ABSTRACT
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.
ABSTRACT
Background: Shigella spp is a frequent cause of diarrhea in children. Antimicrobials decrease the duration of diarrhea and pathogen excretion. However, the increasing resistance limits their therapeutic value. Aim: To study Shigella serotype distribution in the Metropolitan Region in Chile, and its relationship with severity of disease, antimicrobial resistance pattern and clonality. Material and methods: During summer 2004-2005, stool samples from children with diarrhea were collected in Cary Blair transpon medium and cultured. Shigella isolates were serotyped using monoclonal and polyclonal commercial antibodies. In vitro activity of ampicillin, amoxicillin/clavulanic acid, chloramphenicol, cotrimoxazol, nalidixic acid, ciprofloxacin, ceftriaxone and azythromycin was determined by minimal inhibitory concentration (MIC). Clonality was studied by pulsed-field gel electrophoresis (PFGE) using Xbal as restriction enzyme. Results: One hundred thirty nine Shigella strains were isolated (77 S sonnei and 62 S flexneri). S sonnei and S flexneri 2a serotypes were responsible for 95 percent of episodes. Children aged 2-4 years, showed a greater incidence of Shigella infections and 77 percent of episodes were treated on an ambulatory basis. High resistance levels were observed for ampicillin, cotrimoxazole, amoxicillin-clavulanic acid and chloramphenicol (67 percent, 60 percent, 56 percent and 45 percent, respectively). We found 11 resistance patterns and 61,2 percent of strains were multiresistant. There were multiple clones without a strict relationship with resistance patterns. Conclusions: Shigella infections in Metropolitan Region in Chile are associated to a restricted number of serotypes, representing a clonal expansion associated to different antimicrobial resistant patterns.