Francisca Acuña's research while affiliated with University of Santiago, Chile and other places

Anthropogenic environmental change is reducing available habitat for wild species, providing novel selection pressures such as infectious diseases and causing species to interact in new ways. The potential for emerging infectious diseases and zoonoses at the interface between humans, domestic animals, and wild species is a key global concern. In vertebrates, diversity at the major histocompatibility complex MHC is critical to disease resilience, and its study in wild populations provides insights into eco-evolutionary dynamics that human activities alter. In natural populations, variation at MHC loci is partly maintained by balancing selection, driven by pathogenic selective pressures. We hypothesize that MHC genetic diversity differs between guigna populations inhabiting human-dominated landscapes (higher pathogen pressures) versus more natural habitats (lower pathogen pressures). We predict that MHC diversity in guignas would be highest in human-dominated landscapes compared with continuous forest habitats. We also expected to find higher MHC diversity in guignas infected with micro and macro parasites (higher parasite load) versus non infected guignas. We characterized for the first time the genetic diversity at three MHC class I and II exons in 128 wild guignas (Leopardus guigna) across their distribution range in Chile (32-46° S) and Argentina, representing landscapes with varying levels of human disturbance. We integrated MHC sequence diversity with multiple measures of anthropogenic disturbance and both micro and macro parasite infection data. We also assessed signatures of positive selection acting on MHC genes. We found significantly higher MHC class I diversity in guignas inhabiting landscapes where houses were present, and with lower percentage of vegetation cover, and also in animals with more severe cardiorespiratory helminth infection (richness and intensity) and micro-macroparasite co-infection. This comprehensive, landscape-level assessment further enhances our knowledge on the evolutionary dynamics and adaptive potential of vertebrates in the face of emerging infectious disease threats and increasing anthropogenic impacts.

It is widely established that musicians possess a higher level in certain auditory perceptual abilities when compared to non-musicians. This improvement may be mediated, at least in part, by changes in the cochlear response induced by reflex activation of the olivocochlear efferent system. In this review, we describe and analyze the scientific evidence regarding possible differences in the efferent response in musicians and non-musicians. The main evidence observed is that musicians present a greater robustness of the efferent olivocochlear reflex when measured by suppression of otoacoustic emissions and compared to non-musicians. Analyzing the articles presented in this review, it is possible to point out that the differential role of the efferent effect in musicians is not yet established. There is not enough evidence to support the idea that the olivocochlear system favors comparative changes in the properties of musicians’ auditory filters. New studies with psychoacoustic techniques, among others, are needed to measure the effect of the olivocochlear reflex on tuning, gain, compression, or temporal resolution in musicians and non-musicians.

Free-roaming domestic cats can negatively affect wildlife, and understanding how they use space is fundamental to predict their potential impacts. In this study we describe the use of space of 48 owned free-roaming cats and assess the level of care provided by owners in rural areas near priority conservation areas in southern Chile. Additionally, we use camera trap data from two protected areas to assess spatial overlap with wild vertebrates, particularly the guigna (Leopardus guigna), a vulnerable forest-dwelling felid. Cat home ranges were variable (1–47.2 hectares) and their activity was mostly concentrated within 100 meters of the household, with maximum foray distances up to 2.5 km. Cats used wooded areas (12%of fixes on average), mostly native forest, where spatial overlap with endemic and/or threatened species was documented. Nonetheless cats were infrequently detected in nearby protected areas (1.7% of GPS locations and 1% of the cameras). The use of wooded areas was strongly associated with the distance from the household to the forest edge and home range areas were negatively associated with house density. Our findings suggest that in areas isolated from households (>200 m), the problem of cats is marginal and restricted to the edges. Management was in general deficient, observing birth control in only 13% of cats and lack of preventive health care in 86% of cats. Cat impacts could be exacerbated under increasing land subdivision in southern Chile where, without population control strategies, cats may become an emergent threat for native wildlife.

