Molecular study of the status of Angiostrongylus cantonensis in rats in Haiti

Angiostrongylus cantonensis, commonly known as the rat lungworm, causes Eosinophilic meningitis in humans. Our study aimed to investigate the prevalence and distribution of this parasite in rats in Haiti. Rats were trapped at 8 sites, 7 in Artibonite (rural region) and one in an urban area of Port-au-Prince. After euthanasia, hearts and lungs were sampled and preserved in 70% ethanol. Subsequently, the organs were dissected to detect adult worms. Parasite DNA was amplified using PCR targeting either the nematode ITS2 gene for rodent lung tissue or cox1 for isolated worms. Subsequent sequencing allowed parasite identification. A total of 70 rats were captured, i.e. 23 Rattus norvegicus and 47 Rattus rattus. Adult nematodes morphologically compatible with A. cantonensis were isolated from 5/70 rats (7%) and identification was confirmed by sequencing. Molecular analysis of lung tissue revealed a parasite prevalence of 31.4% (22/70), and its presence at 4 of the 8 sites investigated, including Port-au-Prince. The molecular approach on lung tissue targeting the ITS2 gene enabled us to detect a prevalence 4 times higher than the visual search for adult worms alone. Only one COX1 haplotype was identified, belonging to genotype II-G, widely distributed in Brazil, the French Antilles (Guadeloupe), French Polynesia, Hawaii, and Japan. These results confirm that A. cantonensis is an endemic parasite in Haiti not only in the capital Port-au-Prince, but also in several rural areas. Direct molecular screening for Angiostrongylus DNA in rat lung tissue showed higher sensitivity than visual detection of worms during dissection and could be useful for further prevalence studies

Age influence on effectiveness of a novel 3-phytase in barley-wheat based diets for pigs from 12 to 108 kg under commercial conditions

