Zoonotic nematode in the city of La Plata, Argentina: Report of a case of Calodium hepaticum in Rattus rattus.

This study describes a case of Calodium hepaticum (Trichinellida: Capillariidae) infection in an adult rat (Rattus rattus) from the periurban area of the city of La Plata in the province of Buenos Aires, Argentina. The rat was found with neurological signs (ataxia, lethargy, and episodes of unresponsiveness) in the food storage of a goat production facility. The liver was observed with hepatomegaly and diffuse and irregular yellowish-white spots appearing in striae or small nodules on the external surface and inside the liver. Subsequent microscopic and histopathological studies were performed. Eggs were observed by direct microscopy of the impression smear of liver tissue. A multifocal granulomatous tissue reaction with different stages of fibrocellular tissue was observed in the liver parenchyma. The granulomas contained adults and degenerated eggs delimited by an intense infiltrate of mononuclear cells. Macro and microscopic observations and histopathological liver lesions were compatible with C. hepaticum infection. To our knowledge, this is the first confirmation of C. hepaticum infection in R. rattus in Argentina, increasing the host record of this parasite and a new record of distribution in goat production systems in the country.

First report of Sarcocystis spp. (Apicomplexa, Sarcocystidae) in Lagostomus maximus (Desmarest, 1917) (Rodentia, Chinchillidae) in Argentina.

Sarcocystis is a genus of intracellular parasitic protozoa that infects various species of mammals, birds, and reptiles worldwide. At least 46 Sarcocystis species naturally infect rodents as intermediate hosts producing tissue cysts. This study aimed to provide the first report and molecular characterisation of Sarcocystis spp. in muscles from plains viscacha (Lagostomus maximus) in Argentina. Muscle samples of 53 plains viscachas from three provinces of Argentina were processed by homogenisation and optical microscopy to detect tissue cysts. Positive samples were analysed by PCR-sequencing, using the following markers: 18S rRNA, ITS1, and coxI. The 18S rRNA and coxI consensus sequences were aligned with other sequences from Sarcocystis spp., and phylogenetic trees were constructed. Of all animals processed, 13.2% (7/53) harboured Sarcocystis sp. cysts. 18S rRNA consensus sequences were obtained from four muscle samples and one individual cyst, and they showed 99.88-100% similarity, except for the cyst sequence, which showed 97.11% homology. Similarities of only 96-97% were recorded in the 18S rRNA fragment with other Sarcocystis spp. whose sequences are available in the GenBank. The five coxI fragment sequences obtained were 100% identical and showed an identity of 99.41-99.48% with S. canis. For ITS1 only short and low-quality sequences were obtained. In the phylogenetic trees, all the sequences from plains viscachas were positioned together in a branch separated from other Sarcocystis spp. These results could be related to new Sarcocystis spp. producing sarcocysts in plains viscachas. Besides, comprehensive cyst morphological analysis using TEM from the new Sarcocystis species will allow a description of the cyst wall ultrastructure. In this sense, further studies are needed to deepen these findings and elucidate other potential intermediate and possible definitive hosts.

First study of Seoul virus (SEOV) in urban rodents from newly urbanized areas of Gran La Plata, Argentina.

Alterations of ecosystems have deep effects on the distribution of parasites. Big cities of Argentina present structural features that favor the presence of synanthropic species, acting as source of zoonotic diseases, for example in urban rodents: the Norway rat (Rattus norvegicus) and the black rat (R. rattus). One of the important zoonotic pathogens related are the RNA virus Hantavirus, with high prevalence rates in South America. The aim of this study was to explore and identify the presence of Hantavirus in urban rodents from Gran La Plata, Argentina. The presence of anti-hantavirus IgG antibodies was determined by the Enzyme-Linked Immunosorbent Assay. Six samples turned out positive for Seoul virus (SEOV, p = 14.3%). These are the first records of SEOV in urban rodents in Gran La Plata. It represents the first report in R. rattus in Argentina, and in America. This situation underscores the inequality and historical forgetfulness of a portion of society, calling for urgent action to be taken in this regard.

Prevalence of intestinal parasites in children and domestic animals from two peri-urban neighborhoods in northeastern Argentina. / Prevalencia de parásitos intestinales en niños y animales domésticos en dos barrios periurbanos del nordeste de Argentina.

