RESUMO Galinhas criadas ao ar livre podem ingerir oocistos de T. gondii presentes no ambiente e, com isso, albergar cepas virulentas desse parasita em diferentes tecidos, sem sinais clínicos. O isolamento de T. gondii por meio de bioensaios em camundongos e gatos, a partir de tecidos de galinhas naturalmente infectadas, tem sido descrito em vários países. Isso demonstra a importância das galinhas caipiras na epidemiologia desse parasita. O objetivo deste trabalho foi caracterizar genotipicamente isolados de T. gondii obtidos de galinhas caipiras naturalmente infectadas em uma área rural do município de Santa Maria, estado do Rio Grande do Sul, Brasil. Fragmentos de cérebro e de coração, de 12 galinhas soropositivas para T. gondii, foram processados pela técnica de digestão péptica para isolamento do parasita. Das 12 amostras submetidas a bioensaio com camundongos, nove isolados foram obtidos. A caracterização genotípica por RFLP-PCR foi realizada utilizando-se 11 marcadores genéticos: SAG1, 5'-3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 e Apico e revelou a presença de cinco genótipos atípicos de acordo com o ToxoDB (# 11, # 55, # 64, # 140 e # 163). Os resultados mostraram uma ampla diversidade genética de T. gondii em galinhas caipiras nessa região.

ABSTRACT Free-range chickens may ingest oocysts of T. gondii present in the environment and consequently harbor virulent strains of this parasite in different tissues, without any clinical signs. Isolation of T. gondii through bioassays on mice and cats from naturally infected chicken tissues has been described in several countries, demonstrating the importance of free-range chickens in the transmission of this parasite. The aim of this study was the genotypic characterization of T. gondii isolates obtained from naturally infected free-range chickens in a rural area of the state of Rio Grande do Sul, Brazil. Brain and heart tissue from 12 chickens seropositive for T. gondii were processed using peptic digestion technique for parasite isolation. From 12 samples subjected to mouse bioassay, nine isolates were obtained. RFLP-PCR genotypic characterization was performed using 11 genetic markers: SAG1, 5'-3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Genetic characterization of the isolates revealed the presence of five atypical genotypes according to ToxoDB (# 11, # 55, # 64, # 140 and # 163). Our results showed a wide genetic diversity of T. gondii in free-range chickens in this region.

The aim of the present study was to detect Cryptosporidium sp infection in domestic animals and in monkeys from a zoo, in Buenos Aires Province, Argentina. Three hundred and seventy five fecal samples from different animal species were processed by the Ritchie modified sedimentation method (formalin-ether) to concentrate the oocysts. The sediment was stained by the Ziehl Neelsen modified technique. Cryptosporidium sp was detected in 7 of 175 dogs, in 2 of 17 cats, in 4 of 22 sheep, in 21 of 31 goats, in 29 of 109 calves, in 2 of 2 horses and in 2 of 5 Guinea pigs. Fourteen feces samples from monkeys were examined, among them, oocysts were detected in the sample from 1 adult female black howler monkey (Alouatta caraya), in the sample from 1 male adult black spider monkey (Ateles paniscus), in 1 sample of faeces from 7 adult squirrel monkeys (Saimiri boliviensis), in 1 sample from 2 females and 1 male tufted capuchin (Cebus apella), in 1 sample of feces from baboons (Papio hamadryas) and ¡n the sample from 1 young male chimpanzee (Pan troglodytes)