[EN] The main objective of this study was to evaluate the influence of pig's age on the effectiveness of a new microbial 3-phytase, produced by Komagataella phaffii, under commercial conditions in barley-wheat based diets. Two experiments were conducted in weaned, growing and finishing pigs; firstly, to determine phytase efficacy on dry matter, organic matter, energy, protein and mineral (phosphorus, P and calcium, Ca) digestibility (n = 48; Experiment 1), and secondly, to evaluate the effect of phytase on growth performance and bone mineralization (n = 312; Experiment 2). In each experiment, three barley-wheat based diets were formulated following the recommendations for each animal age, of which two versions were manufactured, including 0 and 1000 phytase units (FTU)/kg of feed of the new 3-phytase to be tested. Results showed the new phytase had the potential to increase the digestibility of Ca and P (on av. + 0.05 and +0.06, respectively; P < 0.01), especially P digestibility in growing pigs (+0.10; P < 0.001), consequently decreasing P and Ca excretion. Digestible energy (DE) of the diet increased with the addition of phytase in weaned pigs (+0.69 MJ/kg of dry matter (DM); P < 0.001). Dietary inclusion of new 3-phytase enhanced average daily gain from 46 to 94 days of age (+0.07 kg/d; P < 0.05) and decreased feed conversion ratio from 46 to 154 days of age (on av. -0.13; P < 0.05), although no significant effect was observed from 154 to 185 days of age. Addition of the new 3-phytase also promoted bone mineralization, increasing the weight of the bones (+3.99 and +3.64 g of tibia at 95 days and metacarpus at 100 days of age, respectively; P < 0.05) and the ash, Ca and P content in these bones (e.g. + 0.46 and +0.33 g of P in tibia at 95 days and metacarpus at 100 days of age, respectively; P < 0.001). In conclusion, pig age affected the efficacy of a new 3-phytase on P and Ca digestibility both in weaned and growing diets and DE content of the weaned diets, which also resulted in improvements in growth, feed conversion and bone development until 154 days of age. These effects seem to be reduced during the finishing period, although the advantages of the new 3-phytase on bone mineralization were maintained until 185 days of age.We thank the technical staff at the experimental farms of the Research and Technology Animal Centre (CITA-IVIA), the Institute of Animal Science and Technology (Universitat Politècnica de Valencia) and Javier Gómez (Crianzas Campovivo) for expert technical assistance and experimental support.Cambra López, M.; Cerisuelo, A.; Ferrer, P.; Ródenas Martínez, L.; Aligué, R.; Moset, V.; Pascual Amorós, JJ. (2020). Age influence on effectiveness of a novel 3-phytase in barley-wheat based diets for pigs from 12 to 108 kg under commercial conditions. Animal Feed Science and Technology. 267:1-13. https://doi.org/10.1016/j.anifeedsci.2020.114549S113267Adeola, O., & Cowieson, A. J. (2011). BOARD-INVITED REVIEW: Opportunities and challenges in using exogenous enzymes to improve nonruminant animal production. Journal of Animal Science, 89(10), 3189-3218. doi:10.2527/jas.2010-3715Almeida, F. N., Sulabo, R. C., & Stein, H. H. (2013). Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing pigs. Journal of Animal Science and Biotechnology, 4(1). doi:10.1186/2049-1891-4-8Arredondo, M. A., Casas, G. A., & Stein, H. H. (2019). Increasing levels of microbial phytase increases the digestibility of energy and minerals in diets fed to pigs. Animal Feed Science and Technology, 248, 27-36. doi:10.1016/j.anifeedsci.2019.01.001Atakora, J. K. A., Moehn, S., Sands, J. S., & Ball, R. O. (2011). Effects of dietary crude protein and phytase–xylanase supplementation of wheat grain based diets on energy metabolism and enteric methane in growing finishing pigs. Animal Feed Science and Technology, 166-167, 422-429. doi:10.1016/j.anifeedsci.2011.04.030Blaabjerg, K., Nørgaard, J. V., & Poulsen, H. D. (2012). Effect of microbial phytase on phosphorus digestibility in non-heat-treated and heat-treated wheat–barley pig diets1. Journal of Animal Science, 90(suppl_4), 206-208. doi:10.2527/jas.53920Brady, S., Callan, J., Cowan, D., McGrane, M., & O’Doherty, J. (2002). Effect of phytase inclusion and calcium/phosphorus ratio on the performance and nutrient retention of grower-finisher pigs fed barley/wheat/soya bean meal-based diets. Journal of the Science of Food and Agriculture, 82(15), 1780-1790. doi:10.1002/jsfa.1262Braña, D. V., Ellis, M., Castañeda, E. O., Sands, J. S., & Baker, D. H. (2006). Effect of a novel phytase on growth performance, bone ash, and mineral digestibility in nursery and grower-finisher pigs. Journal of Animal Science, 84(7), 1839-1849. doi:10.2527/jas.2005-565Dersjant‐Li, Y., Awati, A., Schulze, H., & Partridge, G. (2014). Phytase in non‐ruminant animal nutrition: a critical review on phytase activities in the gastrointestinal tract and influencing factors. Journal of the Science of Food and Agriculture, 95(5), 878-896. doi:10.1002/jsfa.6998Eeckhout, W., & De Paepe, M. (1994). Total phosphorus, phytate-phosphorus and phytase activity in plant feedstuffs. Animal Feed Science and Technology, 47(1-2), 19-29. doi:10.1016/0377-8401(94)90156-2EMIOLA, A., AKINREMI, O., SLOMINSKI, B., & NYACHOTI, C. M. (2009). Nutrient utilization and manure P excretion in growing pigs fed corn-barley-soybean based diets supplemented with microbial phytase. Animal Science Journal, 80(1), 19-26. doi:10.1111/j.1740-0929.2008.00590.xGonzález-Vega, J. C., Walk, C. L., & Stein, H. H. (2015). Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs1. Journal of Animal Science, 93(5), 2255-2264. doi:10.2527/jas.2014-8215Harper, A. F., Kornegay, E. T., & Schell, T. C. (1997). Phytase supplementation of low-phosphorus growing-finishing pig diets improves performance, phosphorus digestibility, and bone mineralization and reduces phosphorus excretion. Journal of Animal Science, 75(12), 3174. doi:10.2527/1997.75123174xHaug, W., & Lantzsch, H.