Transplacental transmission of cutaneous Leishmania mexicana strain in BALB/c mice.

The vertical transmission of leishmaniasis has been reported in species that cause visceral leishmaniasis. However, this condition has scarcely been documented in species that cause cutaneous leishmaniasis. The aim of this study was to determine experimentally whether L. mexicana is transmitted vertically. A control group of BALB/c mice and a group infected with L. mexicana were mated, the gestation was monitored, and females were killed before delivery. Four resorptions (P = 0.023) and eight fetal deaths (P = 0.010) were observed in the infected female group; furthermore, the offspring body weight of the infected group was lower than the body weight of the healthy group (P = 0.009). DNA amplification by polymerase chain reaction (PCR) revealed that all placentas and maternal spleens as well as 39 of 110 fetal spleens obtained from the offspring of infected mothers tested positive for Leishmania. In conclusion, L. mexicana is transmitted transplacentally and causes fetal death, resorption, and reduction in offspring body weight.

The Neospora caninum-Spain 7 isolate induces placental damage, fetal death and abortion in cattle when inoculated in early gestation.

The Nc-Spain 7 isolate of Neospora caninum, which was newly obtained from an asymptomatic congenitally infected calf, demonstrated a similar virulence as Nc-1 strain in mouse models. The aim of this study was to characterize the pathogenesis of Nc-Spain 7 isolate in cattle after experimental infection at 65 days of gestation. For this purpose, thirteen pregnant heifers were divided into three groups as follows: group A: 7 heifers inoculated with 1 × 10(8) tachyzoites of Nc-Spain 7 isolate; group B: 4 heifers inoculated with 1 × 10(8) tachyzoites of Nc 1 strain; and group C: 2 heifers received PBS. Serum samples were collected weekly and heparinized blood samples were collected three times (0, 28 and 42 days after inoculation) by jugular venipuncture. Placenta and fetal tissue samples were collected at time of necropsy. Specific antibody response in the dams was tested by IFAT, indirect ELISA, and rNcGRA7 and rNcSAG4 based-ELISA. Specific antibody response in fetal fluids was tested by IFAT. IFN-γ production was measured after in vitro culture of PBMC and the supernatant was assessed using a commercial kit (BOVIGAM). A significant increase in N. caninum antibody responses was detected in groups A and B by IFAT and by i-ELISA from day 14 after inoculation onwards. Besides, antibody response against rNCGra7 protein was also detected in all inoculated heifers by rNcGra7-based ELISA. Four fetuses from group A and one from group B were aborted between 3 and 5 weeks after infection. In the recovered fetuses, only 3 out of 4 fetal fluids from fetuses of group A and 1 out of 3 of group B were seropositive by IFAT, but all of them were positive by PCR. Transplacental transmission could be determined in all fetuses from groups A and B by PCR and/or IHC. Heifers of group C and their fetuses remained negative by all techniques. The results of this study demonstrate that the NC-Spain 7 isolate could be transmitted transplacentally, and produced fetal death and abortion in cattle.

Aborto ovino associado com infecção por Sarcocystis sp / Ovine abortion associated with Sarcocystis sp. infection

Infecções por protozoários têm distribuição mundial e podem causar aborto, nascimentos prematuros e ou morte fetal em diversas espécies animais. Em julho de 2004, oito ovinos Corriedale apresentaram problemas reprodutivos caracterizados por aborto e natimortalidade no terço final da gestação. Dessas oito perdas, um natimorto macho foi enviado ao Setor de Patologia Veterinária para necropsia. Alterações macroscópicas não foram observadas durante a necropsia. Lesões histológicas foram observadas principalmente no cérebro e coração e se caracterizaram por encefalite não-supurativa multifocal acentuada associada à presença de protozoários no interior de células endoteliais e vasos sanguíneos e miocardite não-supurativa focal leve. Alguns desses organismos apresentaram formato de roseta. O teste de imunoistoquímica anti-Toxoplasma gondii foi negativo, mas houve reação cruzada com anticorpo anti-Neospora caninum. O exame de imunofluorescência direta para Leptospira sp. foi negativo. A bacteriologia aeróbica e micro-aeróbica não revelou crescimento significativo. Esses achados foram compatíveis com o diagnóstico de Sarcocystis sp.

