Detecção de DNA leptospiral em amostras de urina de bovinos assintomáticos abatidos em frigorífico de Pelotas (RS)

Abstract

Leptospirosis is a zoonosis caused by spirochetes of the Leptospira genus. In Brazil, bovine leptospirosis is endemic and considered a disease that causes severe economic losses in herds. Microscopic agglutination test (MAT) remains the reference test for the diagnosis of leptospirosis but is inadequate for the detection of carrier cattle status. Thus, the objective of this work was to perform a Polymerase Chain Reaction (PCR) to detect leptospiral DNA in the urine of asymptomatic cattle slaughtered in Pelotas city. To perform PCR, 123 urine samples were collected from asymptomatic cattle belonging to eight municipalities in the southern region of the State of Rio Grande do Sul (RS). Genomic DNA (gDNA) was extracted using the Brazol method, following the manufacturer's instructions and PCR was used for amplification of genes encoding for the outer membrane protein LipL32 and for the 16S fraction of the ribosome (16SRNA) of leptospires. After amplification, the samples obtained were submitted to electropherosis and the result was evaluated in a transilluminator. Of the 123 samples, 20 (16.3%) amplified gDNA encoding for LipL32 protein and 23 (18.7%) amplified for 16SRNA. This work reveals important insights into a one health context that bovines slaughtered in Pelotas city may be a potential source of leptospirosis for humans, animals and environment. Moreover, PCR in the format employed here may be used for the leptospiral DNA detection in asymptomatic beef cattle in slaughterhouse of Pelotas.