The prospective role of the land snail Rumina decollata as a potential paratenic host of Toxocara cati for domestic cats was studied. R. decollata specimens and cats' feces were collected from the open spaces of a Buenos Aires city hospital. Cats' feces were analyzed and snails were digested to identify T. cati stages, by morphological and molecular analyses. T. cati larval eggs were recovered from 23.5% (4/17) of the sampled feces. Twenty percent of snail pools (5/25) were confirmed to be positive for Toxocara spp. third larval stage (L3) by PCR. The mean value of total larvae recovered per gram of snail in all positive pools was 5.1, with a maximum 33 L3/pool. This is the first report of T. cati infective larvae in R. decollata domestic snail as a paratenic host, since the relationship between infection in snails and in cats' feces could be demonstrated in a common environment.

Se estudió el rol prospectivo de Rumina decollata como potencial hospedador paraténico de Toxocara cati para los gatos domésticos. Se recolectaron caracoles R. decollata y heces de gatos de un hospital de la Ciudad Autónoma de Buenos Aires. Se procesaron las heces y los caracoles fueron digeridos para identificar estadios de T. cati por análisis morfológico y molecular. El 23,5% (4/17) de las muestras de heces resultaron positivas a huevos larvados de T. cati. El 20% (5/25) de los pooles de caracoles fue positivo a larvas de tercer estadío (L3) de Toxocara spp. por PCR. El promedio de larvas totales recuperadas por gramo de caracol en todos los pooles positivos fue de 5.1, con un máximo de 33 L3/pool. Se trata del primer reporte de R. decollata como hospedador paraténico de T. cati, puesto que ha sido demostrada la infección en caracoles y gatos en un ambiente común.

Since 1916 to date, it has been suspected that vertical transmission of parasites from the genus Trichinella could occur in pregnant or lactating women during the parenteral phase of infection. The aim of the present study was to evaluate the transmammary transmission of T. patagoniensis in BALB/c mice. Twenty 7-week-old BALB/c mice were distributed into two groups of 10 individuals each, depending on the time of gestation when they were infected, 15 or 18 days after detection of the vaginal plug. Each group was subdivided into two subgroups of 5 mice each, which were given an oral dose of 100 or 500 infective larvae respectively. Euthanasia and subsequent artificial digestion was performed in the pups and the dams. No T. patagoniensis L1 larvae were found in any of the offsprings analyzed. The observed results suggest that vertical transmission of T. patagoniensis would not be possible in BALB/c mice.

Desde 1916 se sospecha que la transmisión vertical de parásitos del género Trichinella podría ocurrir en mujeres embarazadas o lactantes durante la fase parenteral de la infección. El objetivo del presente trabajo fue evaluar la transmisión galactógena de T. patagoniensis en ratones BALB/c. Se utilizaron 20 ratones que se dividieron en 2 grupos de 10 individuos, según el momento de la gestación en que fueron infectados, 15 o 18 días después de detectar el tapón mucoso. Cada grupo se subdividió a su vez en 2 subgrupos, los que recibieron una dosis oral de 100 o de 500 larvas infectantes, respectivamente. Se procedió a la eutanasia y posterior digestión artificial de las crías y de las madres. No se encontraron larvas L1 de T. patagoniensis en ninguna de las crías analizadas. Estos resultados indican que no habría transmisión galactógena de T. patagoniensis en ratones BALB/c.

