Alexis Ribas

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University of Barcelona | UB · Department of Microbiology and Healthy Parasite

This study investigates the helminth absence in the invasive blackchin tilapia (Sarotherodon melanotheron) in Thailand, testing the Enemy Release Hypothesis (ERH). The recent introduction of S. melanotheron in Thailand has raised concerns about its ecological and economic impacts.

The formalin-ethyl acetate concentration technique (FECT) is one of the most sensitive diagnostic method not only for all helminths, but also for Opisthorchis viverrini infections in stool examinations. However, it remains a diagnostic problem for light infections. We modified the one-step FECT to determine the low-intensity of O. viverrini infecti...

The study of sperm characteristics has proven useful for elucidating interrelationships in several groups of Platyhelminthes, such as digeneans. Thus, in the present work, the ultrastructural organization of the mature spermatozoon of the digenean Artyfechinostomum malayanum (Echinostomatidae), a parasite of Rattus norvegicus (Rodentia: Muridae) fr...

Heterakis spumosa, a parasitic worm infecting rodents, is globally prevalent in black rats, brown rats, and house mice. It is hypothesized to originate from Asia due to its widespread presence in Southeast Asia in various Murinae. Previous molecular studies focused on European, African, and Japanese specimens, but none included samples from the put...

Host–parasite interactions are influenced by present and past eco‐evolutionary interactions and the local environment. An ecological community defines the potential host range of each parasite and the potential parasite diversity of each host species. Past and present processes translate potential to realised interaction niches of parasite and host...

The present study aims at clarifying the poorly known phylogenetic relationships and systematics of cestodes of the family Davaineidae Braun, 1900 (Cyclophyllidea), primarily the genus Raillietina Fuhrmann, 1920 and of the subfamily Inermicapsiferinae (Anoplocephalidae) from mammals (mostly rodents, 31 new isolates) and birds (eight new isolates)....

Nematodes belonging to the genus Oesophagostomum frequently infect wild chimpanzees ( Pan troglodytes ) across widely separated field sites. Nodular lesions (granulomas) containing Oesophagostomum are commonly seen in the abdomen of infected chimpanzees post‐mortem. At Taï National Park, Côte d'Ivoire, previous studies have identified larvae of a v...

Simple Summary Leptophallus nigrovenosus is a trematode parasite found in snakes that requires feeding on amphibians to acquire the parasite. Firstly, this study investigated, in detail, the sensory receptors on the cercariae of these parasites, shedding light on the adaptations that allow them to find their host species. Secondly, the metacercaria...

Dengue is a significant public health problem in mostly tropical countries, including Timor-Leste. Dengue continues to draw attention from the health sector during the COVID-19 phenomenon. Therefore, the goal of this study is to evaluate the dengue incidence rate in comparison with the COVID-19 cumulative number and associated dengue risk factors,...

A paleoparasitological investigation of a vertebrate coprolite from the Huai Hin Lat Formation (Upper Triassic) was carried out. Five morphotypes of potential parasite eggs or sporocysts were identified in the coprolite by microscopic analysis using thin section technique. The rounded or oval shape and thick shell of one of the five morphotypes sug...

Martinez-Silvestre A. et al. 2023. Bull. Soc. Herp. Fr. | Un cas de syndrome d'oedème chez le Calotriton des pyrénées Calotriton asper dans les Hautes-Pyrénées | Summary-For the first time in Calotriton asper (Dugès, 1952) (Urodela : Salamandridae), one specimen with edema syndrome was observed in the French department of Hautes-Pyrénées (65) in th...

A new spirurid nematode, Protospirura canariensis n. sp., a parasite of the black rat Rattus rattus Linnaeus, 1758 (Rodentia: Muridae), in El Hierro Island (Canary Archipelago, Spain), was described by means of light (LM) and scanning electron microscopy (SEM). The most discriminating characteristics between the new species and the remaining specie...

Advances in experimental and theoretical work increasingly suggest that parasite interactions within a single host can affect the spread and severity of wildlife diseases. Yet empirical data to support predicted co-infection patterns are limited due to the practical challenges of gathering convincing data from animal populations and the stochastic...

A new spirurid nematode Protospirura canariensis n. sp., parasite of the black rat Rattus rattus (Rodentia: Muridae) in El Hierro Island (Canary Archipelago, Spain) is described by means of light (LM) and scanning electron microscopy (SEM). The most discriminant characteristics between the new species and the existing species in the genus Protospir...

