Association between the severity of histopathological lesions and Mycobacterium avium subspecies paratuberculosis (MAP) molecular diversity in cattle in southern Chile.

The objective was to evaluate the association between the severity of histopathological lesions caused by Mycobacterium avium subspecies paratuberculosis (MAP) infection and the molecular diversity of this pathogen. Blood, ileum, and mesenteric lymph node samples were collected at slaughter, from 1,352 adult cattle [source population 1 (SP1)]. In addition, 42 dairy herds (n = 4,963 cows) were followed for 2 years, and samples from compatible paratuberculosis clinical cases [source population 2 (SP2)] were collected. MAP infection was confirmed using an ELISA test, liquid media culture, and PCR. Isolates were genotyped using five MIRU-VNTR markers. Tissues from confirmed samples were subjected to a histopathological examination. A histopathological severity score (HSS) system was developed and used to grade (0 to 5) the magnitude of lesions caused by MAP. In general, the HSS system assesses the number of foci and degree of macrophage infiltration, together with the presence of multinucleated giant cells (MGCs) and acid-fast bacilli (AFB), in addition to the fusion of the intestinal villi and hyperplasia of the crypts. Despite the large sampling effort, only 79 MAP isolates were successfully genotyped, where 19 different haplotypes were described. A mixed-effect Poisson regression model was used to assess the relationship between haplotypes and HSS values. The model was controlled by animal age, and the farm was used as a random effect. Haplotypes were grouped based on their relative frequency: the most frequent haplotype (group i, 49.4%), the second most frequent haplotype (group ii, 12.7%), and all other haplotypes (group iii, 37.9%). Model outputs indicated that group i had significantly higher HSS values than group iii. In addition, group i was also associated with higher optical density (OD) values of the ELISA test. These results support the existence of differences in pathogenicity between MAP haplotypes. However, results were based on a relatively small sample size; thus, these should be taken with caution. Despite this, study findings suggest that haplotypes would be associated with differences in disease progression, where the dominant haplotype tends to generate more severe lesions, which could be linked to a greater shed of MAP cells than non-dominant haplotypes, increasing their chances of transmission.

Gastrointestinal helminths and related histopathological lesions in black-necked swans Cygnus melancoryphus from the Carlos Anwandter Nature Sanctuary, Southern Chile / Helmintos gastrintestinais e lesões histopatológicas relacionadas em cisnes de pescoço negro Cygnus melancoryphus do Santuário da Natureza Carlos Anwandter, Sul do Chile

Abstract Black-necked swans are distributed across South America and face conservation problems in Chile according to data of the State institution SAG. The aim of this study was to identify helminths and to assess associated tissue damage via histopathology. A total of 19,291 parasites were isolated from 21 examined birds; 17 species were identified, including nematodes, flukes, and tapeworms. Of these, 12 were new host records, 13 were reported for the first time in Chile, and 5 were new records for the Neotropical region. Further, the flukes Schistosomatidae gen. sp. and Echinostoma echinatum are of zoonotic concern. Regarding histopathology, an inflammatory response was found along the birds' entire digestive tract. Nevertheless, it is difficult to declare that there is a clear association between such lesions and isolated parasites, as other noxa could be responsible as well. Although in some cases there was an evident association, such inflammatory responses and necrosis were minimal, as occurred with Capillaria, Retinometra, Catatropis, Echinostoma, and Schistosomatidae gen. sp. Nevertheless, Epomidiostomum vogelsangi caused granulomatous injuries, an important inflammatory response, and necrosis, but it always circumscribed to superficial layers of the gizzard. Conversely, Paramonostomum was not associated with an inflammatory response despite a high parasitic load.

