Brucellosis is still a widespread zoonotic disease. Very little is known about the interaction betweenBrucella abortus and trophoblastic cells, which is essential for better understanding the pathogenesis of the Brucella-induced placentitis and abortion, a key event for transmission of the disease. The goal of this study was to evaluate the profile of gene expression by bovine trophoblastic cells during infection with B. abortus. Explants of chorioallantoic membranes were inoculated with B. abortus strain 2308. Microarray analysis was performed at 4 h after infection, and expression of cytokines and chemokines by trophoblastic cells was assessed by real-time reverse transcription-PCR at 6 and 12 h after inoculation. In addition, cytokine and chemokine expression in placentomes from experimentally infected cows was evaluated. Expression of proinflammatory genes by trophoblastic cells was suppressed at 4 h after inoculation, whereas a significant upregulation of CXC chemokines, namely, CXCL6 (GCP-2) and CXCL8 (interleukin 8), was observed at 12 but not at 6 h after inoculation. Placentomes of experimentally infected cows had a similar profile of chemokine expression, with upregulation of CXCL6 and CXCL8. Our data indicate that B. abortus modulates the innate immune response by trophoblastic cells, suppressing the expression of proinflammatory mediators during the early stages of infection that is followed by a delayed and mild expression of proinflammatory chemokines, which is similar to the profile of chemokine expression in the placentomes of experimentally infected cows. This trophoblastic response is likely to contribute to the pathogenesis of B. abortus-induced placentitis.Brucella abortus is a facultative intracellular gram-negative bacterium that causes abortion and temporary infertility in cattle (13,19,29). It is also a zoonotic pathogen causing fever, weakness, endocarditis, arthritis, osteomyelitis, and meningitis in humans (51). In cattle, the infection tends to be chronic with tropism for the reproductive system of pregnant cows. Abortion is the most significant clinical sign, but an infected cow may be completely asymptomatic. Transmission of the disease occurs mainly after abortion or parturition of infected cows via contaminated fetus, fetal membranes, and uterine secretions (8,37,38). During the early stages of infection, B. abortus is found mostly in lymph nodes. The infection may progress to bacteremia and colonization of the uterus, where the organism replicates preferentially within trophoblasts in the rough endoplasmic reticulum (9, 10, 29). As a result, the cow develops placentitis, fetal death, and abortion, particularly during the last third of the gestation (2). B. abortus grows primarily in the extracotyledonary trophoblasts and then spreads to the cotyledonary (placental) trophoblasts (3). Therefore, proliferation of B. abortus within trophoblastic cells is a key event in the mechanism of abortion. Trophoblasts favor bacterial growth by producing erythritol and progesterone, which stimu...

Pesq. Vet. Bras. 31(4): 336-344, abril 2011 RESUMO.-A presente atualização trata de duas das mais importantes doenças sexualmente transmitidas de bovinos, a campilobacteriose genital bovina e a tricomonose genital bovina. São abordados aspectos relacionados à epidemiologia destas doenças, principalmente em relação a sua distribuição no Brasil. Também são revisados aspectos importantes de diagnóstico, incluindo as técnicas e interpretação dos resultados, além de medidas de controle para ambas as doenças. INTRODUÇÃOA campilobacteriose genital bovina (CGB) e a tricomonose genital bovina (TGB) são doenças infecto-contagiosas de transmissão sexual, que acometem bovinos em idade reprodutiva e causam grandes perdas econômicas em decorrência dos problemas reprodutivos desencadeados (Dekeyser 1984, Goodger & Skirrow 1986 The present update deals with two of the most important sexually transmitted diseases of cattle: bovine genital campylobacteriosis and bovine genital trichomonosis. Epidemiological aspects, mainly their distribution in Brazil, alongside with their diagnosis in cattle are presented and commented. The main points in their diagnoses, including the description of the techniques and the interpretation of the results are also reviewed. Finally the control and prevention of both diseases are discussed.

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O objetivo nesta revisão é mostrar os principais avanços científicos obtidos na área da reprodução animal e como estes podem afetar a eficiência reprodutiva e produtiva do rebanho bovino brasileiro. Com o conhecimento dos mecanismos envolvidos no controle da fisiologia reprodutiva, em níveis endócrino, celular e molecular, foi possível o desenvolvimento das biotécnicas reprodutivas, destacando-se a IATF, que tem sido utilizada em larga escala, por permitir a multiplicação de animais superiores geneticamente, aumentar a taxa de natalidade e ser eficaz no ajuste da estação reprodutiva notadamente em pecuária de corte. Outras biotécnicas, como a TE, PIVE, clonagem e transgênese, também são fundamentais no desenvolvimento de pesquisas de ciência básica, medicina e preservação animal. São apresentados também os principais fatores de manejo reprodutivo nutricional e sanitário que afetam a produtividade da pecuária leiteira. Contudo, o incentivo às pesquisas é fundamental para que estas biotécnicas sejam aprimoradas e continuem auxiliando o desenvolvimento da pecuária nacional.

The antimicrobial susceptibility of 25 Campylobacter sp strains isolated from calves with and without diarrhea -7 C. coli, 16 C. fetus and 2 C. jejuni -was studied by the disk diffusion method. Eleven antimicrobial agents were tested amikacin, ampicillin, kanamycin, chloramphenicol, erythromycin, gentamicin, neomycin, nitrofurantoin, penicillin G, tetracycline and sulfamethoxazole-trimethoprim. All Campylobacter sp strains were susceptible to amikacin, ampicillin, chloramphenicol, erythromycin, gentamicin, neomycin and nitrofurantoin. Three strains were moderately susceptible to kanamycin (2 C. coli and 1 C. fetus). All the strains were resistant to penicillin G. Two C. fetus strains were moderately susceptible to sulfamethoxazoletrimethoprim and 1 C. coli, 9 C. fetus and 2 C. jejuni strains were resistant. Two C. fetus strains were moderately susceptible to tetracycline and 3 C. coli, 2 C. fetus and 1 C. jejuni strains were resistant. Eleven strains showed multidrug resistance (2 C. coli, 8 C. fetus and 1 C. jejuni). There was no correlation between resistance of Campylobacter sp strains to antimicrobials and the occurrence of diarrhea in calves. The frequency of resistance and, most importantly, multi drug resistance found among Campylobacter sp strains isolated from calves in Minas Gerais, Brazil, were high and the patterns of resistance observed are related to the antimicrobials agents most largely used in cattle in Brazil.

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