Trematode Parasites on the Montseny Brook Newt (Calotriton arnoldi): a new threat? Between 2018 and 2021, two Montseny brook newts were found dead. In addition, five illegal captive newts from the wild were also analysed. The post mortem study included necropsy, skin qPCR to rule out the presence of the fungi Batrachochytrium dendrobatidis and B....

Wildfires simplify ecosystems, modifying the ecological niches of the fauna living in the recently burned areas. Small mammals respond rapidly to changes in habitat structure and composition after fire, but the effects of fire can be ameliorated by some management strategies (e.g., salvage logging). Hence, it is necessary to explore whether alterna...

Leishmaniasis is an infectious zoonotic disease caused by protozoan parasites of the genus Leishmania. In the Mediterranean basin, leishmaniasis is caused by Leishmania infantum and transmitted by bites of sandflies of the genus Phlebotomus, with the dog as the main reservoir host. The most common form is cutaneous leishmaniasis (CL), although visc...

Boletin Asociacion Herpetologica Española. 33:61-65. El síndrome de edema es una enfermedad que afecta a innumerables especies de anfibios y tiene una alta prevalencia. La presente es la primera vez que se describe para ambos grupos (anuros y urodelos) y con un análisis histológico en uno de los ejemplares.

A new rictulariid nematode Pterygodermatites ( Mesopectines ) valladaresi n. sp., parasite of the house mouse Mus musculus (Rodentia: Muridae) in the Canary Islands (Spain) is described by means of light and scanning electron microscopy. The new species belongs to the subgenus Mesopectines characterized by a more or less dorsal orientation of the b...

A redescription of the rictulariid nematode Pterygodermatites (Pterygodermatites) plagiostoma Wedl, 1861, is made by means of light and scanning electron microscopy, including the first data on male specimens. The morphologic study was based on specimens recovered from two Algerian hedgehogs (Atelerix algirus) from Tenerife and Gran Canaria islands...

En abril de 2020 se realizó un control veterinario de 106 salamandras y tritones de una colección privada de más de 500 urodelos exóticos y autóctonos dedicados al intercambio de estas especies en Barcelona. Las pruebas analíticas realizadas fueron negativas a todos los patógenos excepto a Chlamydia y a Bd . Además, se detectaron formas larvarias (...

Because parasite data reveal essential information about the behavior and history of their hosts, it is possible to use them as tracers of host evolution. A table built from the analysis of the data contained in the book by Ashford and Crewe “The Parasites of Homo sapiens” allows counting and cross comparing the parasites according to the main desc...

Helminth parasites in the wood mouse (Apodemus sylvaticus) from Algeria. Helminth parasites of the wood mouse Apodemus sylvaticus (Rodentia, Murinae) were studied for the first time in Algeria. Fifty mice from Mizrana forest were examined in 2017. Our results showed a general prevalence of 82 % and a six species of helminths: four nematodes (Heligm...

Advances in experimental and theoretical work increasingly suggest that parasite interactions within a single host can affect the spread and severity of wildlife diseases. Yet empirical data to support predicted co-infection patterns are limited due to the practical challenges of gathering convincing data from animal populations and the stochastic...

A B C Família Espècie Himasthlidae Aporchis massiliensis Aves: Larus cachinnans Brachylaimidae Brachylaima mascomai Gastropoda: Cornu aspersum (hoste intermediari); Otala punctata (hoste intermediari); Pseudotachea splendida (hoste intermediari); Theba pisana (hoste intermediari). Mammalia: Rattus norvegicus ; Rattus rattus Brachycoeliidae Brachyco...

Two species of hedgehogs are known to occur in northern part of Africa: the Algerian hedgehog Atelerix algirus and the Ethiopian hedgehog Paraechinus aethiopicus . Within each species several subspecies were described based on morphometrical data and pelage coloration, but all these subspecies have enigmatic and unclear definitions. We investigated...

Diputació Barcelona. Presentation on sanitary status of amphibians in general and Montseny brook salamander in particular in Montseny Natural Park in the period 2015 - 2020 . New description of presence of the fungus Batrachochytrium dendrobatidis in wild amphibians, detection of bacteria Chlamydia in a ilegal collection as well as a trematoda cyst...