Resumo O cisne de pescoço negro é distribuído por toda a América do Sul, e enfrenta problemas de conservação no Chile, sendo protegido pela Lei Estadual de Caça. O objetivo deste estudo foi identificar helmintos em cisnes e avaliar o dano tecidual por meio de histopatologia. Um total de 19.291 parasitas foi isolado de 21 aves examinadas, sendo 17 espécies identificadas, entre nematóides, trematódeos e tênias. Destes, 12 são novos registros de hospedeiros, 13 são reportados pela primeira vez no Chile, e 5 são novos registros para a região Neotropical. Além disso, os trematódeos Schistosomatidae gen. sp. e Echinostoma echinatum detectados têm importância zoonótica. Em relação à histopatologia, uma resposta inflamatória foi encontrada em todo o trato digestivo. Entretanto, é difícil estabelecer uma associação estrita de tais lesões com parasitas isolados, porque outros fatores também poderiam ser responsáveis. Em alguns casos, houve uma associação óbvia entre parasitas e lesões, embora a resposta inflamatória e a necrose fossem mínimas, como foi o caso dos gêneros Capillaria, Retinometra, Catatropis, Echinostoma e Schistosomatidae gen. sp. Entretanto, Epomidiostomum vogelsangi causou lesões granulomatosas com importante resposta inflamatória e necrose, mas sempre circunscrita às camadas superficiais da moela. Por outro lado, Paramonostomum não foi associado com uma resposta inflamatória óbvia apesar da alta carga parasitária.

Gastrointestinal helminths and related histopathological lesions in black-necked swans Cygnus melancoryphus from the Carlos Anwandter Nature Sanctuary, Southern Chile.

Black-necked swans are distributed across South America and face conservation problems in Chile according to data of the State institution SAG. The aim of this study was to identify helminths and to assess associated tissue damage via histopathology. A total of 19,291 parasites were isolated from 21 examined birds; 17 species were identified, including nematodes, flukes, and tapeworms. Of these, 12 were new host records, 13 were reported for the first time in Chile, and 5 were new records for the Neotropical region. Further, the flukes Schistosomatidae gen. sp. and Echinostoma echinatum are of zoonotic concern. Regarding histopathology, an inflammatory response was found along the birds' entire digestive tract. Nevertheless, it is difficult to declare that there is a clear association between such lesions and isolated parasites, as other noxa could be responsible as well. Although in some cases there was an evident association, such inflammatory responses and necrosis were minimal, as occurred with Capillaria, Retinometra, Catatropis, Echinostoma, and Schistosomatidae gen. sp. Nevertheless, Epomidiostomum vogelsangi caused granulomatous injuries, an important inflammatory response, and necrosis, but it always circumscribed to superficial layers of the gizzard. Conversely, Paramonostomum was not associated with an inflammatory response despite a high parasitic load.

Helminth and respiratory mite lesions in Pinnipeds from Punta San Juan, Peru.

The tissues and parasites collected from Peruvian fur seals (Arctocephalus australis) and South American sea lions (Otaria byronia) found dead at Punta San Juan, Peru were examined. The respiratory mite, Orthohalarachne attenuata infected 3 out of 32 examined fur seals and 3 out of 8 examined sea lions, however caused moderate to severe lymphohistiocytic pharyngitis only in fur seals. Hookworms, Uncinaria sp, infected 6 of the 32 examined fur seals causing variable degrees of hemorrhagic and eosinophilic enteritis. This parasite caused the death of 2 of these pups. In fur seals and sea lions, Corynosoma australe and Contracaecum osculatum were not associated with significant tissue alterations in the intestine and stomach respectively. Respiratory mites and hookworms have the potential to cause disease and mortality among fur seals, while parasitic infections do not impact significatively the health of sea lions at Punta San Juan, Peru.

Computer tomographic imaging in 4 dogs with primary nasal canine transmissible venereal tumor and differing cellular phenotype.

