South American Camelids, has demonstrated to be involved in multiple physiological reproductive events. Different percentages of seminal plasma (0%, 10% and 50%) were added to thawed llama semen samples with the objective of evaluating the interaction with cryopreserved sperm over time (0, 1.5 and 3 hr at 37°C). A total of 20 ejaculates from five adult llama males (n = 5; r = 4) were evaluated. A significant decrease in sperm motility, membrane function and live sperm was observed in all thawed samples (0%, 10% and 50%) at 0 hr when compared to raw semen. Neither morphology nor chromatin condensation was altered in all thawed samples (p > .05), but a significant increase in the percentage of spermatozoa with fragmented DNA was observed after thawing all samples versus raw semen. When evaluating thawed samples over time, a significant decrease of motility and membrane function was observed, while the percentages of total live sperm were preserved over the 3 hr of incubation in all final concentrations evaluated. To conclude, the addition of 10% or 50% of seminal plasma was incapable of preserving motility or membrane function of frozen-thawed llama sperm during 3 hr of incubation.

TYR Gene in Llamas: Polymorphisms and Expression Study in Different Color Phenotypes

Tyrosinase, encoded by TYR gene, is an enzyme that plays a major role in mammalian pigmentation. It catalyzes the oxidation of L-dihydroxy-phenylalanine (DOPA) to DOPA quinone, a precursor of both types of melanin: eumelanin and pheomelanin. TYR is commonly known as the albino locus since mutations in this gene result in albinism in several species. However, many other TYR mutations have been found to cause diluted phenotypes, like the Himalayan or chinchilla phenotypes in mice. The llama (Lama glama) presents a wide variety of coat colors ranging from non-diluted phenotypes (eumelanic and pheomelanic), through different degrees of dilution, to white. To investigate the possible contribution of TYR gene to coat color variation in llamas, we sequenced TYR exons and their flanking regions and genotyped animals with diluted, non-diluted, and white coat, including three blue-eyed white individuals. Moreover, we analyzed mRNA expression levels in skin biopsies by qPCR. TYR coding region presented nine SNPs, of which three were non-synonymous, c.428A > G, c.859G > T, and c.1490G > T. We also identified seven polymorphisms in non-coding regions, including two microsatellites, an homopolymeric repeat, and five SNPs: one in the promoter region (c.1-26C > T), two in the 3'-UTR, and two flanking the exons. Although no complete association was found between coat color and SNPs, c.1-26C > T was partially associated to diluted phenotypes. Additionally, the frequency of the G allele from c.428A > G was significantly higher in white compared to non-diluted. Results from qPCR showed that expression levels of TYR in white llamas were significantly lower (p < 0.05) than those in diluted and non-diluted phenotypes. Screening for variation in regulatory regions of TYR did not reveal polymorphisms that explain such differences. However, data from this study showed that TYR expression levels play a role in llama pigmentation.

Isolation of Streptococcus agalactiae in a female llama (Lama glama) in South Tyrol (Italy)

BACKGROUND

Streptococcus agalactiae is pathogenic for both animals and humans. In dairy cattle it commonly causes mastitis, with great economic losses, and there is scientific evidence of mastitis, caseous lymphadenitis, contagious skin necrosis and purulent infections associated with S. agalactiae in camels (Camelus dromedarius) as well. In humans, it is a common component of the respiratory and gastrointestinal microflora, but it can also act as a pathogen, especially in elderly people and immunocompromised patients, as well as in pregrant women and newborns.

CASE PRESENTATION

A 10-year old non-pregnant female llama (Lama glama) was conferred to the Institute for Animal Health Control, in Bolzano for necropsy after sudden death. The animal had not shown unusual behaviour and had a low to normal nutritional condition (body condition score 2/5). The breeder had reported a chronic suppurative subcutaneous infection in the intermandibular area, resistant to therapy (therapy unknown). After necropsy, several samples were processed for histological, bacteriological and parasitological examinations.

CONCLUSIONS

This report describes, to the best of our knowledge, the first isolation of S. agalactiae in llamas (Lama glama). The animal came from a herd that counts approximately 200 South American camelids (llamas, alpacas) along with several horses, chicken, rabbits, cats and dogs; this farm offers services, such as trekking and pet therapy activities.

