Rafael C. Costa

Congenital Neosporosis in Goats from the State of Minas Gerais, Brazil

Congenital Neospora caninum infection was diagnosed in two Saanen goat kids from two distinct herds with a history of abortion and weak newborn goat kids in the Southern region of the State of Minas Gerais, Brazil. The first kid was weak at birth, had difficulty to rise and was unable to nurse. Gross lesions of porencephaly and hydrocephalus ex vacuo were seen. Multifocal necrosis, gliosis and non-supurative encephalitis were observed in the brain. Several parasitic cysts with a thick wall that reacted strongly only with polyclonal antiserum to Neospora caninum were seen in the cerebral cortex, brain stem and cerebellum. The second kid was born from a Neospora caninum seropositive mother that aborted in the last pregnancy. It was born without clinical signs. The diagnosis of neosporosis was based on antibody titer of 1:800 to N. caninum by indirect fluorescence antibody test obtained from blood collected before the goat kid ingested the colostrum and Neospora caninum DNA was detected by polymerase chain reaction and sequenced from placenta. This is the first report of neosporosis in goats in the southeast region of Brazil.

Antibody kinetics in goats and conceptuses naturally infected with Neospora caninum

Neospora caninum is a protozoan which can cause abortions in caprines. However, information regarding the humoral immune response and the occurrence of reproductive disorders is scarce. This is the first study in which the kinetics of antibodies is studied in pregnant goats naturally infected by N. caninum, as well as their respective conceptuses. The subclasses of IgG (IgG1 and IgG2) were also evaluated in pregnant goats. Reproductive problems related to neosporosis (abortion and stillbirth) occurred in 15.38% of the goats. There was a statistically significant association between the increased titres of maternal IgG in the second half of the gestational period with the occurrence of endogenous transplacental transmission. The rate of congenital transmission was 77%. During the gestational period of the seropositive goats, there was mainly a predominance of the subclass IgG2, although mixed patterns of IgG2-IgG1 and the IgG1 pattern were also observed. These results indicate that N. caninum is responsible for the occurrence of important alterations in the humoral immune response of naturally infected goats, and is also a potential causative agent for reproductive disorders in goats. The high proportion of infected conceptuses reinforces the suggestion that congenital infection is one of the main routes of parasite transmission in goats.

Histological and immunohistochemical characterization of the inflammatory and glial cells in the central nervous system of goat fetuses and adult male goats naturally infected with Neospora caninum

BackgroundNeospora caninum is an apicomplexan protozoan that is considered one of the main agents responsible for abortion in ruminants. The lesions found in the central nervous system (CNS) of aborted fetuses show multifocal necrosis, gliosis, and perivascular cuffs of mononuclear cells, but the inflammatory and glial cells have not been immunophenotypically characterized. The lesions in the CNS of infected adult animals have rarely been described. Therefore, in this study, we characterized the lesions, the immunophenotypes of the inflammatory and glial cells and the expression of MHC-II and PCNA in the CNS of goats infected with N. caninum. The CNS of eight aborted fetuses and six adult male goats naturally infected with N. caninum were analyzed with lectin histochemistry (RCA1) and immunohistochemistry (with anti-CD3, −CD79α, −GFAP, −MHC-II, and -PCNA antibodies). All animals were the offspring of dams naturally infected with N. caninum.ResultsThe microscopic lesions in the CNS of the aborted fetuses consisted of perivascular cuffs composed mainly of macrophages (RCA1+), rare T lymphocytes (CD3+), and rare B lymphocytes (CD79α+). Multifocal necrosis surrounded by astrocytes (GFAP+), gliosis composed predominantly of monocytic-lineage cells (macrophages and microglia, RCA1+), and the cysts of N. caninum, related (or not) to the lesions were present. Similar lesions were found in four of the six male goats, and multinucleate giant cells related to focal gliosis were also found in three adult goats. Anti-GFAP immunostaining showed astrocytes characterizing areas of glial scarring. Cysts of N. caninum were found in three adult male goats. The presence of N. caninum was evaluated with histopathology, immunohistochemistry, and PCR. Immunohistochemistry demonstrated anti-PCNA labeling of macrophages and microglia in the perivascular cuffs and the expression of MHC-II by microglia and endothelial cells in the CNS of the aborted fetuses and adult male goats.ConclusionsMacrophages and microglia were the predominant inflammatory cells in the CNS of aborted fetuses and healthy adult male goats infected with N. caninum. Activated astrocytes were mainly associated with inflamed areas, suggesting that astrocytes were involved in the resolution of the lesions.