Primary nasal canine transmissible venereal tumor (CTVT) without genital affection is uncommon. The aim of this report was to describe the primary nasal CTVT findings and CT staging in 4 dogs with different cytological phenotypes. Three male dogs and 1 bitch were evaluated for their chronic histories of sneezing, snoring, mucopurulent nasal discharge and nasal deformation. Cytological examination of nasal secretions suggested CTVT, confirmed by histopathological examination and LINE-1/c-myc. Males had the plasmacytoid phenotype of CTVT, and the bitch had the lymphocytoid phenotype. CTVT were staged based on the CT findings using modified Adams staging system. The bitch was classified as stage 1, 2 males were classified as stage 3 and 1 male as stage 4. All dogs had a complete tumoral remission after chemotherapy. Plasmacytoid phenotype was identified in cases with most important damage of the nasal cavity. However, the cytological type did not affect the response to chemotherapy.

Recovery of black-necked swans, macrophytes and water quality in a Ramsar wetland of southern Chile: Assessing resilience following sudden anthropogenic disturbances.

In 2004 migration and mortality for unknown reasons of the herbivorous Black necked swan (Cygnus melancorhyphus (Molina, 1782)) occurred within the Río Cruces wetland (southern Chile), a Ramsar Site and nature sanctuary. Before 2004, this wetland hosted the largest breeding population of this water bird in the Neotropic Realm. The concurrent decrease in the spatial occurrence of the aquatic plant Egeria densa Planch. 1849 - the main food source of swans - was proposed as a cause for swan migration and mortality. Additionally, post-mortem analyses carried out on swans during 2004 showed diminished body weight, high iron loads and histopathological abnormalities in their livers, suggesting iron storage disease. Various hypotheses were postulated to describe those changes; the most plausible related to variations in water quality after a pulp mill located upstream the wetland started to operate in February 2004. Those changes cascaded throughout the stands of E. densa whose remnants had high iron contents in their tissues. Here we present results of a long-term monitoring program of the wetland components, which show that swan population abundance, body weights and histological liver conditions recovered to pre-disturbance levels in 2012. The recovery of E. densa and iron content in plants throughout the wetland, also returned to pre-disturbance levels in the same 8-year time period. These results show the temporal scale over which resilience and natural restoring processes occur in wetland ecosystems of temperate regions such as southern Chile.

Sarcocystis spp. in red deer (Cervus elaphus), fallow deer (Dama dama), and pudu (Pudu pudu) in southern Chile / Sarcocystis spp. em veado (Cervus elaphus), Gamo (Dama dama) e Pudu (Pudu pudu) no sul do Chile

Worldwinde, cervids are considered an important source of infection and dissemination of a wide variety of pathogens, both for farm animals and humans. Among this diseases is sarcosporidiosis, which is a parasitic disease caused by Sarcocystis spp. (Protozoa: Apicomplexa). Most frequent clinical signs are hemolytic anemia, weakness, weight loss and decrease of growth and some species of Sarcocystis might cause abortions. The clinical disease in ruminants is fairly rare but the infection is very frequent. Infections are accumulative and the parasite does not generate immunity in any of the hosts. Ovine sarcosporidiosis is a serious issue in the some regions of Chile due to the macrocysts located in the muscle which means condemnation of the whole carcass. Sarcocystis spp. has been widely reported in red deer and other cervid species but in Chile the situation remains unknown. Nowadays there is little to no evidence of Sarcocystis in foreign deer in Chile and there is only one report of the parasite on pudu. The main goal of this study is to demonstrate the presence of Sarcocystis spp. in myocardium of red deer and fallow deer in Chile, and confirm the presence of Sarcocystis spp. in pudu. All cervid cases from 1994 to 2013 of the Institute of Animal Pathology of the Universidad Austral de Chile were reviewed. The animals selected were those in which a myocardium sample was taken. From the histopathological samples observed, it was found that 5 of the 9 red deer, 1 of the 4 fallow deer and in 11 of the 23 pudu there were Sarcocystis cysts in the myocardium. This study represents the first record for Chile of Sarcocystis spp. in myocardium of red deer and fallow deer. Stablishing the red deer, fallow deer and pudu as hosts of Sarcocystis aids to have a better understanding of the parasite epidemiology in Chile and the role of wild and captive cervids in the maintenance and spread of these parasites.(AU)

