Molecular eco-epidemiology of Paracoccidioides brasiliensis in road-killed mammals reveals Cerdocyon thous and Cuniculus paca as new hosts harboring this fungal pathogen

Wild animals infected with Paracoccidioides brasiliensis represent important indicators of this fungal agent presence in the environment. The detection of this pathogen in road-killed wild animals has shown to be a key strategy for eco-epidemiological surveillance of paracoccidioidomycosis (PCM), helping to map hot spots for human infection. Molecular detection of P. brasiliensis in wild animals from PCM outbreak areas has not been performed so far. The authors investigated the presence of P. brasiliensis through nested-PCR in tissue samples obtained from road-killed animals collected nearby a human PCM outbreak spot, Rio de Janeiro state, Brazil and border areas. Eighteen species of mammals were analyzed: Dasypus novemcinctus (nine-banded armadillo, n = 6), Cerdocyon thous (crab-eating fox, n = 4), Coendou spinosus (hairy dwarf porcupine, n = 2), Lontra longicaudis (Neotropical river otter, n = 1), Procyon cancrivorus (crab-eating raccoon, n = 1), Galactis cuja (lesser grison, n = 1), Tamandua tetradactyla (collared anteater, n = 1), Cuniculus paca (paca, n = 1), and Bradypus variegatus (brown-throated three-toed sloth, n = 1). Specific P. brasiliensis sequences were detected in the liver, spleen, and lymph node samples from 4/6 (66.7%) D. novemcinctus, reinforcing the importance of these animals on Paracoccidioides ecology. Moreover, lymph nodes samples from two C. thous, as well as lung samples from the C. paca were also positive. A literature review of Paracoccidioides spp. in vertebrates in Brazil indicates C. thous and C. paca as new hosts for the fungal pathogen P. brasiliensis.

Hematological and biochemical profile of captive brown-throated sloths Bradypus variegatus, Schinz 1825, feeding on ambay pumpwood Cecropia pachystachya Trécul 1847

ABSTRACT The aim of this study was to establish reference parameters for the hematological and biochemical levels of five healthy captive sloths of the speciesBradypus variegatus(brown-throated sloth) feeding onCecropia pachystachya(Ambay pumpwood), alternating with a period of free diet in the Dois Irmãos State Park (DISP) Recife, Pernambuco - Brazil.

Where to go when all options are terrible: Ranging behavior of sloths in central Amazonian flooded igapó forests

Ranging behaviors performed by animals are influenced by both biotic and abiotic factors. For herbivorous mammals, seasonality in forage production is considered to be the main driver of movement patterns. Here, we investigated the home range and movement in one of the most abundant herbivores in the Americas, and their relationship with plant phenology in an Amazon igapó - a seasonally-flooded riverine forests with strongly-pulsed leaf-production phenology. Using a combination of telemetry and phenological analysis, the study recorded movement patterns of five brown throated three toed sloths (Bradypus variegatus Schinz, 1825) over a six months period, and related these to seasonal and within-forest differences in food availability via monitoring young leaf production of 570 trees. All monitored animals were shown to be permanently resident within igapó flooded forest, maintaining their home range even during flood periods when most trees lacked leaves. We found that seasonal variation in leaf production had no effect on the extent of displacement of the sloths. Accordingly, for herbivores with low metabolism, variation in young leaves availability may not be the main driver of their ranging behavior. In addition, an arboreal habit and well-developed swimming capacity allow igapó sloths to occupy a niche ecologically inaccessible to other mammals.

Cathemeral activity by sloths (Bradypus variegatus, Bradypodidae) in Amazonian black-water floodplain forest (igapó)

Both biotic and abiotic factors are important for maintaining the activity cycles of animals, and may determine the most advantageous periods for eating, moving and sleeping. While the solar day-night cycle is among the most central of abiotic variables, a number of species are active both day and night. Three-toed sloth populations (Bradypus, Linnaeus 1758) across the Neotropics show this pattern, with activity occurring at various points across the 24-hour cycle. In the current study, we used radio tracking techniques to investigate the daily temporal patterning of sloth displacement in Amazonian igapó flooded forest, and compared the results with populations studied in other habitats. We conclude that igapó sloths are cathemeral, and discussed that environmental temperature, nutritional needs and the presence of predators may be the main factors influencing their activity pattern.