Previous field-based studies have evidenced patterns in gastrointestinal helminth (GIH) assemblages of rodent communities that are consistent with “enemy release” and “spill-back” hypotheses, suggesting a role of parasites in the ongoing invasion success of the exotic house mouse (Mus musculus domesticus) in Senegal (West Africa). However, these fi...

The prevalence of Opisthorchis viverrini, a fish-borne zoonotic trematode that can provoke cholangiocarcinoma, is high in the Northeast Thailand. The aim of this study was to determine the prevalence of O. viverrini metacercariae in the cyprinid fish and determine its association of O. viverrini infection among the consumers who regularly buy fish...

Infection probability, load, and community structure of helminths varies strongly between and within animal populations. This can be ascribed to environmental stochasticity or due to individual characteristics of the host such as their age or sex. Other, but understudied, factors are the hosts' behavior and co-infection patterns. In this study, we...

Trichuris spp. is a widespread nematode which parasitizes a wide range of mammalian hosts including rodents, the most diverse mammalian order. However, genetic data on rodent whipworms are still scarce, with only one published whole genome (Trichuris muris) despite an increasing demand for whole genome data. We sequenced the whipworm mitogenomes fr...

In 2018, extensive field studies of diversity and prevalence of helminth infection in synanthropic rodents and non-rodent small mammals from public parks and citified areas in the Bangkok Metropolitan were conducted. Rattus rattus complex was the dominant small mammal in public parks. Of the 197 animals, 147 individuals were infected with one or mo...

The ultrastructural characteristics of the mature spermatozoon of Diplodiscus amphichrus (Digenea, Paramphistomoidea, Diplodiscidae) and their ultrastructural organisation were examined by means of transmission electron microscopy. Live digeneans were collected from the Chinese edible frog Hoplobatrachus rugulosus in Thailand. The male gamete of D....

The whipworm Trichuris muris is known to be associated with various rodent species in the northern hemisphere, but the species identity of whipworm infecting rodents in the Oriental region remains largely unknown. We collected Trichuris of Muridae rodents in mainland and insular Southeast Asia between 2008 and 2015 and used molecular and morphologi...

The impact of carnivore parvovirus infection on wild populations is not yet understood; disease signs are mainly developed in pups and assessing the health of litters in wild carnivores has big limitations. This study aims to shed light on the virus dynamics among wild carnivores thanks to the analysis of 213 samples collected between 1994 and 2013...

In the Mekong Delta region of Vietnam, small-scale chicken farming is common. However, high levels of disease or mortality in such flocks impair economic development and challenge the livelihoods of many rural households. We investigated 61 diseased small-scale flocks (122 chickens) for evidence of infection with 5 bacteria, 4 viruses, and helminth...

Commercial small-scale chicken farms managed as all-in-all-out but operating with low standards of hygiene/biosecurity are increasingly common in Vietnam. These conditions facilitate the transmission of gastrointestinal helminths. However, there are no published data on helminths in these systems. We aimed (1) to determine the prevalence/burden of...

A molecular survey of wild mammals was performed to assess their potential as reservoirs of L. infantum. A total of 156 specimens of wild mammalian fauna were obtained for analysis from areas in Catalonia with a reported incidence of canine leishmaniasis. They consisted of 124 small mammals: 35 Mus spretus (Muridae); 64 Erinaceus europaeus (Erinace...

We investigated the efficiency of discarded drink containers compared with other methods widely used in small mammal studies (live trapping and diet of generalist predators). We collected 225 beverage containers (bottles and cans) from 44 sampling places, and 376 small mammals of seven small mammal species were identified. Species accumulation curv...

The presence and characterization of serovars of Salmonella in small mammals were investigated in Chantaburi Province (east of Thailand). A total of seventy one small mammals were tested, with an overall prevalence of 12.7 % with a single serovar detected (Weltevreden). Of the studied mammal species, the sole individual of Tupaia belangeri (Scadent...

Commercial small-scale chicken farms using all-in-all-out production but operating with low standards of hygiene/biosecurity are increasingly common in Vietnam. These conditions facilitate transmission of gastrointestinal helminths. However, there are no published data on these parasites in these systems. The aims were: (1) to determine the prevale...

