IgM and IgG as markers of infection transplacentary Neospora caninum in bovine fetuses

O objetivo deste estudo foi determinar a ocorrência de anticorpos anti-Neospora caninum em 260 amostras de soro coletadas de fetos bovinos de julho de 2007 a março de 2008, em abatedouro do município de Santa Maria, Rio Grande do Sul, Brasil. Para detecção de anticorpos anti-N. caninum, a técnica de imunofluorescência indireta foi utilizada tanto para a detecção de imunoglobulinas G e M. Amostras com títulos e" 25 foram consideradas positivas. Das 260 amostras testadas, 15% (39/260) foram positivas para anticorpos anti-N. caninum. Destas, em 38 (97,4%) foi detectada a presença de IgG anti-N. caninum e em seis (15,4%) de IgM. Em cinco amostras (12,8%) detectaram-se ambos, IgG e IgM. Os resultados reafirmam a habilidade do N. caninum em determinar infecção fetal. A pesquisa de IgM foi de limitada importância na detecção da infecção via transplacentária em soro fetal bovino.The aim of this study was to determine the occurrence of anti-Neospora caninum antibodies in serum samples collected from 260 bovine fetuses, between July 2007 and March 2008, in an abattoir in the municipality of Santa Maria, Rio Grande do Sul, Brazil. An indirect fluorescent antibody test was used to detect anti-N. caninum immunoglobulins G (IgG) and M (IgM), using a cut-off of 1:25. Considering IgG or IgM detection, 15% (39/260) of the samples tested were found positive. Among the positive samples, 38 (97.4%) were positive for IgG and 6 (15.4%) for IgM. However 5 (12.8%) of it were positive for both IgG and IgM. These results are in agreement with the proven ability of N. caninum to fetal infection. IgM testing was few relevant to detect N. caninum transplacental infection through fetal bovine serum analisys

Ocorrência de anticorpos anti-Neospora caninum e anti-Toxoplasma gondii em cães com leishmaniose visceral

Uninfected dogs and those naturally infected with Leishmania chagasi exhibiting different clinical forms of disease were evaluated for the presence of anti-Neospora caninum and anti-Toxoplasma gondii antibodies. Blood samples were collected from 110 mongrel dogs. Sera were tested using the indirect fluorescent antibody test (IFAT), and the animals with visceral leishmaniasis (VL) (n=60) were classified clinically. Out of the 110 sera investigated, 5 (4.5%) were positive for N. caninum (IFAT≥50) and 36 (32.7%) for T. gondii (IFAT≥16). Anti-L. chagasi antibody titers in asymptomatic dogs (n=10) were found to be significantly lower (P<0.05) than those in oligosymptomatic ones (n=22), which were in turn significantly lower (P<0.05) than those in symptomatic ones (n=28). No association between Leishmania and N. caninum infections was observed. Among dogs infected with L. chagasi, a tendency (P=0.053) towards an association between the infection with T. gondii and the appearance of VL symptoms was observed, suggesting that the clinical manifestation of VL in dogs may enhance their susceptibility to T. gondii. The possible influence of the immunosuppressive status of canine leishmaniasis in the different clinical forms of the disease is discussed.A presença de anticorpos anti-Neospora caninum e anti-Toxoplasma gondii foi avaliada em cães não infectados e naturalmente infectados com Leishmania chagasi manifestando diferentes formas clínicas da enfermidade. Amostras de sangue foram coletadas de 110 cães sem raça definida. Os soros foram avaliados por meio da reação de imunofluorescência indireta (RIFI) e os animais com leishmaniose visceral (LV) (n=60) foram classificados clinicamente. Dos 110 soros analisados, 5 (4,5%) foram reativos para N. caninum (RIFI≥50) e 36 (32,7%) para T. gondii (RIFI≥16). Os títulos de anticorpos anti-L. chagasi em cães assintomáticos (n=10) foram significativamente (P<0,05) mais baixos que aqueles verificados em oligossintomáticos (n=22), que por sua vez foram significativamente menores (P<0,05) que em cães sintomáticos (n=28). Não foi observada associação entre infecções por Leishmania e N. caninum. Entre os cães infectados com L. chagasi, verificou-se uma tendência de associação (P=0.053) entre infecção com T. gondii e aparecimento de sinais clínicos da LV, o que sugere que a manifestação clínica da LV em cães pode aumentar sua susceptibilidade ao T. gondii. A provável influência do quadro de imunossupressão em diferentes formas clínicas da leishmaniose canina é abordada

Early immune responses and parasite tissue distribution in mice experimentally infected with oocysts of either archetypal or non-archetypal genotypes of Toxoplasma gondii

