Detection of Pathogenic Leptospira Spp. in Goats from Slaughterhouses in Southwestern Nigeria Using Isolation, Histochemistry and Immunohistochemistry

Abstract Studies on caprine leptospirosis using isolation, histochemistry and immunohistochemistry are rare. The role of small ruminants in the epidemiology of leptospirosis is scarce. This study investigated the prevalence of Leptospira spp. serovars, and the renal pathology of caprine leptospirosis in slaughterhouses from two states in southwest Nigeria using isolation (IS), Warthin Starry silver (WSs) impregnation and immunohistochemistry (IH). One hundred and sixty-nine kidney samples were randomly obtained from goats between September 2015 and June 2017. Chi-square test was used with a confidence level set at 0.05 to ascertain associations between the positive cases, sex and animal species. Eighty-seven (51.5%) samples were positive on IS, out of which 26/40 and 25/30 were positive on WSs and IH, respectively. Ten (5.9%) kidneys showed macroscopic lesions while interstitial nephritis (48.6%) and tubular nephrosis (64.2%) were the most prominent histopathological changes. The most frequently observed positive reactions were against serovars Hardjo type Prajitno (12/25, 48%), and Gripptotyphosa (5/25, 20%). Other serovars such as Bratislava (2/25, 8%), Canicola (3/25, 12%), Icterohaemorrhagiae (2/25, 8%), and Pomona (1/25, 4.0%) were also detected using IH. The result showed high prevalence of Leptospira infection in goats and the possibility of humans contracting the disease. To date, the detection of leptospirosis from kidneys of goats using IS, WSs and IH has not been reported. This study is the first documentation of evidence of pathogenic Leptospira species in renal tissues of goats.