-J. (1983). Sensitive method for the rapid determination of phytate in cereals and cereal products. Journal of the Science of Food and Agriculture, 34(12), 1423-1426. doi:10.1002/jsfa.2740341217Heaney, R. P., Abrams, S., Dawson-Hughes, B., Looker, A., Looker, A., Marcus, R., … Weaver, C. (2001). Peak Bone Mass. Osteoporosis International, 11(12), 985-1009. doi:10.1007/s001980070020Jørgensen, B. (1995). Effect of different energy and protein levels on leg weakness and osteochondrosis in pigs. Livestock Production Science, 41(2), 171-181. doi:10.1016/0301-6226(94)00048-cKemme, P. A., Jongbloed, A. W., Mroz, Z., & Beynen, A. C. (1997). The efficacy of Aspergillus niger phytase in rendering phytate phosphorus available for absorption in pigs is influenced by pig physiological status. Journal of Animal Science, 75(8), 2129. doi:10.2527/1997.7582129xKiela, P. R., & Ghishan, F. K. (2016). Physiology of Intestinal Absorption and Secretion. Best Practice & Research Clinical Gastroenterology, 30(2), 145-159. doi:10.1016/j.bpg.2016.02.007Kim, J. C., Simmins, P. H., Mullan, B. P., & Pluske, J. R. (2005). The effect of wheat phosphorus content and supplemental enzymes on digestibility and growth performance of weaner pigs. Animal Feed Science and Technology, 118(1-2), 139-152. doi:10.1016/j.anifeedsci.2004.08.016Koch, M. E., & Mahan, D. C. (1985). Biological Characteristics for Assessing Low Phosphorus Intake in Growing Swine. Journal of Animal Science, 60(3), 699-708. doi:10.2527/jas1985.603699xKonietzny, U., & Greiner, R. (2002). Molecular and catalytic properties of phytate-degrading enzymes (phytases). International Journal of Food Science and Technology, 37(7), 791-812. doi:10.1046/j.1365-2621.2002.00617.xLittell, R. C., Henry, P. R., & Ammerman, C. B. (1998). Statistical analysis of repeated measures data using SAS procedures. Journal of Animal Science, 76(4), 1216. doi:10.2527/1998.7641216xMahan, D. C. (1982). Dietary Calcium and Phosphorus Levels for Weanling Swine. Journal of Animal Science, 54(3), 559-564. doi:10.2527/jas1982.543559xMavromichalis, I., Hancock, J. D., Kim, I. H., Senne, B. W., Kropf, D. H., Kennedy, G. A., … Behnke, K. C. (1999). Effects of omitting vitamin and trace mineral premixes and(or) reducing inorganic phosphorus additions on growth performance, carcass characteristics, and muscle quality in finishing pigs. Journal of Animal Science, 77(10), 2700. doi:10.2527/1999.77102700xMoehn, S., Atakora, J. K. A., Sands, J., & Ball, R. O. (2007). Effect of phytase-xylanase supplementation to wheat-based diets on energy metabolism in growing–finishing pigs fed ad libitum. Livestock Science, 109(1-3), 271-274. doi:10.1016/j.livsci.2007.01.118Oryschak, M. A., Simmins, P. H., & Zijlstra, R. T. (2002). Effect of dietary particle size and carbohydrase and/or phytase supplementation on nitrogen and phosphorus excretion of grower pigs. Canadian Journal of Animal Science, 82(4), 533-540. doi:10.4141/a02-016Peter, C. ., Parr, T. ., Parr, E. ., Webel, D. ., & Baker, D. . (2001). The effects of phytase on growth performance, carcass characteristics, and bone mineralization of late-finishing pigs fed maize–soyabean meal diets containing no supplemental phosphorus, zinc, copper and manganese. Animal Feed Science and Technology, 94(3-4), 199-205. doi:10.1016/s0377-8401(01)00300-5Rodehutscord, M., Faust, M., & Lorenz, H. (1996). Digestibility of phosphorus contained in soybean meal, barley, and different varieties of wheat, without and with supplemental phytase fed to pigs and additivity of digestibility in a wheatsoybean-meal diet. Journal of Animal Physiology and Animal Nutrition, 75(1-5), 40-48. doi:10.1111/j.1439-0396.1996.tb00466.xSelle, P. H., & Ravindran, V. (2008). Phytate-degrading enzymes in pig nutrition. Livestock Science, 113(2-3), 99-122. doi:10.1016/j.livsci.2007.05.014Selle, P. H., Cadogan, D. J., & Bryden, W. L. (2003). Effects of phytase supplementation of phosphorus-adequate, lysine-deficient, wheat-based diets on growth performance of weaner pigs. Australian Journal of Agricultural Research, 54(3), 323. doi:10.1071/ar02121She, Y., Su, Y., Liu, L., Huang, C., Li, J., Li, P., … Piao, X. (2015). Effects of microbial phytase on coefficient of standardized total tract digestibility of phosphorus in growing pigs fed corn and corn co-products, wheat and wheat co-products and oilseed meals. Animal Feed Science and Technology, 208, 132-144. doi:10.1016/j.anifeedsci.2015.07.011Van Soest, P. J., Robertson, J. B., & Lewis, B. A. (1991). Methods for Dietary Fiber, Neutral Detergent Fiber, and Nonstarch Polysaccharides in Relation to Animal Nutrition. Journal of Dairy Science, 74(10), 3583-3597. doi:10.3168/jds.s0022-0302(91)78551-2Varley, P. F., Callan, J. J., & O’Doherty, J. V. (2011). Effect of dietary phosphorus and calcium level and phytase addition on performance, bone parameters, apparent nutrient digestibility, mineral and nitrogen utilization of weaner pigs and the subsequent effect on finisher pig bone parameters. Animal Feed Science and Technology, 165(3-4), 201-209. doi:10.1016/j.anifeedsci.2011.02.017Varley, P. F., Flynn, B., Callan, J. J., & O’Doherty, J. V. (2011). Effect of phytase level in a low phosphorus diet on performance and bone development in weaner pigs and the subsequent effect on finisher pig bone development. Livestock Science, 138(1-3), 152-158. doi:10.1016/j.livsci.2010.12.014Vipperman, P. E., Peo, E. R., & Cunningham, P. J. (1974). Effect of Dietary Calcium and Phosphorus Level upon Calcium, Phosphorus and Nitrogen Balance in Swine. Journal of Animal Science, 38(4), 758-765. doi:10.2527/jas1974.384758

