The objective of this trial was to detect leptospires in fragments of kidney, liver and uterus of 96 cows with unknown sanitary status, randomly chosen at slaughter in Paraná, Brazil. All 96 urine samples were submitted to direct examination using dark field microscopy. Positive samples in the direct examination and all kidney, liver and uterus fragments were cultured in EMJH modified medium and Tween 80/40/LH. Sections cut of kidney, liver and uterus were stained by Hematoxylin-Eosin (HE) and indirect immunoperoxidase with hyperimmune serum against serovar Hardjo (Hardjoprajitno) and strain Londrina 14 (LO14), from serovar Canicola, which was isolated in the northern region of Paraná state, Brazil, used as primary antibodies. Direct examination detected leptospires in the urine of four animals. All attempts to isolate leptospires from urine and kidney, liver and uterus fragments were negative after 16 weeks of incubation. In the HE stain, focal infiltrate of mononuclear inflammatory cells was observed in the renal interstitial area of most animals. In the indirect immunoperoxidase assay using hyperimmune serum against LO14 strain, the kidney of only one animal presented positive results. All fragments of kidney, liver and uterus tested with hyperimmune serum against serovar Hardjo were negative.
Leptospire; indirect immunoperoxidase; immunohistochemistry; cows; culture