Human transformation of natural habitats facilitates pathogen transmission between domestic and wild species. The guigna (Leopardus guigna), a small felid found in Chile, has experienced habitat loss and an increased probability of contact with domestic cats. Here we describe the interspecific transmission of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) between domestic cats and guignas and assess its correlation with human landscape perturbation. Blood and tissue samples from 102 free-ranging guignas and 262 domestic cats were collected and analyzed by PCR and sequencing. Guigna and domestic cat FeLV and FIV prevalence were very similar. Phylogenetic analysis showed guigna FeLV and FIV sequences are positioned within worldwide domestic cat virus clades with high nucleotide similarity. Guigna FeLV infection was significantly associated with fragmented landscapes with resident domestic cats. There was little evidence of clinical signs of disease in guignas. Our results contribute to the understanding of the implications of landscape perturbation and emerging diseases.

Landscape anthropization has been identified as one of the main drivers of pathogen emergence worldwide, facilitating pathogen spillover between domestic species and wildlife. The present study investigated Carnivore protoparvovirus‐1 infection using molecular methods in 98 free‐ranging wild guignas (Leopardus guigna) and 262 co‐occurring owned, free‐roaming rural domestic cats. We also assessed landscape anthropization variables as potential drivers of infection. Protoparvovirus DNA was detected in guignas across their entire distribution range, with observed prevalence of 13.3% (real‐time PCR) and 9% (conventional PCR) in guignas, and 6.1% (conventional PCR) in cats. Prevalence in guigna did not vary depending on age, sex, study area or landscape variables. Prevalence was higher in juvenile cats (16.7%) than in adults (4.4%). Molecular characterization of the virus by amplification and sequencing of almost the entire vp2 gene (1746 bp) from one guigna and five domestic cats was achieved, showing genetic similarities to canine parvovirus 2c (CPV‐2c) (one guigna and one cat), feline panleukopenia virus (FPV) (one cat), CPV‐2 (no subtype identified) (two cats), CPV‐2a (one cat). The CVP‐2c‐like sequence found in a guigna clustered together with domestic cat and dog CPV‐2c sequences from South America, suggesting possible spillover from a domestic to a wild species as the origin of infection in guigna. No clinical signs of disease were found in PCR‐positive animals except for a CPV‐2c‐infected guigna, which had hemorrhagic diarrhea and died a few days after arrival at a wildlife rescue center. Our findings reveal widespread presence of Carnivore protoparvovirus‐1 across the guigna distribution in Chile and suggest that virus transmission potentially occurs from domestic to wild carnivores, causing severe disease and death in susceptible wild guignas.

Guignas (Leopardus guigna) are small felids closely associated with native forest habitats. In fragmented landscapes, they use vegetation corridors and forest remnants to move across the landscape. In these contexts, guignas may increase contact probabilities with domestic animals, being therefore relevant to assess their pathogens and parasites. The aim of this study was to characterize the helminth fauna in the gastrointestinal tract and cardiorespiratory system of guignas from central and southern Chile. Between 2015 and 2018, 33 dead free-ranging guignas were found road-killed or were collected from wildlife rescue centers. Thirty-two gastrointestinal tracts and 32 cardiorespiratory organs were analyzed through direct analysis and artificial digestion. We found 81.8% (27/33) guignas were positive for helminth endoparasites (84.4% (27/32) positive for gastrointestinal parasites, 37.5% (12/32) positive for cardiorespiratory parasites). Fourteen parasites were identified (7 at genus level and 7 at species level), with Angiostrongylus sp., Molineus sp., Oslerus sp. And Troglostrongylus sp. As first records in guignas. The most prevalent parasites were the species Toxascaris leonina, Toxocara cati and Uncinaria stenocephala. Uncinaria stenocephala showed the highest intensity of infection. Multiparasitism was observed in 76% of the animals. Significant differences in richness of endoparasites and prevalence of cardiorespiratory parasites were found between geographic zones; higher values in the southern zone are possibly due to favorable environmental characteristics for endoparasite development. There were no statistically significant differences between sexes. All the parasites found in this study have been previously reported in domestic cats. These results are valuable to understand parasite transmission at the domestic-wildlife interface; the possibility of endoparasite transmission between domestic cats and guignas should be clarified with molecular analysis.