Dynamic model development of enteric methane emission from goats based on energy balance measured in indirect open circuit respiration calorimeter

[EN] A dynamic model of methane (CH4) emission in goats was proposed and parameterized from energy balance experimental data. The model focused on dry matter intake and fat content of the diet as explanatory variables for CH4 emission. Experimental and literature data were used to develop the model. Then, data (n = 123) from five energy balance experiments were used to evaluate the model. The model was adequate to represent energy in milk, heat production and CH4 emissions. Residual analysis showed that most of the prediction errors were due to unexplained variations with small mean and slope bias (around zero with exception of CH4; <6%). The model tends to over-predict energy in CH4 at higher energy intake and, energy in milk and heat production at lower energy intake. Random bias was greater than 90%, signifying than more than 90% of the error was non-systematic indicating the mechanism in the model are properly represented. The model is a first step towards a mechanistic description of nutrient use by goats and, useful as a research tool for investigating energy partition in dairy goat systems. The model described in this study should be considered for preparation of enteric CH4 emissions inventories for goats. (c) 2018 The Author. Published by Elsevier B.V.This study was supported by LOW CARBON FEED Project reference LIFE2016/CCM/ES/000088.Fernández Martínez, CJ. (2018). Dynamic model development of enteric methane emission from goats based on energy balance measured in indirect open circuit respiration calorimeter. Global Ecology and Conservation. 15:1-14. https://doi.org/10.1016/j.gecco.2018.e00439S1141

Prevalence of the parasite Angiostrongylus cantonensis in Haiti in rats and gastropods

