<i>Heterosporis sutherlandae</i> n. sp. from yellow perch and walleye.

<p><b>A)</b> Sporophorocyst containing several sporophorous vesicles. The sporophorocyst is lined by a thick wall (double headed arrow). The inner surface of the sporophorocyst is indicated by arrows. The edge of the wall of one sporophorous vesicle is highlighted by arrowhead. Spore is marked by an asterisk. Scale bar is 2 μm. <b>B)</b> Magnification of the sporophorocyst wall (double headed arrow) in a muscle fiber (mf); note the thick external layer, which is formed of microtubules and filaments (tf) and an inner electron dense membrane (arrow). The most internal smooth electron dense layer is a sporophorous vesicle, which is formed of an electron dense amorphous material (white arrowhead). A sporoblast (sb) is near the wall of the sporophorous vesicle. Scale bar is 1 μm. <b>C)</b> Spore wall (sw) of 122–137 nm comprised of an electron dense exospore (ex) measuring 20.78–33.98 nm and an electron lucent endospore (en) measuring 101.76–103.36 nm. Scale bar is 200 nm. <b>D)</b> Longitudinal section of <i>H</i>. <i>sutherlandae</i> displaying a spore wall (wide arrow), posterior vacuole (Pv), coiled filament (white arrowhead), polar filament (white arrow), nucleus (N), and anterior polaroplast. Scale bar is 0.5 μm. Inset: Anchoring disk of a spore. Scale bar is 200 nm. <b>E)</b> Transverse section of the anterior pole of <i>H</i>. <i>sutherlandae</i> displaying a spore wall (wide arrow), polar filament (white arrow), and anterior (Pa) and posterior polaroplast (Pp). Scale bar is 200 nm. <b>F)</b> Longitudinal section of coiled filament of <i>H</i>. <i>sutherlandae</i>. Scale bar is 200 nm. <b>G)</b> Transverse section of polar filaments of <i>H</i>. <i>sutherlandae</i> showing a concentrically multilayer structure. Spore wall (sw). Scale bar is 200 nm.</p

Phylogenetic analysis based on the 3,646bp nearly complete ribosomal RNA gene of <i>Heterosporis</i> sp., corresponding to nucleotide positions 170 to 3,815 of reference sequence AF387331.

<p>The Maximum Likelihood phylogenetic tree was constructed using the General Time Reversible (GTR) model of nucleotide substitution (4 gamma categories) with 1,000 bootstrap replicates.</p

Description of the Microsporidian Parasite, <i>Heterosporis sutherlandae</i> n. sp., Infecting Fish in the Great Lakes Region, USA

<div><p>Heterosporosis is an increasingly important microsporidian disease worldwide, impacting wild and farmed raised fishes in both marine and freshwater environments. A previously undescribed species (<i>Heterosporis</i> sp.), with widespread distribution in the Great Lakes region, was the subject of this study. Three angler-caught fish were submitted to the Minnesota Veterinary Diagnostic Laboratory from 2009–2010 with lesions caused by intracellular proliferation of parasitic spores, resulting in destruction and eventual widespread necrosis of the host skeletal muscles. Mature ovoid (5.8 x 3.5μm) spores of a microsporidian parasite, consistent with the genus <i>Heterosporis</i>, were observed by light and electron microscopy. Molecular identification was performed using primer walking to obtain a near-complete rRNA gene sequence (~3,600 bp). A unique species of <i>Heterosporis</i> was identified, demonstrating less than 96% sequence identity to other published <i>Heterosporis</i> sp. on the basis of partial rRNA gene sequence analysis. <i>Heterosporis sutherlandae</i> n. sp. (formerly <i>Heterosporis</i> sp.) was identified in yellow perch (<i>Perca flavescens</i>), northern pike (<i>Esox lucius</i>) and walleye (<i>Sander vitreus</i>) from inland lakes in Minnesota and Wisconsin. Previous research suggests this species may be even more widespread in the Great Lakes region and should be reexamined using molecular techniques to better understand the distribution of this novel species.</p></div

Description of the Microsporidian Parasite, <i>Heterosporis sutherlandae - Fig 2 </i> n. sp., Infecting Fish in the Great Lakes Region, USA

<p><b>A)</b> Fresh preparation of microsporidia-infected fish. Arrow indicates a spore of <i>Heterosporis sutherlandae</i> n. sp. Arrowhead shows a sporophorous vesicle with several spores. <b>B)</b> Widespread muscle destruction due to <i>H</i>. <i>sutherlandae</i>. Mature spores have replaced muscle cells and are surrounded by loose fibrous tissue (asterisk). The wide arrow indicates a large sporophorocyst containing sporoblast and spores. The narrow arrow shows ruptured sporophorocyst vesicles. Tissue embedded in paraffin and stained with PAS. Scale bar is 100 μm. Inset: Giemsa stained preparation showing a detail of the wall of a sporophorocyst (wide arrow) and the wall of a sporophororous vesicle (arrowhead). Scale bar is 25 μm. <b>C)</b> Sporophorocysts (asterisk) within skeletal muscle cells (sm). Arrows indicate the sporophorocystic wall. Tissue embedded in resin and stained with Toluidine blue. Scale bar is 12 μm.</p

<i>Heterosporis</i>-positive fish submitted to the Minnesota Veterinary Diagnostic Laboratory from 2009–2010.