Motivation for the study. There are few reports on intestinal parasites in children and domestic animals in urban areas in Argentina who live in homes with characteristics that favor the maintenance and transmission of parasites of zoonotic importance. Main findings. More than 50% of children and pets were parasitized, most of them with zoonotic pathogens. Implications. Our results showed the urgent need to improve sanitary control of children and animals, and to implement activities for the prevention of intestinal parasitosis in the homes analyzed.

First study of Seoul virus (SEOV) in urban rodents from newly urbanized areas of Gran La Plata, Argentina

Abstract Alterations of ecosystems have deep effects on the distribution of parasites. Big cities of Argentina present structural features that favor the presence of synanthropic species, acting as source of zoonotic diseases, for example in urban rodents: the Norway rat (Rattus norvegicus) and the black rat (R. rattus). One of the important zoonotic pathogens related are the RNA virus Hantavirus, with high prevalence rates in South America. The aim of this study was to explore and identify the presence of Hantavirus in urban rodents from Gran La Plata, Argentina. The presence of anti-hantavirus IgG antibodies was determined by the Enzyme-Linked Immunosorbent Assay. Six samples turned out positive for Seoul virus (SEOV, p= 14.3%). These are the first records of SEOV in urban rodents in Gran La Plata. It represents the first report in R. rattus in Argentina, and in America. This situation underscores the inequality and historical forgetfulness of a portion of society, calling for urgent action to be taken in this regard.

Update of Dicrocoeliidae (Digenea) parasitizing rodents from the Americas with a description of a new Platynosomoides species from Argentina.

Digeneans are common parasites of small mammals. Dicrocoeliidae is a family with a cosmopolitan distribution, with 18 genera previously recorded from mammals in the Americas, six of them parasitizing rodents in Argentina. In this study, an updated compilation is provided of Dicrocoeliidae from rodents in the Americas. Also, a new Platynosomoides species is described parasitizing the cricetid rodent Akodon montensis of the Atlantic Forest in Argentina. Digital repositories were used to search for Dicrocoeliidae from rodents in the Americas. Rodents were collected in four localities of the Atlantic Forest, Argentina. Digeneans were removed from the rodent's bile duct, and conventional studies were used for the morphological description. A total of 15 Dicrocoeliidae species were found parasitizing 18 rodent species from eight countries in the Americas. The new species of Platynosomoides from Akodon montensis differs from the other two species of genus by the size of body, testes, ovary, cecum length and position and length of the vitelline bands. Dicrocoeliidae show growing diversity, and the compilation of species in a rodent host base allows a clearer comparison and identification of new taxa in the future.

Rodentolepis microstoma isolated from different species of Sigmodontinae rodents (Rodentia: Cricetidae) in the Cuenca del Plata, Argentina: Morphological aspects and molecular characterization.

The purpose of this paper was to study specimens of the genus Rodentolepis isolated from eight species of Sigmodontinae rodents (Rodentia: Cricetidae) from six provinces in the Cuenca del Plata, Argentina, based on morphological, morphometric and molecular characteristics (ITS1 rDNA and cox1 mtDNA). The genetic distances among studied specimens and other Hymenolepididae from rodents available in the GenBank were analyzed and phylogenetic inferences were provided. A total of 955 specimens of Sigmodontinae rodents were examined from seven localities of six provinces in the Cuenca del Plata region in Argentina. Tapeworms were removed from the rodents' small intestines. Conventional studies were used for the morphological and molecular analysis. Specimens of R. microstoma were identified. An amended diagnosis and detailed morphological description of this species is provided. The molecular analyses showed that the specimens studied form the same clade as that of R. microstoma previously studied from other hosts and regions. The genetic polymorphisms of R. microstoma observed corresponded to different groups of species hosts and regions. Moreover, eight species of sigmodontine rodents and 33 localities from the Cuenca del Plata region in Argentina constitute new host and geographical records. This study shows the importance of using integrative taxonomic approaches that combine morphological and molecular characters to understand biological diversity. Moreover, the discovery of R. microstoma in humans suggests the importance of further studies on this zoonotic cestode. This study provides important data on the taxonomy and distribution of R. microstoma to advance knowledge of the transmission dynamics of this parasite.

