Ecological Analysis of the Helminth Community of Microtus lusitanicus (Gerbe, 1879) (Rodentia) in Asturias (NW Spain).

The Lusitanian pine vole, Microtus lusitanicus, an endemic fossorial rodent of the Iberian Peninsula, has a burrowing behaviour and prefers to live underground. It feeds on bark and roots causing severe damage to trees. In Asturias (NW Spain), where M. lusitanicus is considered a pest in several orchards, a faunistic-ecological study was carried out to describe the helminth community of this species and the main factors that could influence its helminth component species. For this purpose, our own collection of 710 voles from several orchards of various locations in Asturias was used. Eight helminth species, four cestodes and four nematodes, were found. Statistical non-parametric tests were used to analyse the effects of extrinsic and intrinsic factors on the diversity of the helminth community and species prevalence and abundance. The results show the influence of climate variables, the year and season of capture, as well as host age, on the diversity of the helminth community and the infection parameters of some helminth species, underlining the importance of their life cycles. In addition to shedding light on the helminth community of this rodent in Asturias, the results obtained could be used to improve the biological methods applied to fight the M. lusitanicus pest.

First Coronavirus Active Survey in Rodents From the Canary Islands.

Since the beginning of the 21st century five new coronaviruses inducing respiratory diseases in humans have been reported. These emergences has promoted research on coronaviruses in wildlife. We started the first eco-epidemiological study to screen the presence of coronaviruses circulating in mice and rats of four Canary Islands. Between 2015 and 2019, we obtained fecal samples of three rodent species (150 Mus musculus, 109 Rattus rattus and 1 Rattus norvegicus) captured in urban and rural areas. Fecal samples were analyzed by nRT-PCR and the resulting sequences were compared to known diversity using Bayesian phylogenetic methods. We only found coronavirus RNA in house mice from El Hierro (10.53%), Tenerife (7.02%) and Lanzarote (5.26%) islands. All coronaviruses detected belong to the species Murine coronavirus belonging to the genus Betacoronavirus and subgenus Embecovirus, being all positive house mice captured in anthropogenic environment. The phylogenetic analysis shows that murine coronaviruses from the Canary Islands are related to European murine coronaviruses. Albeit data are still scarce in the region, the most probable origin of M. coronavirus present in the Canary Islands is continental Europe. According to temporal Bayesian phylogenetics, the differentiation between Canary and continental viruses seems to be quite recent. Moreover, murine coronaviruses from El Hierro, Tenerife and Lanzarote islands tend to segregate in different clades. This enlightens the potential role of rodents or other possibly invasive species in disseminating infectious diseases to remote places through exchanges with the continent. It is important to consider these aspects in the sanitary control of islands, for health and biodiversity preservation concerns.

An identification key for the five most common species of Metastrongylus.

Species of the Metastrongylus genus, the lung nematodes of pigs that require an intermediate host (earthworm) to complete their cycle, pose a potential risk to both livestock and humans. This parasite which can result in lung pathology and mixed infections with other pathogens (e.g. viruses) can be fatal to pigs. Although this genus is distributed worldwide, there are no classification keys for identifying this common parasite species. In this work, we take advantage of parasitological surveys of wild boar (Sus scrofa) in northern and central Spain and southern Poland to develop a morphological identification key for the five most common Metastrongylus species (Metastrongylus apri, Metastrongylus pudendotectus, Metastrongylus salmi, Metastrongylus confusus and Metastrongylus asymetricus). In addition, we provide the first record of M. confusus in Spain, probably unidentified until now due to the lack of appropriate identification keys. We hope that this user-friendly identification key will enable parasitologists and veterinary practitioners to avoid further misclassifications of Metastrongylus species.

Trace element concentrations in Raillietina micracantha in comparison to its definitive host, the feral pigeon Columba livia in Santa Cruz de Tenerife (Canary Archipelago, Spain).

The use of systems involving bird parasites as bioindicators of environmental pollution has been scarcely studied in comparison to other models involving fish and rodent parasites, which have been demonstrated as particularly adequate due to their bioaccumulation capacities. The present study evaluated the accumulation of nine trace elements in the cestode Raillietina micracantha and in its host Columba livia collected from the densely populated city of Santa Cruz de Tenerife (Canary Islands, Spain). Samples (kidney, liver, pectoral muscle, feathers, and R. micracantha) of 27 infected C. livia were selected for trace element analysis by inductively coupled plasma-mass spectrometry. Element levels in pigeon tissues revealed some degree of pollution in Santa Cruz de Tenerife, particularly by Pb and Zn. Pb and Mn mean concentrations were higher in R. micracantha than in the pigeon's soft tissues, with subsequent high bioaccumulation factors for Pb (kidney = 15.38, liver = 10.38, muscle = 79.83) and Mn (kidney = 6.81, liver = 7.52, muscle = 19.89, feathers = 6.11), among others. The negative relations detected for As concentrations between liver and R. micracantha emphasize a possible role of the cestode in As detoxification in host tissues. Considering the obtained bioaccumulation factors, the system R. micracantha/C. livia is proposed as another promising bioindicator system to evaluate environmental toxic element exposure, particularly Pb and Mn, in areas where pollution levels are still relatively low and where both common species are present.