Identification of Blood Meals Imbibed by Phlebotomine Sand Flies Using CytochromebPCR and Reverse Line Blotting

Abstract

Blood meal identification is important for determining the host preferences and the vectorial capacity of hematophagous arthropods. In the past, mostly serological techniques using host-specific antibodies were used, but in recent years more sensitive and accurate polymerase chain reaction (PCR)-based molecular approaches for identifying blood meals have been developed. Here, a vertebrate-specific PCR is combined with reverse line blot analysis for identifying blood meals ingested by female phlebotomine sand fly vectors of leishmaniasis. Species-specific oligonucleotides were covalently linked to nylon membranes, and biotinylated PCR products of the mitochondrial cytochrome b gene were used as probes in a hybridization reaction revealed using colorimetric or enhanced chemiluminescent detection systems. This combination identified blood meals up to 96 hours after ingestion containing minimal amounts of DNA (>0.1 pg). The specific probes discriminated between putative host species in several study areas. The source of blood was identified in 68 of 89 wild-caught sand flies tested (76%). Mixed blood meals were identified in 15 (17%) of those. The advantages and limitations of this method are discussed.