Expresión del ligando de proteína de muerte programada 1 (PD-L1) en linfoma de Hodgkin en pacientes peruanos / Programmed death-ligand 1 (PD-L1) expression in Hodgkin's lymphoma among Peruvian patients

RESUMEN Objetivo: Diversos estudios realizados sobre el linfoma de Hodgkin (LH) han determinado la expresión de la proteína de muerte programada (PD-L1) en las células de Reed-Sternberg-Hodgkin (HRS), con resultados variables. Esta proteína ha adquirido relevancia por su papel en la respuesta inmunitaria en las neoplasias malignas. El objetivo de este trabajo fue determinar la expresión inmunohistoquímica de PD-L1 en las HRS y su relación con la edad, sexo, estadio clínico y supervivencia global en una cohorte de pacientes peruanos. Materiales y métodos: Se evaluaron 25 biopsias de pacientes con diagnóstico de LH, lo que permitió determinar la expresión inmunohistoquímica de PD-L1 en las HRS en asociación con la sobrevida global (SG) y los datos clínicos de los pacientes. Resultados: Todos los casos mostraron expresión de PD-L1 en más del 1 %. No hubo diferencia estadística significativa en la SG cuando se comparó dos grupos de acuerdo con la expresión de PD-L1 con punto de corte en 50 %, ni tampoco con el estadio clínico (EC), la edad y el sexo. Conclusiones: Se ha encontrado una alta expresión de PD-L1 en los tumores con LH previos al tratamiento. No se ha encontrado asociación entre la expresión de PD-L1, la SG, la edad, el sexo o el EC. Son necesarios otros estudios con mayor cantidad de pacientes para reevaluar el impacto pronóstico de la expresión de esta proteína en LH.

ABSTRACT Objective: Various studies on Hodgkin's lymphoma (HL) have determined programmed death-ligand 1 (PD-L1) expression in Hodgkin and Reed-Sternberg (HRS) cells, with variable results. This protein has gained relevance for its role in the immune response in malignant neoplasms. This work aimed to determine PD-L1 immunohistochemical expression in HRS cells and its relationship with age, sex, clinical stage and overall survival (OS) in a cohort of Peruvian patients. Materials and methods: Twenty-five (25) biopsies from patients diagnosed with HL were assessed, which allowed determining PD-L1 immunohistochemical expression in HRS cells in relation to OS and clinical data of the patients. Results: All cases showed PD-L1 expression in more than 1 % of tumor cells. There was no statistically significant difference in OS when two groups were compared in terms of PD-L1 expression with a cut-off point of 50 %, clinical stage (CS), age and sex. Conclusions: High PD-L1 expression was found in pre-treatment HL tumors. No association was found between PD-L1 expression, OS, age, sex or CS. Further studies with a larger number of patients are necessary to reassess the prognostic impact of the expression of this protein in HL.

Hymenolepidid cestodes: Diversity, morphological and molecular characterization of a new species, and phylogeny of parasitic species of rodents from North and South America.

Rodents are hosts of a wide diversity of cestodes. Fifteen genera included in the family Hymenolepididae parasitize rodents, and only four of these genera have been recorded from the Neotropical region. The purpose of this paper is to update species of Hymenolepididae from rodents, describe a new species of Hymenolepis based on morphological and molecular characterization (ITS1 rDNA and cox1 mtDNA), comparing the features among the species from North and South American rodents, and provide phylogenetic inferences of Hymenolepididae from rodents based on sequences available in the GenBank. Rodents were collected in the Parque Provincial Ernesto Tornquist, Buenos Aires, Argentina. Hymenolepis ivanovae n. sp. differs from other Hymenolepis species registered from North and South American rodents by body size, scolex, suckers, cirrus sac, cirrus, testes, and eggs, among others. Comparative morphometric data for Hymenolepis species from North and South American rodents is provided. Molecular analyses place H. ivanovae n. sp. within the genus Hymenolepis with strong support, and show it close to species of zoonotic importance. The new species is the first species of Hymenolepis described from Sigmodontinae rodents.

