BackgroundEndogamy increases the risk of manifestation of deleterious recessive genes. Mitochondrial DNA allows the separation of American Zebu (Bos indicus and Bos taurus) and evaluate the effect of mitochondrial DNA on productive traits of cattle. However, the effect of endogamy and mitochondrial DNA (mtDNA) on the immune system remains unclear. The aim of this study was to evaluate the association between endogamy, mtDNA and immune parameters.ResultsA total of 86 cattle (43 cows and 43 calves) were used in this study. Age, endogamy, milk yield, and origin of mtDNA were measured and their influence on immunological parameters was evaluated. Older cows had increased CD4+ T cells, decreased CD21+ and γδhigh T cells as well as increased CD4+/CD8+ and T/B ratio. Multiple regression analysis indicated that endogamy in calves was associated with increased CD8+ T and CD21+ B lymphocytes, and decreased γδhigh T cells in peripheral blood. Cows with medium and lower endogamy had a lower percentage of B lymphocytes and γδlow T cells and cows with lower endogamy had higher levels of γδ T cells and γδhigh T cells, as well as the CD4+/CD48+ cell ratio. Calves with higher endogamy had higher levels of CD8+ T lymphocytes, whereas calves with lower endogamy had lower levels of γδlow T cells.ConclusionsThese results demonstrated for the first time that endogamy influences the immune system of cattle.

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The production of nitric oxide (NO) by macrophages is important for the killing of intracellular pathogens, such as Toxoplasma gondii. Gamma interferon (IFN-gamma) and lipopolysaccharide stimulate NO production. The aim of this study was to investigate the importance of NO, IFN-gamma and interleukin-12 (IL-12) in the host immune response in AIDS patients suffering from toxoplasmic encephalitis (TE). It was demonstrated that the production of NO, detected as nitrite/nitrate in the sera and in the cerebrospinal fluid (CSF) of 32 AIDS patients with TE, was normal. In addition, levels of IFN-gamma in the sera and in the CSF of patients with TE were not increased. In contrast, serum levels of IL-12 in these patients were significantly increased (6.5 +/- 7.1 pg/ml; P = 0.0368), compared to the control patients (1.7 +/- 3.5 pg/ml). Furthermore, increased but not significant levels of IL-12 were also observed in the CSF of patients with TE (2.2 +/- 4.7 pg/ml; controls: 0.5 +/- 1.9 pg/ml). The results of this study indicate that reactivation or recurrence of T. gondii infection in HIV-1-infected patients is probably due to a down-regulation of IFN-gamma along with a resulting non-optimal NO activity.

BackgroundTrypanosomiasis is a disease caused by Trypanosoma (Dutonella) vivax, a hemoprotozoa that can affect bovines. In South America, the sanguineous form is mechanically transmitted from one mammalian host (ruminant) to another by the bite of a blood-sucking insect or by needles contaminated with infected blood. The negative impact of the parasitosis caused by T. vivax infection on the reproductive activity of male and female ruminants is known to reduce fertility. In males, alterations such as degeneration, diffuse or interlobular inflammatory infiltrate found in ovine and bovine testicles, can affect fertility through decreased sperm quality. This study evaluated the impact of natural infection with T. vivax on Zebu bulls from the Central Station of Artificial Insemination (CSAI) with regard to libido and the negative effects caused by this protozoan on semen quality.MethodsBlood samples of 44 animals were collected to evaluate the presence of the trypomastigote form of T. vivax in blood smears obtained from hematocrit and buffy coat, and antibody titer IgG anti T. vivax in indirect Immunoflorescence (IFI). Furthermore, data related to libido, ejaculate volume, spermatic concentration, and seminal vigor were recorded for these animals employing the criteria of the CSAI.ResultsNine animals (20.45 %) showed T. vivax trypomastigotes and parasitemia between 0.02 and 0.07, and antibody titers from 1:80 to 1:320 in IFI. Twenty nine negative animals in parasitological tests were not reactive in IFI, and six animals presented the antibodies IgG anti T. vivax in IFI. Data on reproductive activity showed that animals infected with T. vivax have a decreased libido and an increased spermatic volume, whereas other factors related to the reproductive process such as spermatic concentration, motility and spermatic force, were unchanged in infected bulls.ConclusionsThe T. vivax infection in Zebu bulls from CSAI caused patent parasitemia, induced a febrile state, promoted reduction in the libido and increased the ejaculate volume. These conditions together may account to decrease the performance of these animals.

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In this chapter, we describe relevant aspects of immunoglobulin Y (IgY) technology for Toxoplasma gondii applications, including comparison of avian IgY antibody with mammalian IgG antibody, egg yolk IgY production and isolation procedures, important applications for IgY antibody, and state of the art and perspectives for IgY-technology in T. gondii studies. T. gondii is a worldwide public health problem. IgY-technology provides an alternative antibody (IgY) to mammalian Immunoglobulin G (IgG) antibody. IgY-technology involves the chicken immunization, yolk IgY isolation, antibody characterization, and purified IgY application to several kinds of methods. Immunized chicken transfers a specific IgY from blood to egg yolk. Phylogenetic distance between chickens and mammals influences the generation of antibody repertoires recognizing an antigen profile. IgY is not bound to rheumatoid factor or mammalian complement protein and thus avoids the false-positive results. Yolk IgY isolation is carried out by simple procedures that are accessible for any laboratory and, also, for IgY isolation at large-scale production. IgY-technology provides antibodies for proteomic studies, diagnostic assays, and immunotherapy. Although IgY-technology is promising, there is a reduced number of investigations with IgY and T. gondii. Future perspectives involve the use of IgY-technology for the screening of new T. gondii antigens for diagnostics, therapy, or vaccine, development of innovative techniques for toxoplasmosis diagnostics and may be an immunotherapy for toxoplasmosis.

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Os microrganismos presentes no trato reprodutivo dos bovinos podem contaminar o sêmen e reduzir o número e a qualidade dos embriões produzidos, resultando em doenças nas receptoras e nos animais nascidos. O macho sendo a fonte de infecção pode desencadear a transmissão direta porém, outros meios de contaminação não podem ser descartadas como: o meio ambiente; a manipulação pelo funcionário; e a água utilizada na preparação do diluente. O presente trabalho teve como objetivo detectar os principais agentes presentes em sêmens comerciais avaliados em espermoculturas e o número de unidades formadoras de colônias por mL (UFC/mL). Foi realizado um estudo retrospectivo, através dos registros de resultados de espermoculturas mantidos no Unidades Formadoras de Colônias/mL (UFC/mL). Fator preocupante, pois estudos da literatura relacionada demonstram que para permitir uma taxa de concepção satisfatória, a faixa aceitável de contaminação é de até 500 UFC/mL. O presente estudo mostra a importância de investigar os tipos de microrganismo presente nas amostras durante todo o processo de industrialização do sêmen, para que assim se descubra as fases de contaminação e estabeleça medidas de controle com o objetivo de minimizar os prejuízos financeiros e a saúde dos animais.