Biology subjects

Paredes-Esquivel, C.

Publications and source records attributed to Paredes-Esquivel, C..

4 recordsLinked to original sources

bioRxiv2025

Strong circulation of Angiostrongylus cantonensis in a protected Mediterranean wetland. Implications for resident and migratory wildlife

Angiostrongylus cantonensis, the rat lungworm, is a metastrongyloid nematode responsible for eosinophilic meningitis and an emerging pathogen of global concern. While its presence has been reported in various regions, including the Canary Islands and mainland Spain, data from the Balearic Islands remain limited. This study investigates the prevalence of A. cantonensis in rodents from the Natural Park of sAlbufera, Mallorca, a protected wetland ecosystem. A total of 43 rodents were captured and necropsied, including Rattus norvegicus, R. rattus and Apodemus sylvaticus. The overall prevalence of A. cantonensis in rats was 46.15% (95% CI: 30.43-62.62%), with no significant differences between species, seasons, or sexes. However, adult rats exhibited significantly higher infection rates than juveniles (p = 0.05). Notably, infection intensity and parasite abundance were positively correlated with host weight ({rho} = 0.60, p < 0.001). Given the co-occurrence of infected rodents and gastropods, our findings suggest the establishment of A. cantonensis in Mallorca, raising concerns about zoonotic transmission risks. The study highlights the need for continued surveillance and public health awareness to mitigate potential human and wildlife exposure in this ecologically significant area.

zoology↗

bioRxiv2022

Improving the detection of A. cantonensis in brain tissues of mammalian hosts

Angiostrongylus cantonensis is an invasive nematode parasite that can cause eosinophilic meningitis in many vertebrate hosts, including humans. This parasite is spreading rapidly through the six continents, with Europe being the final frontier. Sentinel surveillance may be a cost-effective surveillance strategy to monitor the arrival of this pathogen to new geographical regions as this can be easily expanded to incorporate symptomatic wildlife. Necropsy and tissue digestion techniques are often used to recover helminth parasites from vertebrate host tissues, however their application to detect brain parasites is poorly utilized. Here we show that employing these techniques in combination can 1) help resolve false positive and negative animals, 2) provide accurate parasitic load values and 3) establish an accurate prevalence of A. cantonensis. Our adapted tissue digestion technique can be easily performed, especially in wildlife hospitals where animal infections often precede human cases. Early detection of the parasite increases the efficacy of prevention, treatment, and disease control strategies not only in humans, but also in susceptible animal populations. Key FindingsO_LIOptimized brain digestion techniques can detect parasitic helminths (A. cantonensis) in mammalian hosts. C_LIO_LIAccuracy identifying neurotropic parasitic infections can be increased if a standard digestion protocol is applied. C_LIO_LIThe technique presented here can be easily implemented to detect brain nematodes in wildlife hospitals. C_LI

zoology↗

bioRxiv2022

Multiple invasions, Wolbachia and human-aided transport drive the genetic variability of Aedes albopictus in the Iberian Peninsula

The Asian tiger mosquito, Aedes albopictus, is a highly invasive species that has been spreading rapidly throughout tropical and temperate regions worldwide since the late 1970s. On the Iberian Peninsula, it was first recorded in 2004 near Barcelona. Since then, the species has spread along the Mediterranean coast and is now colonising the Peninsulas inner territories. As with other species of the genus Aedes, the spread of the tiger mosquito has been linked to global shipping routes and road networks. In particular, the transport of adult mosquitoes by car has been shown to augment its natural spreading capacity by orders of magnitude. Much remains unknown, however, about the impact of human-mediated dispersal on the genetic variability of this species. This study aimed to ascertain the factors that have contributed to the spread and the current genetic variation of Ae. albopictus across the Iberian Peninsula, through complex dispersal mechanisms and endosymbiosis with bacteria like Wolbachia. We do so through population genetic analysis of mitochondrial (COI) and nuclear (ITS2) DNA sequences. Overall, both COI and ITS2 markers showed a lack of genetic structure among sampled regions and the presence of worldwide dominant haplotypes, suggesting a pattern of multiple introductions from abroad. We found extremely low levels of variation in COI compared to ITS2, and this lack of mitochondrial polymorphism is likely explained by high Wolbachia prevalence (79%). Multilevel models revealed that greater mosquito fluxes (estimated from commuting patterns and tiger mosquito population distribution) and spatial proximity between sampling sites were associated with lower ITS2 genetic distance, suggesting that rapid short- and medium-distance dispersal is facilitated by humans through vehicular traffic. This study highlights the significant role of human transportation in shaping the genetic attributes of Ae. albopictus and promoting regional gene flow, and underscores the need for a territorially integrated surveillance across scales of this disease-carrying mosquito. Author SummaryThe tiger mosquito, Aedes albopictus, is one of the most invasive species in the world. Native to the tropical forests of Southeast Asia, over the past 30 years it has rapidly spread throughout tropical and temperate regions of the world. Its dramatic expansion has resulted in public health concerns as a consequence of its vector competence for at least 16 viruses. Previous studies showed that Ae. albopictus spread has been facilitated by human-mediated transportation, but much remains unknown about how this has affected its genetic attributes. Here we examined the factors that contributed to shaping the current genetic constitution of Ae. albopictus in the Iberian Peninsula, where the species was first found in 2004, by combining population genetics and Bayesian modelling. We found that both mitochondrial and nuclear DNA markers showed a lack of genetic structure and the presence of worldwide dominant haplotypes, suggesting regular introductions from abroad. Mitochondrial DNA showed little genetic diversity compared to nuclear DNA, likely explained by infection with maternally transmitted bacteria of the genus Wolbachia. Our models indicated that human transportation plays a role in shaping Ae. albopictus nuclear genetic structure by means of passive dispersal of adult tiger mosquitoes through the road network.

genetics↗

bioRxiv2018

Opening the Pandora Box: DNA-barcoding evidence limitations of morphology to identify Spanish mosquitoes

Cryptic speciation is frequent in the medically important mosquitoes. While most findings have been reported in tropical regions, it is an unexplored topic in countries where mosquito-borne diseases are not endemic, like Spain. The occurrence of recent outbreaks in Europe has increased the awareness on the native and invasive mosquito fauna present in the continent. Therefore, the central question of this study is whether the typological approach is sufficient to identify Spanish mosquitoes. To address this problem, we confronted the results of the morphological identification of 62 adult specimens collected from four different regions of Spain (La Rioja, Navarra, Castellon and the Island of Majorca) with the results obtained through DNA-barcoding. We conducted a comprehensive phylogenetic analysis of the COI gene region and compared this with the results of four species delimitation algorithms (ABGD initial partition, ABGD P=0.46%, bPTP and TCS). We report strong evidence for cryptic speciation in Anopheles algeriensis and Aedes vexans and reproductive isolation of the rock pool mosquito Aedes mariae. In addition, we report that the character present in the wings is not efficient to distinguish species Culiseta annulata from Culiseta subochrea, which distribution in the country may be different than previously described.

zoology↗