Resistencia a antimicrobianos en E. coli y Salmonella spp. de terneros del sur de Chile

Objective: Description of antimicrobial resistance in E. coli and Salmonella spp. isolates from calves <30 days of age from southern Chile. Material and methods: Necropsy and microbiology reports of 107 calves <30 days of age received at the Animal Pathology Institute between 2002 and 2015 were considered. Additionally, an antimicrobial resistance score was generated to allow comparisons among isolates with different antimicrobial susceptibility profiles. Results: There was no clear trend in antimicrobial resistance during the study period, with similar levels of resistance for E. coli, β-hemolytic E. coli and Salmonella spp. Approximately 50% of isolates were sensitive to antimicrobials, and between 19 and 36% of samples showed possible extended- or pan- drug resistance. Multiple different antimicrobial resistance patterns were found, including 32 for E. coli, 17 for β-hemolytic E. coli and 10 for Salmonella spp. Conclusions: Overall, E. coli samples were most sensitive to ceftriaxone; β-hemolytic E. coli to florfenicol; and Salmonella spp. to gentamicin. In contrast, these agents were resistant to amoxicillin, ampicillin and oxytetracycline respectively. This study is unique in its approach and provides useful information for veterinarians and producers on the antibiotic resistance patterns of bacteria posing a serious threat to calves. These results can help field veterinarians to control and treat bacterial diarrhea in calves.Objetivo: Describir los hallazgos de resistencia a antimicrobianos en aislados de Salmonella spp. y E. coli obtenidos de terneros de menos de 30 días de edad en el sur de Chile. Materiales y métodos: Se obtuvieron reportes de necropsia y microbiología de 107 terneros en el período comprendido entre 2002 y 2015. Adicionalmente se generó un Score de Resistencia a antimicrobianos para permitir la comparación entre aislados que fueron evaluados contra un set de distintos antimicrobianos. Resultados: No se observa una clara tendencia en la resistencia en el período en estudio, con similares niveles de resistencia observados para E. coli, E. coli β-hemolítica y Salmonella spp. Aproximadamente 50% de los aislados mostraron amplia sensibilidad a antimicrobianos, y entre 19 y 36% de los aislados demostraron potencial de resistencia extendida y pan resistencia respectivamente. Se encontraron múltiples patrones de resistencia, incluyendo 32 para E. coli, 17 para E. coli β-hemolítica y 10 para Salmonella spp. Conclusiones: En general, E. coli se mostró más sensible a ceftriaxona, E. coli β-hemolítica a Florfenicol y Salmonella spp. a gentamicina. En contraste, estos agentes fueron resistentes a amoxicilina, ampicilina y oxitetraciclina respectivamente. Este estudio es único en su aproximación y provee de información útil para médicos veterinarios y productores sobre los patrones de resistencia que amenazan la salud de los terneros. Estos resultados pueden ayudar a médicos veterinarios de campo a enfrentar y controlar efectivamente las diarreas en terneros.

Sarcocystis spp. in red deer (Cervus elaphus), fallow deer (Dama dama), and pudu (Pudu pudu) in southern Chile

ABSTRACT: 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

Paratuberculosis: new histopathological findings in red deer (Cervus elaphus) and fallow deer (Dama dama) in Chile

ABSTRACT: Paratuberculosis is a disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) that affects domestic and wild ruminants. The most common gross lesions are emaciation and corrugation and thickening of the mucosa of the small intestine. Mesenteric lymph nodes might be enlarged. For the present study, 14 red deer and 9 fallow deer from game reserves or venison farms were analyzed. The lesions found correspond to those found by other authors in other geographic locations, except for some differences in histopathological examinations. Among these differences, stands out that intestinal lesions were concentrated mostly in the ileum and granulomas were shown to be more frequent in this section of the intestine than in the corresponding lymph node. Furthermore, in multibacillary lesions the inflammatory infiltrate in the lymph nodes was mainly composed of macrophages. These differences may be due to individual variations of the animals, the stage of disease or a different strain of the pathogen. This study allowed to obtain basic information about the disease and to describe patterns of lesions found in red deer and fallow deer with prediagnosis of clinical paratuberculosis which were not described in the literature before

Seroprevalence and risk factors for Neospora caninum in small dairy farms in central Chile