No mundo, os cervos são considerados uma fonte de infecção e propagação de uma grande variedade de patógenos para animais de criação e para os seres humanos. Entre estas doenças está a sarcosporidiosis, que é uma doença parasitária causada por Sarcocystis spp. (Protozoa: Apicomplexa). Os sinais clínicos mais comuns são anemia hemolítica, fraqueza, perda de peso e diminuição do crescimento e em algumas espécies de Sarcocystis podem causar abortos. A doença clínica em ruminantes é bastante rara, mas a infecção é muito comum. As infecções são cumulativos e o parasita não gera imunidade em nenhum dos seus hospedeiros. A Sarcosporidiosis ovina é um problema grave em algumas regiões do Chile devido a microcistos localizados no músculo provocando a reprovação total da carcaça. Sarcocystis spp. tem sido amplamente relatado em cervos vermelhos e outras espécies de cervídeos, mas no Chile a sua situação permanece desconhecida. Atualmente há pouca ou nenhuma evidência de Sarcocystis em cervos introduzidos no Chile e há apenas um relatório do parasita em pudú. O principal objetivo deste estudo é demonstrar a presença de Sarcocystis spp. no miocárdio no veado vermelho e cervo gamo no Chile e confirmar a presença de Sarcocystis spp. em pudus. Revisaram-se todos os casos de cervos desde 1994-2013 do Instituto de Patologia Animal da Universidad Austral de Chile. Os animais selecionados para o estudo foram aqueles em que se tomou amostra de miocárdio. Das amostras histopatológicas observadas, verificou-se que em cinco dos nove cervos vermelhos, em um dos quatro veados gamo e 11 dos 23 pudus tinham cistos de Sarcocystis no miocárdio. Este estudo representa o primeiro relatório para o Chile de Sarcocystis spp. no miocárdio de veados vermelhos e cervo gamo. Definir o veado vermelho, o cervo gamo e os pudú como anfitriões de Sarcocystis ajuda a uma melhor compreensão da epidemiologia deste parasita no Chile e o papel de cervos selvagens e em cativeiro para a manutenção e divulgação deste parasita.(AU)

Case Report: Strawberry Disease in Farmed Chilean Rainbow Trout.

Strawberry disease is a chronic, nonlethal skin condition that affects Rainbow Trout Oncorhynchus mykiss in the United States and several European countries, where it is also known as red-mark syndrome. We provide the first identification and characterization of three strawberry disease outbreaks occurring at two aquaculture farms in southern Chile. Clinically affected fish weighing an average of 400 g presented multiple bright-red, usually raised, skin lesions on the flank, ventral surface, and dorsal surface. A PCR using Rickettsia-like-organism (RLO)-specific primers was performed on nine affected fish, and all skin samples were positive for the RLO 16S ribosomal RNA sequence. All PCR results for Flavobacterium psychrophilum and other bacterial and viral pathogens were negative. Histopathological examination of the skin lesions revealed extensive dermatitis, with severe lymphocytic infiltration in advanced cases. This report is the first to describe strawberry disease in farmed Chilean Rainbow Trout. Additional studies are needed to evaluate the risk for Rainbow Trout culture; fish challenge experiments should be performed to fulfill Koch's postulates and to demonstrate that RLO is the cause of this disease. Received December 27, 2014; accepted October 23, 2015.

Immunosuppressive syndrome in juvenile black-faced ibises (Theristicus melanopis melanopis) in southern Chile.

