Improvement of Leptospira spp. diagnosis in aborted bovine fetuses by qPCR.

Leptospirosis is a disease with major economic impact on livestock industry. The objective of this work was to determine the presence of Leptospira spp. DNA by qPCR in bovine fetuses with presumptive diagnosis of leptospirosis as the cause of abortion. Leptospira spp. DNA was detected by qPCR in 11 out of 34 fetuses. These specimens (10/11) had histopathological findings in hepatic and/or renal tissues compatible with leptospirosis. qPCR detection rate (32.4 %) was higher compared with direct immuno-fluorescence antibody test (DFAT) (11.8 %). The concordance coefficient between both techniques was 0.44. qPCR is a rapid and sensitive technique for the diagnosis of leptospirosis and improved the detection rate in fetal tissues compared with DFAT. Implementation of molecular techniques may increase the accurate detection of leptospirosis as a cause of bovine abortion allowing the application of rapid therapeutic and prophylactics measures in order to reduce the impact of this zoonotic disease.

Effect of time of gestation on fatty acid transporters mrna expression in bovine placenta / Efeito do tempo de gestação em expressão de arnm de transportadores de ácidos graxos mrna em placenta bovinos

The objective of the study was to evaluate the effect of time of gestation on fatty acid transporter mRNA expression in maternal and fetal bovine placenta. Placentas from twelve cows at different thirds of gestation (n=4 per third) were sampled at slaughter to measure FATP-1, FATP-4, FABP-1 mRNA concentration in maternal (caruncles) and fetal (cotyledons) side. Once the placenta was removed, 1cm2 was dissected and, divided into caruncles and cotyledons, stored in sterile tubes, dropped into liquid nitrogen and kept at -80° C until rtPCR analysis. Data were analyzed as a complete randomized design with a 3 x 2 factorial arrangement, using the mixed procedure (SAS 9.3) with repeated measurements on space. Time of gestation, side of the placenta and their interaction were fixed factors, whereas animal was a random factor. There was a time by treatment interaction (P < 0.01) on FATP-1 mRNA expression due to a greater mRNA expression in cotyledons on the first third of gestation as compared with the concentration in caruncles. On the second and third stages of gestation, the mRNA concentration in cotyledons decreased, reaching a similar concentration to that observed in caruncles. Fatty acid transport protein -4 and FABP-1 mRNA concentration were not different (P >0.1). We conclude that FATP-1 might play an important role in fatty acid transport during early fetal development.

O objetivo do estudo foi avaliar o efeito do tempo de gestação na expressão de mRNA de transportador de ácidos graxos em placenta bovina materna e fetal. Foram colhidas amostras de placentas de 12 vacas em diferentes terços da gestação (n = 4 por terço) no abatedouro para medir a expressão de mRNA de FATP-1, FATP-4, FABP-1 no lado materno (carúnculos) e fetal (cotilédones). Uma vez que a placenta foi removida, 1 cm2 foi dissecado e, dividido em carúnculos e cotilédones, armazenado em tubos estéreis, caiu em nitrogenio líquido e mantido a -80 ° C até a análise rtPCR. Os dados foram analisados como um delineamento inteiramente casualizado com esquema fatorial 3 x 2, utilizando o procedimento misto (SAS 9.3) com medidas repetidas no espaço. O tempo de gestação, o lado da placenta e sua interação foram fatores fixos, enquanto que o animal foi um fator aleatório. Houve um tempo de interação do tratamento (P <0,01) na expressão de mRNA de FATP-1 devido a uma maior expressão de mRNA em cotilédones no primeiro terço da gestação em comparação com a concentração em carúnculas. No segundo e terceiro terços da gestação, a expressão de mRNA nos cotilédones diminuiu, atingindo uma expressão semelhante à observada em carúnculas. A proteína de transporte de ácidos graxos 4 e a expressão de mRNA de FABP-1 não foram diferentes (P> 0,1). Concluímos que a FATP-1 poderia desempenhar um papel importante no transporte de ácidos graxos durante o desenvolvimento fetal precoce.