Evaluation of response to anti-leptospira bacterin vaccination in pregnant ewes and the passive transfer of antibodies to their offspring

Leptospirosis in sheep is often underestimated, and leads to great economic losses for the sheep farming industry. The aim of this study was to evaluate the humoral immune response in pregnant ewes, after the injection of a commercial polyvalent vaccine for leptospirosis, and to observe the transmission of anti-Leptospira antibodies through the colostrum to the offspring. For this, 24 pregnant ewes were vaccinated for leptospirosis.  Blood samples were collected prior to vaccination and then 7, 14, 21, 28, 35, 42 and 49 days after vaccination. In order to evaluate passive immunity transfer, blood samples of 32 lambs were collected during the first 48 hours after birth, and another collection was performed 10 to 21 days after birth. The lambs were placed into 2 groups: Group A (n=16): singleton lambs; and group B (n=16): twins. The sera samples were submitted to the Microscopic Agglutination Test (MAT), in which 21 Leptospira serovars were tested. The results were analyzed in a descriptive form. The number of sheep reactive to MAT gradually increased until 21 days after vaccination, and decreased right after. Of all the serovars contained in the vaccine, the largest proportion of animals were seroconverted to Hardjoprajtino serovar, Serjoe serogroup. Anti-Leptospira antibodies transferred through colostrum to lambs were detected by MAT in the serum collected 24-48 hours after birth.  It was observed that 65.6% (21 out of 32) of the lambs were reactive. In the subsequent collections that occurred from 10 to 21 days after birth, a decrease in the number of animals reactive to the MAT was detected. There was no significant statistical difference for the passive transfer of antibodies between single or twin lambs

Detection of Enterobacteriaceae and evaluation of the antimicrobial resistance profile of isolated strains from swine\'s oral fluid

O monitoramento de doenças na suinocultura é muito importante para manter o bem-estar animal e aumentar a produtividade. O fluido oral tem sido apresentado como uma amostra biológica alternativa para a detecção de patógenos e anticorpos. Apesar de muitos estudos descreverem o uso dessa amostra para detecção de agentes virais, pouco tem sido aplicado para o monitoramento de doenças bacterianas de importância na saúde pública. Este trabalho avaliou o isolamento de Escherichia coli e Salmonella enterica subsp. enterica através do fluido oral de suínos, assim como avaliou o perfil de resistência das cepas isoladas e a presença de genes de toxinas de E. coli enterotoxigênica (ETEC), em cinco granjas comerciais de ciclo completo do Estado de São Paulo. Não houve resultados de isolamento de Salmonella enterica subsp. enterica através dos protocolos de cultura, assim como não houve detecção de genes de Salmonella spp. por PCR convencional. Não houve diferença entre os isolamentos de E. coli realizados através de fezes e fluido oral (P>0,05), e os mesmos obtiveram resistência à antimicrobianos importantes para a saúde humana. Sugere-se assim que o fluido oral possa ser utilizado como amostra biológica para a monitoria sanitária de E. coli, e ressalta-se a importância do monitoramento do perfil de resistência de cepas isoladas como indicadores do impacto do uso de antimicrobianos nas produções animais.The screening of diseases in swine production is very important to maintaining animal welfare and increasing productivity. The oral fluid has been shown as an alternative biological sample for detecting pathogens and antibodies. Although many studies have described the utilization of this sample for viral agents, little has been applied in monitoring bacteria diseases of public health importance. This study tested the isolation of Escherichia coli and Salmonella enterica subsp. enterica from pigs\' oral fluid, and evaluated the antimicrobial resistance profile of the isolated strains, as well as the presence of virulence genes of enterotoxigenic E. coli (ETEC) from five swine farms in the state of Sao Paulo, Brazil. There was no isolation of Salmonella enterica subsp. enterica through the protocols tested, neither there was detection of Salmonella spp. genes through conventional PCR. There was no difference when comparing the isolation of E. coli from feces and oral fluid (P>0,05), and the isolates showed resistance to important antimicrobial formulas in human health. We suggest that oral fluid can be used as a biological sample for the detection of E. coli, and we highlight the importance of monitoring the resistance of isolated strains as an indicator of antimicrobial usage in animal husbandry