In the austral summer of 2011, in the rural area of Villarrica county, southern Chile (39 degrees 16'S, 72 degrees 19'W), seven black-faced ibis juveniles (approximately 4 mo old) were observed in the field with weakness; they were unable to follow the group and struggling to take flight. Three of these birds were euthanatized, and complete necropsies were performed. Gross examination showed severe infestation with Colpocephalum trispinum and Ardeicola melanopis lice, moderate emaciation, pale musculature, bursal atrophy, and severe hemorrhagic enteritis due to a heavy proventricular and intestinal infection with Porrocaecum heteropterum nematodes. Fungal pneumonia and severe lymphoid depletion on thymus, spleen, and bursa were diagnosed by microscopic examination. Bursal lesions included apoptosis and necrosis of lymphoid cells, and several cystic follicles. The presence of severe lymphoid depletion associated with fungal pneumonia and severe external and internal parasite infections suggest the presence of an immunosuppressive syndrome in these birds that caused the death of several black-faced ibis juveniles in southern Chile during the summer of 2011.

European hares in Chile: a different lagomorph reservoir for Mycobacterium avium subsp. paratuberculosis?

Ruminants are the principal host for infection by Mycobacterium avium subsp. paratuberculosis (Map), the cause of Johne's disease. Based on studies of a Map-infected population of European rabbits (Oryctolagus cuniculus) in Scotland, lagomorphs as a broad taxonomic order were proposed as potential nonruminant reservoirs for Map. To determine whether a different lagomorph species may serve as a wildlife reservoir, we investigated Map infection in European hares (Lepus europaeus) sharing habitat with known Map-infected dairy cattle in southern Chile. Fecal, mesenteric lymph node, and ileal samples were aseptically collected from 385 wild hares for liquid culture and real-time polymerase chain reaction identification of acid-fast isolates. All tissue samples were also acid-fast stained and examined microscopically. We isolated Map from at least one tissue from 48 hares (12.6%) and fecal samples from 16 hares (4.2%). No Map was found in tissues of eight of the fecal-culture-positive hares. Histologically, all tissues from all hares were within normal limits, and no acid-fast organisms were observed in any sample. Active infection, implying amplification of the organism secondary to resultant disease, was not evident. With this report Map isolations on a population versus incidental detection have now been made from two lagomorph species. However, although the rabbit population studied in Scotland appears to function as a Map reservoir, the hares studied in Chile appear to be a dead-end host, serving only as potential mechanical vectors for the organism.

Determinación de la presencia de Helicobacter spp. en perros, mediante biopsia gástrica obtenida por endoscopía / Determination of Helicobacter spp. by gastric biopsy obtained by endoscopy in dogs

Con el objeto de determinar la frecuencia de presentación de Helicobacter spp. se realizó un estudio en caninos de Valdivia, Chile, a través de biopsia gástrica de las zonas fúndica y pilórica obtenida por endoscopía y analizadas mediante las pruebas de ureasa e histología. Los resultados indican que la bacteria Helicobacter spp. fue detectada en todos los perros. La prueba de ureasa dio resultados positivos a Helicobacter en el 86,2 por ciento de las muestras de la zona fúndica y en el 75,9 por ciento del antro pilórico. El examen histológico reveló la bacteria en todas las muestras fúndicas y en el 92 por ciento de las muestras del antro pilórico. En la zona fúndica las frecuencias obtenidas entre la prueba de ureasa e histología resultaron estadísticamente significativas, a diferencia de lo que se obtuvo en la zona del antro pilórico. La bacteria fue encontrada en perros de todas las edades de ambos sexos. Las muestras que resultaron positivas a la prueba de ureasa, reaccionaron principalmente entre las 3 y 24 horas de incubación. En el examen histológico se determinó el grado de infección por el Helicobacter spp., siendo las muestras clasificadas mayormente en los grados moderado a marcado, ubicándose sobre la superfiscie de la mucosa, en las fosas gástricas, glándulas gástricas y en las células parietales.

