Ascaris suum in pigs of the Zona da Mata, Minas Gerais State, Brazil / Ascaris suum em suínos da Zona da Mata, Estado de Minas Gerais, Brasil

Among the parasites that affect pigs, Ascaris suum stands out for causing the greatest losses to livestock production systems. This parasite can be monitored during the slaughter of animals through the identification of milk spots or white patches on the liver caused by its larval migration. However, infection in the herd is usually subclinical, which is why the presence of this parasite in industrial pig production has been overlooked. The aim of the study was therefore to evaluate the occurrence of milk spots on the liver of animals slaughtered in the micro-region of Ponte Nova in the Zona da Mata - Minas Gerais, Brazil, and to associate these lesions with the time of year, herd size and source of origin of the animals. An evaluation was made of 1,069 lots, totaling 108,073 animals, based on data extracted from the Federal Inspection Service. The animals were slaughtered during the period of January 2011 to June 2013. Out of the total number of slaughtered animals, 10,535 (9.75%) tested positive for these lesions. Therefore, veterinarians and producers should be warned about the inefficiency of the deworming protocols that are used, and the need to develop and/or review control strategies for this parasite in production systems.

Dentre os parasitas que acometem os suínos, Ascaris suumdestaca-se como o mais impactante nos sistemas de criação. Seu monitoramento pode ser realizado durante o abate dos animais, por meio da identificação de milk spots ou manchas de leite presentes no fígado, decorrentes da sua migração larval. Entretanto devido ao fato da infecção ocorrer no rebanho normalmente de forma subclínica, a presença desse parasita na produção industrial de suínos vem sendo negligenciada. O objetivo do estudo foi avaliar a ocorrência de manchas de leite no fígado de animais abatidos na micro-região de Ponte Nova, na Zona da Mata de Minas Gerais - Brasil, e associar tais lesões com a época do ano, tamanho do rebanho e local de origem dos animais. Foram avaliados 1.069 lotes, totalizando 108.073 animais. Os dados foram extraídos do Serviço de Inspeção Federal, e eram referentes aos animais abatidos, durante o período de janeiro de 2011 a junho de 2013. Do total de animais abatidos, 10.535 (9,75%) foram positivos para a lesão. Portanto, veterinários e produtores devem ser alertados quanto à ineficiência dos protocolos de vermifugação utilizados e a necessidade do desenvolvimento e/ou revisão de estratégias de controle para este parasita na produção.

Antígenos de larvas pulmonares de Ascaris suum reconocidos por anticuerpos producidos en Oryctolagus cuniculus / Ascaris suum lung larvae antigens recognized by antibodies produced in Oryctolagus cuniculus

El presente trabajo tuvo como objetivo determinar mediante la técnica de Western Blot los antígenos de larvas pulmonares de Ascaris suum que son detectados por anticuerpos producidos en Oryctolagus cuniculus inmunizado experimentalmente. Las larvas pulmonares (L3 y L4) fueron obtenidas en 120 ejemplares de Mus musculus cepa BALB/c ratón infectados experimentalmente por vía oral con huevos infectivos de A. suum. Parte de estas larvas fueron cultivadas en el medio Eagle (MEM) para la obtención de antígenos de excreción/secreción y la otra fue sonificada para la obtención de antígenos somáticos, los cuales sirvieron para inmunizar dos ejemplares de O. cuniculus, utilizando Adyuvante Completo e Incompleto de Freund. A las 5 semanas de inmunización se obtuvo sangre de los conejos por punción cardiaca a fin de recuperar el suero, parte del cual fue purificado parcialmente por precipitación salina y diálisis. Mediante la técnica de electroinmuno-transferencia (Western Blot) y usando sueros de los conejos inmunizados se detectaron en los antígenos de excreción/secreción de 20 horas de cultivo reducidos con dithiothreitol, 12 bandas antigénicas de 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KDa, siendo las más reactivas las de 100, 72.4, 16.9, 15.5 y 14.9 KDa. En los antígenos somáticos bajo condiciones de reducción, se detectaron solamente seis bandas de 42.7, 39.8, 34.6, 30.2, 28 y 25.2 KDa de poca reactividad. Estos resultados permiten afirmar que los antígenos de excreción/secreción de A. suum de 20 horas de incubación en el medio MEM inducen la producción de un mayor número de anticuerpos de tipo IgG en conejos inmunizados experimen-talmente.

Excretory/secretory antigens (E/SAg) and somatic antigens (SAg) of Ascaris suum lung larvae that induce the immunoglobulin G antibodies production in Oryctolagus cuniculus experimentally immunized was determined. For this purposes, specimens of Mus musculus BALB/c were inoculated orally with infective eggs of A. suum obtained from pigs naturally parasitized in order to obtain the lung larvae. Part of these larvae was cultured in Minimum Essential Medium (MEM) to obtain E/SAg and another part was sonicated to obtain the SAg too. Both, E/SAg and SAg mixed with complete and incomplete Freund's adjuvant were used for rabbits immunization. Five weeks after the immunization, the rabbits were bled by cardiac puncture obtaining the immunosera by centrifugation, which was purified partially by saline precipitation and dialysis. By using an Western blot technique with purified immunoserum and E/SAg obtained to 20 hours and reduced with dithiothreitol, fourteen antigens bands of 100, 72.4, 56.2, 42.7, 39.8, 34.6, 31.6, 30.2, 19.5, 16.9, 15.5 y 14.9 KD, were detected. The bands of 100, 72.4, 16.9, 15.5 and 14.9 KDa were been the most reactives. Thereby the SAg, also reduced with dithiothreitol, seven bands of 42.7, 39.8, 34.6, 30.2, 28.0 and 25.2 KDa were detected. They were a bit clear. In conclusion, the E/SAg induce the highest production of immunoglobulin G antibodies in rabbits experimentally immunized.