La antropización del paisaje se considera una de las principales causas de emergencia de enfermedades en fauna silvestre. La güiña es un felino endémico de Chile y una parte de Argentina altamente amenazado por la transformación de su hábitat. Se han estudiado los efectos de la antropización del paisaje en la transmisión interespecífica de leucemia felina (FeLV), inmunodeficiencia felina (FIV), Protoparvoirus de los carnívoros-1 (CPPV) y hemoplasma entre güiñas (n=102) y gatos (n=262) de Chile. Se han realizado análisis de variables del paisaje asociadas con la infección, así como análisis filogenéticos de los patógenos. Las prevalencias de FeLV, FIV y CPPV fueron muy similares en güiña y gato (FeLV=20.6% güiña/20.2% gato; FIV=3% ambos; CPPV=9.2%güiña/6.1% gato). En gato se hallaron las tres especies de hemoplasma descritas en felinos y en güiña dos de ellas (C.Mycoplasma haemominutum [15.7% guigna; 10.3% gato], M.haemofelis [9.8% guigna, 6.1% gato]. C.M. turicensis [0.38% gato]). En ambos se halló posible nueva especie no descrita previamente (Mycoplasma sp. 1.9% guigna, 0.38% gato). Las variables del paisaje mostraron diferencias significativas con mayor prevalencia de FeLV en güiñas procedentes de ambientes fragmentados. Contrario a nuestra hipótesis, se obtuvo una mayor prevalencia de hemoplasma en güiñas procedentes de paisajes prístinos. Los análisis filogenéticos mostraron alta similitud nucleotídica entre las secuencias de FeLV y FIV de gato y güiña. Una misma secuencia de CPPV obtenida en güiña y gato mostró alta similitud con CPV-2c de perros latinoamericanos. Esto sugiere transmisión interespecífica de estos patógenos entre especies silvestres y domésticas. Para hemoplasma se obtuvo especie-especificidad de CMhm en güiña y gato, si bien, la alta similitud de secuencias de Mhf y Mycoplasma sp. en ambos hospedadores sugiere transmisión interespecífica de estos patógenos pero probablemente poco frecuente. Los resultados muestran cómo la antropización del paisaje puede facilitar la transmisión de patógenos entre fauna doméstica y silvestre suponiendo una potencial amenaza para la supervivencia de las poblaciones silvestres.

The co-occurrence of domestic cats (Felis silvestris catus) and wild felids in rural landscapes can facilitate pathogen transmission. However, in the relatively-isolated regions of southern South America there have been no comprehensive studies to assess disease transmission risks between domestic cats and forest-dwelling wild felids such as guigna (Leopardus guigna). We evaluated hemoplasma infection and the possibility of transmission between domestic cats and guignas by comparing spatial and phylogenetic patterns of pathogen prevalence. Blood/spleen samples were collected from 102 wild guignas and 262 co-occurring rural domestic cats across the entire distribution range of guigna in Chile. Hemoplasma infection was assessed by direct sequencing of the 16S RNA gene. Infection with hemoplasmas was common and geographically widespread across different bioclimatic areas for both species. The most common feline Mycoplasma species in guigna and domestic cats were Candidatus M. haemominutum (CMhm) (15.7% guigna; 10.3% domestic cat) and Mycoplasma haemofelis (Mhf) (9.8% guigna, 6.1% domestic cat). A previously undescribed Mycoplasma sp. sequence was found in two guignas and one cat. Continuous forest-landscapes were associated with higher hemoplasma-prevalence in guignas. Shared hemoplasma nucleotide sequence types between guigna and domestic cats were rare, suggesting that cross-species transmission between guignas and domestic cats may occur, but is probably uncommon. Ectoparasites, which have been linked with hemoplasma transmission, were not found on guignas and were infrequent on domestic cats. Our results suggest that transmission pathways vary among hemoplasma species and, contrary to our predictions, domestic cats did not appear to be the main driver of hemoplasma infection in guignas in these human-dominated landscapes.