Blood analytes of electrocuted mantled howler monkeys (Alouatta palliata) in the Nicoya peninsula of Costa Rica.

BACKGROUND: Several species of Costa Rican wildlife are suffering terrible injuries along the power lines in rural areas of the country due to the increasing human development in rural areas, but this has also brought the problem of poorly designed electric infrastructure, where arboreal mammals find their normal tree routes cut down so that the only way for them to cross is on the power lines where they can get electrocuted. METHODS: Blood samples for complete blood count (CBC) and biochemistry panels (alkaline phosphatase, aspartate aminotransferase, amylase, total bilirubin, plasma urea, Ca, P, creatinine, glucose, Na, K, total protein, globulins, and albumin) were collected from 34 electrocuted mantled howler monkeys (Alouatta palliata) individuals that arrived at the Nosara Refuge for Wildlife between May 2018 and May 2019. RESULTS: From the total sample, 18 were males (11 juveniles and eight adults), and 16 were females (six juveniles and 10 adults). From those individuals, 13 animals survived: five females (three juveniles and two adults) and eight males (six juveniles and two adults). Then, 22 animals died after the event from 1 to 102 days (22.41 ± 31.17) after they arrived at the center. Of these 22 animals, 11 were females (three juveniles and eight adults), and 11 were males (six juveniles and five adults). CONCLUSIONS: The preliminary results showed significant differences in the plasma glucose, with adults being significantly higher than the juveniles, and there was also a significant difference in the plasma urea with the deceased ones being higher than the ones that survived the incident. These results may provide a better way to understand and predict the possible outcome of an electrical accident with these primates and assist with returning them back to their natural environment in the least time possible.

SEROPREVALENCE AND MOLECULAR CHARACTERIZATION OF FERLAVIRUS IN CAPTIVE VIPERS OF COSTA RICA.

Ferlaviruses (FV, previously referred to as ophidian paramyxoviruses, OPMV), are enveloped viruses with a negative-strand RNA genome, affecting snakes in captivity worldwide. Infection is characterized by respiratory and nervous clinical signs and carries high mortality rates, but no specific treatment or vaccine is currently available. Costa Rica has 16 species of vipers, found in captivity in collections essential for antivenom production, reintroduction, and public education. FV circulation in these populations was previously unknown, and the risk of introducing the viruses into naïve collections or free-ranging populations exists if the virus's presence is confirmed. The objective of this study was to determine seroprevalence and FV shedding in 150 samples from captive vipers in nine collections across Costa Rica. A hemagglutination inhibition (HI) assay was performed to determine the antibody titer against two Ferlavirus strains, Bush viper virus (BV) and Neotropical virus (NT), and reverse-transcriptase polymerase chain reaction (RT-PCR) and sequencing to determine virus secretion in cloacal swabs. Ferlavirus strains were replicated in Vero cells, and chicken anti-FV polyclonal antibodies were produced and used as a positive control serum for the HI. Results demonstrate that seroprevalence of anti-FV antibodies in viper serum was 26.6% (n = 40) for the BV strain and 30% (n = 45) for the NT strain in the population tested. Furthermore, molecular characterization of FV group A was possible by sequencing the virus recovered from three cloacal swabs, demonstrating circulation of FV in one collection. This study demonstrates for the first time serological evidence of FV exposure and infection in vipers in captivity in Costa Rica, and suggests cross reactivity between antibodies against both strains. Appropriate biosafety measures could prevent the spread of FV between and within collections of reptiles in the country.

On the significance of aspartate aminotransferase and creatine kinase in wild reptile health studies.

In reptile medicine, the enzymes aspartate aminotransferase (AST) and creatine kinase (CK) have been used in clinical diagnostics, where CK is considered an enzyme specific to muscle cell damage, while AST is a nonspecific enzyme that is mainly produced in the liver and muscle. When many native reptiles are sampled, it is evident that there are important differences between species and individuals belonging to the same species, making the AST and CK ranges very wide. The minimum and maximum values, variations and standard deviations were extracted for each enzyme from 17 wild reptile studies, revealing high variation and a wide range of variation for each species. AST and CK must be interpreted with caution in wild reptiles since there appears to be an important amount of individual and specific variation due to the muscular origin of these enzymes, and such variations tell us that there are considerable differences between individuals, physiological characteristics or sampling methods; thus, there is no apparent value derived from these kinds of studies on the utility of AST for evaluating liver damage, but the measurement of AST and CK can be useful for reptile health assessments or any manipulative study since they can eventually be used as indicators or potential biomarkers for restraint techniques or holding time.

Hematology and biochemistry parameters of the Central American bushmaster (Lachesis stenophrys) under human care in Costa Rica.