Percepción social sobre roedores urbanos y riesgo sanitario en barrios del Gran La Plata, Provincia de Buenos Aires, Argentina / Social perception on urban rodents and sanitary risk in neighborhoods from Gran La Plata, Province of Buenos Aires, Argentina

NTRODUCCIÓN: Los roedores sinantrópicos, representados por el ratón doméstico (Mus musculus), la rata parda (Rattus norvegicus) y la rata negra (Rattus rattus), representan un riesgo importante para la salud. En Sudamérica, la fragmentación socioeconómica se refleja en marcadas diferencias entre centros urbanos y áreas periféricas, y se asocia a un registro heterogéneo. El objetivo fue relevar datos por encuestas a los habitantes de dos barrios del Gran La Plata con características contrastantes para explorar, describir y evaluar la percepción en relación con la presencia de roedores en domicilio, peridomicilio y barrio como vehículos de transmisión de enfermedades. MÉTODOS: A partir de un diseño descriptivo exploratorio, se confeccionaron y realizaron encuestas siguiendo la técnica de muestreo estratificado. Se consideraron las variables género y grupo, de tal manera que la muestra tuviese la misma distribución. La información se transfirió a una base de datos y se analizó a través de IBM SPSS Statistics V25. RESULTADOS: Existe una preocupación común respecto al rol de los roedores urbanos como reservorios y fuentes de infección de patologías zoonóticas. En el barrio más vulnerable, la presencia de roedores fue más frecuente que en el centro de la ciudad. DISCUSIÓN: Este estudio provee un abordaje diferente en relación con roedores y patologías asociadas, considerando la percepción social y revelando su importancia para los programas de manejo y control.

Hassalstrongylus dollfusi (Nematoda, Heligmonellidae): rediscovery in native South American rodents, six decades after its description.

Hassalstrongylus dollfusi (Díaz-Ungría, 1963) Durette-Desset, 1971 was described in a wild house mouse, Mus musculus, from Venezuela and, since then, has never been reported again in the type host or in any other host. In this work, specimens assignable to H. dollfusi were found at 10 localities in Northeast Argentina, in five species of sigmodontine rodents. The nematodes were attributed to H. dollfusi based on diagnostic characters such as: synlophe with 22-31 subequal ridges; in males, hypertrophy of right ray 4 of the male bursa, thickening of the dorsal ray and bases of rays 8, distal tip of the spicules bent and spoon shaped; and, in females, presence of subventral postvulvar alae supported by hypertrophied struts. The new host recorded are: Oligoryzomys fornesi, O. flavescens, O. nigripes, Holochilus chacarius and Akodon azarae. The parasite showed a strong preference for host species of Oligoryzomys, which appear to act as primary hosts. The parasite could be present, parasitizing different species of Oligoryzomys, in a geographic area from the type locality in Venezuela southward to north Corrientes in Argentina. It has not been reported from populations of Oligoryzomys spp. of the Argentinean and Brazilian Atlantic Forest, nor south of 28° S, which may be explained by constraints in the environmental conditions required by the free-living stages of the parasite. This study provides the first identification and redescription of H. dollfusi in southern South America, from autochthonous hosts, six decades after its description.

TITLE: Hassalstrongylus dollfusi (Nematoda, Heligmonellidae) : redécouverte chez des rongeurs autochtones d'Amérique du Sud, six décennies après sa description. ABSTRACT: Hassalstrongylus dollfusi (Díaz-Ungría, 1963) Durette-Desset, 1971 a été décrit chez une souris grise sauvage, Mus musculus, au Venezuela et, depuis lors, n'a plus jamais été signalé chez l'hôte-type ni chez aucun autre hôte. Dans ce travail, des spécimens attribuables à H. dollfusi ont été trouvés dans dix localités du nord-est de l'Argentine, chez cinq espèces de rongeurs Sigmodontinae. Les nématodes ont été attribués à H. dollfusi sur la base de caractères diagnostiques tels que : synlophe avec 22­31 crêtes subégales; chez le mâle, hypertrophie de la côte 4 droite de la bourse, épaississement de la côte dorsale et des bases des côtes 8, extrémité distale des spicules recourbée et en forme de cuillère; et, chez les femelles, présence d'ailes postvulvaires subventrales à fort support cuticulaire. Les nouveaux hôtes signalés sont : Oligoryzomys fornesi, O. flavescens, O. nigripes, Holochilus chacarius et Akodon azarae. Le parasite a montré une forte préférence pour les espèces hôtes du genre Oligoryzomys, qui semblent agir comme hôtes primaires. Le parasite pourrait être présent, parasitant différentes espèces d'Oligoryzomys, dans une zone géographique allant de la localité-type au Vénézuéla vers le sud jusqu'au nord de Corrientes en Argentine. Il n'a pas été signalé dans les populations d'Oligoryzomys spp. de la Forêt Atlantique argentine et brésilienne, ni au sud de 28° S, ce qui peut s'expliquer par des contraintes dans les conditions environnementales requises par les stades libres du parasite. Cette étude fournit la première identification et redescription d'H. dollfusi dans le sud de l'Amérique du Sud, à partir d'hôtes autochtones, six décennies après sa description.

