Search Results (13)

Background/Objectives: In 2023, we reported that the tamarins (genus Saguinus) Saguinus imperator and Saguinus midas have had an extensive independent expansion of Platy-1 SINEs compared to previously characterized platyrrhine genomes among traditional cebids. This study investigates the amplification dynamics of Platy-1 insertions across thirteen diverse genomes representing each Platyrrhini family, including two from Pitheciidae and three from Atelidae. Methods: By comparing the distribution of Platy-1 subfamily content, total interspersed repeat content and the proximity of Platy-1 insertions to, or within, other repeats across evolutionary taxa, this study begins to identify genomic landscape features that are unique to family Callithrichidae that correlate with LINE (L1). Results: Platy-1 radiation in non-callithrichid taxa derives primarily from older subfamilies 1-4, 1-4a (as reported here for genus Alouatta) and 1-5, whereas callithrichids proliferate higher numbers of Platy-1 copies via independent bursts from much younger sources. Linage-specific Platy-1 activity was notable in two of the new genomes studied, Bolivian titi and mantled howler monkey, both with a relatively low copy number. Variable presence/absence patterns across evolutionary taxa support the traditional platyrrhine branching order Pitheciidae–Atelidae–Cebidae. Only one Platy-1-4a insertion polymorphism placed Aotidae between Atelidae and Cebidae, as opposed to between Cebidae and Callithrichidae. Conclusions: This study shows that callithrichids, and Saguinus tamarins in particular, are unique among platyrrhines with regard to their extensive rate of Platy-1 mobilization, a dynamic that appears to be correlated with LINE (L1) genomic content. Alouatta has two young lineage-specific Platy-1 subfamilies. With strong evidence of incomplete lineage sorting (ILS) and rapid radiation, the accurate placement of Aotus remains elusive. Full article

The microbiome of howler monkeys is being studied as a potential indicator of forest health. This explorative research aimed to analyze the microbiome, antibiotic resistance genes, and virulence factors of the howler monkey (Alouatta seniculus) in two Colombian Andean forests. A total of six samples were collected from three monkeys in two different forests. The samples were processed and sequenced using 16S rRNA V3-V4 metabarcoding and shotgun metagenomics. No significant differences in microbial diversity were observed between locations. A total of 43 possible resistance genes were identified, 11 of which were associated with plasmids, while 66 virulence genes were detected. The bacterial genera with the highest number of resistance genes were Escherichia and Enterococcus, whereas Escherichia and Citrobacter exhibited the highest number of virulence factors. The bacteria were predominantly resistant to fluoroquinolones, macrolides and beta-lactams, while adherence was the dominant virulence mechanism. This exploratory study suggests that the locations provide similar habitats for howler monkeys and that the presence of resistance genes is primarily due to intrinsic bacterial resistance mechanisms and natural resistance in wild populations despite the environmental presence of bacterial genera with resistance genes and virulence factors. However, acquisition through interaction with domestic animals was not evaluated. Full article

Yellow fever (YF) causes severe morbidity and mortality in Africa and South America. It is an arthropod-borne viral disease endemic to tropical regions of Africa and South America. Yellow fever virus (YFV) is transmitted by mosquitoes and frequently affects both non-human primates (NHPs) and humans. Neotropical primates (NTPs) are generally more severely afflicted by YFV than African primates. Asian primates appear not to be susceptible to this disease. Susceptibility varies among NTP species: asymptomatic infections are described in some NTP species, whereas severe epizootic mortality events are described in others. The genus Alouatta (howler monkeys) is considered to be the most susceptible among the NTPs. Epizootic events resulting in the death of thousands of NTPs have been recorded in recent history. As a result, YFV poses a threat to the survival of some NTP species. In most cases, NTPs are found dead without showing prior clinical signs. In cases where clinical signs are observed, they are mostly non-specific. Due to their high susceptibility, epizootic events in NTPs are used as epidemiological predictors for human YF outbreaks. YFV infection may be diagnosed by means of virus isolation, reverse transcription polymerase chain reaction, serology, histopathology, or immunohistochemistry. Animals that survive the disease develop neutralizing antibodies to YFV. Currently, no specific treatment is available. Sustained YF control strategies must rely on surveillance and accurate diagnostics to allow for early detection of outbreaks and rapid implementation of control measures. Prophylaxis should be based on a One Health perspective that recognizes the intricate interplay between human health, primate health, and the environment. Vaccines for YF are available, with the human 17DD vaccine effectively preventing disease in primates. However, mitigation strategies continue to rely more and more on vector control, preferably using eco-friendly methods. Climate change and human activities, and their impact on local ecology, are assumed to increase the risk of YF transmission in the next decades. Full article

