A ehrlichiose monocítica equina (EME) na região Sul do Rio Grande do Sul tem demonstrado ser importante nas criações de cavalos Crioulos. A enfermidade foi relatada e diagnosticada como causa de diarreia, prejuízos com tratamentos e com a morte de equinos não estabulados, sendo apontada como um fator limitante na criação de equinos em algumas regiões. O modo de transmissão pela via oral, intermediada por trematódeos em ambientes aquáticos, tem sido sustentado. Caracóis dulciaquícolas estão envolvidos como hospedeiros intermediários de trematódeos albergadores de Neorickettsia risticii. Um total de 16.846 caracóis Heleobia foi coletado nos municípios de Arroio Grande, Rio Grande, Palmares do Sul e Santa Vitória do Palmar, 92,2% dos quais foram encontrados nas raízes de aguapés (Eichornea spp.). A frequência de trematódeos presentes nos caracóis variou de 2,3 a 12,8% nas propriedades coletadas. Foram encontrados três tipos de cercárias, morfotipo 1, morfotipo 2 e morfotipo 3, e dois morfotipos de metacercárias nos caracóis. Um total de 357 insetos da ordem Odonata foi coletado, fases de metacercárias foram encontradas no tegumento da subordem Anisoptera com frequência de 5,3%. Mais estudos são necessários para identificar as fases larvais encontradas, bem como para conhecer o hospedeiro definitivo, identificar o parasito adulto e a relação de seu ciclo de vida com a ocorrência da ehrlichiose monocítica equina.

The equine monocytic ehrlichiosis in the region South of the Rio Grande do Sul has demonstrated to be important in the creations of Crioulo horses. It has been reported as cause of diarrhea in equine not surround and as cause of losses with treatments and death of the animals, being pointed as a limited factor in the range breeding in some regions. The way of transmission for the oral way, intermediated for trematodes in aquatic environments, has been supported. Freshwater snails are involved as intermediate hosts of trematodes and harbor of the Neorickettsia risticii. A total of 16,846 Heleobia snails had been collected in the cities of Arroio Grande, Rio Grande, Palmares do Sul and Santa Vitoria do Palmar, 92.2% of which had been found in the roots of aquatics plants (Eichornea spp.). The frequency of trematodes present in the snails varied of 2.3 to 12.8% in the collected regions. Three types of cercariae were found, morphology type 1, morphology type 2 and morphology type 3, and two morphologic type of metacercariae of the snails. A total of 357 insects of the Odonata order were collected, stages of metacercariae had been found in the tissues of suborder Anisoptera with 5.3% of frequency. More studies are necessary for identification of the joined larval phases, as well as knowing the host definitive and identifying the adult parasite and the relation of its cycle of life with the occcurrence of equine monocytic ehrlichiosis.

Introduction: bovine mastitis is a major problem in dairy production, mainly caused by Gram-positive bacteria. The search for active ingredients that act upon these microorganisms is growing due to occurrence of bacterial multiresistance. Objectives: to assess the minimum bactericidal concentration (MBC) of Origanum vulgare L. (oregano) essential oil against bacteria isolated from mastitic milk. Methods: the antimicrobial activity of O. vulgare essential oil was measured against 71 bacteria from the genera Streptococcus, Staphylococcus and Corynebacterium isolated from the bovine milk and against three pattern strains, that is, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. The technique was dilution in microplate. Results: the mean minimal bactericidal concentration (MBC) ranged from 0.23 % to 2 % against the bacteria isolated from bovine milk, with the lowest concentration for Streptococcus genus and the highest for coagulase-negative Staphylococcus. Regarding the pattern strains, the MBC was 3.17 % and 0.35 % for S. aureus and Escherichia coli respectively and showed no effect for Pseudomonas aeruginosa. Conclusions: the results confirmed the in vitro activity of Origanum vulgare L. oil against the bovine mastitis-related bateria.

Introducción: la mastitis bovina es el mayor problema en la producción lechera, causada principalmente por bacterias grampositivas. La búsqueda de principios activos que actúen en esos microrganismos es creciente, sobre todo por la ocurrencia de multirresistencia bacteriana. Objetivos: evaluar la concentración bactericida mínima del aceite esencial de Origanum vulgare L. (orégano) frente a bacterias aisladas de leche mastítica. Métodos: se evaluó la actividad antimicrobiana del aceite esencial de O. vulgare frente a 71 bacterias aisladas de leche bovina, de los géneros Streptococcus, Staphylococcus y Corynebacterium; y 3 cepas patrón de Pseudomonas aeruginosa, Staphylococcus aureus y Escherichia coli. La técnica utilizada fue de dilución en microplaca. Resultados: la concentración bactericida mínima media varió de 0,23 a 2 % frente a las bacterias aisladas de leche bovina, con la menor concentración para el género Streptococcus y la mayor para Staphylococcus coagulasa negativa. En cuanto a las cepas patrones la concentración bactericida mínima fue de 3,17 y 0,35 % para S. aureus y Escherichia coli, respectivamente; no presentó efecto para Pseudomonas aeruginosa. Conclusiones: en los resultados se comprobó la actividad in vitro del aceite de orégano frente a las bacterias relacionadas con la mastitis bovina.

Introduction: the agro-ecological system of milk production is limited in terms of sustainable alternatives for animal health promotion. The control of mastitis with medicinal plants can be economically and environmentally viable. Objectives: to evaluate the use of antiseptics in the post-milking teat disinfection. Methods: the comparison of conventional and herbal extracts in treating the new intramammarial infections. Results: the weekly prevalence of California Mastitis Test ranged from 29.5 to 17.1 % in group 1 and from 29.7 to 19.6 % in group 2 but no significant difference was found in any week. The incidence of positive culture for Staphylococcus/Streptococcus was 3.93 and 6.96/1 000 quarters/day for groups 1 and 2 respectively, being p= 0.057. There were four cases of clinical mastitis during the experiment, two cases in each treatment. Conclusions: the use of plant extracts in the post-milking teat disinfection may be useful for agro-ecological systems of milk production.

Introducción: el sistema de producción de leche agroecológico está limitado por alternativas sostenibles de promoción a la salud animal. El control de la mastitis con plantas medicinales puede ser viable de modo económico y ecológicamente. Objetivos: evaluar la aplicación de antisépticos en la desinfección de pezones posordeño. Métodos: se comparó un convencional y extracto de plantas medicinales en un rebaño comercial y tuvo como principal encierre las nuevas infecciones intramamarias. Resultados: la prevalencia semanal del California Mastitis Test varió en el grupo 1 entre 29,5 y 17,1 %, y en el grupo 2 de 29,7 a 19,6 %, no diferenciándose de modo significativo, en ninguna de las semanas. La incidencia de cultura positiva para Staphylococcus/Streptococcus fue de 3,93 y 6,96/1 000 cuartos/d para los grupos 1 y 2, respectivamente; con p= 0,057. Hubo 4 casos de mastitis clínica durante el experimento, 2 en cada tratamiento. Conclusiones: el uso de extractos de plantas en la desinfección de pezones posordeño puede ser útil a los sistemas de producción de leche agroecológicos.