Gastropods as intermediate hosts of Angiostrongylus spp. in the Americas: bioecological characteristics and geographical distribution.

BACKGROUND: Intermediate hosts are key organisms in maintaining parasite life cycles, because they can act as amplifiers in the transmission from natural reservoirs to humans. One of the most important groups of intermediate hosts for zoonotic nematode infections are gastropods,slugs and snails. These are essential organisms in the larval development of Angiostrongylus species. OBJECTIVES: The objective of this paper is to review reports of Angiostrongylus spp. in naturally infected gastropods from the Americas, taking into account the diagnostic methods used in their identification, to be able to provide more accurate list of their intermediate hosts. We also discuss the factors that aid the dispersion of Angiostrongylus spp. in the Americas. METHODS: This study reviews scientific publications and book sections on Angiostrongylus spp. in the Americas, including original works assessing larvae of Angiostrongylus in intermediate hosts. The eligible reports were classified accordingly to their geographical location, year of first record, and the larvae identification methodologies used. Digital repositories were used for the search. The bioecological characteristics of the main intermediate hosts are summarised. FINDINGS: A total of 29 gastropod species that are naturally infected with Angiostrongylus spp. have been reported as intermediate hosts, 16 of which are land snails, two are freshwater snails, and 11 land slugs. MAIN CONCLUSIONS: This study highlights the importance of integrative studies, analysing both the etiological agent and its transmission dynamic in the environment, the biological and ecological characteristics of the hosts, and the impact on host populations. It is necessary to increase interdisciplinary studies to determine the potential epidemiological health risk of angiostrongyliasis in the Americas, and thus be able to establish prevention, monitoring and contingency strategies in the region.

Digenean parasites of Sigmodontinae rodents from Argentina: a list of species, new host, and geographical records.

INTRODUCTION: Among Argentinean rodents, only one species of Muridae and seven of Cricetidae were reported as digenean hosts. Despite the available data, the taxonomic diversity of the Digenea from rodents has been little explored. An update on digeneans of Sigmodontinae rodents (Cricetidae-Muroidea) in Cuenca del Plata is provided. New host and geographical data are recorded and taxonomic and ecological data are summarized. METHODS: Rodents were collected from 11 localities in the region Cuenca del Plata, Argentina. Moreover, other unidentified specimens from four localities, deposited in the Colección de Helmintología del Museo de La Plata, were studied. Prevalence, mean intensity, and mean abundance are provided. RESULTS: Eight species of digeneans belonging to four families were identified. Twelve new geographical records for five provinces of Argentina are presented. In addition, six new host-parasite associations are reported. The information is presented in a taxonomic list for each digenean species: site of infection, host records, locality records, and comments. CONCLUSIONS: It becomes interesting to explore the diets and habits of each rodent species to understand the dispersal and transmission ability of each group of digeneans. This survey constitutes an update on digeneans of Sigmodontinae rodents in Cuenca del Plata, Argentina.

Morphological and molecular identification of hymenolepidid cestodes in children and synanthropic rodents from rural Mexico.

Hymenolepidid cestodes of synanthropic rodents represent a risk for public health. In order to describe the occurrence of hymenolepidids in children and the role of rodents as a potential source of infection, we conducted a morphological and molecular survey on cestodes in two rural villages from Yucatan, Mexico. One hundred and thirty-five stool samples from children (64 from Paraíso and 71 from Xkalakdzonot), 233 Mus musculus (159 from Paraíso and 74 from Xkalakdzonot) and 125 Rattus rattus (7 from Paraíso and 118 from Xkalakdzonot) were analyzed for the presence of cestodes. Three hymenolepidid species were identified morphologically: Hymenolepis nana in 7.8% of children from Paraíso, Hymenolepis microstoma in 4.4% of M. musculus from Paraíso and Hymenolepis diminuta in 15.3% of R. rattus from Xkalakdzonot. The molecular characterization and phylogenetic analysis based on mitochondrial cytochrome c subunit 1 (CO1) gene and ribosomal internal transcribed spacer 1 (ITS1) region, confirmed the identity of the three cestodes isolated from Yucatan. Phylogeny of the CO1 gene identified intraspecific genetic differences within H. nana ranging from 0 to 5%, in H. microstoma from 0 to 0.4%, and in H. diminuta ranged from 0 to 6.5% which suggests, the presence of complex species within H. nana and H. diminuta infecting humans and rodents, as reported by other authors. Based on the morphological and molecular results, and the epidemiological evidence, infections with H. nana suggest a non-zoonotic transmission; however, the presence of H. microstoma and H. diminuta in synanthropic rodents serve as a possible source for human infection.