Internal Macroscopic Anatomy and Electrical Evaluation of the Bradypus variegatus Heart

Background: The Bradypus variegatus species presents peculiar anatomophysiological properties and many aspects of its organic systems still need to be clarified, especially regarding the cardiovascular system, given its participation in vital activities. Disorderly anthropic action has had drastic consequences in sloth populations and the need to treat sick and injured animals is increasingly common. To this end, the importance of knowing its characteristics is emphasized. Therefore, this study proposed to describe the internal macroscopic structures of the sloth's heart, as well as to measure the ventricular walls and indicate the electrical activity of the organ.Materials, Methods and Results: For the dissections, 15 Bradypus variegatus cadavers were used (1 young female, 9 adults females and 5 adult males) belonging to the Área de Anatomia of the Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco (UFRPE), Recide, PE, Brazil. After they were fixed and preserved, the specimens received a midsagittal incision in the chest, followed by soft tissue folding and removal of ribs to access the heart. The organ was derived from the cavity and sectioned sagittal medially to identify its internal anatomy. Ventricular walls and interventricular septum were measured with a steel caliper (150 mm / 0.02 mm). An electrocardiogram was performed to determine the electrical profile on 5 healthy B. variegatus sloths, living under semi-livestock conditions at the Recife Zoo, PE, Brazil. The electrodes were taken from the regions, scapular and glutes of the animals that were called hugging a keeper during the procedure, carried out in the Zoo itself, using a portable device. Based on the data obtained, sloths have cardiac chambers separated by septa, however between atria and ventricles, in both antimeres, there are atrioventricular ostia, where valves are found, consisting of 3 valves on the right and 2 on the left. The atria are practically smooth inside and have their cavity enlarged by the atria, the right being larger than the left, these having a greater amount of pectineal muscles in relation to the atria. The ventricles have trabeculae and papillary muscles, 3 on the right and 2 on the left. These muscles hold the tendinous chords that connect the valves. The existence of trabeculae marginal septum was not evidenced. The thickness of the wall of the left ventricle, as well as that of the interventricular septum, proved to be greater than the thickness of the wall of the right ventricle, regardless of the age or sex of the animals. Based on the electrocardiographic recordings, the sloths presented sinus rhythm, with a heart rate between 67 and 100 bpm. The electrical axis ranged from -60º to -90º. The P wave is smoother than the QRS complex. While the S-T segment was classified as isoelectric. The T wave was shown to be + and predominantly > or = at 25% of the S wave, which characterized an rS type QRS deflection in both females and males.Discussion: The general characteristics of the cardiac chambers in sloths are similar to those observed in other domestic and wild mammals. However, the presence of pectineal muscles associated with the atria and auricles differs from that observed in mammals such as the paca and raccoon and in birds such as the ostrich, which have trabecular structures in these cavities. The number of valves in sloths is equal to the anteater. However, it has a marginal trabeculae septum, not seen in Bradypus variegatus. According to the electrocardiographic findings, the rhythm was sinus, but much lower than that observed in the capuchin monkey, which also maintains arboreal habits. Keywords: Xenarthra, common sloth, internal anatomy, heart, electrocardiogram.Descritores: Xenarthra, preguiça-comum, anatomia interna, coração, eletrocardiograma.

Identification and characterization of satellite DNAs in two-toed sloths of the genus Choloepus (Megalonychidae, Xenarthra)

Choloepus, the only extant genus of the Megalonychidae family, is composed of two living species of two-toed sloths: Choloepus didactylus and C. hoffmanni. In this work, we identified and characterized the main satellite DNAs (satDNAs) in the sequenced genomes of these two species. SATCHO1, the most abundant satDNA in both species, is composed of 117 bp tandem repeat sequences. The second most abundant satDNA, SATCHO2, is composed of ~ 2292 bp tandem repeats. Fluorescence in situ hybridization in C. hoffmanni revealed that both satDNAs are located in the centromeric regions of all chromosomes, except the X. In fact, these satDNAs present some centromeric characteristics in their sequences, such as dyad symmetries predicted to form secondary structures. PCR experiments indicated the presence of SATCHO1 sequences in two other Xenarthra species: the tree-toed sloth Bradypus variegatus and the anteater Myrmecophaga tridactyla. Nevertheless, SATCHO1 is present as large tandem arrays only in Choloepus species, thus likely representing a satDNA exclusively in this genus. Our results reveal interesting features of the satDNA landscape in Choloepus species with the potential to aid future phylogenetic studies in Xenarthra and mammalian genomes in general.

Fatal disseminated toxoplasmosis in a brown-throated sloth (Bradypus variegatus) from Northern Brazil – Case report

The clinical and pathological findings of a case of fatal disseminated toxoplasmosis in a captive brown-throated sloth (Bradypus variegatus) from the northern region of Brazil are reported. Clinical signs were nonspecific and included apathy, prostration, dyspnoea, and loss of appetite. Treatment with penicillin was attempted, but the animal died within five days of the onset of clinical signs. Microscopically, there was acute inflammation in the liver, spleen, and lungs associated with necrosis and a few cysts and extracytoplasmic tachyzoites, with a morphology compatible with Toxoplasma gondii. Tissue sections were submitted for immunohistochemistry that confirmed T. gondii as the aetiological agent. To the authors’ knowledge, this is the first report of toxoplasmosis in B. variegatus.