El objetivo del trabajo fue detectar infecciones por Cryptosporidium sp en animales domésticos y en monos de un zoológico, en la provincia de Buenos Aires, Argentina. Se procesaron 375 muestras de materia fecal de distintas especies mediante la técnica de sedimentación de Ritchie modificada (formol -éter) para concentrar los ooquistes. El sedimento se tiñó mediante la técnica de Ziehl-Neelsen modificada. Se detectaron ooquistes de Cryptosporidium sp en 7 de 175 muestras de materia fecal de perro, en 2 de 17 de gato, en 4 de 22 de ovinos, en 21 de 131 cabras, en 29 de 109 de terneros, en 2 de 2 de equinos y en 2 de 5 de cobayos (Cavia porcellus). Se examinaron 14 muestras de heces de monos, entre ellas, se detectaron ooquistes en la muestra de 1 hembra carayá (Alouatta caraya) adulta, en la de 1 mono araña (Ateles paniscus) macho adulto, en la muestra colectiva de 7 monos saimiri (Saimiri boliviensis) adultos, en la muestra de 2 hembras y 1 macho caí (Cebus apella), en la muestra colectiva de hamadríades (Papio hamadryas) y en la de 1 chimpancé joven (Pan troglodytes)

Neospora caninum causes abortions in cattle worldwide. The Neospora-cycle of life is heteroxenous. Dogs (Canis familiaris) and coyotes (Canis latrans) are the definitive hosts known at present. Although, transplacental infection is an efficiently mode of transmission in cattle; there are also experimental and field data that prove horizontal transmission. Several techniques are available for diagnosis since neosporosis is recognized as a disease that causes economic losses in cattle. The mechanisms that produce the abortion are not completely understood. The immunomodulation observed during the pregnancy, is associated with a susceptible period where Neospora-abortion can occur. Resistance to the parasite is dependent on T helper cell 1 cytokine responses. This has important repercussions for pregnant female bovine because strong T helper cell 1 cytokine responses are incompatible with successful pregnancy. However, it was demonstrated that chronically infected cows develop immune mechanisms against the abortion caused by a second Neospora-exposure. The comprehension of those mechanisms is needed for the formulation of Neospora-vaccines that prevent bovine neosporosis. General concepts about neosporosis with emphasis in the immune response and perspectives for vaccination are mentioned in the present review.

Neospora caninum es agente causal de aborto en bovinos de regiones ganaderas de todo el mundo. Su ciclo de vida es heteroxeno siendo el perro (Canis familiaris) y el coyote (Canis latrans) los hospedadores definitivos reconocidos hasta el presente. La infección transplacentaria es un eficiente mecanismo de transmisión de la enfermedad pero existe evidencia que demuestra la transmisión postnatal en los bovinos. Debido a las pérdidas económicas que causa la neosporosis, diversas técnicas diagnósticas han sido desarrolladas. La fisiopatología del aborto causado por N. caninum no ha sido completamente esclarecida. La modulación del sistema inmune por efecto de la preñez ocasiona un período de susceptibilidad al aborto por N. caninum. Aunque la resistencia al parásito ha sido asociada con una respuesta de linfocitos T tipo 1, dicha respuesta inmune es incompatible con una preñez exitosa. Sin embargo, los mecanismos inmunes presentes en animales crónicamente infectados protegen del aborto ante una segunda exposición al protozoo. La comprensión de esa respuesta inmune adquirida constituye un desafío para el desarrollo de inmunógenos. Este trabajo menciona conceptos generales de la neosporosis bovina haciendo énfasis en los mecanismos inmunes y las perspectivas para la vacunación.

Avaliou-se a técnica de imunofluorescência indireta (IFA) na detecção de anticorpos contra o vírus da imunodeficiência felina (FIV) numa pesquisa epidemiológica do FIV na Argentina. A IFA foi modificada e comparada com duas outras técnicas imunológicas: western blot (WB) e imunocromatografia em camadas (SI) com kit comercial e também com reação em cadeia de polimerase (PCR) para detecção do DNA proviral. A IFA mostrou ser um teste com alta sensibilidade e especificidade e poderá ser empregada como ferramenta útil em estudos epidemiológicos. A baixa porcentagem de reatividade não específica pode ser esclarecida com testes mais avançados ou usando métodos alternativos.

