First morphological and molecular analysis of Eucoleus boehmi like eggs in dogs from Argentina.

The canid parasites Eucoleus aerophilus (syn. Capillaria aerophila) and Eucoleus boehmi (syn. Capillaria boehmi) parasitize the lower and the upper respiratory tract, respectively. Reports and descriptions of these nematodes are scarce in Argentina, possibly due to misdiagnosis of morphologically similar trichuroids eggs, and the lack of knowledge about the species of Eucoleus in this geographical area. Scanning electron microscopy is a useful tool for identification of E. boehmi eggs based on the characteristics of the shell structure which differentiate between species. Molecular analysis complements morphological identification. Until now, there are no studies based on the analysis of E. boehmi eggs in Argentina. The aim of the present work was to study by morphological, morphometric, and molecular analysis, eggs attributable to E. boehmi isolated from dogs naturally infected in Mar del Plata city, Argentina. Eggs isolated from two dog fecal samples were analyzed by light and scanning electron microscopy. A fragment of mitochondrial DNA (mtDNA) of the cytochrome c oxidase subunit I gene (cox1) from eggs was sequenced, and phylogenetic analysis was performed in this study. According to morphological results based on the wall surface ultrastructure, the eggs studied were assigned to E. boehmi. Molecular analysis supported the morphological identification. The divergence of 9-12% with the European isolated could suggest a new geographical genetic variation of E. boehmi, but also question the possible existence of cryptic species. This is the first characterization of E. boehmi eggs in dogs from Argentina.

Reprint of "Survey and first molecular characterization of Echinococcus granulosus sensu stricto (G1) in Pampas fox (Lycalopex gymnocercus) in Buenos Aires province, Argentina".

Echinococcosis is a zoonosis caused by tapeworms of the genus Echinococcus. Echinococcus granulosus sensu lato (s. l.) has a world-wide distribution and its transmission is primarily maintained in a synanthropic cycle with dogs as definitive hosts and livestock species as intermediate hosts. However, many wild canids also function as definitive hosts for E. granulosus s. l. Echinococcosis in humans is mainly caused by E. granulosus sensu stricto (s. s.) G1 genotype. In the present work, we expanded the epidemiological study on echinococcosis reported cases in Pampas fox (Lycalopex gymnocercus) to provide a prevalence estimate for rural areas of southern Buenos Aires province, Argentina. Ninety-five whole intestines were analyzed using the sedimentation and counting technique with a result of 83 foxes (87.37%) harboring at least one helminth species. E. granulosus s. l. adults were found in one Pampas fox (1.05%). These adult helminthes were E. granulosus s. s. (G1) according to the genotyping analysis of a 450-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene.

Survey and first molecular characterization of Echinococcus granulosus sensu stricto (G1) in Pampas fox (Lycalopex gymnocercus) in Buenos Aires province, Argentina.

Echinococcosis is a zoonosis caused by tapeworms of the genus Echinococcus. Echinococcus granulosus sensu lato (s. l.) has a world-wide distribution and its transmission is primarily maintained in a synanthropic cycle with dogs as definitive hosts and livestock species as intermediate hosts. However, many wild canids also function as definitive hosts for E. granulosus s. l. Echinococcosis in humans is mainly caused by E. granulosus sensu stricto (s. s.) G1 genotype. In the present work, we expanded the epidemiological study on echinococcosis reported cases in Pampas fox (Lycalopex gymnocercus) to provide a prevalence estimate for rural areas of southern Buenos Aires province, Argentina. Ninety-five whole intestines were analyzed using the sedimentation and counting technique with a result of 83 foxes (87.37%) harboring at least one helminth species. E. granulosus s. l. adults were found in one Pampas fox (1.05%). These adult helminthes were E. granulosus s. s. (G1) according to the genotyping analysis of a 450-bp region of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene.

The Pampas fox (Lycalopex gymnocercus) as new definitive host for Spirometra erinacei (Cestoda: Diphyllobothriidae).

Spirometra erinacei, Faust, Campbell and Kellogg, 1929, is a pseudophyllidean cestode of the family Diphyllobothriidae. The genus Spirometra is cosmopolitan and these parasites infect carnivores, specially felids and canids. In Argentina, S. erinacei and S. mansonoides have been reported sporadically only in domestic definitive hosts. The Pampas fox, Lycalopex gymnocercus, is the most abundant native carnivore in southern South America, where it inhabits grasslands and open woodlands and areas highly modified by extensive ranching and agricultural activities. This report describes the first finding of S. erinacei infecting Pampas fox, and provides an estimate prevalence of this cestode in rural areas of southern Buenos Aires province, Argentina based on 78 complete Pampas fox intestine samples analysis. This study found a 15.4% of prevalence of S. erinacei in small intestine (adult stage) and a 21.8% in fecal samples (egg stage). In the present work, the first case of S. erinacei in a wild definitive host from Argentina was reported expanding the list of definitive hosts of S. erinacei in South America.

Epidemiological studies on Echinococcus in Pampas fox (Lycalopex gymnocercus) and European hare (Lepus europaeus) in Buenos Aires province, Argentina.

In Argentina, hydatid disease caused by Echinococcus granulosus is widespread. The south of Buenos Aires province, Argentina, is one of the three regions where hydatidosis is endemic. Although domestic dogs and sheep are considered to be the main hosts for E. granulosus, the potential role of wildlife in the local transmission of E. granulosus has not been investigated. The aim of this study was to estimate the hydatidosis/echinococcosis prevalence in European hare (Lepus europaeus) and Pampas fox (Lycalopex gymnocercus), two abundant species with a strong predator-prey relationship in rural areas of Buenos Aires province using different diagnostic tests. A total of 61 fox intestines were examined, finding that 52 (85.2%) harbored at least one helminth species. However, no adult or immature form of Echinococcus sp. was found in the intestinal contents. Coproparasitological analysis and Copro-ELISA followed by Copro-PCR were used as supplementary diagnostic tests. Only one (1.7%) of 59 fecal samples was positive to Taeniidae eggs by coproparasitological analysis, but this same sample was negative by the Copro-ELISA test. The analysis by Copro-ELISA showed 6 of 57 (10.6%) positive samples, but the Copro-PCR tests carried out on these samples were negative to E. granulosus. A total of 6,808 lungs, 3,576 livers, and 3,542 hearts of hunted hares were examined and palpated, but no structure resembling hydatid cysts were detected. Our results suggest that hares and Pampas foxes are not currently important wild reservoirs of E. granulosus in the studied area.