Human DNA profiles from mosquito blood meal for forensic application in tropical country

Abstract

In Thailand, mosquitoes are prevalent in every location and season. Thus, mosquitoes can be used as evidence in forensic investigations. A number of crime scenes can be solved by using STR markers to amplify DNA extracted from the mosquito abdomen. Nevertheless, there are several restrictions to their usage that may be of concern. One of them is that DNA testing more than two days after mosquitoes have eaten blood becomes problematic. Additionally, mosquito species may be implicated in blood degradation. The aim of the current study was to identify human DNA profiles from human blood obtained by three mosquito species, namely Culex quinquefasciatus, Aedes aegypti, and Aedes albopictus, at various post-feeding hours. DNA from unfed and fed mosquitoes at time points was extracted. DNA quality and quantity were determined using multiplex PCR and qPCR techniques with three sets of CADM1 primers. Human DNA profiles were identified by STR genotyping for 16 STR loci. Three species of mosquitoes with high-quality and quantity DNA were detected from 0–24 h post-feeding and decreased at 36 h. Complete DNA profiling was able to be achieved at 0–36 h post-feeding. Human DNA profiles could not be detected at 48–60 h post-feeding. Of note, the present study demonstrated human DNA profiles from C. quiquefasciatus blood meal mixture between two individuals at 0–36 h post-feeding. The findings of the present study may prove to be useful for the identification of human DNA profiles from mosquito blood meal for forensic application.