Na cultura da soja, a inoculação conjunta de Bradyrhizobium japonicum e Azospirillum brasilense pode ser uma estratégia promissora, combinando a FBN e a produção de fito-hormônios. Nesse âmbito o trabalho teve como objetivo avaliar o efeito da coinoculação com diferentes doses de Bradyrhizobium japonicum e de Azospirillum brasilense, no desenvolvimento morfofisiológico e nodulação da soja. O ensaio foi realizado em estufa na Universidade Federal de Lavras (UFLA), no setor de Grandes Culturas do Departamento de Agricultura Lavras - MG, Brasil. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições, em esquema fatorial 5 x 2, sendo utilizadas cinco doses de Azospirillum brasilense (0, 0,5, 1,0, 1,5 e 2,0 mL kg-1 de semente) e duas doses de Bradyrhizobium japonicum (0 e 3,0 mL kg-1 de semente), ambas veiculadas via sementes. A cultivar de soja utilizada foi a ‘BRS Favorita RR’, cultivada em vasos de 5 dm³. No início da floração (R1) determinaram-se os seguintes parâmetros: altura de plantas, número de trifólio, peso seco da parte aérea, da parte radicular e dos nódulos, volume radicular, teor de clorofila foliar e teor de nitrogênio foliar. O uso da dose de 3 mL de Bradyrhizobium japonicum kg-1 de semente, proporciona melhor desempenho morfofisiológico e maior nodulação na cultura da soja cultivada em vaso. A utilização de Azospirillum brasilense isoladamente e em coinoculação com Bradyrhizobium japonicum não promove efeitos significativos nos parâmetros avaliados.

In soybean, the combined use of Bradyrhizobium japonicum and Azospirillum brasilense may be a promising strategy, joining biological nitrogen fixation (BNF) and phytohormone production. In this context, the aim of this study was to evaluate the effect of co-inoculation at different application rates of Bradyrhizobium japonicum and Azospirillum brasilense on the morphophysiological development and nodulation of soybean. The experiment was carried out in a greenhouse at the Federal University of Lavras (UFLA), in the Field Crop sector of the Department of Agriculture, Lavras, MG state, Brazil. A completely randomized experimental design was used with four replications in a 5 x 2 factorial arrangement consisting of five application rates of Azospirillum brasilense (0, 0.5, 1.0, 1.5 and 2.0 mL kg-1 of seed) and two application rates of Bradyrhizobium japonicum (0 and 3.0 mL kg-1 of seed), both transmitted via seeds. The soybean cultivar used was ‘BRS Favorita RR’, grown in 5 dm³ pots. At the beginning of flowering (R1), the following features were determined: plant height, number of trifoliate leaves, shoot dry matter, root dry matter, nodules dry matter, root volume, leaf chlorophyll content, and leaf nitrogen content. Application of Bradyrhizobium japonicum at the rate of 3 mL kg-1 of seed led to the best morphophysiological performance and the greatest nodulation in the potted soybean crop. The use of Azospirillum brasilense alone and in co-inoculation with Bradyrhizobium japonicum did not have a significant effect on the parameters evaluated.

Se realizó la infección experimental de doce cerdos con aproximadamente 100.000 huevos infectivos de Toxocara cati. Los huevos de T. cati utilizados en la inoculación fueron recolectados de heces felinas. Otro grupo de tres cerdos no infectados se utilizó como control. Grupos de cerdos infectados se eutanaciaron a los 7,14,21 y 28 días posinoculación (pi). Se tomaron muestras de tejidos para digestión y evaluación de cambios histopatológicos en la etapa temprana de la infección. El número de larvas recuperadas de los pulmones se incrementó en los días 7 y 14 pi, recuperándose también los días 21 y 28 pi. Se encontraron larvas de T. cati en los linfonódulos del intestino delgado y grueso los días 7,14 y 28 pi y los días 7,14,21 y 28 pi respectivamente. En los restantes tejidos estudiados o no se recuperaron larvas o los valores fueron menores a una larva por gramo de tejido. La respuesta patológica observada en el hígado y los pulmones a los 7 y 14 días posinoculación, mostró en la superficie del hígado manchas blancas y en los pulmones áreas de consolidación. Los pulmones presentaron una reacción inflamatoria con presencia de larva en el centro en el día 28 pi. En el hígado se observó una hepatitis periportal y perilobular. Los linfonódulos del intestino presentaron una linfoadenitis eosinofílica con un centro reactivo conteniendo formas parasitarias en algunos de ello. En ninguno de los tejidos se observó la típica reacción granulomatosa. El rol de los restantes tejidos examinados fue de menor significancia. Queda evidenciada la importancia de éste parasito como un agente etiológico que desarrolla la enfermedad en hospederos paraténicos.