<p>All samples were confirmed by gross lesions, light microscopy, and sequence analysis. Fish were collected by hook and line recreational fishing.</p

Phylogenetic analysis based on a 1,200 bp nucleotide sequence, corresponding to nucleotide positions 600 to 1,800 of reference sequence AF387331.

<p>The Maximum Likelihood phylogenetic tree was constructed using the General Time Reversible (GTR) model of nucleotide substitution (4 gamma categories) model with 1,000 bootstrap replicates.</p

Avaliação lectino-histoquímica de fígado e rim de ovinos com fotossensibilização causada por Brachiaria decumbens

Embora sejam as forrageiras mais importantes para a pecuária de corte (bovinocultura de corte) no Brasil, em certas épocas ou condições, Brachiaria spp. podem ser tóxicas e causar surtos de fotossensibilização hepatógena que determinam significativas perdas econômicas. Animais que se alimentam em pastos de Brachiaria spp. comumente apresentam macrófagos espumosos isolados ou agrupados, além de cristais no interior de ductos biliares. Saponinas esteroidais têm sido identificadas nestes cristais e são responsabilizadas por lesar o fígado levando ao acúmulo de filoeritrina. Por vezes, imagens negativas desses cristais podem estar presentes no citoplasma de macrófagos espumosos. A patogênese de formação e o tipo de material armazenado nas células espumosas ainda são desconhecidos. A técnica de lectino-histoquímica visa auxiliar na detecção desses macrófagos e, consequentemente, no diagnóstico, além de identificar quais os resíduos de açúcares específicos que estão presentes no citoplasma das células espumosas. Assim, este trabalho teve por objetivo identificar quais lectinas são mais indicadas na detecção de saponinas esteroidais no fígado e rim de ovinos com fotossensibilização causada por Brachiaria decumbens. Fragmentos de fígado e rim de quinze ovinos, de ambos os sexos e idade variável, oriundos de Conceição do Mato Dentro, Minas Gerais, e um ovino mantido em pastagem livre de Brachiaria spp. foram avaliados pela técnica de lectino-histoquímica. Quatorze lectinas foram utilizadas (Con-A, DBA, SBA, PNA, SJA, RCA-I, UEA-I, WGA, SWGA, GSL, PSA, PHA-L, PHA-E e LCA). Verificou-se que, no fígado de ovinos com fotossensibilização provocada pela ingestão de Brachiaria decumbens, a lectina PNA apresentou especificidade e acentuada reatividade aos macrófagos espumosos, bem como especificidade e leve reatividade aos hepatócitos; a lectina WGA teve especificidade e moderada reatividade aos macrófagos espumosos do fígado e especificidade e leve reatividade aos hepatócitos; e as lectinas SBA, GSL e LCA apresentaram especificidade e moderada reatividade aos macrófagos espumosos, entretanto, não foram específicas para hepatócitos. No rim dos ovinos, a lectina PNA foi a que apresentou maior reatividade. Avaliações lectino-histoquímicas ainda não haviam sido realizadas em fígado e rim de ovinos com fotossensibilização provocada por Brachiaria spp

Spongy Myelinopathy in Newborn Beef Calves Associated with Consumption of Corn Infected with Stenocarpella maydis

Stillbirth and perinatal mortality with neurological signs and lesions were diagnosed in two calves following ingestion by their dams of corn infected with Stenocarpella maydis during the third trimester of gestation. Grossly, the brain and spinal cord were unremarkable. Microscopically, diffuse severe status spongiosis of the white matter was detected in the cerebral hemispheres, brainstem, spinal cord and cerebellum. To the best of our knowledge this is the first pathological description of congenital disease in calves associated with the consumption of S. maydis-infected corn; the findings resemble those reported for the naturally occurring and experimentally induced disease in lambs.EEA BalcarceFil: Odriozola, Ernesto Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Armién, Aníbal Guillermo. University of Minnesota. Veterinary Diagnostic Laboratory; Estados UnidosFil: Cora Ibarra, Juan Facundo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Llada, Ignacio Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Erreguerena, Ignacio Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Hecker, Yanina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina