Cryptosporidiosis, caused by Cryptosporidium parvum, is a major cause of enteric disease and gut microbiota disruption in neonatal ruminants. It can lead to impaired growth, increased susceptibility to pathogens, and long-term gut dysfunction. In this study, we investigated whether supplementation with a live yeast probiotic (Saccharomyces cerevisiae Sc47) could help preserve gut microbiota resilience and functional homeostasis during an experimental C. parvum oral infection in goat kids. Thirty male French Alpine goat kids were assigned to three groups: uninfected control (healthy), infected, and infected with yeast supplementation. Longitudinal 16S rRNA gene sequencing, network analysis, and functional metagenomic predictions were used to assess microbial diversity, community composition, co-occurrence patterns, and metabolic potential, with a focus on short-chain fatty acid (SCFA) biosynthesis. Infection induced marked dysbiosis, characterised by a substantial reduction in microbial richness and a widespread loss of SCFA-producing commensals and metabolic functions. In contrast, yeast supplementation significantly reduced oocyst excretion by more than 84% throughout the experiment, attenuated pathogen-induced community shifts, and maintained beneficial genera such as Butyricicoccus and members of the Oscillospiraceae family. Furthermore, network analysis revealed that probiotic treatment preserved microbial association structures and reduced community fragmentation. Consistent with these findings, functional profiling showed the retention of pathways involved in carbohydrate metabolism, amino acid biosynthesis, and SCFA production, suggesting enhanced microbiota resilience. These findings demonstrate that S. cerevisiae supplementation can mitigate infection-associated dysbiosis by controlling pathogenic overgrowth while sustaining commensal bacterial stability and functional capacity. This highlights its potential as a microbiota-targeted strategy to support gut health in neonatal ruminants.

Background: Cryptosporidium and Giardia are common intestinal protozoa that infect humans, as well as domestic and wild animals. They rank among the most prevalent waterborne parasites and are particularly widespread in developing countries. The advent of molecular diagnostic tools has played a major role in improving our understanding of the transmission of Cryptosporidium spp. and Giardia duodenalis. A thorough understanding of their molecular diversity, geographical distribution, and the environmental and climatic factors that influence their prevalence is essential for effective control in vulnerable populations. However, knowledge about their epidemiology in Africa remains limited. Both parasites negatively impact child growth and development, particularly when affected individuals suffer from aggravating factors, such as malnutrition and HIV. Aim: This review highlights research conducted in Côte d’Ivoire involving humans, animals, and the environment, and emphasizes the importance of the One Health framework. Methods: Relevant publications from March 1990 to December 2024 were sourced from PubMed and ResearchGate. Results: Out of the 26 studies identified, only 9 employed molecular tools and 17 used microscopy tools to detect G. duodenalis and Cryptosporidium spp. Findings confirmed the presence of the parasite in humans, livestock (including cattle, sheep, and camels), and environmental samples (water and soil). The prevalence and genetic diversity of G. duodenalis isolates varied by region and age group in both humans and animals. Conclusions: This study shows that Cryptosporidium and Giardia are widespread in humans and animals in Côte d’Ivoire, with both anthroponotic and zoonotic transmission cycles.

Hybrids between Schistosoma haematobium and Schistosoma bovis contribute to human and animal infections, highlighting complex interspecies interactions that facilitate schistosomiasis transmission. Schistosoma bovis infects multiple ruminant hosts, promoting cross-species transmission and increasing zoonotic risk. This study explores transcriptomic plasticity as a mechanism enabling hybrid schistosomes to adapt to different definitive hosts. We analysed two contexts: (1) introgressed S. haematobium × S. bovis hybrids, which exhibited higher virulence in sheep than parental S. bovis; and (2) S. bovis infecting different mammalian hosts. Introgression, the transfer of genetic material between species through hybridization and repeated backcrossing, was associated with 366 differentially expressed genes (4% of coding genes) between introgressed hybrids and S. bovis in sheep. Additionally, S. bovis showed host-dependent transcriptomic changes, with 30% of genes differentially expressed between infections in hamsters and sheep. Enriched biological processes shared across introgression and host adaptation included nuclear mRNA catabolism and inner mitochondrial membrane organization, indicating increased gene expression plasticity and metabolic adaptation to environmental stress. These findings suggest that transcriptomic plasticity enhances the adaptability of S. bovis and hybrid worms, increasing their zoonotic potential. This raises concerns for schistosomiasis control, as such plasticity could expand transmission capacity and complicate intervention strategies. This article is part of the Royal Society Science+ meeting issue 'Parasite evolution and impact in action: exploring the importance and control of hybrid schistosomes in Africa and beyond'.