Gametogony of Eimeria macusaniensis Guerrero, Hernandez, Bazalar and Alva, 1971 in llama (Lama glama)

Camelids (llama, alpaca, vicunãs, guanacos) are important for the economy of South America and Eimeria infections are an important cause of mortality in camelids. Of the six species of Eimeria in camelids, Eimeria macusaniensis, considered the most pathogenic, is distinctive; its oocysts are the largest among all Eimeria species in animals, its prepatent period is more than 1 month, and its oocysts have been found in mummies from prehistoric times. Although, E. macusaniensis gametogonic stages are found associated with enteritis in naturally infected camelids, the schizogonic stages are unknown and clinical disease has been reported in some camelids with no oocysts in feces. Described herein are morphological details of gametogonic development and oocyst formation of E. macusaniensis in a naturally infected llama (Lama lama), solely infected with this parasite. Microgamonts, macrogamonts and oocysts were located in large (up to 300 µm diameter) parasitophorous vacuoles of enterocytes in the ileum. Schizonts were not found. Review of previous reports suggests that multinucleated microgamonts have been mistaken for schizonts. Gametogonic development described in the present study can serve as a guide for differential diagnosis of Eimeria species in the histological sections of intestines.

Identification of Lama glama as Reservoirs for Acinetobacter lwoffii

South American Camelids have an increasing relevance in local economies, worldwide. These animals are bred for their meat, fur and as companion and therapy animals. Thus, their sanitary status should be well-established. According to the OIE (World Organization for Animal Health), respiratory infections mainly produced by Pasteurella spp. have been reported for camelids. It has been stated that this microorganism causes a mild disease, although many authors report it is an important cause of mortality among alpacas. Nevertheless, the incidence of infection by Pasteurella spp. in camelids still needs to be investigated. The aim of the present study was to analyze the occurrence of nasopharyngeal colonization of Lama glama by respiratory bacteria, and to assess the usefulness of serological tests for clinical diagnosis. The colonization was studied by culture techniques carried out with material taken by nasopharyngeal swabs. Bacterial isolates were first phenotypically characterized and then identified by MALDI/TOF-MS. The presence of specific serum antibodies was studied by ELISA and Western blot. In the present work Pasteurella spp. was not found. Nevertheless, we report for the first time, the colonization of L. glama by bacteria of the Acinetobacter lwoffii, at a reliable level in 19.4% of the animals. Acinetobacter species are found in different environmental sources, as well as vegetables, animals, and humans, and their role in infections has recently gained relevance. The results presented herein contribute to a better understanding of the respiratory microbiota in camelids, and increase the knowledge about environmental distribution of Acinetobacter non-baumanii species. Given that these respiratory bacteria might be the cause of infection among cattle, and even humans, this report highlights the need for further research.

Lama glama αS1-casein: Identification of new polymorphisms in the CSN1S1 gene

South American camelids have been poorly genetically investigated and little information is available in llamas (Lama glama) regarding the diversity of the caseins at the protein and gene level. Exon skipping and duplication events previously reported in the α_S1-casein gene (CSN1S1) led us to investigate the genetic variability at this locus. Seventy-two positive clones for the α_S1-casein transcripts were analyzed and randomly sequenced. The comparative analysis of the sequences revealed 2 transitions, c.366A>G and c.690T>C, at the 10th nucleotide of exon 12 and 94 bp of exon 19, respectively. These SNP are responsible for 2 amino acid changes, Ile→Val in position 86 and Tyr→His in position 194 of the mature protein. Both polymorphisms clarify the genetic events behind the protein variants A and B. This result was confirmed by isoelectric focusing analysis of llama milk samples. Quick methods based on PCR-RFLP and allele-specific PCR were set up for allelic discrimination in a population of 128 animals. Based on genotyping results, 4 haplotypes were observed and the estimated frequencies indicated B as the most common haplotype (0.629) in the investigated population. These data add knowledge to the genetic variability of a species little investigated, and open opportunity for new investigation in the field of milk protein for South American camelids, including the possibility, in the future, to select alleles with favorable characteristics.

Combining somatic mutations present in different in vivo affinity-matured antibodies isolated from immunized Lama glama yields ultra-potent antibody therapeutics

Highly potent human antibodies are required to therapeutically neutralize cytokines such as interleukin-6 (IL-6) that is involved in many inflammatory diseases and malignancies. Although a number of mutagenesis approaches exist to perform antibody affinity maturation, these may cause antibody instability and production issues. Thus, a robust and easy antibody affinity maturation strategy to increase antibody potency remains highly desirable. By immunizing llama, cloning the 'immune' antibody repertoire and using phage display, we selected a diverse set of IL-6 antagonistic Fabs. Heavy chain shuffling was performed on the Fab with lowest off-rate, resulting in a panel of variants with even lower off-rate. Structural analysis of the Fab:IL-6 complex suggests that the increased affinity was partly due to a serine to tyrosine switch in HCDR2. This translated into neutralizing capacity in an in vivo model of IL-6 induced SAA production. Finally, a novel Fab library was designed, encoding all variations found in the natural repertoire of VH genes identified after heavy chain shuffling. High stringency selections resulted in identification of a Fab with 250-fold increased potency when re-formatted into IgG1. Compared with a heavily engineered anti-IL-6 monoclonal antibody currently in clinical development, this IgG was at least equally potent, showing the engineering process to have had led to a highly potent anti-IL-6 antibody.