Gastropods as intermediate hosts of Angiostrongylus spp. in the Americas: bioecological characteristics and geographical distribution

BACKGROUND Intermediate hosts are key organisms in maintaining parasite life cycles, because they can act as amplifiers in the transmission from natural reservoirs to humans. One of the most important groups of intermediate hosts for zoonotic nematode infections are gastropods,slugs and snails. These are essential organisms in the larval development of Angiostrongylus species. OBJECTIVES The objective of this paper is to review reports of Angiostrongylus spp. in naturally infected gastropods from the Americas, taking into account the diagnostic methods used in their identification, to be able to provide more accurate list of their intermediate hosts. We also discuss the factors that aid the dispersion of Angiostrongylus spp. in the Americas. METHODS This study reviews scientific publications and book sections on Angiostrongylus spp. in the Americas, including original works assessing larvae of Angiostrongylus in intermediate hosts. The eligible reports were classified accordingly to their geographical location, year of first record, and the larvae identification methodologies used. Digital repositories were used for the search. The bioecological characteristics of the main intermediate hosts are summarised. FINDINGS A total of 29 gastropod species that are naturally infected with Angiostrongylus spp. have been reported as intermediate hosts, 16 of which are land snails, two are freshwater snails, and 11 land slugs. MAIN CONCLUSIONS This study highlights the importance of integrative studies, analysing both the etiological agent and its transmission dynamic in the environment, the biological and ecological characteristics of the hosts, and the impact on host populations. It is necessary to increase interdisciplinary studies to determine the potential epidemiological health risk of angiostrongyliasis in the Americas, and thus be able to establish prevention, monitoring and contingency strategies in the region.

Toxoplasma gondii and Neospora caninum infections in synanthropic rodents from Argentina.

Toxoplasma gondii and Neospora caninum are closely related coccidian parasites (phylum Apicomplexa). This is the first study from urban synanthropic rodent species that involved serological and molecular diagnosis of T. gondii and N. caninum infection, and genotyping of T. gondii in Argentina. A total of 127 rodent samples were trap captured: Mus musculus (n = 78), Rattus norvegicus (n = 26) and Rattus rattus (n = 23). Antibodies against T. gondii and N. caninum were detected by IFAT in 32.8% (40/122) and 0.8% (1/122) of rodent samples, respectively, demonstrating contact with these protozoans. Additionally, T. gondii DNA was detected in 3.3% (4/123) of rodent central nervous system samples and 2 samples were genotyped by multilocus nPCR-RFLP. Neospora caninum DNA was not detected by PCR. The 2 genotyped samples were type III allele for all markers except for SAG-1 (type I for Rat1Arg and type II/III for Rat2Arg) and were identified as #48 and #2 (likely) according to the allele combinations reported on Toxo DB (Toxo-DB). The results of the present study revealed a wide distribution of T. gondii and less for N. caninum, in synanthropic rats and mice in the studied area.

Toxoplasma gondii and Neospora caninum infections in synanthropic rodents from Argentina / Infecções por Toxoplasma gondii e Neospora caninum em roedores sinantrópicos da Argentina

Abstract Toxoplasma gondii and Neospora caninum are closely related coccidian parasites (phylum Apicomplexa). This is the first study from urban synanthropic rodent species that involved serological and molecular diagnosis of T. gondii and N. caninum infection, and genotyping of T. gondii in Argentina. A total of 127 rodent samples were trap captured: Mus musculus (n = 78), Rattus norvegicus (n = 26) and Rattus rattus (n = 23). Antibodies against T. gondii and N. caninum were detected by IFAT in 32.8% (40/122) and 0.8% (1/122) of rodent samples, respectively, demonstrating contact with these protozoans. Additionally, T. gondii DNA was detected in 3.3% (4/123) of rodent central nervous system samples and 2 samples were genotyped by multilocus nPCR-RFLP. Neospora caninum DNA was not detected by PCR. The 2 genotyped samples were type III allele for all markers except for SAG-1 (type I for Rat1Arg and type II/III for Rat2Arg) and were identified as #48 and #2 (likely) according to the allele combinations reported on Toxo DB (Toxo-DB). The results of the present study revealed a wide distribution of T. gondii and less for N. caninum, in synanthropic rats and mice in the studied area.