In the history of yellow fever (YF) outbreaks in Brazil, howler monkeys (Alouatta sp.) and marmosets (Callithrix sp.) have been among the most affected genera, exhibiting significant hepatic injuries similar to those seen in humans. However, limited information exists regarding yellow fever virus (YFV) infection in their central nervous system (CNS). To address this gap, an epidemiological study was conducted to assess tissue changes, viral detection, and cytokine profiles in the brains of both neotropical primate species when they are naturally infected with YFV. A total of 22 brain samples from these species (8 from Alouatta sp. and 14 from Callithrix sp.) showing infection with YFV in the liver via immunohistochemistry (IHC) were selected. From them, YFV antigen detection occurred in 35.7% (5/14) of Callithrix sp. brain samples and 87.5% (7/8) of Alouatta sp. samples, with a higher frequency of viral antigen quantification in Callithrix sp. Both species exhibited similar CNS lesions, characterized by congestion, low hemorrhage, limited inflammatory infiltration interstitial and perivascular edema associated with neuronal degeneration, neurophagy, and higher cell death (necrosis and apoptosis) quantification. Pro- and anti-inflammatory cytokine profiles were balanced, with TNF-α and IL-1β playing a key role in inflammation, while IL-10 and IL-13 exhibited a prominent role in immunomodulation, suggesting an anti-inflammatory modulation typical of flaviviruses occurs. This study demonstrates that YFV can induce CNS lesions in neotropical primates, establishing it as a secondary target of viral tropism. These findings highlight the importance of collecting nervous tissue during epizootics, particularly in Callithrix sp., as such tissue is often overlooked despite its critical role in disease monitoring. Full article

Habitat loss is considered a major global threat to biodiversity. Yet, the effects of fragmentation are strongly debated, with studies showing positive, negative, or null effects on species. Understanding the effects of fragmentation has key conservation implications as negative effects prioritize large, contiguous habitats; null or weak effects highlight the protection of all habitat patches, regardless of their size; and positive effects support the preservation of small patches. This information is particularly important for highly threatened species with declining populations, such as primates. In this study, we assessed the independent effects of habitat amount (forest cover) and fragmentation (patch density) on the patch occurrence of the brown howler monkey (Alouatta guariba) across 956 forest patches in Brazil, using data from 53 studies. We found that both forest cover and patch density positively, but non-significantly, affect the occurrence of the brown howler monkey in forest patches. Weak effects of forest cover on patch occurrence are likely due to the ability of howlers to cope with habitat loss, although the long-term consequences of habitat destruction are considered negative for the species. Weak effects of fragmentation underscore the importance of maintaining both small and large forest patches for the conservation of the brown howler monkey. Full article

In captive environments, mammals are frequently exposed to various parasitic protozoa and other vector-borne pathogens that can impact both animal health and public health. Monitoring these pathogens is essential for animal welfare and zoonotic disease control. This study aimed to investigate the prevalence of parasitic protozoa and other vector-borne pathogens in captive mammals through molecular detection methods at the Belo Horizonte Zoo, Brazil. Between November 2021 and March 2023, whole blood samples were collected from 40 mammals. Molecular analyses identified piroplasms, Leishmania spp., granulocytic/platelet Anaplasma/Ehrlichia spp., monocytic Ehrlichia spp., Bartonella spp. and hemotropic Mycoplasma spp. with a 72.5% positivity rate. Piroplasms were found in 22.5% (two Pantanal cats, two gorillas, one white rhinoceros, one spider monkey, one jaguar, one tufted capuchin and one hippo) and Leishmania spp. in 12.9% (four maned wolves). Granulocytic/platelet Anaplasma/Ehrlichia spp. were found in 12.5% of the samples (one gorilla and four maned wolves), Ehrlichia canis in 2.5% of the animals (one maned wolf), Bartonella spp. in 42.5% (six howler monkeys, two maned wolves, one gorilla, one white rhino, one southern tamandua, one common woolly monkey, one tufted capuchin, one brown brocket deer, one agouti, one cougar and one hippo), hemotropic Mycoplasma spp. in 17.5% (one gorilla, one maned wolf, one white rhino, one howler monkey, two common woolly monkeys and one European fallow deer). Five Artiodactyla members tested negative for A. marginale. Coinfections occurred in 34.5% of the positive samples. Sequencing revealed that Theileria spp. and Cytauxzoon spp. are closely related to Theileria bicornis and Cytauxzoon felis; Ehrlichia canis and Bartonella spp. are closely related to B. clarridgeiae and B. henselae; and hemotropic Mycoplasma spp. are closely related to Candidatus Mycoplasma haemominutum. Our results showed a high occurrence of vector-borne pathogens in captive animals, including zoonotic species, which may pose a risk to animal and human public health. Full article

