The aim of this study was to evaluate the viability of canine melanoma transplanta- tion in immunodeficient mice. A piece of a spontaneous canine vulvar melanoma was inocu- lated subcutaneously into 3 N:NIH (S)-Fox1 nu specific pathogen free mice. One of those was killed 5 days later. The tumour was re-inoculated into 8 mice, which were killed at 5, 13, 20 and 27 days. At necropsy an encapsulated nodule, black to yellow, varying in size from 0.5 to 1.4 cm in diameter was observed in all of the mice. Histological examination confirmed the presence of neoplastic melanocytes arranged in clusters, surrounding a necrotic area. These preliminary results suggest that canine melanoma transplantation in nude mice is feasable and that the development of a canine melanoma mouse model might be considered.
espanolEl empleo de los biopesticidas fungicos, como un metodo alternativo al control quimico de insectos plaga, es una estrategia fitosanitaria sin efectos contaminantes sobre el medio ambiente. Entre los hongos entomopatogenos, el hifomicete Beauveria bassiana ha demostrado su capacidad como agente de biocontrol de insectos plaga de la agricultura. Entre estos se encuentran los gorgojos y carcomas que atacan a los granos almacenados destinados al consumo humano y animal. Debido a los riesgos toxicologicos vinculados con la bovericina, una micotoxina metabolizada por B. bassiana, la utilizacion del hongo como agente de control biologico esta sujeto a la determinacion de su inocuidad en mamiferos. El objetivo de este trabajo fue evaluar la toxicidad de una cepa de B. bassiana patogena de Tribolium castaneum y Sitophilus oryzae, inoculada por via oral e intraperitoneal (IP) en ratas y ratones de experimentacion. En el primer caso, los animales recibieron duran te 60 dias una dieta de granos de trigo mezclados con micelio de B. bassiana,mientras que el segundo grupo fue inyectado con sus pensiones conidiales del hongo vivo o muerto por calor y solucion fisiologica esteril para el tratamiento y los dos testigos, respectiva mente. El contenido de bovericina del hongo se determino por HPLC en fase reversa. Los ratones se sacrificaron a los 30 y 60 dias (infeccion por via oral) y a los 15,30 y 60 dias(infeccion por via IP)de las infecciones fungicas.Luego de las necropsias, se realizaron los estudios micologicos e histopatologicos en muestras de bazo, higado, pulmon, cere bro y rinon.No se hallaron signos de B. bassiana ni lesiones en los tejidos de los organos analizados,por lo que se sugiere que no existirian riesgos toxicologicos para los mamiferos expuestos al contacto con este biopesticida EnglishFungal biopesticides used as an alternative method to chemical control of insect pests are a strategy without deleterious effects on the environment. Among entomopathogenic fungi, the hyphomycete Beauveria bassiana has been found to be highly effective for the control of herbivorous insects. Among these insects, there are weevils and borers that attack stored grains used as human and animal foodstuffs. Due to the toxicological risks of beauvericin, a mycotoxin produced by B. bassiana, the use of this fungus in biological control programs must be previously assessed by safety procedures such as its innocuity in mammals. The aim of this study was to evaluate the toxicity of a strain of B. bassiana found to be pathogenic on Tribolium castaneum and Sitophilus oryzae. The strain of the fungus was inoculated orally (OI) and intraperitoneally (IP) to rats and mice. Animals were orally inoculated by feeding them with a mix of wheat grain and B. bassiana mycelium for 60 days. A second group of animals was infected intraperitoneally with a fungal suspension. Two control groups were included, one injected with heat-killed fungus and the other with sterile physiological saline. Analysis of beauvericin was performed by high-performance liquid chromatography (HPLC). The animals were killed at 30 and 60 days (OI) and 15, 30 and 60 days (IP) after infection. Mycological and histopathological studies were performed in liver, lung, brain and kidney. Negative results obtained with the live fungus as well as the two control groups, suggest no toxicity of beauvericin towards mammals exposed to the biopesticide.
Propósito: este artículo pretende mostrar una alternativa que ofrezca solución eficiente ante situaciones de refacciones en bioterios a través del empleo de bioterios satélites modulares.
