Os protozoários Neospora caninum e N. hughesi infectam os equinos e podem provocar diferentes sinais clínicos associados a problemas reprodutivos ou a distúrbios neurológicos, respectivamente. A patogenia da neosporose é pouco conhecida nos equinos, bem como as fontes de infecção horizontal de N. hughesi. Além disso, há dúvidas quanto ao papel da transmissão vertical de Neospora spp. na sua manutenção em populações equinas. Neste estudo avaliaram-se: (1) a ocorrência da infecção por Neospora spp. na população de éguas em idade reprodutiva em um haras de cavalos da raça Crioula; e (2) a possível associação entre o status sorológico destas éguas com o de suas crias, como meio de investigar, indiretamente, a relevância da transmissão transplacentária na ocorrência da infecção por Neospora spp. nestes animais. A associação entre o status sorológico das éguas e o de suas crias foi altamente significativa. Os animais descendentes de éguas soropositivas tiveram maior ocorrência de anticorpos anti-Neospora spp. do que os descendentes de éguas soronegativas, embora expostos aos mesmos fatores de risco ambientais. A associação entre parentesco em primeiro grau e status sorológico indica a influência da infecção vertical (transplacentária) na ocorrência de Neospora spp. na população equina estudada.

A infestação por carrapatos em bovinos é responsável por perdas econômicas significativas à indústria animal em várias regiões brasileiras, incluindo o Rio

No abstract

Neospora caninum (Apicomplexa, Sarcocystidae) é um protozoário de grande relevância para a bovinocultura por estar envolvido com problemas reprodutivos, sendo considerado um dos principais agentes determinantes de abortos em bovinos (Anderson et al., 1991). A infecção é caracterizada por perdas reprodutivas em fêmeas, podendo determinar morte embrionária durante o primeiro terço da gestação e abortos durante o segundo. No terço final da gestação, a infecção dificilmente resulta em morte fetal e abortos, mas sim em nascimento de bezerros persistentemente infectados (PI), o que também pode ocorrer no segundo terço gestacional. Os animais PI, clinicamente normais, são soropositivos e abrigam o parasito encistado em vários tecidos, sendo, dessa forma, considerados portadores do agente.Apresentam grande importância epidemiológica ao manterem o agente no rebanho (Dubey, 2003). A possível reativação da infecção em fêmeas prenhes persistentemente infectadas, provavelmente, está relacionada à imunossupressão fisiológica da gestação e pode resultar em transmissão transplacentária do agente ao feto. Na maioria dos animais, a infecção não é capaz de induzir imunidade protetora, e as consequências reprodutivas da infecção podem ocorrer repetidas vezes durante a vida dos animais infectados (Innes et al., 2002

Pesq. Vet. Bras. 33(3):331-338, março 2013 331 RESUMO.-[Recombinante do herpesvírus bovino tipo 5 com deleção na timidina quinase estabelece infecção latente porém reativa ineficientemente em ovinos.] A capacidade de um recombinante do herpesvírus bovino tipo 5 com deleção no gene da timidina quinase (BoHV-5tk∆) em estabelecer e reativar infecção latente foi investigada em cordeiros. Durante a infecção aguda, o vírus recombinante replicou na mucosa nasal em títulos moderados, porém menores do que os da cepa parental. Aos 40 dias pós-infecção (pi) DNA viral latente foi detectado no gânglio trigêmeo (TG) The ability of thymidine kinase (tk)-deleted recombinant bovine herpesvirus 5 (BoHV--5tkD) to establish and reactivate latent infection was investigated in lambs. During acute infection, the recombinant virus replicated moderately in the nasal mucosa, yet to lower titers than the parental strain. At day 40 post-infection (pi), latent viral DNA was detected in trigeminal ganglia (TG) of all lambs in both groups. However, the amount of recombinant viral DNA in TGs was lower (9.7-fold less) than that of the parental virus as determined by quantitative real time PCR. Thus, tk deletion had no apparent effect on the frequency of latent infection but reduced colonization of TG. Upon dexamethasone (Dx) administration at day 40 pi, lambs inoculated with parental virus shed infectious virus in nasal secretions, contrasting with lack of infectivity in secretions of lambs inoculated with the recombinant virus. Nevertheless, some nasal swabs from the recombinant virus group were positive for viral DNA by PCR, indicating low levels of reactivation. Thus, BoHV-5 TK activity is not required for establishment of latency, but seems critical for efficient virus reactivation upon Dx treatment.INDEX TERMS: BoHV-5, recombinant, TK, latency, qPCR. minação por PCR em tempo real. Assim, a deleção do gene tk (timidina quinase) não produziu efeito aparente sobre a frequência da infecção latente, porém reduziu a colonização do TG. Após a administração de dexametasona (Dx) no dia 40pi, os cordeiros inoculados com o vírus parental excretaram partículas virais infecciosas, contrastando com a falta de infectividade nas secreções nasais dos animais inoculados com o vírus recombinante. Entretanto, alguns suabes nasais dos cordeiros do grupo do vírus recombinante foram positivos para o DNA viral por PCR, indicando baixos níveis de reativação. Assim, a atividade da enzima timidina quinase não é requerida para o estabelecimento de latência pelo BoHV-5, mas parece fundamental para reativação eficiente da infecção latente após tratamento com Dx.