Habitat modification due to human activities threatens species survival. While some species can inhabit habitat patches in anthropogenic landscapes, their occurrence often depends on landscape structure. We assessed the effects of landscape structure on brown howler monkey (Alouatta guariba clamitans) occurrence in an urban scenario. We conducted censuses in 59 forest patches from 2014 to 2016 in Rio Grande do Sul State, Brazil. We evaluated patch occurrence (presence/absence) in response to landscape composition (forest cover, arboreal crops, urban areas, open areas, and water) and configuration (patch density), considering the scale of effect. Water, urban, and open areas were the most important predictors of howler presence. Their presence was notably higher in landscapes with more water, likely because these landscapes consist of rural areas with low urbanization, less farming, and relatively high forest cover. Presence of howlers was positively associated with forest cover and negatively related to urban areas, open areas, and arboreal crops. Resource scarcity and increased mortality risks from human pressures, such as domestic dog attacks, electrocution, and roadkill on these land covers may explain these relationships. We highlight the importance of conserving and increasing forest cover in anthropogenic landscapes to protect species reliant on forested habitats, like howler monkeys. Full article

Nowadays, wild animals are threatened by humans, with the number of species and individuals decreasing during recent years. Wildlife rescue centers play a vital role in the conservation of wildlife populations. This study aims to describe a new release technique, the Speaker Method, to rescue and facilitate the reunion of different baby mammals that arrived at a wildlife rescue center with their mothers within their natural habitat, avoiding the need for captivity. This method is based on a recorded baby’s cry played on a speaker to make a “call effect” in the mother. The efficacy of the Speaker Method for babies’ reunion with their mothers was 45.8% in Hoffmann’s two-toed sloths (Choloepus hoffmanni) and 91.9% in brown-throated sloths (Bradypus variegatus). Among the mantled howler monkeys (Alouatta palliata), 50% of the babies could be released using this new technique. The findings suggest that the method could be helpful in the early release of young individuals, highlighting higher release outcomes in these three species compared to traditional nursery care provided by human caretakers, who face inherent difficulties in raising young animals without their mothers. Full article

Argentina lies within the southernmost distributional range of five neotropical primates, the brown howler monkey Alouatta guariba, the black-and-gold howler monkey Alouatta caraya, the black-horned capuchin Sapajus nigritus, the Azara’s capuchin Sapajus cay, and the Azara’s owl monkey Aotus azarae; the first three of which are globally threatened. These species occupy different ecoregions: the Alto Paraná Atlantic forest, the Araucaria moist forest, the humid Chaco, the Southern Cone Mesopotamian savanna, the Paraná Ffooded savanna, and the Southern Andean Yungas. The recently approved National Primate Conservation Plan of Argentina calls for identifying priority areas to focus conservation actions for these species. We used species distribution models to estimate species ranges and then used the Zonation software to perform a spatial conservation prioritization analysis based on primate habitat quality and connectivity to identify potential areas of importance at national and ecoregional levels. Only 7.2% (19,500 km²) of the area inhabited by primates in Argentina is under protection. Outside the current protected areas, the top-ranked 1% and 5% priority areas identified in our analysis covered 1894 and 7574 km², respectively. The top 1% areas were in the Atlantic forest of Misiones province, where S. nigritus, A. guariba, and A. caraya are distributed, and in the humid portion of eastern Chaco and Formosa provinces, where A. azarae and A. caraya are present. The top 5% areas included portions of the Yungas, where S. cay is the only primate present. Priority areas in Chaco and Formosa provinces are particularly relevant because of the paucity of protected areas and the high deforestation rate. The endangered A. guariba population will benefit from the better protection of the priority areas of Misiones. The potential priority areas proposed herein, considered within a context of a broad participatory process involving relevant stakeholders and local people, will help guide new and innovative conservation policies and practices while supporting management objectives. Full article