The feral rock pigeon (Columba livia domestica) and wood pigeon (Columba palumbus) are ubiquitous species found in cities worldwide. Its interaction with humans, domestic animals and wild birds makes them potential carriers of transmissible pathogens, including zoonotic parasites. The aim of this study was to identify protozoan parasites belonging to the genera Cryptosporidium spp. and Giardia spp. in these two pigeon species hosted at the Wildlife Animal Hospital of the Veterinary School of Alfort, in France. Fecal samples from 367 pigeons (Columba livia and Columba palumbus) including a wide majority of juveniles, were collected and analysed using both direct immunofluorescence and molecular identification techniques, including PCR targeting the small subunit ribosomal RNA and the 60 kDa glycoprotein gene of SSU rDNA. Eighty-six and 12 fecal samples tested positive for Cryptosporidium spp. and Giardia spp. by immunofluorescence, respectively. Young pigeons appeared to be infected by Cryptosporidium spp. more frequently than adults. In addition, wood pigeons seemed to be infected by Giardia spp. more often, while rock pigeons had a higher occurrence of Cryptosporidium spp. Phylogenetic analysis revealed the presence of zoonotic species including C. meleagridis, C. parvum, and G. duodenalis assemblage B. As these species are known to infect humans, pigeons could represent a potential source of zoonotic transmission.

ABSTRACT Background Cryptosporidiosis is an emerging worldwide zoonosis caused by an opportunistic protozoon, Cryptosporidium spp. In Tunisia, the lack of knowledge on the occurrence and genetic characteristics of Cryptosporidium spp. limits the understanding of its epidemiology, impact and transmission routes. Objectives The present review aims to collect, compile and summarise data on the prevalence of Cryptosporidium spp. infections in humans, animals and the environment contamination in Tunisia. Methods A systematic review was conducted across international databases using PRISMA 2020 Guidelines. Data from 15 selected studies were extracted and organised into thematic categories, including prevalence rates, risk factors, diagnostic methods, and population groups affected. A qualitative synthesis approach was used to analyse and compare findings across studies, highlighting trends, gaps, and public health implications. Results The publications indicate that Cryptosporidium spp. infections are prevalent in both humans and animals, but the results remain confusing and may not reflect the real impact of the disease. In animals, only three studies were conducted in livestock and poultry. Only Cryptosporidium parvum (IIa and IId) was identified in the three studies from adult asymptomatic animals. Therefore, this finding may not reveal the true impact of the parasite on animal health. In humans, all studies were conducted in hospitals on adult and child patients diagnosed with either cancer or immunodeficiency. Cryptosporidium parvum and Cryptosporidium hominis were by far the predominant species suggesting potential zoonotic and anthroponotic transmission routes in humans. Of the two studies conducted on wastewater, five Cryptosporidium species (C. parvum, C. hominis, Cryptosporidium meleagridis, Cryptosporidium muris, Cryptosporidium andersoni, Cryptosporidium ubiquitum) and three genotypes were identified, highlighting the potential role of water as a potential route of Cryptosporidium spp. transmission. Conclusions The current review give an overview of the circulating Cryptosporidium spp. species and genotypes but they remain insufficient to fully understand the transmission dynamics, zoonotic potential and animal welfare implications of Cryptosporidium spp. in Tunisia.

La cryptosporidiose est une maladie parasitaire largement répandue dans le monde, fréquemment responsable d’épidémies d’origine hydrique et alimentaire. Les progrès en biologie moléculaire ont permis d’améliorer la compréhension des modes de transmission de Cryptosporidium , notamment de sa dimension zoonotique. Ces outils occupent aujourd’hui une place centrale dans la surveillance de la maladie dans les pays industrialisés. Bien que le diagnostic repose encore principalement sur l’observation microscopique, les méthodes moléculaires, en particulier la PCR et le séquençage, se développent rapidement. Elles offrent un diagnostic plus précis et permettent une meilleure caractérisation des espèces impliquées, contribuant ainsi à une meilleure compréhension de l’épidémiologie et des voies de contamination de la cryptosporidiose.