Tema: unidades móviles para su uso como bioterios experimentales.
Desarrollo: en el 2012, se presentó una situación problemática en un laboratorio privado cuando decidieron remodelar su bioterio sin tener la posibilidad de interrumpir los ensayos con animales que allí se realizaban. Del análisis pormenorizado de las posibilidades existentes y entre diferentes alternativas, se consensuó instalar un bioterio satélite, provisorio, en dos contenedores marítimos conectados entre sí. Se elaboró un diseño que permitió compartimentar los ambientes, quedando un sector de ingreso y vestuario, un sector de cuarentena, uno para mantenimiento de los animales y una pequeña sala para experiencias. Se planificaron las terminaciones con materiales recomendados por los estándares internacionales, se suministraron los servicios básicos de agua y electricidad, se colocaron desagües, y se instalaron los equipos de aire acondicionado, ventilación y humedad (hvac) para el mantenimiento de ratas de experimentación.
Conclusiones: este tipo de proyecto permitió una alternativa rápida y económica comparada con una construcción convencional. Permitió reubicar los animales, continuar con los ensayos, capacitar al personal para el trabajo durante la transición y desocupar totalmente el sector del bioterio a remodelar para poder comenzar con las obras.
Clostridium piliforme produces a fatal infection in mice, as hepatitis involving the intestine and interferes in experimental results. The aim of this work was to evaluate the interference caused by Clostridium piliforme in N:NIH(S)-nu mice (nude) transplanted with the tumor line A 549. One hundred nude mice were divided into four groups of 25 animals each one: group 1, animals with tumor and experimentally infected with Clostridium piliforme; group 3 animals with no tumor and inoculated with the microorganism; and control groups 2 and 4 with and without tumor respectively, not infected with the microorganism. In group 1, nineteen mice showed clinical signs 4 days after inoculation, typical lesions in liver and intestine were observed. In group 3; 20 mice showed clinical signs 4 days after inoculation, 5 of them died, necropsy was performed on the rest of the animals, the same kind of lesions as in group 1 were found. In groups 2 and 4 no lesions were observed. 78% of the animals inoculated with Clostridium piliforme have shown clinical signs 4 days after inoculation. There were observed no differences in the animals with or without tumor transplantation. It was concluded that Clostridium piliforme interferes causing the death of the animals with or without tumor.
Routine microbiological monitoring of rodent colonies in animal facilities is essential to evaluate the health status of the animals used in research studies. In the present study, animals were examined for the presence of selected microbial infections. In order to determine the contamination rates of mice and rats in Argentina, animals from 102 conventional facilities were monitored from 2012 to 2016. The most frequent bacteria isolated were Pseudomonas aeruginosa and Proteus spp. The common parasites identified were Syphacia spp. and Tritrichomonas spp. Serological assays demonstrated the highest prevalence for Mouse hepatitis virus in mice and Sialodacryoadenitis virus in rats. The results indicate that there is a high incidence of infections, so it is suggested that an efficient management system and effective sanitary barriers should be implemented in conventional facilities in Argentina in order to improve sanitary standards. Los controles microbiológicos de rutina en colonias de roedores en bioterios son esenciales para evaluar el estado de salud de los animales que se utilizan en las investigaciones. En el presente estudio se examinaron animales de bioterios de Argentina con el objeto de detectar la presencia de infecciones microbianas seleccionadas. Con el fin de determinar los porcentajes de contaminaciones en estos individuos, se controlaron animales de 102 bioterios convencionales entre 2012 y 2016. Las bacterias más frecuentes aisladas fueron Pseudomonas aeruginosa y Proteus spp. Los parásitos comunes identificados fueron Syphacia spp. y Tritrichomonas spp. Los ensayos serológicos demostraron la mayor prevalencia del virus de hepatitis del ratón en ratones y del virus de la Syalodacryoadenitis en ratas. Los resultados indican que hay una alta incidencia de infecciones, por lo que se sugiere que se debe implementar un sistema de gestión eficiente y barreras sanitarias eficaces en instalaciones convencionales en Argentina con el objeto de mejorar los estándares sanitarios.