Putative replication-associated protein (REP) and capsid-like (CAP) proteins are encoded by circular single-stranded DNA viruses (CRESS DNA), which have been found in samples from most eukaryotic groups. However, the details of these viruses’ life cycles and their significance in diseases have yet to be established. We presented and analyzed two full-length CRESS DNA genomes acquired from two children diagnosed with acute gastroenteritis (GI) in the northeast state of Tocantins, Brazil, using next-generation sequencing and a virus-like filtration approach. Both sequences (named SmaCV3BR08 and SmaCV3BR291) are closely similar to a prior CRESS DNA sequence discovered in the feces of a new world monkey (Alouatta caraya) from the United States in 2009 and termed Howler monkey-associated porprismacovirus 1 (Genbank ID: NC 026317). According to our comparative study, these porprismacovirus genomes deviate by 10% at the nucleotide level. For comparative reasons, the divergence between our sequences (SmaCV3BR08 and SmaCV3BR291) and a porprismacovirus recently identified in a human fecal sample from Peru is 37%. These data suggest that there is a great diversity of porprismacoviruses in South America, perhaps more than two species. In addition, the finding of closely related sequences of porprismacoviruses in humans and native monkeys highlights the zoonotic potential of these viruses. Full article

Nighttime studies are underrepresented in ecological research. Even well-known behaviors, such as the loud call of howler monkeys, are rarely studied at night. Our goal was to help fill this knowledge gap by studying the 24 h vocal behavior of the Guianan red howler monkey (Alouatta macconnelli) and to compare the acoustic structures of howling bouts made during the day to those made at night. We used passive acoustic monitoring coupled with automatic acoustic detection to study three groups of howlers over three months in the Viruá National Park, Roraima, Brazil. The automatic classifier we built detected 171 howling bouts with a 42% recall rate and 100% precision. Though primarily diurnal, howlers vocalized mainly at night. Greater vocal activity before nautical twilight might be associated with territorial and resource defense behaviors, with howlers calling from roosting sites before starting their daily routines. We also found that during the day, howling bouts were longer and had lower harmonic-to-noise ratios, lower frequencies, and more symmetric energy distributions than bouts at night. Our study adds to growing evidence that passive acoustic monitoring and automatic acoustic detection can be used to study primates and improve our understanding of their vocal behavior. Full article

The 2021 re-emergence of yellow fever in non-human primates in the state of Rio Grande do Sul (RS), southernmost Brazil, resulted in the death of many howler monkeys (genus Alouatta) and led the state to declare a Public Health Emergency of State Importance, despite no human cases reported. In this study, near-complete genomes of yellow fever virus (YFV) recovered from the outbreak were sequenced and examined aiming at a better understanding of the phylogenetic relationships and the spatio-temporal dynamics of the virus distribution. Our results suggest that the most likely sequence of events involved the reintroduction of YFV from the state of São Paulo to RS through the states of Paraná and Santa Catarina, by the end of 2020. These findings reinforce the role of genomic surveillance in determining the pathways of distribution of the virus and in providing references for the implementation of preventive measures for populations in high risk areas. Full article

Previous studies have reported filarial parasites of the genus Dipetalonema and Mansonella from French Guiana monkeys, based on morphological taxonomy. In this study, we screened blood samples from nine howler monkeys (Alouatta macconnelli) for the presence of filaria and Wolbachia DNA. The infection rates were 88.9% for filaria and 55.6% for wolbachiae. The molecular characterization, based on the 18S gene of filariids, revealed that A. macconnelli are infected with at least three species (Mansonella sp., Brugia sp. and an unidentified Onchocercidae species.). Since the 18S and cox1 generic primers are not very effective at resolving co-infections, we developed ITS genus-specific PCRs for Mansonella and Brugia genus. The results revealed coinfections in 75% of positives. The presence of Mansonella sp. and Brugia sp. was also confirmed by the 16S phylogenetic analysis of their associated Wolbachia. Mansonella sp., which close to the species from the subgenus Tetrapetalonema encountered in New World Monkeys, while Brugia sp. was identical to the strain circulating in French Guiana dogs. We propose a novel ITS1Brugia genus-specific qPCR. We applied it to screen for Brugia infection in howler monkeys and 66.7% were found to be positive. Our finding highlights the need for further studies to clarify the species diversity of neotropics monkeys by combining molecular and morphological features. The novel Brugia genus-specific qPCR assays could be an effective tool for the surveillance and characterization of this potential zoonosis. Full article