Molecular typing of phlebotomine sand flies in al-madinah and asir regions, Saudi Arabia using PCR-RFLP of 18S ribosomal RNA gene

Studies on the distribution of sand flies are important for the control of leishmaniasis in endemic and neighboring areas. In the present study polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) was used to identify the distribution of sand flies in Al-Madinah and Asir Regions of Saudi Arabia using PCR-RFLP of 18S ribosomal RNA gene. Based on the morphological characteristics, the sand flies were differentiated into seven species viz., Phlebotomus papatasi, Phlebotomus sergenti, Phlebotomus bergeroti, Sergentomyia clydei, Sergentomyia antennata, Sergentomyia fallax and Sergentomyia schwetzi. PCR-RFLP of 18S ribosomal RNA (rRNA) genes with eight different restriction enzymes resulted in species-specific agarose gel electrophoresis banding patterns. Of the eight restriction enzymes used, not a single restriction enzyme by itself could separate species belonging to the same genera (like P. papatasi and P. sergenti by AseI) as well as those belonging to different genera (like P. papatasi and S. clydei by AseI). We therefore conclude that the genetic diversity within sand fly species based on PCR-RFLP technique was nonspecific. Studies are in progress to study the viability of alternate techniques like low-stringency single specific primer polymerase chain reaction which can be used for molecular typing.