For the best of our knowledge, there is no information about molecular characterization of Iraqi
isolates of visceral leishmaniasis, the present work aimed to characterize three different Iraqi
isolates of Leishmania infantum by polymerase chain reaction (PCR), restriction fragment
length polymorphism (RFLP) and sequencing methods.
Three isolates from bone marrow of Iraqi patients infected with kala azar were used in this
study. The isolates were already diagnosed by isoenzyme as Leishmania infantum. Patients were
inhabiting different parts of Baghdad. The samples after microscopic examination were cultured
on modified NNN media. Then DNA was extracted for amplifying ITS1 (internal transcribed
spacer 1) gene by PCR. Identification of samples was studied using RFLP (digestion with Apo1
restriction enzyme) and sequencing of PCR products.
The PCR of all samples showed a band under about 500 bp. The results by using PCR-RFLP
method showed no restriction with digestion with Apo1 restriction enzyme. The results of
sequencing showed differences with all separated gene from Leishmania infantum in the gene
bank.
In this study we found that the sequences of ITS1 gene of Leishmania infantum separated from
Iraqi patients are different from other samples, as there is no similarity with Leishmania
infantum (MHOM/TN/80/IPI1). The more similarity is with the Iranian isolate of Leishmania
infantum (MCAN/IR/97/LON) with 41%, whereas the similarity with Crithidia luciliae internal
transcribed spacer 1, ITS1 is 96%.