Ma recherche examine la prévalence et la répartition du parasite Angiostrongylus cantonensis en Haïti, également connu sous le nom de ver pulmonaire du rat, et qui est la première cause de méningite à éosinophiles chez l’homme dans le monde. Ce parasite a un cycle de vie complexe impliquant à la fois des hôtes définitifs (rats) et des hôtes intermédiaires (escargots et les limaces). J’ai documenté l'écologie du parasite et sa persistance deux décennies après sa découverte initiale dans le pays. Trois objectifs ont été fixés : synthétiser les connaissances sur les dimensions spatiales et écologiques d’A. cantonensis, déterminer sa présence et sa répartition en Haïti parmi les populations de rats et de gastéropodes à l'aide d'analyses moléculaires et morphologiques, et identifier les similitudes génétiques entre les souches haïtiennes et celles provenant d’autres régions du monde. Nous avons ciblé deux contextes écologiques contrastés : la vallée de l'Artibonite (milieu rural) et la zone urbaine de Port-au-Prince. L'échantillonnage a eu lieu pendant la saison des pluies et à la fin de la saison des pluies en raison de l'influence potentielle de la saisonnalité hydrologique sur la prévalence du parasite.Une revue systématique utilisant la méthode PRISMA a synthétisé les connaissances existantes sur la niche écologique du parasite, en mettant l'accent sur les facteurs abiotiques et biotiques affectant sa dynamique. Soixante-dix rats ont été capturés :23 Rattus norvegicus et 47 Rattus rattus. Sous la loupe binoculaire, nous avons récupéré des vers adultes chez seulement cinq rats (7%, 5/70) mais la détection moléculaire a révélé une prévalence d'A. cantonensis dans les poumons de rat de 31,4 %, (22/70), le parasite étant détecté dans quatre des huit sites, dont Port-au-Prince. La prévalence du parasite n’était pas reliée de manière significative aux variables prédictives telles que l'âge, la saison, le sexe et l'espèce de rat. Un seul haplotype COX1, le génotype II-G, a été identifié en Haïti, ce qui suggère une large répartition similaire à celle d'autres régions. La technique qPCR AcanR3990 a permis d'identifier deux échantillons positifs d'espèces de gastéropodes : Subulina octona à Port-au-Prince et une limace de la famille des Veronicellidae dans l’Artibonite, concordant avec la présence du parasite retrouvé chez les rats à ces endroits.C'est la première étude sur A. cantonensis en Haïti portant à la fois sur les hôtes définitifs et intermédiaires. Les diagnostics moléculaires par PCR révèlent une prévalence plus élevée que l'identification morphologique, ce qui est prometteur pour l'étude systématique de la contamination potentielle des espèces hôtes. Les résultats indiquent une endémicité du parasite potentiellement principalement liée à deux espèces de gastéropodes : l'escargot terrestre S. octona et les limaces Veronicellidae, ainsi que les rats R. rattus et R. norvegicus, soulignant les risques importants pour la santé des populations locales.My research examines the prevalence and distribution of the parasite Angiostrongylus cantonensis, also known as the rat lungworm, in Haiti. It is the leading cause of eosinophilic meningitis in humans worldwide. This parasite has a complex life cycle involving definitive hosts (rats) and intermediate hosts (snails and slugs). I documented the parasite's ecology and persistence two decades after its initial discovery in the country. Three objectives were set: synthesizing knowledge on the spatial and ecological dimensions of A. cantonensis’ niche, determining its presence and distribution in Haiti among rat and gastropod populations using molecular and morphological analyses, and identifying genetic similarities between Haitian strains and those from other regions of the world. We targeted two contrasting ecological contexts: the Artibonite Valley (rural environment) and the urban area of Port-au-Prince. Sampling occurred during and at the end of the rainy season due to the potential influence of hydrological seasonality on parasite prevalence. A systematic review using the PRISMA method synthesized existing knowledge on the parasite's ecological niche, focusing on abiotic and biotic factors affecting its dynamics. Seventy rats were captured:23 Rattus norvegicus and 47 Rattus rattus. Under a binocular loupe, we recovered adult worms from only five rats (7%, 5/70), but molecular detection revealed a prevalence of A. cantonensis in rat lungs of 31.4% (22/70), with the parasite detected in four of the eight sites, including Port-au-Prince. Parasite prevalence was not significantly related to predictive variables such as age, season, sex, and rat species. Only one COX1 haplotype, genotype II-G, was identified in Haiti, suggesting a widespread distribution similar to other regions. The qPCR technique AcanR3990 identified two positive samples of gastropod species: Subulina octona in Port-au-Prince and a Veronicellidae slug in the Artibonite, indicating the presence of the parasite found in rats at these locations. This is the first study on A. cantonensis in Haiti addressing both definitive and intermediate hosts. Molecular diagnostics by PCR reveal a higher prevalence than morphological identification, promising for the systematic study of potential host species contamination. Results indicate that endemicity of the parasite may primarily be linked to two gastropod species: the land snail S. octona and Veronicellidae slugs, as well as R. rattus and R. norvegicus rats, highlighting significant health risks for local populations

Prévalence du parasite Angiostrongylus cantonensis en Haïti chez les rats et gastéropodes

