DIAGNOSIS OF LEISHMANIA USING THE POLYMERASE CHAIN-REACTION - A SIMPLIFIED PROCEDURE FOR FIELD WORK

Oligonucleotide primers directed to the minicircle kinetoplast DNA of Leishmania strains supported enzymatic amplification of this DNA by th e polymerase chain reaction (PCR). A single product of 70 basepairs wa s obtained from parasites belonging exclusively to the L. braziliensis complex. Direct sequencing of the amplified product confirmed its min icircle origin. Skin biopsy specimens from human patients were used di rectly for the PCR. A pulse incubation of such specimens with deoxyrib onuclease I prior to the PCR increased the reliability of the assay. N uclease disruption of the kinetoplast network was expected to make mor e copies of the minicircle accessible to amplification. Comparative re sults between the PCR and conventional parasitologic detection procedu res indicate that the DNA detection approach presented is by far more sensitive for diagnostic purposes. Innovations in the PCR protocol are presented that adapt the diagnosis of leishmaniasis to settings with minimal equipment and that are distant from central laboratories.