Resumo Toxoplasma gondii e Neospora caninum são parasitas coccídeos intimamente relacionados (filo Apicomplexa). Este é o primeiro estudo de espécies de roedores sinantrópicos urbanos, o qual envolveu diagnósticos sorológicos e moleculares da infecção por T. gondii e N. caninum e genotipagem de T. gondii na Argentina. Um total de 127 amostras de roedores foram obtidas: Mus musculus (n = 78), Rattus norvegicus (n = 26) e Rattus rattus (n = 23). Anticorpos contra T. gondii e N. caninum foram detectados pela IFAT em 32,8% (40/122) e 0,8% (1/122) das amostras de roedores, respectivamente, demonstrando contato com esses protozoários. Adicionalmente, o DNA de T. gondii foi detectado em 3,3% (4/123) das amostras do sistema nervoso central de roedores e duas amostras foram genotipadas por nPCR-RFLP multilocus. O DNA de N. caninum não foi detectado por PCR. As 2 amostras genotipadas eram do tipo III para todos os marcadores, exceto para SAG-1 (tipo I para Rat1Arg e tipo II / III para Rat2Arg) e foram identificadas como # 48 e # 2 (provavelmente) de acordo com as combinações de alelos relatadas no Toxo DB (Toxo-DB). Os resultados do presente estudo indicam uma ampla distribuição de T. gondii e menor para N. caninum , em ratos e camundongos sinantrópicos na área estudada.

A new Trichuris species (Nematoda: Trichuridae) from capybaras: Morphological-molecular characterization and phylogenetic relationships.

A new species of Trichuris (Nematoda: Trichuridae) is described from the capybara, Hydrochoeris hydrochaeris (Rodentia: Caviidae), from two localities of Corrientes Province, based on morphological characteristics and ITS1 and ITS2 of nuclear rDNA region sequences. This species present morphological differences with 28 species of the genus described from North and South American rodents. Also, the new species is molecularly characterized and differentiated from those species from Muridae, Cricetidae and Myocastoridae rodents recorded from North and South America, Europe and Africa. Trichuris cutillasae n. sp. constitutes the ninth record from rodents of Argentina, and the second record for Caviidae. The phylogenetic analysis showed that the specimens of new species are in the same clade, and separated from specimens of T. myocastoris (ITS1and ITS2), T. navonae, T. bainae, Trichuris sp. and T. pardinasi (ITS2). Similarly, analysis of concatenated sequences ITS1 and ITS2 added further evidence that T. cutillasae n. sp. is a different species from those previously analyzed.

Calodium hepaticum (Nematoda: Capillariidae) in wild rodent populations from Argentina.

Calodium hepaticum (Nematoda; Capillariidae) is a parasitic nematode of mammals with a cosmopolitan distribution. Adults of this nematode can infect the liver of many mammalian species, including humans, but the main hosts are members of the superfamily Muroidea. Among these, Rattus spp. have the highest apparent prevalences reported worldwide. There are only two reports of C. hepaticum infecting Sigmodontinae species (Muroidea: Cricetidae). In this survey, we examined the occurrence of C. hepaticum in two assemblages of Sigmodontinae rodents from Argentina (Santa Fe and Entre Ríos provinces). The diagnosis was made by morphological features, histopathological exam, and molecular characterization of 18S ribosomal RNA gene region. Here, we show that C. hepaticum is a common parasite of Sigmodontinae. We report the infection in six species (all new hosts): Akodon azarae, Calomys callidus, Calomys venustus, Oligoryzomys flavescens, Oligoryzomys nigripes, and Oxymycterus rufus. This is the first report of C. hepaticum in Sigmodontinae rodents from Argentina and the second record in this subfamily for South America. It is also the first confirmation of C. hepaticum infection in Sigmodontinae by molecular diagnosis. The genetic findings and the prevalences observed, together with the existing information on C. hepaticum, lead us to propose that Rattus spp. brought C. hepaticum to the New World exposing Sigmodontinae rodents, which are frequently infected by this parasite. The high prevalence of infection in A. azarae (41.2%) suggests that this host may be playing an important role in C. hepaticum dynamics in the New World.