Protozoal infection has worldwide distribution and may cause abortion, premature parturition or fetal death in almost all domestic animals. In July 2004, eight Corriedale sheep showed abortion and stillbirth in the third trimester of gestation. Of these reproductive losses, one stillborn male was submitted to the Laboratory of Veterinary Pathology for necropsy investigation. The direct immunofluorescence test for Leptospira sp. was negative. No significant bacteria was isolated from lung and liver by aerobic and microaerobic cultures. Macroscopic lesions were not found in any fetal tissue. The histological lesions were observed mainly in the brain and heart and consisted primarily of severe multifocal nonsupurative encephalitis and nonsuppurative myocarditis. Schizonts of a protozoan parasite consistent with Sarcocystis sp. were found in the endothelial cells and vascular endothelium in several organs. Many schizonts with merozoites arranged in a rosette-like pattern were observed in brain and kidney tissues. In sections stained with periodic acid-Schiff (PAS), the limiting membrane of some schizonts appeared to be weakly PAS-positive. Merozoites and nuclei were PAS-negative. Protozoa did not react immunohistochemically to the antibody anti-Toxoplasma gondii; however, cross-reactivity was observed with Neospora caninum antibody. These findings were consistent with the diagnosis of Sarcocystis sp.

Aborto ovino associado com infecção por Sarcocystis sp / Ovine abortion associated with Sarcocystis sp. infection

Infecções por protozoários têm distribuição mundial e podem causar aborto, nascimentos prematuros e ou morte fetal em diversas espécies animais. Em julho de 2004, oito ovinos Corriedale apresentaram problemas reprodutivos caracterizados por aborto e natimortalidade no terço final da gestação. Dessas oito perdas, um natimorto macho foi enviado ao Setor de Patologia Veterinária para necropsia. Alterações macroscópicas não foram observadas durante a necropsia. Lesões histológicas foram observadas principalmente no cérebro e coração e se caracterizaram por encefalite não-supurativa multifocal acentuada associada à presença de protozoários no interior de células endoteliais e vasos sanguíneos e miocardite não-supurativa focal leve. Alguns desses organismos apresentaram formato de roseta. O teste de imunoistoquímica anti-Toxoplasma gondii foi negativo, mas houve reação cruzada com anticorpo anti-Neospora caninum. O exame de imunofluorescência direta para Leptospira sp. foi negativo. A bacteriologia aeróbica e micro-aeróbica não revelou crescimento significativo. Esses achados foram compatíveis com o diagnóstico de Sarcocystis sp.(AU)

Protozoal infection has worldwide distribution and may cause abortion, premature parturition or fetal death in almost all domestic animals. In July 2004, eight Corriedale sheep showed abortion and stillbirth in the third trimester of gestation. Of these reproductive losses, one stillborn male was submitted to the Laboratory of Veterinary Pathology for necropsy investigation. The direct immunofluorescence test for Leptospira sp. was negative. No significant bacteria was isolated from lung and liver by aerobic and microaerobic cultures. Macroscopic lesions were not found in any fetal tissue. The histological lesions were observed mainly in the brain and heart and consisted primarily of severe multifocal nonsupurative encephalitis and nonsuppurative myocarditis. Schizonts of a protozoan parasite consistent with Sarcocystis sp. were found in the endothelial cells and vascular endothelium in several organs. Many schizonts with merozoites arranged in a rosette-like pattern were observed in brain and kidney tissues. In sections stained with periodic acid-Schiff (PAS), the limiting membrane of some schizonts appeared to be weakly PAS-positive. Merozoites and nuclei were PAS-negative. Protozoa did not react immunohistochemically to the antibody anti-Toxoplasma gondii; however, cross-reactivity was observed with Neospora caninum antibody. These findings were consistent with the diagnosis of Sarcocystis sp.(AU)

[Effects of acute and chronic Trypanosoma cruzi infection in pregnant mice]. / Efectos de la infección aguda y crónica por Trypanosoma cruzi en la gestación de los ratones.

Pathogens may impair reproduction in association or not with congenital infections. We have investigated the effect of acute infection with Trypanosoma cruzi, the protozoan agent of Chagas disease, on reproduction of female mice. In the acute, parasitemic, phase of the infection, female mice were totally unable to reproduce. Most of them (80%) were infertiles and did not develop any gestation. In the few gravid infected mice, implantation numbers were as in uninfected control mice. However, their fetuses presented a weight meanly reduced by 40% as compared to those of uninfected females, and all of them died during the gestation or whithin 48 h after birth. Such massive mortality did not result from congenital infection, which did not occur. The infertility and the fetal mortality occuring early in gestation (resorptions) were significantly correlated with a high maternal parasitemia, whereas later fetal mortality was associated with the presence of intracellular parasites in the utero-placental unit. The decidua was particularly receptive to T. cruzi multiplication, since this tissue harboured 125 fold more amastigotes than the maternal heart or other placental tissues. In addition, placentas of dead fetuses presented histopathological lesions (inflammatory infiltrates, fibrine deposits and ischemic necrosis). Such harmfull effects of acute infection were not observed when female mice were in the chronic phase of the infection, since these reproduce normally. Their fetuses only suffered from moderate and reversible growth retardation. These results indicate that, following the maternal parasite burden, T. cruzi infection may induce very deleterious effects on gestation.

