Volumen y Número: Nº 1

Sección especial: Los mamíferos como hospedadores de parásitos

Evidences of non-lethal rabies virus exposure in free-ranging wild carnivores from Brazilian Pampa

, , , , , , , , , , , ,

Rabies virus (RABV) may infect wildlife, domestic mammals, and humans worldwide, and outbreaks have been associated with population declines of wild carnivores. Although RABV infection has been considered almost invariably fatal, there has been growing evidence of non-lethal RABV exposure in wildlife. The aim of this study is to investigate the occurrence of RABV antibodies, as evidence of non-lethal exposure to the virus in free-living wild canids and felids from the Brazilian Pampa. Animals were live-trapped in three protected and two unprotected areas in Southern Brazil, and the presence of antibodies against RABV was verified by the RFFIT test. A total of 98 specimens without clinical signs of disease were live-trapped: 35 Cerdocyon thous, 23 Lycalopex gymnocercus, 29 Leopardus geoffroyi, 11 Leopardus wiedii. Thirteen out of 98 wild carnivores were considered seropositive to RABV: five C. thous, one L. gymnocercus, five L. geoffroyi, and two L. wiedii. All five localities where animals were sampled had at least one seropositive individual. The results support previous conclusions regarding the possible involvement of C. thous in the rabies ecology and expand the findings of RABV-seropositivity in free-living wildlife, representing the first record for the following species: L. gymnocercus, L. geoffroyi, and L. wiedii. Our findings also suggest that RABV circulation and non-lethal exposure in Neotropical wild carnivores may be more common than previously assumed. Furthermore, rabies and its sylvatic cycle should be taken into account in any conservation effort for wild carnivores.

Evidências de exposição não-letal ao vírus da raiva em carnívoros silvestres de vida livre no Pampa brasileiro. O vírus da Raiva (RABV) pode infectar mamíferos silvestres, domésticos e humanos em todo o mundo, e surtos têm sido associados com declínios populacionais em carnívoros silvestres. Apesar da infecção pelo RABV ser considerada invariavelmente fatal, há evidências crescentes de exposição não-letal em animais silvestres. O objetivo deste trabalho é investigar a ocorrência de anticorpos contra RABV, como evidência de exposição não-letal ao vírus em canídeos e felídeos de vida livre no Pampa brasileiro. Os animais foram capturados em três áreas de preservação e duas áreas não-protegidas do Sul do Brasil, e a presença de anticorpos contra RABV foi verificada por RFFIT. Um total de 98 espécimes sem sinais de doença foram capturados: 35 Cerdocyon thous, 23 Lycalopex gymnocercus, 29 Leopardus geoffroyi e 11 Leopardus wiedii. Treze dos 98 carnívoros silvestres foram considerados soropositivos para RABV: cinco C. thous, um L. gymnocercus, cinco L. geoffroyi, e dois L. wiedii. Todas as cinco localidades onde os animais foram amostrados apresentaram ao menos um indivíduo soropositivo. Os resultados corroboram conclusões anteriores sobre o possível envolvimento de C. thous na ecologia da raiva, e expandem os achados de soropositividade para RABV em animais silvestres, representando o primeiro registro para as seguintes espécies: L. gymnocercus, L. geoffroyi e L. wiedii. Nossos resultados também sugerem que a circulação do RABV e a exposição não-letal em carnívoros silvestres neotropicais pode ser mais comum do que previamente assumido. Outrossim, a raiva e seu ciclo silvestre devem ser levados em consideração em qualquer esforço de conservação de carnívoros silvestres.

Graphical abstract for the article “Evidences of non-lethal rabies virus exposure in free-ranging wild carnivores from Brazilian Pampa” (Padilha et al., 2024)

Nematodos parásitos en epidídimos de dos especies del género Sturnira (Chiroptera: Phyllostomidae): ¿transmisión sexual de nematodos en murciélagos?