Background: The Central American bushmaster (Lachesis stenophrys) is one of the largest pitvipers in the Americas, with relatively low abundance, suspected population declines, and continuing loss, fragmentation, and habitat degradation. Aim: Conservation actions, both in the wild and in captivity, bear the need for health parameters that allow managers and veterinarians to have a better understanding of health, especially when there are relatively few individuals in captivity to obtain robust information since there is no published information on the genus. To have hematological and biochemical reference ranges on the genus Lachesis. Methods: Blood samples were collected from 32 individuals (18 females and 14 males) under human care from 7 zoological institutions from August 2022 to January 2023 and performed hematological and biochemical analyses. Results: Reference intervals of hematological analytes included packed cell volume (17.51%-37.27%), total red blood cell count (0.36-0.92 × 1012/l), hemoglobin (61.73-145.23 g/l), white blood cell count (3.18-13.79 × 109/l), lymphocytes (2.16%-11.23%), azurophils (0.50%-4.20%), monocytes (0.00%-0.21%), heterophils (0.05%-1.12%), eosinophils (0.00%-0.19%), basophils (0.00%-2.00%), and total thrombocyte count (0.68-6.68 × 109/l), and biochemistry reference intervals included total protein (41.76-111.31 g/l), albumin (11.46-28.69 g/l), globulins (29.25-85.14 g/l), aspartate aminotransferase (1.44-68.75 U/l), creatinine kinase (52.72-625.00 U/l), uric acid (20.02-438.53 µmol/l), glucose (0.68-3.29 mml/l), cholesterol (41.74-13.25 mmol/l), calcium (1.78-6.06 mmol/l), and phosphorus (0.72-2.26 mmol/l). Conclusion: This is the first report on the genus Lachesis reporting hematological and biochemical reference ranges.

First Report of a Multidrug-Resistant ST58 Escherichia coli Harboring Extended-Spectrum Beta-Lactamase of the CTX-M-1 Class in a Fecal Sample of a Captive Baird's Tapir (Tapirus bairdii) in Costa Rica, Central America.

Objective: This study's main objective was to analyze the antibiotic susceptibility profile of Escherichia coli isolates obtained from a fecal sample of a captive Baird's tapir (Tapirus bairdii) in Costa Rica. Materials and Methods: The fecal sample was collected inside the enclosure on March 3, 2017, right after the animal defecated. Samples were cultured on MacConkey agar plates nonsupplemented and supplemented with 2 µg/mL of cefotaxime. Bacterial identification and antibiotic susceptibility were performed with the Vitek 2 Compact System and the Kirby Bauer disk diffusion method, respectively. Polymerase chain reaction amplification was performed to detect blaCTX-M beta-lactamase genes. Resistant isolates were subjected to whole-genome sequencing (WGS). Results: After evaluating several antibiotic classes, a multidrug-resistant E. coli strain with extended-spectrum beta-lactamase phenotype was isolated. Resistance to cefotaxime, cefepime, ampicillin, ampicillin/sulbactam, and tetracycline was detected. WGS analysis showed the presence of blaCTX-M-1, blaTEM-1B, and tet(B) genes. The presence of IncN plasmids and Col156 was also detected. Conclusion: Our findings are according with the notion that animals' high density enhances the spread of resistant determinants in a captive environment in a limited space, where the likelihood of direct or indirect contact with other animals and humans is more frequent.

Health status of Polychrus gutturosus based on physical examination, hematology and biochemistry parameters in Costa Rica.

Studies evaluating the health status and characteristics of free-ranging wildlife populations are scarce or absent for most species. Saurian health assessments are usually performed in species that have conservation issues or that are kept in captivity. The Berthold's bush anole (Polychrus guturossus) is one of eight species belonging to the genus Polychrus, the only representative of the family Polychrotidae. Only a handful of studies have been reported concerning these lizard's morphological variation, ecology, and natural history, probably because P. gutturosus is a canopy dweller and it can be difficult to locate individuals. It is believed that deforestation and habitat modification could pose a threat for this species, although to date no health assessment has been done. The aim of this study was to generate health baseline data on P. gutturosus. Forty Berthold's bush anoles (20 males and 20 females) were sampled at the Pacific versant in Costa Rica, where physical examination, skin and cloacal temperatures, and blood samples were obtained from individuals immediately after capture. Animals from the studied population were all healthy (body condition 2.5-3.0/5.0). No lesions or ectoparasites were detected, but hemoparasites were found in nine individuals. Hematological and biochemical values were obtained, and the morphology of leukocytes were found to be similar to other iguanians. A positive correlation was found between the tissue enzymes aspartate aminotransferase (AST) and creatinine kinase (CK) and a negative correlation was found between skin and cloacal temperatures and AST and CK. There were positive correlations between female weight and total protein, calcium, and the calcium and phosphorus ratio. No significant inter-sex differences were found in biochemical values, despite females being larger than males. This is the first health assessment performed on a free-ranging canopy dwelling lizard. These findings provide baseline data that may be useful for future monitoring if the species faces changes in health status due to anthropogenic causes or natural disturbances.

Demographic and Pathogens of Domestic, Free-Roaming Pets and the Implications for Wild Carnivores and Human Health in the San Luis Region of Costa Rica.

