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Background & Aims: Microbial dysbiosis and aberrant hostâmicrobe interactions in the gut are believed to contribute to the development and progression of Crohnâs disease (CD). Microbiome studies in CD typically have focused on microbiota in feces or superficial mucosal layers of the colon because accessing DNA from deeper layers of the bowel is challenging. In this study, we analyzed the deep tissue microbiome in patients who underwent surgical resection of the small intestine. Methods: Paraffin blocks were obtained from 12 CD patients undergoing ileocecal resection, and healthy ileum samples (inflammatory bowel diseaseâfree controls) were obtained from 12 patients undergoing surgery for right-sided colon cancer. Diseased and healthy-appearing ileum was identified using microscopy, and paraffin blocks were macrodissected using a core needle to specifically isolate DNA. Illumina Whole Genome Sequencing was used for microbial sequence identification and subsequent taxonomic classification using the PathSeq tool. Results: We observed significant differences between the microbiome of CD samples vs inflammatory bowel diseaseâfree controls, including depletion of Bacteroidetes and Clostridia. Notably, microbial composition at the phyla level did not differ markedly between healthy and diseased areas of CD patients. However, we observed enrichment of potentially pathogenic organisms at the species level. Conclusions: Our study showed dysbiosis within deeper layers of the ileum of CD patients, specifically enrichment of enterotoxigenic Staphylococcus aureus and an environmental Mycobacterium species not described previously. Future studies with larger cohort sizes are warranted to confirm these findings. Studies would benefit from effective microbial DNA extraction methods from paraffin sections and host nucleic acid depletion approaches to increase microbial read coverage. Keywords: Crohn's Disease, Deeper Mucosal Layers, Microbial Dysbiosis

Abstract Secondary production is the formation of heterotrophic biomass across time, which integrates several important ecological processes that affect the life of organisms, populations, communities and ecosystems, but its study has poor developed in South America. The objectives of this work were to describe the diversity of benthic macroinvertebrate assemblages in terms of abundance and biomass, and to quantify their secondary production for the first time in Andean rivers. A quantitative sampling scheme was implemented, using a Surber sampler, in three forested streams. Physical-chemical variables, nutrients, organic matter and chlorophyll were measured also. The macroinvertebrates were separated and identified mostly at the species level. Each taxon was assigned to a functional feeding group. Secondary production was estimated for 38 taxa, mostly Diptera, Trichoptera, Coleoptera, and Ephemeroptera. The annual production varied from 3769 to 13916 mg dry mass m-2 y-1. Most abundant taxa were also those with higher production, dominated by Ephemeroptera (Baetidae), Trichoptera (Hydropsychidae) and Diptera (Chironomidae and Simuliidae). Density, biomass, and production of collectors and predators were much higher than the other feeding groups. We expect that our results will be useful to evaluate the effects on stream functioning produced by global warming and other anthropogenic disturbances in our region.

Abstract: A new species of Stethelmis, S. shepardi sp. nov., is described for Patagonia, Argentina from adults of both sexes. A full description and illustrations of both the adult and the larva of the new species are provided with comments on its habitat and distribution. Adults of the new species are compared with those of S. kaszabi (Hinton 1970) and S. chilensis (Hinton 1945). The larva of S. shepardi is compared with that of S. kaszabi, the other Stethelmis larva described. We also describe and illustrate for the first time the male genitalia of S. kaszabi. A key to the known species of Stethelmis is also included.

Se presenta una lista de insectos acuáticos colectados en el Parque Provincial Urugua-í, en la provincia de Misiones. Se colectaron 136 especies de insectos acuáticos, distribuidas en 75 géneros de 26 familias, correspondientes a siete órdenes. Se mencionan nuevas citas de la provincia y de Argentina, así como la presencia de especies nuevas para la ciencia.

La Familia Elmidae incluye coleópteros acuáticos de tamaño pequeño a mediano. Suelen ser comunes en aguas corrientes con buen contenido de oxí - geno, por lo cual se las utiliza como indicadoras de calidad de agua. Los élmidos tienen una distribución mundial, aunque se encuentran muy diversificados en la región Neotropical, con 46 géneros descriptos hasta la actualidad y aproximada - mente 435 especies. En este trabajo se presenta un resumen de toda la información conocida de Elmidae para la región Neotropical. Se actualiza la distribución de los géneros y el número de especies conocidas para cada uno. Se provee el número de especies por países y una lista actualizada de especies con larvas conocidas.