, , , , ,

Los murciélagos juegan un importante rol en la salud pública. Su capacidad para volar, la diversidad de hábitats que ocupan, su comportamiento social de vivir en grandes colonias o en pequeños grupos, su diversidad trófica y las posibles interacciones con los humanos facilitan la transmisión y propagación de diferentes patógenos. A pesar de ello y de la amplia variedad de parásitos que albergan, existe muy poco conocimiento respecto de su fauna parasitaria, ciclos de vida, modos de transmisión y, menos aún, cómo influyen sobre la reproducción y la supervivencia del hospedador. El objetivo del presente estudio es informar por primera vez larvas de nematodos en el epidídimo de los murciélagos frugívoros Sturnira erythromos y Sturnira lilium, y analizar una posible transmisión sexual de macroparásitos. Se analizaron, a nivel histológico, los tractos reproductores y las gónadas de 272 murciélagos de diferentes localidades del noroeste de Argentina. En los epidídimos de siete machos de S. erythromos y uno de S. lilium observamos parásitos, que se identificaron como larvas por sus dimensiones y, por la presencia de una estructura interna similar a esticosomas, se cree que podrían ser de la Superfamilia Trichinelloidea. Si bien esto no es prueba suficiente de una transmisión sexual, no descartamos esta posibilidad; creemos que aún faltan más estudios para probar que las larvas efectivamente pasan a través de la eyaculación al tracto reproductor femenino, desde donde luego migrarían para colonizar otros órganos.

Parasitic nematodes in epididymima of two species of the genus Sturnira (Chiroptera: Phyllostomidae): sexual transmission of nematodes in bats? Bats play an important role in public health. Their ability to fly, the diversity of habitats they occupy, their social behavior of living in large colonies or small groups, their trophic diversity, and possible interactions with humans facilitate the transmission and spread of different pathogens. Despite this and the wide variety of parasites they harbor, very little is known about their parasitic fauna, life cycles, modes of transmission, and even less about how they influence host reproduction and survival. The objective of this study is to report for the first time nematode larvae in the epididymis of the frugivorous bats Sturnira erythromos and Sturnira lilium, and to analyze a possible sexual transmission of macroparasites. The reproductive tracts and gonads of 272 bats from different locations in northwestern Argentina were histologically analyzed. In the epididymis of seven males of S. erythromos and one of S. lilium, we observed parasites, which due to their dimensions, were identified as larvae, and due to the presence of an internal structure similar to sticosomes, it is believed that they could be from the superfamily Trichinelloidea. Although this is not sufficient proof of sexual transmission, we do not rule out this possibility; we believe that more studies are still needed to prove that the larvae actually pass through ejaculation to the female reproductive tract, from where they would later migrate to colonize other organs.

Graphical abstract for the article “Nematodos parásitos en epidídimos de dos especies del género Sturnira (Chiroptera: Phyllostomidae): ¿transmisión sexual de nematodos en murciélagos?” (Miotti et al., 2024)

Domestic dogs as host of ectoparasites carrying Rickettsia, Bartonella and Mycoplasma in urban, peri-urban and rural areas from center Argentina

, , ,

The domestic dog (Canis lupus familiaris) plays a vital role in transmitting zoonotic ectoparasites and vector-borne pathogens, often being an important source of pathogens in spillover and spillback processes between domestic and wild animals. The aim of this study was to analyze the diversity and prevalence of ectoparasites and their associated bacteria, Rickettsia, Bartonella, and Mycoplasma, in dogs from urban, peri-urban, and rural environments in central Argentina. A total of 180 dogs were examined, and 308 ectoparasites were collected. Diversity and prevalence (P) for the environment were: Urban (Ptotal = 78%) [Ctenocephalides felis felis (P = 78.1%); Rickettsia felis (P = 25%); Bartonella sp. (P = 8.3%); Mycoplasma suis (P = 8.3%)]; Peri-urban (Ptotal = 83%) [C. felis felis (P = 80%); Rhipicephalus sanguineus s.l. (P = 20%); R. felis (P = 19.2%); Bartonella sp. (P = 25%); M. suis (P = 3.8%)]; Rural (Ptotal = 50%) [Pulex irritans (P = 45.4%); R. sanguineus s.l. (P = 15.1%); R. felis (P = 7.4%); M. suis (P = 8.7%)]. These results present new insights into bacteria distribution across environments, emphasizing the role of dogs in their circulation. Pulex irritans, a flea with the highest prevalence in foxes, exclusively found in the rural environment, supports the hypothesis that wild and domestic sympatric carnivores share ectoparasite species. The detection of M. suis for the first time in all analyzed ectoparasite species and environments raises questions regarding the potential reservoir role of dogs for this pathogen. Furthermore, it suggests that dogs infested with ectoparasites may be exposed to an unknown range of potentially invasive vector-borne pathogens. These findings reinforce the importance of parasitological and epidemiological studies in domestic mammals under the “One Health” paradigm.

