Pathological, immunohistochemical and bacteriological findings in kidneys of cattle with contagious bovine pleuropneumonia (CBPP)

Between 1990 and 1993, 61 outbreaks of contagious bovine pleuropneumonia (C BPP) were reported in Lombardy, Northern Italy. In this study, gross pathol ogical examination was carried out on 3129 slaughtered cattle, 716 of which (22.9%) showed typical CBPP Pulmonary lesions. Single or multiple renal in farets at different stages of development were observed in 88 (12.2%) of th ese 716 cattle. The kidneys of 77 cattle whose lungs showed typical CBPP le sions and were bacteriologically and immunohistochemically mic positive for the small colony type of Mycoplasma mycoides subspecies mycoides (M. m. my coides SC) were selected and submitted to histological, immunohistochemical and bacteriological examination. Histologically, in chronic CBPP cases, in farets were characterized by fibrosis, calcification of cortical tubules an d tubular atrophy, accompanied by the presence of interstitial inflammatory infiltrates composed of lymphocytes, plasma cells and histiocytes. M.m myc oides SC antigen was detected immunohistochemically in 65 (84.4%) of the 77 kidneys examined. The antigen was detected in the lumen of blood vessels a nd in glomerular cells. Immunolabelled interstitial cells and tubular epith elial cells were seen in chronic cases only. M. ni. mycoides SC was isolate d from the kidneys of 12 animals(15.6%) and more frequently in cases with r enal infarcts. This study confirms previous observations that demonstrated a renal involvement ill cases of CBPP. Moreover, the immunohistochemical re sults indicated that M. m. mycoides SC antigen was frequently detectable in different renal structures and cells in spontaneous cases of CBPP. (C) 200 1 Harcourt Publishers Ltd.