Nested PCR for diagnosis of canine leishmaniosis in peripheral blood, lymph node and bone marrow aspirates

A nested polymerase chain reaction (PCR) assay was developed using primers selected from the genomic DNA of Leishmania infantum and applied to the dia gnosis of leishmaniosis in peripheral blood in dogs. Blood of 39 dogs of di fferent breeds, all sampled in Catalonia (Spain), were tested for leishmani osis by enzyme linked immunosorbent assay (ELISA), western blotting (WB) an d peripheral blood mononuclear cell (PBMC) culture and nested PCR. Twenty n egative controls (healthy dogs less than 1-year-old that bad not been expos ed to a sandfly season) were also studied. Nineteen of the 39 dogs studied were positive by ELISA and/or WB, and 18 of these had a positive PBMC neste d PCR. PBMC nested PCR was negative in all the remaining animals that were negative by serological examination, including the 20 negative controls. Pa rasitological examination and nested PCR of bone marrow and lymph node aspi rate from the 19 dogs positive by serological examination, were also positi ve. These results indicate that PBMC nested PCR is a sensitive and specific tool to diagnose leishmaniosis in dogs. The use of PBMC has the advantage over bone marrow and lymph node aspirates in that it is a less invasive sam ple. (C) 2001 Elsevier Science B.V. All rights reserved.