Perros domésticos como hospedadores de ectoparásitos portadores de bacterias Rickettsia, Bartonella y Mycoplasma en áreas urbanas, peri-urbanas y rurales del centro de Argentina. El perro doméstico (Canis lupus familiaris) desempeña un papel fundamental en la transmisión de ectoparásitos y patógenos transmitidos por vectores, y muchas veces es una fuente importante en el proceso de traspaso de patógenos entre animales silvestres y domésticos. El objetivo de este trabajo fue analizar la diversidad y prevalencia de ectoparásitos y bacterias de los géneros Rickettsia, Bartonella y Mycoplasma en perros provenientes de ambientes urbanos, peri-urbanos y rurales del centro de Argentina. Se examinaron 180 perros, y se recolectaron 308 ectoparásitos. La diversidad y prevalencia (P) por ambiente fue: urbano (Ptotal = 78%) [Ctenocephalides felis felis (P = 78,1%); Rickettsia felis (P = 25%); Bartonella sp. (P = 8,3%); Mycoplasma suis (P = 8,3%)]; periurbano (Ptotal = 83%) [C. felis felis (P = 80%); Rhipicephalus sanguineus s. l. (P = 20%); R. felis (P = 19,2%); Bartonella sp. (P = 25%); M. suis (P = 3,8%)], y rural (Ptotal = 50%) [Pulex irritans (P = 45,4%); R. sanguineus s.l. (P = 15,1%); R. felis (P = 17,4%); M. suis (P = 8,7%)]. Aportamos nueva información sobre la distribución de las bacterias en distintos ambientes, y se destaca el papel del perro para su circulación. La presencia exclusiva de Pulex irritans, pulga con mayor prevalencia en zorros, en el ambiente rural, refuerza la hipótesis de que carnívoros silvestres y domésticos simpátricos comparten especies de ectoparásitos. La detección de M. suis por primera vez, en todos los ambientes y especies ectoparásitas, plantea interrogantes sobre el papel potencial del perro como reservorio de este patógeno. Además, sugiere que los perros infestados con ectoparásitos pueden estar expuestos a una variedad desconocida de patógenos transmitidos por vectores. Estos resultados refuerzan la importancia de los estudios parasitológicos y epidemiológicos en mamíferos domésticos bajo el paradigma de «Una Salud».

Graphical abstract for the article “Domestic dogs as host of ectoparasites carrying Rickettsia, Bartonella and Mycoplasma in urban, peri-urban and rural areas from center Argentina” (Acosta et al., 2024)

Parásitos intestinales del piche (Zaedyus pichiy) en Malargüe, Mendoza: efecto de los factores ambientales y del hospedador

, , , , , ,

El piche es un xenartro endémico del centro y sur de Argentina y Chile. El objetivo del presente trabajo fue describir los parásitos intestinales de una población de piches de Malargüe (Mendoza, Argentina) y evaluar qué factores (intrínsecos o extrínsecos) tienen mayor influencia sobre aquellos. Se estudiaron heces de 120 piches colectadas entre 2015 y 2016 mediante análisis coproparasitológicos, y se estimó la prevalencia total parasitaria. Se evaluó la influencia de factores intrínsecos del hospedador (sexo, edad y condición física) y extrínsecos (estacionalidad y año) sobre la dinámica de la estructura parasitaria usando modelos lineales generalizados (GLM). El 95% de las muestras estuvieron parasitadas. Se hallaron cuatro tipos diferentes de ooquistes de coccidios, huevos de Cestoda y de Nematoda (Aspidodera y dos morfotipos de Trichostrongylina). Coccidia sp. 2, Aspidodera spp. y Trichostrongylina morfotipo 2 (Tricho 2) fueron las más prevalentes. Los GLM indicaron que en invierno el parasitismo de los adultos de Z. pichiy por Trichostrongylina morfotipo 1 (Tricho 1) estuvo influenciado por la condición física de los hospedadores. Por otro lado, la prevalencia de Coccidia sp. 2 y Tricho 2 estuvo influenciada por el año. Para los individuos analizados en 2016 la prevalencia con Tricho 1 también estuvo afectada por la condición física, y la de Coccidia sp. 4 y Tricho 2 por la estacionalidad. La prevalencia de Tricho 2 en 2016 fue mayor en los juveniles que en los adultos y la prevalencia para ambas edades disminuyó durante el verano. Este estudio permitió conocer la parasitofauna y la sinergia de diferentes factores en la prevalencia de los parásitos en la población estudiada.