Habitat loss and degradation, restricted ranges, prey exploitation, and poaching are important factors for the decline of several wild carnivore populations and additional stress from infectious agents is an increasing concern. Given the rapid growth of human populations in some regions like Costa Rica, pathogens introduced, sustained, and transmitted by domestic carnivores may be particularly important. To better understand the significance of domestic carnivore pathogens for wildlife, we determine the prevalence of infection and possible mechanisms for contact between the two groups. The demographics, role in the household, and pathogens of pet dogs and cats was studied during three annual spay/neuter clinics in San Luis, Costa Rica. Most dogs were owned primarily as pets and guard animals, but ~10% were used for hunting. Cats were owned primarily as pets and for pest control. Both roamed freely outdoors. We detected high prevalences of some pathogens (e.g., carnivore protoparvovirus 1 and Toxoplasma gondii). Some pathogens are known to persist in the environment, which increases the probability of exposure to wild carnivores. This study demonstrated that domestic pets in San Luis, home to a number of protected and endangered wildlife species, are infected with pathogens to which these wild species are potentially susceptible. Additionally, results from our questionnaire support the potential for domestic and wild animal contact, which may result in disease spillover.

Differences in plasmatic butyrylcholinesterases (BChE) values between Pacific and Caribbean populations of terciopelo (Bothrops asper) in Costa Rica.

The terciopelo (Bothrops asper) inhabits human-modified environments such as agricultural areas, becoming more prone to be exposed to organophosphate insecticides. These chemicals can inhibit plasmatic butyrylcholinesterases (BChE) activity in B. asper. Caribbean and Pacific populations of B. asper belong to two divergent lineages that exhibit robust genetic partitioning; however, differences across versants in biochemistry and hematology have not yet been examined, especially in BChE variations. This study aims to evaluate the differences of BChE plasmatic values, hematology parameters, and some biochemical analytes as biomarkers in the presence of organophosphates between the Pacific and Caribbean population of B. asper in Costa Rica. A total of 89 snakes (41 Pacific and 48 Caribbean) were used, and hematology parameter, albumin, aspartate aminotransferase (AST), total protein and BChEs were evaluated. Differences in hemoglobin content, thrombocytes, white cell count, AST, and BChE values were found between both versants. Intrinsic genetic factors might influence the variation found in BChE and AST values in the snakes sampled from both versants; moreover, understanding this variation in BChE and AST values across the B. asper's distribution can be useful in future ecotoxicology, biomonitoring, genetic and other clinical/health studies.

Effect of exposition to chlorpyrifos upon plasmatic cholinesterases, hematology and blood biochemistry values in Bothrops asper (Serpentes: Viperidae).

The terciopelo (Bothrops asper), is one of the most important venomous snakes in Costa Rica and common on agriculture where insecticides are frequently used for pest control. To assess the exposure to organophosphates on captive B. asper, an experiment using chlorpyrifos and butyrylcholinesterase (BChE), as a biomarker was conducted. In addition to BChE, hematology, aspartate aminotransferase (AST), total proteins (TP) and albumin were measured after exposure. Different concentrations of chlorpyrifos were used in Group A (0.1%) and B (1%), while the Control Group received distilled water; each group was composed of 5 snakes. Values of BChE, AST, TP, and albumin were measured before exposure, and at 6, 12, 24, 196, 360 and 528 h post-exposure. Hematology values were measured after 24 h post-exposure. As result, an important variation between subjects in all groups before exposure was obtained. Moreover, BChE activity showed 37% inhibition of Group A when compared to Control Group at 12 h post-exposure, and a higher inhibition of Group B (97%) related to Control Group, at 6 h post-exposure. Recovery of BChE occurred towards 528 h, never reaching initial values. Despite some variation in the rest of parameters used, a marked relative lymphopenia and monocytosis occurred at 24 h, assuming stress as the main cause.

Haematology and biochemistry of the San Cristóbal Lava Lizard (Microlophus bivittatus).

The San Cristóbal lava lizard, Microlophus bivittatus, is one of nine species of lava lizards endemic to the Galápagos Islands of Ecuador. No information presently exists about baseline health parameters for any of these species. We analysed blood samples drawn from 47 lizards (25 males and 22 females) captured at two locations on San Cristóbal Island. A portable blood analyser (iSTAT) was used to obtain near-immediate field results for total CO2, lactate, sodium, potassium, ionized calcium, glucose and haemoglobin. Standard laboratory haematology techniques were employed for differential white blood cell counts and haematocrit determination. Body temperature, heart rate and body measurements were also recorded. We found significant differences in haematocrit values between males and females. The values reported in this study provide baseline data that may be useful in detecting changes in health status among lava lizards affected by natural disturbances or anthropogenic threats. Our findings might also be helpful in future efforts to demonstrate associations between specific biochemical or haematological parameters and disease. Because there are several related species on different islands in the Galápagos archipelago, comparisons between populations and species will be of interest. Lay Summary:Haematology and biochemistry values of the San Cristóbal lava lizard Microlophus bivittatus, along with several other health parameters (morphometrics and temperature), are reported for the first time.