This study evaluated an indirect immunofluorescence assay (IFA) to detect feline immunodeficiency virus infection (FIV) antibody in a comprehensive epidemiological survey of FIV in Argentina. IFA modified in our laboratory, was compared with two other immunoassays, western blot (WB) and a sandwich immunochromatographic commercial kit (SI), and also with a direct polymerase chain reaction (PCR) method that detects proviral DNA. IFA showed to be a test with high sensitivity and specificity, and could be useful as a diagnostic tool in epidemiological studies. The presence of a low percentage of results with non-specific reactivity in the IFA could be resolved with further testing or use of an alternative method.

The purposes of this study was to characterize the stillborn piglets, based on gross pathological findings, and to determine the presence of potentially related infectious agents using immunoserological tests of pleural fluid. The study was conducted in three "in doors" farms (A, B, and C) with intensive management, in Buenos Aires Province, Argentina. In total 1.024 stillbirths were classified in antepartum (mommified or non-mommified) and intrapartum. Two hundred randomly selected samples of pleural fluid were processed for detection of antibodies to porcine parvovirus, Aujeszky's disease virus, Leptospira interrogans (4 serogroups) and Brucella suis. Antibodies to Toxoplasma gondii were studied in 738 samples. The stillbirths in farms A, B, and C were 4.1 , 3.4 , and 10.8%, respectively, with variable numbers for the three different types. In farms A and C the intrapartum type reached the highest percentages (61.8 and 92.2), while farm B presented the highest mummy rate (54.8). For farms A and C values were associated with Leptospira interrogans serogroup Icterohemorrhagiae antibodies and the ones in farm B with parvovirus antibodies. Antibodies to Toxoplasma gondii were detected in the three farms, and the high rate in farm B was related to abundant cat population. All samples were negative for Brucella suis and Aujeszky's disease virus. According to the results, it can be concluded that characterization of stillbirths, in association with immunoserological studies of pleural fluid is a simple and effective method that can contribute to the knowledge about the exposure of breeding stocks to reproductive pathogens

Los objetivos de este trabajo fueron caracterizar los lechones mortinatos provenientes de tres granjas de cría intensiva en confinamiento de la provincia de Buenos Aires, Argentina, sobre la base de los hallazgos anatomopatológicos macroscópicos y determinar, mediante estudios inmunoserológicos del líquido pleural, la presencia de algunos agentes infecciosos que inciden en su presentación. Se realizó la necropsia de 1.024 mortinatos, los que se clasificaron en intraparto, anteparto momificados y anteparto no momificados. Se tomaron muestras de líquido pleural, de las cuales 200 fueron procesadas para la determinación de anticuerpos contra parvovirus porcino, virus de la enfermedad de Aujeszky, Leptospira interrogans (4 serogrupos) y Brucella suis. Para Toxoplasma gondii fueron procesadas 738 muestras. Los porcentajes de mortinatos totales en las granjas A, B y C fueron 4.1 , 3.4 y 10.8%, respectivamente. En las granjas A y C el mayor porcentaje fue para los intraparto (61.8 y 92.2%), mientras que en la B fue para los anteparto momificados (54.8%). En A y C, el alto porcentaje de mortinatos intraparto se asoció con la presencia de anticuerpos contra L. interrogans serogrupo Icterohemorrhagiae, mientras que en la B el alto porcentaje de momias se relacionó con la presencia de anticuerpos contra parvovirus porcino. En las 3 granjas se observó positividad al T. gondii, en particular en la B, siendo este hallazgo coincidente con la presencia de gatos. La determinación de anticuerpos contra virus de la enfermedad de Aujeszky y B. suis fue negativa en las 3 granjas. La caracterización de los mortinatos asociada a la determinación de anticuerpos en líquido pleural constituyó un método simple y efectivo, resultando de utilidad como herramienta complementaria en la determinación del perfil serológico de exposición a patógenos que producen trastornos reproductivos