Background: Many cases of cutaneous leishmaniasis (CL) have been recorded in the Jenin District based on their
clinical appearance. Here, their parasites have been characterized in depth.
Methods: Leishmanial parasites isolated from 12 human cases of CL from the Jenin District were cultured as
promastigotes, whose DNA was extracted. The ITS1 sequence and the 7SL RNA gene were analysed as was the
kinetoplast minicircle DNA (kDNA) sequence. Excreted factor (EF) serotyping and multilocus enzyme electrophoresis
(MLEE) were also applied.
Results: This extensive characterization identified the strains as Leishmania tropica of two very distinct sub-types
that parallel the two sub-groups discerned by multilocus microsatellite typing (MLMT) done previously. A high
degree of congruity was displayed among the results generated by the different analytical methods that had
examined various cellular components and exposed intra-specific heterogeneity among the 12 strains.
Three of the ten strains subjected to MLEE constituted a new zymodeme, zymodeme MON-307, and seven
belonged to the known zymodeme MON-137. Ten of the 15 enzymes in the profile of zymodeme MON-307
displayed different electrophoretic mobilities compared with the enzyme profile of the zymodeme MON-137. The
closest profile to that of zymodeme MON-307 was that of the zymodeme MON-76 known from Syria.
Strains of the zymodeme MON-307 were EF sub-serotype A2 and those of the zymodeme MON-137 were either A9
or A9B4. The sub-serotype B4 component appears, so far, to be unique to some strains of L. tropica of zymodeme
MON-137. Strains of the zymodeme MON-137 displayed a distinctive fragment of 417 bp that was absent in those
of zymodeme MON-307 when their kDNA was digested with the endonuclease RsaI. kDNA-RFLP after digestion
with the endonuclease MboI facilitated a further level of differentiation that partially coincided with the
geographical distribution of the human cases from which the strains came.
Conclusions: The Palestinian strains that were assigned to different genetic groups differed in their MLEE profiles
and their EF types. A new zymodeme, zymodeme MON-307 was discovered that seems to be unique to the
northern part of the Palestinian West Bank. What seemed to be a straight forward classical situation of L. tropica
causing anthroponotic CL in the Jenin District might be a more complex situation, owing to the presence of two
separate sub-types of L. tropica that, possibly, indicates two separate transmission cycles involving two separate
types of phlebotomine sand fly vector.