Intestinal parasites of pichis (Zaedyus pichiy) in Malargüe, Mendoza: effect of environmental and host factors. The pichi is an endemic xenarthran from central and southern of Argentina and Chile. The aim of the present work was to describe the intestinal parasites of a pichis population from Malargüe (Mendoza, Argentina), and to assess which factors (intrinsic or extrinsic) have a major influence on them. Feces from 120 pichis were collected between 2015 and 2016, studied by coproparasitological analysis and the total prevalence was estimated. By means of generalized linear models (GLM), the influence of intrinsic factors of the host (sex, age and physical condition) and extrinsic (seasonality and year) on the dynamics of the parasite structure was evaluated. Virtually all the samples were parasitized (95%). Four different types of coccidian oocysts, eggs of Cestoda and Nematoda (Aspidodera and two morphotypes of Trichostrongylina) were found. Coccidia sp. 2, Aspidodera spp. and Trichostrongylina morphotype 2 (Tricho 2) were the most prevalent. GLM indicated that in winter the parasitism in adults of Z. pichiy by Trichostrongylina morphotype 1 (Tricho 1) was influenced by the physical condition of the host. On the other hand, prevalence of Coccidia sp. 2 and Tricho 2 was influenced by the year. Regarding hosts analyzed in 2016, prevalence with Tricho 1 is also affected by physical condition, and that of Coccidia sp. 4 and Tricho 2 by seasonality. Prevalence of Tricho 2 in 2016 was higher in juveniles than in adults, and the prevalence for both ages decreased during the summer. This study allowed us to know the parasitic fauna and the synergy of different factors in the prevalence between parasites in the studied population.

Graphical abstract for the article “Parásitos intestinales del piche (Zaedyus pichiy) en Malargüe, Mendoza: efecto de los factores ambientales y del hospedador” (Pagnutti et al., 2024)

Sigmodontinae rodents (Muroidea: Cricetidae) as hosts of Cestoda from Argentina

, , , , , ,

In Argentina, parasitological studies on Cricetidae rodents have been carried out mainly on nematodes. However, some research has shown that cestodes are also common components of their parasitic assemblages. In this study, Sigmodontinae rodents (Cricetidae–Muroidea) from the Cuenca del Plata, Argentina, are studied as hosts of cestodes. New host species, geographical areas, and parasitic infection parameters are provided. A total of 1675 specimens from 28 species of rodents from 67 localities were sampled for cestodes. Five taxa of cestodes belonging to three families were identified, including 20 new geographical records. In addition, nine new host-parasite associations are reported. These records help us to increase our understanding of the richness of cestodes in the region by providing a database to evaluate the effect of intrinsic and extrinsic factors on ecological indicators such as prevalence, abundance, and host specificity, among others.

Roedores Sigmodontinae (Muroidea: Cricetidae) como hospedadores de Cestoda de Argentina. En Argentina, los estudios parasitológicos en roedores Cricetidae han sido principalmente de nematodes. Sin embargo, algunas investigaciones han demostrado que los cestodes son componentes comunes de sus ensambles parasitarios. Los roedores Sigmodontinae (Cricetidae–Muroidea) de la región de la Cuenca del Plata, Argentina, son estudiados como hospedadores de cestodes. Se brindan nuevos registros hospedatorios y geográficos, y parámetros de infección parasitaria. Se examinaron 1675 especímenes pertenecientes a 28 especies de roedores de 67 localidades con el fin de hallar especímenes de cestodes. Se identificaron cinco taxones de cestodes pertenecientes a tres familias, entre los que se incluyen 20 nuevos registros geográficos. Además, se informan nueve nuevas asociaciones parásito-hospedador. Estos registros nos ayudan a aumentar nuestra comprensión de la riqueza de los cestodes en la región, y proporcionan una base de datos para evaluar el efecto de los factores intrínsecos y extrínsecos sobre los indicadores ecológicos, como prevalencia, abundancia, especificidad hospedatoria, entre otros.

Graphical abstract for the article “Sigmodontinae rodents (Muroidea: Cricetidae) as hosts of Cestoda from Argentina” (Guerreiro Martins et al., 2024)