The presence of Neospora caninum Dubey, Carpenter, Speer, Topper et Uggla, 1988 in small mammals (i.e. murid rodents, Erinaceomorpha, Eulipotyphla and Scadentia) was explored for first time in South-East Asia. A total of 192 individuals from six localities across Thailand were analysed. A general prevalence of N. caninum of 22% was observed, with s...

The present study integrates several aspects of a parasitological survey in a rural community village combining community knowledge of parasites, their potential transmission routes and health risk factors. A rural community located in Northern Thailand was surveyed for intestinal parasites, and an overall prevalence of 45.2% for helminths and 4.8%...

Two-hundred and thirty-one wild carnivores belonging to 10 species of in Spain were analyzed for the presence of DNA of hemotropic mycoplasmas (hemoplasmas) by means of a universal real-time PCR targeting a 16S rRNA gene fragment. Positive reactions were found for wolf (Canis lupus: 6/37), fox (Vulpes vulpes: 1/41), Eurasian badger (Meles meles: 49...

In the Norway rat, Rattus norvegicus, anticoagulant rodenticide resistance is mainly associated with mutations in the third exon of the Vitamin K epoxide reductase complex subunit 1 (VKORC1). Identification of the resistant wild populations is very important to improve the control practices and to limit the damages due to inadequate use of the anti...

The present study describes the ultrastructural organization of the mature spermatozoon of the digenean Glypthelmins staffordi (Glypthelminthidae) by means of transmission electron microscopy. Live digeneans were collected from the Chinese edible frog (Hoplobatrachus rugulosus) in Udon Thani Province (Thailand). The ultrastructural study reveals th...

More than a dozen Gongylonema spp. (Spirurida: Spiruroidea: Gongylonematidae) have been described from a variety of rodent hosts worldwide. Gongylonema neoplasticum (Fibiger & Ditlevsen, 1914), which dwells in the gastric mucosa of rats such as Rattus norvegicus (Berkenhout) and Rattus rattus (Linnaeus), is currently regarded as a cosmopolitan nema...

Phylogenetic relationships, evolutionary history and systematics of tapeworms of the family Catenotaeniidae were studied using nucleotide sequences of the partial 28S nuclear rDNA (ca. 1,500 bp) and mitochondrial 12S–16S DNA (ca. 820 bp) genes. The tapeworm material consists of 29 species, including type species of the genera Catenotaenia Janicki,...

Changes in species distributions open novel parasite transmission routes at the human–wildlife interface, yet the strength of biotic and biogeographical factors that prevent or facilitate parasite host shifting are not well understood. We investigated global patterns of helminth parasite (Nematoda, Cestoda, Trematoda) sharing between mammalian wild...

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as wa...

A new species, Demodex bandicotae sp. nov. (Acariformes: Demodecidae), is described based on adult stages from the hairy skin of the greater bandicoot rat Bandicota indica (Bechstein, 1800), collected in Lao People’s Democratic Republic (Laos). Parasites were noted in 41.7% of bandicoot rats, with a mean intensity of 5.6 parasites in the tested ski...

Genetic diversity may decrease from the centre to the margin of a species distribution range due to neutral stochastic processes. Selection may also alter genetic diversity in non-neutral markers, such as genes associated with the immune system. Both neutral processes and selection on the immune system are thus expected to affect the spatial distri...

The present study records the ultrastructural organization of the mature spermatozoon of Opisthorchis viverrini by means of transmission electron microscopy. The spermatozoon of O. viverrini is a filiform cell, tapered at both extremities. It exhibits the characteristics of type IV spermatozoon of digeneans, namely with two axonemes of the 9+‘1’ tr...

Whipworms were collected from rodents (Muridae) from six West African countries: Burkina-Faso, the Islamic Republic of Mauritania, and the Republics of Benin, Guinea, Mali and Senegal. Molecular sequences (ITS-1, 5.8S and ITS-2 of the ribosomal DNA gene) and morphometric characters were analysed in Trichuris (Nematoda: Trichuridae) specimens found...

An integrated epidemiological study of Opisthorchis viverrini consisting of risk factors analysis and parasitation prevalence determination in humans, as well as the assessment the roles of host reservoirs (dogs and cats) and intermediate hosts (cyprinid fish) was carried out in the vicinity of Huay Luang dam, Udon Thani province, in the north east...