Abortos por Neosporacaninum em bovinos do sul de Minas Gerais

The present study evaluates the participation of Neospora caninum in bovine abortions from farms in the southern region of Minas Gerais state, Brazil, through histopathological, immunohistochemical (IHQ) analysis and DNA detection by polymerase chain reaction (PCR). The material used in this study was obtained through retrospective study of bovine abortion cases received by the Setor de Patologia Veterinaria da Universidade Federal de Lavras and by necropsies performed in fetuses from 2011 to 2013. From 60 fetuses studied, 30 (50%) had microscopic lesions; 19 (63%) of them had histologic lesions compatible with N. caninum abortion, characterized by multifocal non-suppurative encephalitis, necrosis and gliosis in the central nervous system and multifocal nonsuppurative myocarditis and myositis. From the 19 fetuses with protozoa lesions in 14 the final diagnosis was performed; five were confirmated only by IHQ staining and five were positive only by PCR. Four fetuses were positive in IHC and in PCR. In five fetuses from the retrospective study lesions compatible with N. caninum were seen, but the presence of the protozoan was not confirmed by IHQ labeling. The findings demonstrate that N. caninum is an important agent associated with abortion in cattle from Minas Gerais. Therefore, beyond the microscopic lesions association between IHC and PCR was essential to confirm the diagnosis.

Aspectos patológicos e parasitológicos da infecção por Tanaisia (Paratanaisia) bragai em pavões (Pavo cristatus)

Trematodes belonging to the family Eucotylidae, including Tanaisia(Paratanaisia)bragaiSantos, 1934are parasites of the kidney and ureter that affect several species of domestic and wild birds. Tanaisia bragaiis considered a low pathogenic parasite, but high worm burdens may determine clinical complications, including signs of apathy, weight loss, diarrhea and death. This paper describes the first report of infection by T. bragai in peacocks (Pavo cristatus), which constitutes a new host record and offers data on the lesions associated to this parasitism, although the degree of pathogenicity and parasite load may be considered mild. These birds did not exhibit clinical signs of parasitism. The macroscopic exam revealed discreet yellow spots on the liver. In the histological sections of the kidney, specimens of T. bragai were found in the collecting ducts, which were markedly dilated, with a thickened wall. Other findings included a mild inflammatory reaction in the wall of the ducts (but sometimes absent), flattening of lining epithelial cells and small, multifocal points of calcification around the collecting ducts. The microscopic examination of the parasites revealed trematodes with an elongated body, well-developed sub terminal oral sucker, pharynx present, short esophagus, cecum somewhat undulating or not, with blind end, testes symmetrical, equatorial, irregular in shape or slightly lobed, vitelline fields extending in both pre-ovarian and post ovarian fields, uterus very long, intercecal or sometimes overlapping the cecum and containing large quantities of eggs. The present findings suggest the need for further diagnostic studies on the prevalence of this trematode in peacocks as well as pathologic studies for the determination of the potential pathogenicity of this parasite in this species of bird. Moreover, infected peacocks could serve as carriers of T. bragai to be transferred to other bird species, thereby contributing to the dispersion of the parasite.

Caracterização morfológica e imuno-histoquímica de lesões em casos de aborto bovino bacteriano e viral no sul de Minas Gerais

The paper evaluates the participation of bacterial and viral agents in bovine abortions in farms of southern Minas Gerais state, Brazil. Histopathological and immunohistochemical analysis was performed in aborted fetuses of cattle received by the Setor de Patologia Veterinaria, Universidade Federal de Lavras, from 1999 to 2013. From 60 fetuses studied, 30 (50%) had microscopic lesions. From these, eight had lesions consistent with bacterial agents and three had lesions suggestive of viral agents. In the bacterial abortions, one fetus presented lesions compatible with leptospirosis, characterized by jaundice, cholestasis, lymphoplasmacytic intersticial nephritis, and tubular nephrosis. Seven fetuses had purulent pneumonia or bronchopneumonia and one of them had also fibrinous pleuritis and peritonitis; two of them presented positive immunostaining for Brucella abortus. One of the three fetuses with lesions of viral infection revealed positive imunostaining for bovine herpesvirus. The results showed that abortions of bacterial and viral origin occur in the Region of this study and prophylactic measures should be adopted on the farms. This study also demonstrates that immunohistochemistry associated with histopathology is a useful and viable tool for the diagnosis, especially when microbiological and/or serological tests are not available.