Two horses with Rhodococcus equi infection were examined post mortem by an
immunohistochemical method (peroxidase-antiperoxidase; PAP) with a monoclon
al antibody (Mab 10G5) to the 15-17 kDa antigen of R. equi. One of the hors
es was also examined bacteriologically, R. equi being isolated in culture.
Immunolabelling with this Mab was marked and widespread. On the other hand,
the immunohistochemical reactivity of infected macrophages with a polyclon
al antibody specific for lysozyme was slight. Thus, Mab 10G5 would appear t
o be a useful diagnostic reagent in R. equi infection, with or without cult
ural confirmation. (C) 2000 Harcourt Publishers Ltd.