Biology subjects

Gasparini, J.

Publications and source records attributed to Gasparini, J..

4 recordsLinked to original sources

bioRxiv2026

Leptospira infection in European hedgehogs (Erinaceus europaeus): occurrence, diversity and associated risk factors in Greater Paris, France.

Background Leptospirosis is a zoonotic infectious disease whose prevalence is increasing in mainland France. While rodents are common reservoirs of pathogenic Leptospira, the pathogen diversity detected in French human clinical cases exceeds that currently identified in local rodents, suggesting that some unidentified host species may carry strains of public health importance. The aim of this study was to investigate Leptospira infection in a population of rescued injured hedgehogs (Erinaceus europaeus) in Ile-de-France, as well as to characterize the circulating genotypes and serogroups. Methodology/principal findings In 2023-2024, kidneys from 270 dead hedgehogs collected by the Veterinary University Hospital for Wild Fauna at the National Veterinary School of Alfort, France, were tested for leptospiral DNA by real-time PCR. Twenty-two percent of individuals were qPCR-positive. Positive samples were genotyped to identify circulating species and species-groups (SGs) with L. interrogans SG5 being the most common. In addition, the Microscopic Agglutination Test was performed on 245 blood samples, with Australis identified as the predominant serogroup. The effect of individual and environmental variables on Leptospira infection status of hedgehogs was assessed, with age and season identified as significant predictors of infection. Conclusions/significance Our findings suggest that hedgehogs can harbour pathogenic Leptospira in Ile-de-France. Further investigation is warranted to establish the epidemiological links between hedgehogs and other host species, including humans. A finer-scale analysis of the ecological features at the sampling sites could also help better understand the risk factors of Leptospira infection in hedgehogs at a smaller spatial scale.

molecular biology↗

bioRxiv2025

Lead exposure positively affects coccidia abundance in feral pigeons (Columba livia)

O_LIIn urban environments, organisms are exposed to high levels of pollutants, including trace metals, whose concentrations can be increased by anthropogenic activities. Numerous studies have shown the toxic effects of pollutants on exposed organisms. However, due to their life within the host, parasites can also be affected by exposure to these pollutants. Overall, previous correlative findings reveal that the effects of parasite exposure to pollutants through the host can vary, from positive to negative, highlighting the complexity of host-parasite-environment interactions in relation to pollution. C_LIO_LIIn this study, we experimentally tested whether lead exposure affects the abundance of ecto-, meso-, and endoparasites in wild pigeons (Columba livia), which host a wide variety of parasites and are naturally exposed to trace metals in urban environments. As we had previously reported the toxic effects of lead on the immune system of pigeons, we expected lead exposure to be indirectly beneficial for the parasites. C_LIO_LITo test this, we used a sample of wild pigeons captured in Paris, half of which were experimentally exposed to lead concentrations similar to those found in Paris. We then measured the abundance of several parasites: blood parasites (hemosporidian parasites), ectoparasites (Columbicola columbae and Campanulote compar), coccidia and helminths. Additionally, we measured the intensity of the pigeons antiparasitic behavioral response (grooming) through behavioral analyses. C_LIO_LIOur results did not reveal toxic effects of lead exposure on the parasites. On the contrary, we found positive effects of this exposure on coccidia abundance in male pigeons. This result could be explained by a toxic effect of lead on the hosts antiparasitic immune strategy, making the hosts less hostile to parasites. However, we found no effect of lead exposure on the abundance of lice, blood parasites and helminths. This could be explained by the lack of impact of lead exposure on grooming antiparasitic activity in our experiment, and by seasonal variations in the activity of blood parasite vectors, which may have masked potential effects of our treatment. C_LIO_LIIn conclusion, our study highlights the importance of considering the host environment, particularly pollutants, to understand parasite dynamics. C_LI

ecology↗

bioRxiv2025

Interactions between parasites within the host: helminth infection reduces lice abundance in feral pigeons (Columba livia)

O_LIWithin a host, parasites form a community and interact with each another. They can interact directly through competition for space or indirectly through competition for resources, or even via the hosts immune response. These interactions can influence infection patterns within the host. In particular, helminths are capable of facilitating the infection of other parasites through their immunosuppressive effects or hindering it by activating immune responses that reduce the ability of other species to infest the host. C_LIO_LIIn this study, we aimed to test the existence of parasite interactions in the wild pigeon host (Columba livia). More specifically, we experimentally tested whether helminth infestation influences the infestation dynamics of ecto- and endoparasites in pigeons. C_LIO_LIOur predictions were tested on a sample of pigeons captured in Paris, half of them were exposed to an anthelmintic treatment. We then assessed the effects of this deworming treatment on the abundance of blood parasites (hemosporidian parasites, Haemoproteus spp., Plasmodium spp., and Leucocytozoon spp.), lice (Columbicola columbae and Campanulote compar), as well as on the intensity of antiparasitic behavioral responses (preening). C_LIO_LIWe detected a negative relationship between helminth presence and lice abundance, with higher lice abundance when helminths were reduced (with anthelmintic treatment) and lower lice abundance when helminths were more abundant (without anthelmintic treatment), indicating inhibitory effects of helminths on ectoparasite abundance. However, these results were not supported by differences in preening activity between the two experimental groups, suggesting that other mechanisms are involved. Our results showed no effect of anthelmintic treatment on the abundance of blood parasites. The mechanism by which helminths induced ectoparasite repulsion remains to be demonstrated. C_LIO_LIOur study highlights the importance of considering interactions between different types of parasites in an eco-epidemiological approach when taking into account the factors affecting parasite prevalence and abundance. C_LI

ecology↗

bioRxiv2017

Effects of confinement on body mass and site fidelity of feral pigeons during the setting-up of pigeon houses.

Feral pigeons can reach high densities in the urban environments and have thus been subject to various regulation programs. Recently, an alternative ethical regulation strategy based on the installation of artificial breeding facilities has been tested in European cities. In Paris (France), pigeons are first confined for several weeks within the pigeon house before being released. According to authorities, this method allows to retain confined pigeons in this new habitat and to attract more conspecifics. This study aims at evaluating the efficiency and potential side-effects of this method by assessing pigeon fidelity behaviour and pigeon welfare after release. Results show that confinement in pigeon houses induced a significant body mass loss in birds. Only 19% of confined pigeons became faithful to their new habitat. This fidelity depended on the origin of birds suggesting that pigeons captured closer to the pigeon houses are more likely to stay in the vicinity of the pigeon house one year after. Investigations on methods of regulation on animal behavior may help to improve management procedures.

ecology↗