Detection of Wolbachia pipientis, including a new strain containing the wsp gene, in two sister species of Paraphlebotomus sandflies, potential vectors of zoonotic cutaneous leishmaniasis

Abstract

Individual, naturally occurring Phlebotomus mongolensis and Phlebotomus caucasicus from Iran were screened for infections with the maternally inherited intracellular Rickettsia-like bacterium Wolbachia pipientis via targeting a major surface protein gene (wsp). The main objective of this study was to determine if W. pipientis could be detected in these species. The sandflies were screened using polymerase chain reaction to amplify a fragment of the Wolbachia surface protein gene. The obtained sequences were edited and aligned with database sequences to identify W. pipientis haplotypes. Two strains of Wolbachia were found. Strain Turk 54 (accession EU780683) is widespread and has previously been reported in Phlebotomus papatasi and other insects. Strain Turk 07 (accession KC576916) is a novel strain, found for first time in the two sister species. A-group strains of W. pipientis occur throughout much of the habitat of these sandflies. It is possible that Wolbachia is transferred via horizontal transmission. Horizontal transfer could shed light on sandfly control because Wolbachia is believed to drive a deleterious gene into sandflies that reduces their natural population density. With regard to our findings in this study, we can conclude that one species of sandfly can be infected with different Wolbachia strains and that different species of sandflies can be infected with a common strain.

Fig. 1. schematic presentation of the Wolbachia surface protein (wsp ) gene, an appropriate candidate as an antigenic serotyping for strain typing of pathogenic bacteria of Wolbachia .

Fig. 2. alignments of the two Wolbachia surface protein gene sequence of Wolbachia pipientis isolated from Iranian sandflies strain Turk 54 isolated first from Phlebotomus papatasi and then most different sandfly species with the GenBank sequence EU780683, Turk 07 isolated from Paraphlebotomus mongolensis and Paraphlebotomus cacusicus . Nucleotide differences are marked by a star.

Fig. 3. unrooted neighbour-joining tree showing the relationships of the haplotypes of the Wolbachia surface protein gene fragment for the isolates of Wolbachia listed in Table II.