My research examines the prevalence and distribution of the parasite Angiostrongylus cantonensis, also known as the rat lungworm, in Haiti. It is the leading cause of eosinophilic meningitis in humans worldwide. This parasite has a complex life cycle involving definitive hosts (rats) and intermediate hosts (snails and slugs). I documented the parasite's ecology and persistence two decades after its initial discovery in the country. Three objectives were set: synthesizing knowledge on the spatial and ecological dimensions of A. cantonensis’ niche, determining its presence and distribution in Haiti among rat and gastropod populations using molecular and morphological analyses, and identifying genetic similarities between Haitian strains and those from other regions of the world. We targeted two contrasting ecological contexts: the Artibonite Valley (rural environment) and the urban area of Port-au-Prince. Sampling occurred during and at the end of the rainy season due to the potential influence of hydrological seasonality on parasite prevalence. A systematic review using the PRISMA method synthesized existing knowledge on the parasite's ecological niche, focusing on abiotic and biotic factors affecting its dynamics. Seventy rats were captured:23 Rattus norvegicus and 47 Rattus rattus. Under a binocular loupe, we recovered adult worms from only five rats (7%, 5/70), but molecular detection revealed a prevalence of A. cantonensis in rat lungs of 31.4% (22/70), with the parasite detected in four of the eight sites, including Port-au-Prince. Parasite prevalence was not significantly related to predictive variables such as age, season, sex, and rat species. Only one COX1 haplotype, genotype II-G, was identified in Haiti, suggesting a widespread distribution similar to other regions. The qPCR technique AcanR3990 identified two positive samples of gastropod species: Subulina octona in Port-au-Prince and a Veronicellidae slug in the Artibonite, indicating the presence of the parasite found in rats at these locations. This is the first study on A. cantonensis in Haiti addressing both definitive and intermediate hosts. Molecular diagnostics by PCR reveal a higher prevalence than morphological identification, promising for the systematic study of potential host species contamination. Results indicate that endemicity of the parasite may primarily be linked to two gastropod species: the land snail S. octona and Veronicellidae slugs, as well as R. rattus and R. norvegicus rats, highlighting significant health risks for local populations.Ma recherche examine la prévalence et la répartition du parasite Angiostrongylus cantonensis en Haïti, également connu sous le nom de ver pulmonaire du rat, et qui est la première cause de méningite à éosinophiles chez l’homme dans le monde. Ce parasite a un cycle de vie complexe impliquant à la fois des hôtes définitifs (rats) et des hôtes intermédiaires (escargots et les limaces). J’ai documenté l'écologie du parasite et sa persistance deux décennies après sa découverte initiale dans le pays. Trois objectifs ont été fixés : synthétiser les connaissances sur les dimensions spatiales et écologiques d’A. cantonensis, déterminer sa présence et sa répartition en Haïti parmi les populations de rats et de gastéropodes à l'aide d'analyses moléculaires et morphologiques, et identifier les similitudes génétiques entre les souches haïtiennes et celles provenant d’autres régions du monde. Nous avons ciblé deux contextes écologiques contrastés : la vallée de l'Artibonite (milieu rural) et la zone urbaine de Port-au-Prince. L'échantillonnage a eu lieu pendant la saison des pluies et à la fin de la saison des pluies en raison de l'influence potentielle de la saisonnalité hydrologique sur la prévalence du parasite.Une revue systématique utilisant la méthode PRISMA a synthétisé les connaissances existantes sur la niche écologique du parasite, en mettant l'accent sur les facteurs abiotiques et biotiques affectant sa dynamique. Soixante-dix rats ont été capturés :23 Rattus norvegicus et 47 Rattus rattus. Sous la loupe binoculaire, nous avons récupéré des vers adultes chez seulement cinq rats (7%, 5/70) mais la détection moléculaire a révélé une prévalence d'A. cantonensis dans les poumons de rat de 31,4 %, (22/70), le parasite étant détecté dans quatre des huit sites, dont Port-au-Prince. La prévalence du parasite n’était pas reliée de manière significative aux variables prédictives telles que l'âge, la saison, le sexe et l'espèce de rat. Un seul haplotype COX1, le génotype II-G, a été identifié en Haïti, ce qui suggère une large répartition similaire à celle d'autres régions. La technique qPCR AcanR3990 a permis d'identifier deux échantillons positifs d'espèces de gastéropodes : Subulina octona à Port-au-Prince et une limace de la famille des Veronicellidae dans l’Artibonite, concordant avec la présence du parasite retrouvé chez les rats à ces endroits.C'est la première étude sur A. cantonensis en Haïti portant à la fois sur les hôtes définitifs et intermédiaires. Les diagnostics moléculaires par PCR révèlent une prévalence plus élevée que l'identification morphologique, ce qui est prometteur pour l'étude systématique de la contamination potentielle des espèces hôtes. Les résultats indiquent une endémicité du parasite potentiellement principalement liée à deux espèces de gastéropodes : l'escargot terrestre S. octona et les limaces Veronicellidae, ainsi que les rats R. rattus et R. norvegicus, soulignant les risques importants pour la santé des populations locales

