Detection of leptospires in clinically healthy piglets born from sows experimentally infected with Leptospira interrogans serovar Canicola

Brazilian Journal of Microbiology

Francisco Rafael M. Soto²  Sérgio Santos De Azevedo¹  Zenaide Maria De Morais²  Sônia Regina Pinheiro²  Ádina Cléia B. Delbem²  Andréa Micke Moreno²  Renata Paixão²  Erlete R. Vuaden²  Sílvio Arruda Vasconcellos² 

[1] ,Universidade de São Paulo Faculdade de Medicina Veterinária e Zootecnia Departamento de Medicina Veterinária Preventiva e Saúde AnimalSão Paulo SP ,Brasil

关键词: Experimental swine leptospirosis;    Leptospira spp.;    serovar Canicola;    vertical transmission;    Leptospirose suína experimental;    Leptospira spp.;    sorovar Canicola;    transmissão vertical;   

DOI  :  10.1590/S1517-83822006000400034

来源: SciELO

【 摘 要 】

Leptospirosis is an important zoonosis that causes reproductive disorders in swine. The isolation of leptospires from aborted fetuses, stillbirths and weak piglets was obtained in several occasions, however, the bacteria was never isolated from apparently healthy piglets born from apparently healthy infected dams. Six sows of the Landrace breed with a known date of service and pregnancy confirmed by ultrasonography were infected intravenously with 5ml of Leptospira interrogans serovar Canicola inoculum between 76 and 90 days of gestation, and one week after farrowing, at least one piglet per sow was euthanized and samples of liver, kidneys, lungs, heart, spleen and gastric content were taken and examined by PCR. Reproductive disorders or any clinical sign of infection were not observed in the inoculated sows. The piglets born from these animals presented no clinical signs or macroscopic lesions that could be attributed to leptospirosis. All inoculated sows presented anti-leptospires antibodies by microscopic serum-agglutination test (MAT) in the postinoculation serum samples and leptospires were not found in the urine as well as were not detected by PCR applied in this material, however, PCR accomplished in kidneys and liver from a euthanized sow presented positive results. Of the total of 12 euthanized piglets, 10 (83.3%) presented positive results by PCR in at least one of the kidney, liver, heart, spleen, lung and gastric content samples. The present study reports the vertical transmission of the infection and the detection of leptospires in clinically healthy piglets born from experimentally infected sows, which is important of the epidemiological point of view as the maintenance of clinically healthy infected animals may allow the persistence of the bacteria in the herd, exposing other animals to the risk of infection.

【 授权许可】

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