RESUMO
Leishmania chagasi, the agent of visceral leishmaniasis in dogs in the Americas has a tropism to the male genital system, particularly the epididymis, prepuce, and glans penis, resulting in shedding of Leishmania in the semen. The goal of this study was to verify the possibility of venereal transmission of L. chagasi. Twelve Leishmania-free bitches, housed in the absence of the insect vector, copulated with multiple naturally infected dogs that were shedding Leishmania in the semen. PCR analysis of serially collected ejaculates indicated that shedding of Leishmania in the semen is intermittent. Three bitches seroconverted, and six were PCR positive by the end of the experimental period (165 days after the last copulation). These data support the notion that L. chagasi may be sexually transmitted from naturally infected dogs to susceptible bitches in the absence of the biological insect vector.
Assuntos
Doenças do Cão/transmissão , Leishmaniose Visceral/veterinária , Infecções Sexualmente Transmissíveis/veterinária , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Leishmania/isolamento & purificação , Leishmaniose Visceral/transmissão , Masculino , Sêmen/parasitologia , Infecções Sexualmente Transmissíveis/parasitologiaRESUMO
Nramp1 (Slc11a1) is linked to resistance to Leishmania in mice, but its role in canine leishmaniasis is not clear. In this study we sequenced the Nramp1 cDNA from dogs whose macrophages allowed or restricted intracellular growth of Leishmania chagasi. Peripheral blood monocyte-derived macrophages were isolated from 29 dogs, cultured and inoculated with L. chagasi. This approach resulted in the identification of dogs whose macrophages were resistant or susceptible to L. chagasi. Nramp1 cDNA sequences of these dogs were identical. mRNA levels of Nramp1, IFNgamma, IL-4 and the subunit p35 of IL-12 were assessed in the spleen of naturally infected symptomatic and asymptomatic dogs in comparison to uninfected controls. Although not statistically significant, asymptomatic dogs had a tendency for higher levels of Nramp1 mRNA (p = 0.11). Expression of Nramp1 was then compared between phenotypically resistant and susceptible dogs, without any significant difference between these groups.
Assuntos
Proteínas de Transporte de Cátions/genética , DNA Complementar/genética , Doenças do Cão/genética , Predisposição Genética para Doença , Leishmaniose Visceral/veterinária , Animais , Sequência de Bases , Proteínas de Transporte de Cátions/imunologia , Cães , Regulação da Expressão Gênica/imunologia , Leishmaniose Visceral/genética , Leishmaniose Visceral/imunologia , Macrófagos/parasitologiaRESUMO
Recent reports indicate that Leishmania chagasi has tropism to the male canine genital system, which is associated with shedding of the organism in the semen, supporting the hypothesis of venereal transmission. The aim of this study was to describe the lesions and assess parasite load in the genital system of bitches with canine visceral leishmaniasis (CanL). Symptomatic (n=5) and asymptomatic (n=5) bitches seropositive for CanL were randomly selected at the Center for Zoonosis Control (Belo Horizonte, State of Minas Gerais, Brazil). Five serologically negative, healthy, adult bitches also from the CZC were used as controls. Samples from genital organs (vulva, vagina, cervix, uterine body, uterine horns, uterine tubes, and ovaries), liver, and spleen were histologically evaluated and processed for immunodetection of Leishmania sp., and PCR. The most significant histological change was a mild to moderate vulvar dermatitis, characterized by a histio-plasma-lymphocytic infiltrate. This change was detected in all asymptomatic, four symptomatic, and three uninfected control bitches. In one symptomatic and one asymptomatic bitch intracytoplasmic amastigotes were observed within macrophages in the inflammatory infiltrate. Samples from all the segments of the genital tract were positive in at least one infected animal, in the absence of detectable amastigotes in the tissue. These findings support the notion that L. chagasi does not have genital tropism in the bitch, which is in contrast to our previous findings in naturally infected male intact dogs.
Assuntos
Doenças do Cão/transmissão , Doenças dos Genitais Femininos/veterinária , Genitália Feminina/parasitologia , Leishmania infantum/patogenicidade , Leishmaniose Visceral/veterinária , Animais , DNA de Protozoário/análise , Transmissão de Doença Infecciosa/veterinária , Doenças do Cão/patologia , Cães , Feminino , Doenças dos Genitais Femininos/parasitologia , Doenças dos Genitais Femininos/patologia , Doenças dos Genitais Masculinos/parasitologia , Doenças dos Genitais Masculinos/patologia , Doenças dos Genitais Masculinos/veterinária , Genitália Feminina/patologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/patologia , Leishmaniose Visceral/transmissão , Masculino , Sêmen/parasitologiaRESUMO
This report describes a case of insulin-secreting pancreatic beta cell carcinoma in a crab-eating fox (Cerdocyon thous). The animal died approximately 60 days after the first clinical signs. At necropsy, a nodule (2 x 3 cm) was observed in the pancreas. Microscopic features were consistent with a pancreatic islet cell carcinoma. By immunohistochemistry, neoplastic cells were strongly positive for insulin and synaptophysin while negative for glucagon. These results supported the diagnosis of insulinoma, which to the best of our knowledge is the first documented case of this tumor in a crab-eating fox.