A study was carried out in order to determinate Helicobacter spp. in dogs of Valdivia city, Chile. Gastric mucosal biopsy from fundus and pyloric antrum were obtained by endoscopy and analized by urease test and histology.Stomach endoscopic appearance, frecuency presentation of Helicobacter spp. according to sex and age, time reaction to urease test, degree of infection and distribution Helicobacter spp. were analized. Results indicated that Helicobacter spp. was detected in all dogs. The urease test was positive in 86.2% of the fundus samples and in 75.9% of the pyloric antrum samples. Histological examination revealed the bacterium in all of the fundus samples and in 92% of the antrum samples. In fundus samples the frecuency obtained by urease test and histology resulted statistically significant, different to the results obtained in the antrum region. Helicobacter spp. was found in young and old animals of both sexes. Samples that gave positive results in the urease test reacted mainly between 3 to 24 hours post incubated. Histological examination to determinate degree of infection to Helicobacter spp., were classified moderate to marked degree and detected on the mucosal surface, gastric pits, gastric glands and parietal cells.

Goat paratuberculosis in Chile: first isolation and confirmation of Mycobacterium avium subspecies paratuberculosis infection in a dairy goat.

In October 2004, 41 goats > 2 years old from a Saanen dairy goat herd located in Purranque County, 10th Region, Chile, were sampled and tested for paratuberculosis. While collecting samples it was observed that several goats were thin and emaciated. One goat was sufficiently debilitated to warrant humane euthanasia. This animal was brought to the Veterinary School at the Universidad Austral de Chile for necropsy. The goat selected for necropsy was a 12-year-old doe. The animal showed classical clinical signs of caprine paratuberculosis: emaciation despite willingness to eat, dry and rough hair coat, and no evidence of diarrhea. Gross pathology and histopathology of the necropsied goat were consistent with paucibacillary paratuberculosis. Bacteriology, serology, and PCR confirmed the diagnosis. This is the first published report of goat paratuberculosis in Chile confirming a case of caprine paucibacillary paratuberculosis.

Caso clínico: brote de enfermedad del músculo blanco o miodegeneración nutricional en terneros / Clinical case: outbreak of white muscle disease or nutritional muscular dystrophy in calves

Un brote de Enfermedades del Músculo Blanco, EMB, o miodegeneración nutricional afectó una crianza de 56 terneros Frisones Rojos. En 45 días murieron 18 animales, de aproximadamente 5 meses de edad. Los signos eran taquipnea, dificultad para caminar, sin fiebre, taquicardia e ingurgitación de venas y yugulares. Sin alteraciones nerviosas ni digestivas. Los músculos de los miembros pélvicos, de la región lumbar y glutea preentaban endurecimiento moderado y leve dolor a la presión. En el rebaño se observaron muertes súbitas de terneros o a las pocas horas de presentarse los primeros signos. En la sangre la actividad de la enzima selenio (Se) dependiente glutatión peroxidasa, GSH-Px, estaba disminuida, señalando una deficiencia marginal de selenio. La actividad de enzimas asociadas a daños musculares, aspartato aminotransferasa (AST), y creatín quinasa (CK), estaban muy aumentadas. La necropsia reveló cardiomegalia con hipertrofia del ventrículo derecho, zonas con finas estriaciones longitudinales blanquecinas en epicardio y en el miocardio múltiples áreas irregulares también de color blanquecino. Los músculos esqueléticos en general estaban pálidos y se observaron con aspecto blanquecino. El examen histopatológico del miocardio evidenció células musculares eosinofílicas e irregulares, con pérdidas de la estación, destrucción segmental, núcleos grandes y pleomórficos; las células de Purkinje presentaban intensa eosinofilia y degeneración hiana de Zenker. También se observó degeneración hialina en los músculos esqueléticos. Se diagnostica Enfermedad del Músculo Blanco. Los terneros sobrevivientes fueron tratados con solución inyectable intramuscular de Se y vitamina E, en dosis equivalente a 8 mg de Se más 340 U.I. de vitamina E, repitiéndose a los 7 días. Instaurado el tratamiento no se presentaron nuevos casos.