Experimental inoculations of approximately 100,000 infective Toxocara cati larval eggs were done in twelve pigs. The T. cati eggs used for inoculation were collected from cat's feces. Another group of three pigs served as an uninfected control. Groups of infected pigs were euthanized at seven, 14, 21, and 28 days post-inoculation (dpi). Tissue samples were taken for digestion and histopathology changes in early phase. The number of larvae recovered from the lungs peaked at seven and 14 dpi and were also present at 21, and 28 dpi. Larvae of T. cati were present in the lymph nodes of the small and large intestine at seven, 14, and 28 dpi and at seven, 14, 21, and 28 dpi respectively. In other studied tissues, no larvae or less than one larva per gram was detected. The pathological response observed in the liver and lungs at seven and 14 dpi, showed white spots on the liver surface and areas of consolidation were observed in the lungs. The lungs showed an inflammatory reaction with larvae in center at 28 dpi. In the liver we observed periportal and perilobular hepatitis. The lymph nodes of the intestines displayed eosinophil lymphadenitis with reactive centers containing parasitic forms in some of them. The granulomatous reaction was not observed in any tissues. The role of the other examined tissues had less significance. The relevance of this parasite as an etiological agent that leads to disease in paratenic hosts is evident.

Toxocara cati larvae are able to migrate through the tissues of the cat, remaining infective. The objective of this study was to determine the presence of different stages ofT. cati in naturally infected cats. Twelve cats found dead in the street were necropsied and samples of faeces were collected for coproparasitological analysis. Samples of muscle, the lungs, kidneys, liver, mammary gland and brain were removed. They were processed by the rapid artificial digestion technique to detect T. cati larvae. Coproparasitological analysis was positive for T. cati by 25%, to Toxascaris leonina at 16, 66% and 8.33% to both species. The 50% of animals presented adult parasites ofT. cati, of which 20% were positive to T. leonina. Statistically significant differences were found between the presence of adult parasites and cat's age. No statistically significant differences were observed in regard to sex. No larvae ofT. cati were recovered from tissues. The differences in the results obtained between the coproparasitological technique and the necropsy could be due to the presence of immature stages of the parasites or to intermittent elimination of eggs in faeces. The absence of larvae in tissues raises several questions related to the migratory behaviour of T. cati larvae. Increasing the number of felines studied will contribute to ensure the validity of the results and will provide a better understanding about the behavior ofT. cati larvae during the migratory phase in the cat.

Las larvas de T. cati tienen la capacidad de realizar migraciones por los tejidos del gato, permaneciendo infectivas. El objetivo del presente estudio fue determinar la presencia de distintos estadios de T. cati en gatos naturalmente infectados. Se efectuó la necropsia de 12 gatos hallados muertos en la vía pública. Se tomaron muestras de materia fecal para análisis coproparasitológico y muestras de músculo, la totalidad de los pulmones, ríñones, hígado y cerebro. Se utilizó la técnica de digestión artificial rápida para detectar la presencia de larvas de Toxocara cati en los tejidos. El análisis coproparasitológico fue positivo a T. cati en un 25%, a Toxascaris leonina en un 16, 66% y en un 8,33% a ambas especies. El 50% de los animales presentó parásitos adultos de T. cati, de los cuales el 20% presentó parasitosis mixta con T. leonina. La existencia de parásitos adultos y su relación con la edad del animal fue estadísticamente significativa. No resultó estadísticamente significativa con respecto al sexo. En el análisis de las muestras de órganos y tejidos no se detectaron larvas de T. cati. Las diferencias obtenidas en los resultados con la técnica coproparasitológica y con la necropsia podrían deberse a la presencia de estadios inmaduros o a la eliminación intermitente de huevos por materia fecal. La ausencia de larvas en los tejidos plantea diversos interrogantes que podrían condicionar el comportamiento migratorio de las mismas en el gato. Es necesario incrementar la cantidad de felinos estudiados y realizar estudios bajo condiciones controladas de infección para obtener un mayor conocimiento sobre el comportamiento de las larvas de T. cati durante la fase migratoria en el gato.