Prévalence du parasite Angiostrongylus cantonensis en Haïti chez les rats et gastéropodes

My research examines the prevalence and distribution of the parasite Angiostrongylus cantonensis, also known as the rat lungworm, in Haiti. It is the leading cause of eosinophilic meningitis in humans worldwide. This parasite has a complex life cycle involving definitive hosts (rats) and intermediate hosts (snails and slugs). I documented the parasite's ecology and persistence two decades after its initial discovery in the country. Three objectives were set: synthesizing knowledge on the spatial and ecological dimensions of A. cantonensis’ niche, determining its presence and distribution in Haiti among rat and gastropod populations using molecular and morphological analyses, and identifying genetic similarities between Haitian strains and those from other regions of the world. We targeted two contrasting ecological contexts: the Artibonite Valley (rural environment) and the urban area of Port-au-Prince. Sampling occurred during and at the end of the rainy season due to the potential influence of hydrological seasonality on parasite prevalence. A systematic review using the PRISMA method synthesized existing knowledge on the parasite's ecological niche, focusing on abiotic and biotic factors affecting its dynamics. Seventy rats were captured:23 Rattus norvegicus and 47 Rattus rattus. Under a binocular loupe, we recovered adult worms from only five rats (7%, 5/70), but molecular detection revealed a prevalence of A. cantonensis in rat lungs of 31.4% (22/70), with the parasite detected in four of the eight sites, including Port-au-Prince. Parasite prevalence was not significantly related to predictive variables such as age, season, sex, and rat species. Only one COX1 haplotype, genotype II-G, was identified in Haiti, suggesting a widespread distribution similar to other regions. The qPCR technique AcanR3990 identified two positive samples of gastropod species: Subulina octona in Port-au-Prince and a Veronicellidae slug in the Artibonite, indicating the presence of the parasite found in rats at these locations. This is the first study on A. cantonensis in Haiti addressing both definitive and intermediate hosts. Molecular diagnostics by PCR reveal a higher prevalence than morphological identification, promising for the systematic study of potential host species contamination. Results indicate that endemicity of the parasite may primarily be linked to two gastropod species: the land snail S. octona and Veronicellidae slugs, as well as R. rattus and R. norvegicus rats, highlighting significant health risks for local populations.Ma recherche examine la prévalence et la répartition du parasite Angiostrongylus cantonensis en Haïti, également connu sous le nom de ver pulmonaire du rat, et qui est la première cause de méningite à éosinophiles chez l’homme dans le monde. Ce parasite a un cycle de vie complexe impliquant à la fois des hôtes définitifs (rats) et des hôtes intermédiaires (escargots et les limaces). J’ai documenté l'écologie du parasite et sa persistance deux décennies après sa découverte initiale dans le pays. Trois objectifs ont été fixés : synthétiser les connaissances sur les dimensions spatiales et écologiques d’A. cantonensis, déterminer sa présence et sa répartition en Haïti parmi les populations de rats et de gastéropodes à l'aide d'analyses moléculaires et morphologiques, et identifier les similitudes génétiques entre les souches haïtiennes et celles provenant d’autres régions du monde. Nous avons ciblé deux contextes écologiques contrastés : la vallée de l'Artibonite (milieu rural) et la zone urbaine de Port-au-Prince. L'échantillonnage a eu lieu pendant la saison des pluies et à la fin de la saison des pluies en raison de l'influence potentielle de la saisonnalité hydrologique sur la prévalence du parasite.Une revue systématique utilisant la méthode PRISMA a synthétisé les connaissances existantes sur la niche écologique du parasite, en mettant l'accent sur les facteurs abiotiques et biotiques affectant sa dynamique. Soixante-dix rats ont été capturés :23 Rattus norvegicus et 47 Rattus rattus. Sous la loupe binoculaire, nous avons récupéré des vers adultes chez seulement cinq rats (7%, 5/70) mais la détection moléculaire a révélé une prévalence d'A. cantonensis dans les poumons de rat de 31,4 %, (22/70), le parasite étant détecté dans quatre des huit sites, dont Port-au-Prince. La prévalence du parasite n’était pas reliée de manière significative aux variables prédictives telles que l'âge, la saison, le sexe et l'espèce de rat. Un seul haplotype COX1, le génotype II-G, a été identifié en Haïti, ce qui suggère une large répartition similaire à celle d'autres régions. La technique qPCR AcanR3990 a permis d'identifier deux échantillons positifs d'espèces de gastéropodes : Subulina octona à Port-au-Prince et une limace de la famille des Veronicellidae dans l’Artibonite, concordant avec la présence du parasite retrouvé chez les rats à ces endroits.C'est la première étude sur A. cantonensis en Haïti portant à la fois sur les hôtes définitifs et intermédiaires. Les diagnostics moléculaires par PCR révèlent une prévalence plus élevée que l'identification morphologique, ce qui est prometteur pour l'étude systématique de la contamination potentielle des espèces hôtes. Les résultats indiquent une endémicité du parasite potentiellement principalement liée à deux espèces de gastéropodes : l'escargot terrestre S. octona et les limaces Veronicellidae, ainsi que les rats R. rattus et R. norvegicus, soulignant les risques importants pour la santé des populations locales