Human schistosomiasis is a zoonotic disease, meaning that wild animals or livestock can serve as reservoirs for the disease. This sustains active parasite transmission in regions where extensive treatment initiatives are underway, potentially undermining efforts to combat schistosomiasis. In multi-host and multi-parasite systems, achieving disease elimination necessitates the incorporation of all reservoir hosts. For this reason, animal diagnosis is crucial to enable accurate targeting of treatment. However, methods for diagnosing animals remain underdeveloped. We have evaluated two commercially available serological diagnostics, the Schistosoma IgG ELISA produced by Bordier Affinity Products, and the Schisto II Western Blot IgG kit produced by LDBIO Diagnostics which are commonly employed for human diagnosis. The diagnostics were carried out on a collection of 175 sheep serum samples from 35 sheep experimentally infected with S. haematobium, S. bovis and various strains resulting from mate crossing between these two species. The diagnosis of these samples was possible using the two methods tested, with an adaptation of the protocol of both methods by replacing the conjugate. The kappa coefficient highlights substantial agreement between each newly tested method and the adult worm recovery during animal necropsy, suggesting robust consistency in the results obtained with the two serological diagnostics. In both instances, further studies are required for validation and standardization to facilitate field application and to specify the specificity of the Western-Blot.

Contexte : Le pigeon (Columba livia) est une espèce d’oiseau domestique qui entre fréquemment en contact avec les humains. Les pigeons hébergent et disséminent de nombreux pathogènes zoonotiques, notamment des parasites apicomplexes du genre Cryptosporidium, un parasite protiste commun des vertébrés. Ces dernières années, les populations de pigeons ont augmenté dans les zones urbaines et périurbaines, ce qui peut constituer un risque pour la santé publique. Objectif : Une revue systématique a été réalisée pour examiner la présence et la prévalence de Cryptosporidium chez les pigeons à l’échelle mondiale. Méthodes : Les articles publiés ont été obtenus dans la base de données PubMed, couvrant la période du 1er janvier 1994 au 1er août 2024. Au total, 38 publications ont été incluses dans cette revue. Résultats : L’infection à Cryptosporidium chez les pigeons a été signalée pour la première fois en Turquie en 1994, avec des symptômes cliniques comprenant la dépression, l’inactivité, la diarrhée et le plumage piqué. L’examen histologique a révélé la présence de Cryptosporidium dans l’épithélium intestinal. Des études ultérieures ont confirmé la prévalence de Cryptosporidium à l’échelle mondiale, avec des méthodes de diagnostic traditionnelles révélant une prévalence moyenne de 14,8 %, tandis que les outils moléculaires ont montré une prévalence plus élevée (28,4 %). Les taux les plus élevés ont été observés en Irak, les pigeons captifs étant plus fréquemment infectés que les pigeons sauvages. Les données moléculaires, bien que limitées, suggèrent une plus grande diversité chez les pigeons domestiques que chez les pigeons sauvages. C. meleagridis, C. parvum et C. hominis étaient les principales espèces zoonotiques identifiées chez les pigeons à l’échelle mondiale. L’analyse microscopique a montré des variations dans l’intensité de l’infection, avec un taux d’oocystes allant de 3 000 à 36 000 par gramme de fèces. De nombreux génotypes de Cryptosporidium spp. sont considérés comme zoonotiques, avec des cas connus d’infection humaine chez des personnes manipulant des pigeons, soulignant sa pertinence pour la santé publique. Conclusions : Des études supplémentaires sont nécessaires pour clarifier la pathogénicité et les voies de transmission de Cryptosporidium spp. chez les pigeons. La prévention et le contrôle de cette zoonose chez les pigeons devraient constituer une priorité de santé publique, en particulier dans les régions où les populations de pigeons sont importantes, telles que les zones urbaines où ils vivent en contact étroit avec les humains et d’autres animaux.