ABSTRACT Objective. To provide information about seroprevalence and risk factors of Neospora caninum infection in bovines of central Chile. Material and Methods. The study population are small dairy farms that are part of a Government Technical Support Service (SAT) in the O´Higgins region in central Chile. Sera samples were collected from milking cows and analyzed by a commercial ELISA kit. Additionally, a questionnaire was applied to farmers to identify risk factors through logistic regression. Results. The farm level prevalence was found to be 67%, and within farms seroprevalence 55%. Abortion history (p= 0.037, OR=5.09), dogs feed source (p= 0.0429, OR=6), cattle drinking water source (p=0.034, OR=4.5) and abortions management (p=0.017, OR=7.43) were found as significant risk factors for infection. Conclusion. There is a high N. caninum seroprevalence in small SAT´s dairy farms in O´Higgins region. These results highlight the need of improving N. caninum surveillance, and the development of preventive measures to avoid losses related with this disease.RESUMEN Objetivos. Proveer información sobre la seroprevalencia y factores de riesgo asociados a la infección por Neospora caninum en bovinos en Chile central. Materiales y métodos. La población estudiada corresponde a pequeñas lecherías que son parte de un programa gubernamental de Asistencia Técnica (SAT), en la región de O´Higgins en Chile central. Muestras de suero fueron recolectadas desde vacas en lactancia y analizadas mediante un kit comercial ELISA. Además, se aplicó un cuestionario a los dueños de los animales para la identificación de factores de riesgo a través de regresión logística. Resultados. Se identificó una prevalencia a nivel de granja del 67%, mientras que dentro de las granjas positivas, esta fue en promedio de 55%. El historial de abortos (p= 0.037, OR=5.09), la fuente de alimentación de perros (p= 0.0429, OR=6), la fuente de agua de bebida de las vacas (p=0.034, OR=4.5) y el manejo de los abortos (p=0.017, OR=7.43) fueron identificados como factores de riesgo para la infección. Conclusiones. Se observa una alta seroprevalencia de N. caninum en pequeños productores lecheros pertenecientes al SAT en Chile central. Los resultados presentados resaltan la necesidad de mejorar las acciones de vigilancia de esta enfermedad y el desarrollo de medidas preventivas para evitar las pérdidas asociadas a esta enfermedad

Seroprevalencia y factores de riesgo de Neospora caninum en pequeñas granjas lecheras de la zona central de Chile

Objective. To provide information about seroprevalence and risk factors of Neospora caninum infection in bovines of central Chile. Material and Methods. The study population are small dairy farms that are part of a Government Technical Support Service (SAT) in the O´Higgins region in central Chile. Sera samples were collected from milking cows and analyzed by a commercial ELISA kit. Additionally, a questionnaire was applied to farmers to identify risk factors through logistic regression. Results. The farm level prevalence was found to be 67%, and within farms seroprevalence 55%. Abortion history (p= 0.037, OR=5.09), dogs feed source (p= 0.0429, OR=6), cattle drinking water source (p=0.034, OR=4.5) and abortions management (p=0.017, OR=7.43) were found as significant risk factors for infection. Conclusion. There is a high N. caninum seroprevalence in small SAT´s dairy farms in O´Higgins region. These results highlight the need of improving N. caninum surveillance, and the development of preventive measures to avoid losses related with this disease.Objetivos. Proveer información sobre la seroprevalencia y factores de riesgo asociados a la infección por Neospora caninum en bovinos en Chile central. Materiales y métodos. La población estudiada corresponde a pequeñas lecherías que son parte de un programa gubernamental de Asistencia Técnica (SAT), en la región de O´Higgins en Chile central. Muestras de suero fueron recolectadas desde vacas en lactancia y analizadas mediante un kit comercial ELISA. Además, se aplicó un cuestionario a los dueños de los animales para la identificación de factores de riesgo a través de regresión logística. Resultados. Se identificó una prevalencia a nivel de granja del 67%, mientras que dentro de las granjas positivas, esta fue en promedio de 55%. El historial de abortos (p= 0.037, OR=5.09), la fuente de alimentación de perros (p= 0.0429, OR=6), la fuente de agua de bebida de las vacas (p=0.034, OR=4.5) y el manejo de los abortos (p=0.017, OR=7.43) fueron identificados como factores de riesgo para la infección. Conclusiones. Se observa una alta seroprevalencia de N. caninum en pequeños productores lecheros pertenecientes al SAT en Chile central. Los resultados presentados resaltan la necesidad de mejorar las acciones de vigilancia de esta enfermedad y el desarrollo de medidas preventivas para evitar las pérdidas asociadas a esta enfermedad.FONDECYT, 1112126