Background: Balantidium coli is a commensal protozoan that infects several animals, but it has pigs as its natural reservoir. In the presence of predisposing factors, B. coli can become pathogenic for swine, causing enteric lesions. Infections determined by this protozoan may be a risk to public health, due to dysentery in animal keepers and veterinarians. This study aimed to determine the occurrence of infection by B. coli in pigs of distinct husbandry categories, as well as unlike physiological state, kept in farms with different hygienic-sanitary standards, located in the central region of Rio Grande do Sul State in Brazil.Materials, Methods & Results: Stool samples were collected from 12 different farms with different hygienic-sanitary standards being four farms of finisher pigs (G1; n = 287), four farms with pregnant females (G2; n = 60) and four farms with lactation sows (G3;  n = 40), and all samples were submitted to coproparasitological analyses to verify the presence of cysts or trophozoites of B. coli. The infection levels were considered mild (1-100 cyst/trophozoite), moderate (101300 cyst/trophozoite) and high (>300 cysts/trophozoite). In addition, information about hygienic-sanitary conditions of each farm was collected. The occurrence of B. coli infection in all swine stool samples analyzed was 60.9% (236/387); however, in G1, G2 and G3 was 54.7% (157/287), 91.7% (55/60) and 65% (26/40) respectively. There was significant difference in the occurrence of G1 (P < 0.05) except between farms B and C (67.9% and 56.6% respectively). There was also a significant difference (P < 0.05) between the occurrence of B. coli found in G2 and G3. The infection levels were considered predominantly mild in G1; and mild to moderate in G2 and G3.Discussion: In this research it was confirmed the presence of B. coli in swine farms located in the central region of Rio Grande do Sul State in Brazil. This area is known as being an important producer of pigs in Brazil. The results obtained in this study, demonstrated that swine farms with better hygienic and sanitary standards, had mild infections by B. coli. However, the presence of intestinal parasites, especially protozoa, can occur even in properties with good management practices. However, protozoa infections can cause important production losses, especially when associated with other pathogens or nutritional problems. The occurrence of B. coli observed in pregnant (G2) and lactating (G3) females was significant, and the infection level was mild to moderate. These conditions suggest that pregnancy, childbirth and lactation are critical stages for females, mainly due to physiological stress, resulting in a change in the hormonal levels and immune status of the animals. Thus, these factors cause declines in the immune response of pigs making them susceptible to infections and the increase of cyst excretion of B. coli in feces. The abundance of protozoan cysts in feces contaminates the environment and increases the risk of infections in humans. In addition, it was demonstrated the occurrence of B. coli in an important site of swine production in RS, Brazil. B. coli is related to the physiological state of the animals and the hygienic and sanitary management in different categories of swine. In conclusion, this study highlights the epidemiological importance of swine as natural reservoir of Balantidium coli and the risk potential of infection to animals and humans. Additionally, sanitary program in farming pigs must be improved in order to guarantee healthy and food-safe product for consumers.

The clinical signs of infection in dogs with Neospora caninum are usually associated with neurological disorders and are seen in young dogs. In this brief case report we observed multifocal ulcerative and exudative skin nodules on the neck and pelvic limbs of a 10-year-old cocker spaniel dog. Infection with N. caninum was diagnosed on the basis of cytology and examination of skin tissues by PCR. The dog initially responded to treatment with clindamycin and then relapsed; the dog died. Infection with N. caninum may have been due in part to immune suppression due to hyperadrenocorticism; which either allowed for the development of a primary infection or reactivation of a latent infection by N. caninum with the occurrence of skin lesions.

The aim of this study was to examine the intra-uterine exposure to Sarcocystis spp. antigens, determining the number of foals with detectable concentrations of antibodies against these agents in the serum, before colostrum ingestion and collect data about exposure of horses to the parasite. Serum samples were collected from 195 thoroughbred mares and their newborns in two farms from southern Brazil. Parasite specific antibody responses to Sarcocystis antigens were detected using the indirect immunofluorescent antibody test (IFAT) and immunoblot analysis. In 84.1% (159/189) of the pregnant mares and in 7.4% (14/189) of foals we detected antibodies anti-Sarcocystis spp. by IFAT. All samples seropositive from foals were also positive in their respective mares. Serum samples of seropositive foals by IFAT, showed no reactivity on the immunoblot, having as antigens S. neurona merozoites. In conclusion, the intrauterine exposure to Sarcocystis spp. antigens in horses was demonstrated, with occurrence not only in mares, but also in their foals, before colostrum ingestion these occurrences were reduced.