In most of the world Toxoplasma gondii is comprised of archetypal types (types I, II and III); however, South America displays several non-archetypal strains. This study used an experimental mouse model to characterize the immune response and parasite kinetics following infection with different parasite genotypes. An oral inoculation of 50 oocysts per mouse from T. gondii M4 type II (archetypal, avirulent), BrI or BrIII (non-archetypal, virulent and intermediate virulent, respectively) for groups (G)2, G3 and G4, respectively was used. The levels of mRNA expression of cytokines, immune compounds, cell surface markers and receptor adapters [interferon gamma (IFNγ), interleukin (IL)-12, CD8, CD4, CD25, CXCR3 and MyD88] were quantified by SYBR green reverse transcription-quantitative polymerase chain reaction. Lesions were characterized by histology and detection by immunohistochemistry established distribution of parasites. Infection in G2 mice was mild and characterized by an early MyD88-dependent pathway. In G3, there were high levels of expression of pro-inflammatory cytokines IFNγ and IL-12 in the mice showing severe clinical symptoms at 8–11 days post infection (dpi), combined with the upregulation of CD25, abundant tachyzoites and tissue lesions in livers, lungs and intestines. Significant longer expression of IFNγ and IL-12 genes, with other Th1-balanced immune responses, such as increased levels of CXCR3 and MyD88 in G4, resulted in survival of mice and chronic toxoplasmosis, with the occurrence of tissue cysts in brain and lungs, at 14 and 21 dpi. Different immune responses and kinetics of gene expression appear to be elicited by the different strains and non-archetypal parasites demonstrated higher virulence

Fatal systemic toxoplasmosis in Valley quail (Callipepla californica)

An adult, captive raised male Valley quail (Callipepla californica) acquired by a southern Brazilian aviary suddenly showed severe apathy, dyspnea and diarrhea, and died 18 hours after the onset of illness. At necropsy, pale muscles and whitish areas in the heart, splenomegaly, hepatomegaly, and consolidated red lungs were observed. Histological findings were mainly mononuclear inflammation with necrosis of liver, heart, spleen, bone marrow and lung. There were large numbers of Toxoplasma gondii tachyzoitesorganisms in the liver, heart, spleen, bone marrow, lungs, trachea, kidneys, adrenal glands, testes, intestines, and pancreas. These organisms were seen free in the organs' stroma or within macrophages and stained positively with polyclonal antiserum to T. gondii. Genomic DNA was extracted from the tissues and PCR was used to target the B1 gene of T. gondii. The genotypic characterization by PCR-RFLP with 11 markers (SAG1, SAG2 and alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3) revealed the ToxoDB-PCR-RFLP #87 genotype, the same as previously identified in a backyard chicken (TgCkBr156) in Rio Grande do Sul, Brazil

Analysis of the influence of PTPN22 gene polymorphisms in systemic sclerosis

Contains fulltext : 96632.pdf (publisher's version ) (Closed access)OBJECTIVE: Two functional single nucleotide polymorphisms (SNP) in the PTPN22 gene (rs24746601 and rs33996649) have been associated with autoimmunity. The aim of this study was to investigate the role of the R263Q SNP for the first time and to re-evaluate the role of the R620W SNP in the genetic predisposition to systemic sclerosis (SSc) susceptibility and clinical phenotypes. METHODS: 3422 SSc patients (2020 with limited cutaneous SSc and 1208 with diffuse cutaneous SSc) and 3638 healthy controls of Caucasian ancestry from an initial case--control set of Spain and seven additional independent replication cohorts were included in our study. Both rs33996649 and rs2476601 PTPN22 polymorphisms were genotyped by TaqMan allelic discrimination assay. A meta-analysis was performed to test the overall effect of these PTPN22 polymorphisms in SSc. RESULTS: The meta-analysis revealed evidence of association of the rs2476601 T allele with SSc susceptibility (p(FDRcorrected)=0.03 pooled, OR 1.15, 95% CI 1.03 to 1.28). In addition, the rs2476601 T allele was significantly associated with anticentromere-positive status (p(FDRcorrected)=0.02 pooled, OR 1.22, 95% CI 1.05 to 1.42). Although the rs33996649 A allele was significantly associated with SSc in the Spanish population (p(FDRcorrected)=0.04, OR 0.58, 95% CI 0.36 to 0.92), this association was not confirmed in the meta-analysis (p=0.36 pooled, OR 0.89, 95% CI 0.72 to 1.1). CONCLUSION: The study suggests that the PTPN22 R620W polymorphism influences SSc genetic susceptibility but the novel R263Q genetic variant does not. These data strengthen evidence that the R620W mutation is a common risk factor in autoimmune diseases