This study reports a new therapeutic approach for canine giardiasis, the most common intestinal protozoan infection caused by Giardia intestinalis. It is based on the use of the probiotic strain Lactobacillus johnsonii CNCM I-4884 and, in particular, its bile salt hydrolase enzymatic activities. Clinical trials in dogs demonstrated that daily administration of L. johnsonii CNCM I-4884 significantly reduced Giardia cyst shedding after 14 days. These results highlight the potential of this probiotic as a promising alternative to antimicrobials, such as nitroimidazoles or benzimidazoles, for the treatment of giardiasis in dogs. Moreover, they provide a novel approach for the veterinary industry to develop innovative products targeting this parasite. In addition to its direct anti-Giardia effect, L. johnsonii CNCM I-4884 may also act as an adjuvant therapy, supporting intestinal homeostasis, enhancing host defense mechanisms, and promoting recovery of gut balance during or after antiparasitic treatments. This dual role suggests that the strain could be considered not only as a complementary therapy but, in specific cases, as a potential stand-alone probiotic treatment for canine giardiasis.

Giardiasis, a widespread intestinal parasitosis affecting humans and animals, is a growing concern due to the emergence of drug-resistant strains of G. intestinalis. Probiotics offer a promising alternative for preventing and treating giardiasis. Recent studies have shown that the probiotic Lactobacillus johnsonii CNCM I-4884 inhibits G. intestinalis growth both in vitro and in vivo. This protective effect is largely mediated by bile salt hydrolase (BSH) enzymes, which convert conjugated bile acids (BAs) into free forms that are toxic to the parasite. The objective of this study was to use adaptive evolution to develop stress-resistant derivatives of L. johnsonii CNCM I-4884, with the aim of improving its anti-Giardia activity. Twelve derivatives with enhanced resistance to BAs and reduced autolysis were generated. Among them, derivative M11 exhibited the highest in vitro anti-Giardia effect with enhanced BSH activity. Genomic and proteomic analyses of M11 revealed two SNPs and the upregulation of the global stress response by SigB, which likely contributed to its increased BAs resistance and BSH overproduction. Finally, the anti-Giardia efficacy of M11 was validated in a murine model of giardiasis. In conclusion, our results demonstrate that adaptive evolution is an effective strategy to generate robust food-grade bacteria with improved health benefits.

Giardia duodenalis est un parasite protozoaire qui infecte principalement l’intestin grêle de divers mammifères, y compris les humains. Il s’agit d’un complexe d’espèces composé de plusieurs génotypes connus sous le nom d’assemblages A à H. Les assemblages A et B sont considérés comme les plus zoonotiques, présentant ainsi un risque significatif pour la santé humaine, tandis que les assemblages C à H se trouvent chez les animaux de compagnie, le bétail, les rongeurs et les vertébrés marins. La giardiose, due à G. duodenalis, est l’infection parasitaire intestinale la plus courante dans le monde. En Algérie, il existe des données limitées sur l’occurrence et les caractéristiques génétiques de G. duodenalis, entravant la compréhension de son épidémiologie, de son impact et de son potentiel zoonotique. Cette revue se concentre sur la recherche menée en Algérie, couvrant les humains, les animaux et l’environnement, en mettant l’accent sur l’approche «Une seule santé». Les bases de données PubMed et ResearchGate ont été utilisées pour accéder aux publications pertinentes sur la présence de G. duodenalis chez les humains, les animaux ou dans l’environnement de janvier 2000 à avril 2023. Dix-sept publications ont été identifiées, parmi lesquelles seuls quatre articles utilisaient des outils moléculaires pour identifier G. duodenalis. Les résultats ont révélé la présence de G. duodenalis chez les humains, les animaux d’élevage (bovins, ovins et chameaux) et dans l’environnement (échantillons d’eau et de sol). La prévalence et la diversité génétique des isolats de G. duodenalis variaient selon les régions et les groupes d’âge, aussi bien chez les humains que chez les animaux. L’assemblage A était couramment trouvé chez les humains et les animaux, indiquant une transmission zoonotique potentielle. Des études supplémentaires sont nécessaires pour comprendre de manière approfondie la dynamique de transmission de G. duodenalis, son potentiel zoonotique et les implications pour la santé publique et le bien-être animal en Algérie. Aborder G. duodenalis nécessite des efforts collaboratifs dans le cadre du concept «Une seule santé», impliquant des vétérinaires, des biologistes, des écologistes et des professionnels de la santé. La mise en oeuvre de stratégies de prévention et de contrôle adaptées à des régions spécifiques et l'amélioration des pratiques d’hygiène et d’élevage sont essentielles pour réduire la charge de la giardiose tant chez les humains que chez les animaux.