Efectos de la infección aguda y crónica por Trypanosoma cruzi en la gestación de los ratones / Effects of acute and chronic Trypanosoma cruzi infection in pregnant mice

Pathogens may impair reproduction in association or not with congenital infections. We have investigated the effect of acute infection with Trypanosoma cruzi, the protozoan agent of Chagas disease, on reproduction of female mice. In the acute, parasitemic, phase of the infection, female mice were totally unable to reproduce. Most of them (80%) were infertiles and did not develop any gestation. In the few gravid infected mice, implantation numbers were as in uninfected control mice. However, their fetuses presented a weight meanly reduced by 40% as compared to those of uninfected females, and all of them died during the gestation or whithin 48 h after birth. Such massive mortality did not result from congenital infection, which did not occur. The infertility and the fetal mortality occuring early in gestation (resorptions) were significantly correlated with a high maternal parasitemia, whereas later fetal mortality was associated with the presence of intracellular parasites in the utero-placental unit. The decidua was particularly receptive to T. cruzi multiplication, since this tissue harboured 125 fold more amastigotes than the maternal heart or other placental tissues. In addition, placentas of dead fetuses presented histopathological lesions (inflammatory infiltrates, fibrine deposits and ischemic necrosis). Such harmfull effects of acute infection were not observed when female mice were in the chronic phase of the infection, since these reproduce normally. Their fetuses only suffered from moderate and reversible growth retardation. These results indicate that, following the maternal parasite burden, T. cruzi infection may induce very deleterious effects on gestation.

Heifers immunized with whole-cell and membrane vaccines against Tritrichomonas foetus and naturally challenged with an infected bull.

The performance of a whole-cell vaccine and the other vaccine with cellular membranes of Tritrichomonas foetus applied to heifers naturally challenged by mating with an infected bull was determined. Forty heifers were divided into three groups: a control group (n=16) without immunizing, another group (n=12) immunized with whole cells (10(8)/dose) and a third group (n=12) immunized with cellular membranes (300 micro g of membranes/dose protein). The females were subcutaneously vaccinated at 3-week on two occasions and received a third intravaginal booster dose. After 3 weeks of the last vaccinal doses, the heifers were served by a T. foetus infected bull over 90-day period. The mean duration of infection for membrane-vaccinated heifers was 60 days +/-25, compared with 63 days +/-35.8 of infection for whole-cell-vaccinated heifers and 79 days +/-41.3 for control heifers. Calving rates were 6/12 for membrane-vaccinated heifers, 3/12 for whole-cell-vaccinated animals, and 2/16 for control animals. Fetal mortality rates were 3/12 for membrane-vaccinated animals, 4/12 for those vaccinated with whole cells and 10/16 for control animals. These reproductive parameters were significantly different (P<0.05) between heifers vaccinated with membranes and control heifers. The hemolytic test and enzyme-linked immunoabsorbent assay (ELISA) with T. foetus antigen showed that serum immunoglobulins peaked before and during the breeding period. The heifers vaccinated with membranes developed an important response during the critical period of fetal loss, second and third month of the breeding time, and another month after the same period. The ELISA method was more sensitive and more reliable than the hemolytic test for the evaluation of the systemic immune response in females infected and/or vaccinated with T. foetus.

Detection of antibodies to Toxoplasma gondii in stillborn piglets in Argentina.

Fetal fluids of 738 stillborn piglets from three swine farms in Argentina were examined for antibodies to Toxoplasma gondii. Antibodies were detected in 15 samples at a 1:20 dilution in the indirect fluorescent antibody test and 10 samples were positive in the modified agglutination test (MAT) at a dilution of 1:25; four of these samples had a MAT titer of > or = 1:100. This survey indicates a low rate of congenital T. gondii infection in stillborn pigs in Argentina.

Toxoplasmosis y aborto en evolución / Toxoplasmosis and abortion in evolution

Para conocer la prevalencia de toxoplasmosis en población abierta de Comitán Chiapas, se realizó estudio serológico por inmunofluorescncia indirecta en voluntarios sanos. Además se identifico la presencia de anticuerpos anti Toxoplasma gondii en 50 mujeres con aborto en evolución. Los resultados mostraron que alrededor de 5 por ciento de la población general tiene títulos positivos de anticuerpos anti Toxoplasma gondii, y el 18 por ciento en el caso de las mujeres con aborto en volución. Se concluyó que la seropositividad para esta parasitosis estadísticamente es signficativa en los casos de aborto que entre la población general (P<0.006) y también, es significativamente mayor a las mujeres con aborto, que con respecto a la mujeres de la población general de Comitán Chiapas (P<0.01)