Molecular study of the status of

Angiostrongylus cantonensis, commonly known as the rat lungworm, causes Eosinophilic meningitis in humans. Our study aimed to investigate the prevalence and distribution of this parasite in rats in Haiti. Rats were trapped at 8 sites, 7 in Artibonite (rural region) and one in an urban area of Port-au-Prince. After euthanasia, hearts and lungs were sampled and preserved in 70% ethanol. Subsequently, the organs were dissected to detect adult worms. Parasite DNA was amplified using PCR targeting either the nematode ITS2 gene for rodent lung tissue or cox1 for isolated worms. Subsequent sequencing allowed parasite identification. A total of 70 rats were captured, i.e. 23 Rattus norvegicus and 47 Rattus rattus. Adult nematodes morphologically compatible with A. cantonensis were isolated from 5/70 rats (7%) and identification was confirmed by sequencing. Molecular analysis of lung tissue revealed a parasite prevalence of 31.4% (22/70), and its presence at 4 of the 8 sites investigated, including Port-au-Prince. The molecular approach on lung tissue targeting the ITS2 gene enabled us to detect a prevalence 4 times higher than the visual search for adult worms alone. Only one COX1 haplotype was identified, belonging to genotype II-G, widely distributed in Brazil, the French Antilles (Guadeloupe), French Polynesia, Hawaii, and Japan. These results confirm that A. cantonensis is an endemic parasite in Haiti not only in the capital Port-au-Prince, but also in several rural areas. Direct molecular screening for Angiostrongylus DNA in rat lung tissue showed higher sensitivity than visual detection of worms during dissection and could be useful for further prevalence studies

Valorisation of fruit and vegetable discards by fungal submerged and solid-state fermentation for alternative feed ingredients production

The present research describes an integral strategy for valorisation of fruit and vegetable discards (FVd) in feeding application, using solid-state fermentation (SSF) and submerged fermentation (SmF), for both solid and liquid fractions obtained during these by-products handle and processing, using a strain of Rhizopus After SSF, fermented biomass had 1.9 times higher protein content (up to 20.2 +/- 1.7\% DM) than the original mass and an improved amino acid (AA) profile (45.7 +/- 1.8\% essential AAs). Fatty acid (FA) profile was also modified during fermentation process, with higher monounsaturated (MUFA) and lower polyunsaturated fatty acid (PUFA) percentage in the final product compared with initial substrate. Phenolic compound concentration was double in final biomass than in initial substrate (up to 8.9 +/- 1.5 mg GAE/g DM) and fermented product had higher antioxidant activity (DPPH reduction of 81.3 +/- 7.7\% and TEAC of 3.6 +/- 0.3 mg/g DM). Compared with previously reported results, fruit complementation with vegetables increased the available nitrogen and resulted in higher biomass production. The fruit and vegetable leachate (FVL) obtained by centrifugation was treated by SmF and led, per liter of substrate, to 10.6 +/- 1.4 g of fungal biomass and 3.3 g protein after 7 days of fermentation. Obtained fungal biomass was rich in PUFAs (27.1 +/- 7.2\% of total FA) and had an AA profile comparable to soybean meal, with 45.3 +/- 1.5\% of essential amino acids (EAA). In conclusion, results demonstrate that combined solid and liquid fermentation is a successful strategy for FVd valorisation to produce valuable alternative feed ingredient due to their high protein and the well-balanced lipid content and amino acid profile