We are currently witnessing the endemization of urogenital schistosomiasis in southern Europe. The incriminated parasite is a hybrid between a human parasite and a livestock parasite. Using an experimental evolutionary protocol, we created hybrid lines from pure strains of both parasite species. We showed that the host spectrum of the human parasite is enlarged to the livestock parasite after genomic introgression. We also evidenced that the tropism of the parasites within the host changes and that some hybrid lines are more virulent than the parental strains. These results engage a paradigm shift from human to zoonotic transmission of urogenital schistosomiasis.

In Europe, tick-borne diseases (TBDs) cause significant morbidity and mortality, affecting both human and animal health. Ticks can transmit a wide variety of pathogens (bacteria, viruses, and parasites) and feed on many vertebrate hosts. The incidence and public health burden of TBDs are tending to intensify in Europe due to various factors, mainly anthropogenic and often combined. Early detection of tick-borne pathogens (TBPs), preventive measures and treatment are of great importance to control TBDs and their expansion. However, there are various limitations in terms of the sensitivity and/or specificity of detection and prevention methods, and even in terms of feasibility. Aptamers are single-stranded DNA or RNA that could address these issues as they are able to bind with high affinity and specificity to a wide range of targets (e.g., proteins, small compounds, and cells) due to their unique three-dimensional structure. To date, aptamers have been selected against TBPs such as tick-borne encephalitis virus, Francisella tularensis, and Rickettsia typhi. These studies have demonstrated the benefits of aptamer-based assays for pathogen detection and medical diagnosis. In this review, we address the applications of aptamers to TBDs and discuss their potential for improving prevention measures (use of chemical acaricides, vaccination), diagnosis and therapeutic strategies to control TBDs.

Cryptosporidium spp. remain a major cause of waterborne diarrhea and illness in developing countries and represent a significant burden to farmers worldwide. Cryptosporidium parvum virus 1 (CSpV1), of the genus Cryspovirus, was first reported to be present in the cytoplasm of C. parvum in 1997. Full-length genome sequences have been obtained from C. parvum from Iowa (Iowa), Kansas (KSU) and China. We aimed at characterizing the genome of CSpV1 from France and used sequence analysis from Cryptosporidium isolates to explore whether CSpV1 genome diversity varies over time, with geographical sampling location, C. parvum genetic diversity, or ruminant host species. A total of 123 fecal samples of cattle, sheep and goats were collected from 17 different French departments (57 diseased animal fecal samples and 66 healthy animal fecal samples). Subtyping analysis of the C. parvum isolates revealed the presence of two zoonotic subtype families IIa and IId. Sequence analysis of CSpV1 revealed that all CSpV1 from France, regardless of the subtype of C. parvum (IIaA15G2R1, IIaA17G2R1 and IIdA18G1R1) are more closely related to CSpV1 from Turkey, and cluster on a distinct branch from CSpV1 collected from C. parvum subtype IIaA15G2R1 from Asia and North America. We also found that samples collected on a given year or successive years in a given location are more likely to host the same subtype of C. parvum and the same CSpV1 strain. Yet, there is no distinct clustering of CSpV1 per French department or ruminants, probably due to trade, and transmission of C. parvum among host species. Our results point towards (i) a close association between CSpV1 movement and C. parvum movement, (ii) recent migrations of C. parvum among distantly located departments and (iii) incidental transmission of C. parvum between ruminants. All together, these results provide insightful information regarding CSpV1 evolution and suggest the virus might be used as an epidemiological tracer for C. parvum. Future studies need to investigate CSpV1's role in C. parvum virulence and on subtype ability to infect different species.