Se presentan los resultados de la recolección de coleópteros acuáticos y semiacuáticos del Parque Provincial Salto Encantado y Valle del Cuñá Pirú, con el objeto de contribuir al conocimiento de la biodiversidad del área protegida mencionada, de la provincia de Misiones. Los sitios de muestreo incluyeron ambientes lóticos y lénticos. Se registraron 74 especies de coleópteros, distribuidas en 44 géneros y 14 familias: Haliplidae, Noteridae, Dytiscidae, Gyrinidae, Hydrochidae, Hydrophilidae, Hydraenidae, Staphylinidae, Scirtidae, Psephenidae, Limnichidae, Lutrochidae, Dryopidae y Elmidae. Se mencionan nuevas citas para la provincia y para la Argentina, así como la presencia de especies nuevas para la ciencia.This paper presents a list of aquatic and semiaquatic Coleoptera collected during a biodiversity study carried out in Salto Encantado and Valle del Cuñá Pirú Provincial Park. This study aims to improve the knowledge of this protected area located in Misiones Province. Permanent and semi-permanent lotic and lentic habitats were sampled. Seventy-four species of beetles in 44 genera and 14 families were recorded: Haliplidae, Noteridae, Dytiscidae, Gyrinidae, Hydrochidae, Hydrophilidae, Hydraenidae, Staphylinidae, Scirtidae, Psephenidae, Limnichidae, Lutrochidae, Dryopidae and Elmidae. New records for the province and for Argentina are listed, and the presence of new species is mentioned.

Se citan por primera vez para la Argentina Austrolimnius (Helonoma) eris Hinton, Austrolimnius (Telmatelmis) formosus (Sharp), Austrolimnius (Telmatelmis) nyctelioides (Germain), Macrelmis aequalis (Hinton) y Microcylloepus plaumanni Hinton, todas especies de la subfamilia Elminae (Coleoptera: Elmidae). Se describe por primera vez el macho de A. (Telmatelmis) nyctelioides. Todas las especies se comparan con las especies conocidas más relacionadas, dentro de cada género. Se ilustran con más detalle los genitalia masculinos y femeninos, así como algunos caracteres de importancia específica. Se provee una clave para los adultos de las especies argentinas de Austrolimnius Carter & Zeck.Austrolimnius (Helonoma) eris Hinton, Austrolimnius (Telmatelmis) formosus (Sharp), Austrolimnius (Telmatelmis) nyctelioides (Germain), Macrelmis aequalis (Hinton) and Microcylloepus plaumanni Hinton, all belonging to the subfamily Elminae, are cited for the first time for Argentina. The male of A. (Telmatelmis) nyctelioides is described for the first time. All species are compared to other known species of each genus. Male and female genitalia and some specific characters are illustrated. A key to distinguish the adults of the Argentinean species of Austrolimnius Carter & Zeck is included.

Elmidae is a family of aquatic beetles common in clean water streams and widely used in studies of environmental bioindication. This work was proposed in order to recognize the richness of the Elmidae genera in the department of Valle del Cauca and recopile information about its distribution since biological colection data. A total of 3305 specimens (larvae and adults) were examined, mainly stored in the Museum of Entomology at the University of Valle and associated with field work completed between 1991 and 2014. The samples were collected from 116 locations within 19 municipalities, and are representative of 63 streams, mainly belonging to the Anchicayá, Cauca, Dagua and San Juan rivers basin and the Andean and Pacific natural regions. A total of 16 genera were documented: eleven Elminae (Austrolimnius, Cylloepus, Heterelmis, Huleechius, Macrelmis, Microcylloepus, Neoelmis, Notelmis, Onychelmis, Xenelmis and Stenhelmoides, the last not found in local collection) and five Larainae (Disersus, Hexanchorus, Phanocerus, Pharceonus and Pseudodisersus). These genera were distributed from 110 to 2440 m a.s.l., with greater taxonomic representation between 1000 and 2000 m a.s.l. The two genera most widely distributed were Macrelmis and Heterelmis, while the river with the highest taxonomic representation was Guabas. The distribution area for Austrolimnius, Huleechius, Notelmis and Xenelmis was expanded to the Valle del Cauca region.