Meiklejohn Kelly A, Schal Coby, Lodhi Khalid M
Department of Population Health and Pathobiology, North Carolina State University, College of Veterinary Medicine, Raleigh, North Carolina, USA.
Department of Entomology and Plant Pathology, North Carolina State University, College of Agriculture and Life Sciences, Raleigh, North Carolina, USA.
J Forensic Sci. 2025 Jan;70(1):264-270. doi: 10.1111/1556-4029.15638. Epub 2024 Oct 14.
Insects have long played a role in forensic investigations and can be used to estimate minimum time since death, corpse translocation, and link an individual to a crime scene. Bed bugs (Cimex lectularius) are wingless ectoparasitic insects of potential forensic utility, given that all mobile life stages feed on vertebrate blood. Successful profiling of autosomal short tandem repeats (STRs) from human DNA isolated from bed bugs has been previously reported. This proof-of-concept study looked to expand this work and determine any possible limitations of using bed bugs for both rapid stain identification (RSID™) for human blood and Y-STR profiling. To achieve this, bed bugs were fed either human male only or human pooled (female:male) blood for 30 min and subsequently collected at 12-h intervals up to 108 h post-blood meal (PBM). RSID™ blood testing was successful from the bed bug carcass remaining after DNA isolation, regardless of blood meal type and time of collection PBM. Complete Y-STR profiles were generated from bed bugs <60 h PBM. As the time PBM increased, DNA quantity decreased, while the degradation index increased. Collection of bed bugs at a crime scene could provide a valuable source of human blood for Y STR profiling and be used to link an individual to a crime scene or for potential male suspect exclusion. Future studies should look to replicate the results of this proof-of-concept study with larger numbers of bed bugs, more diverse blood donors, and additional STR profiling kits.
昆虫长期以来在法医调查中发挥着作用，可用于估计最短死亡时间、尸体转移情况，并将个人与犯罪现场联系起来。臭虫（温带臭虫）是一种无翅的体外寄生昆虫，具有潜在的法医应用价值，因为其所有活动阶段均以脊椎动物血液为食。此前已有报道成功从臭虫体内分离的人类DNA中对常染色体短串联重复序列（STR）进行分型。这项概念验证研究旨在扩展这项工作，并确定使用臭虫进行人类血液快速染色鉴定（RSID™）和Y-STR分型的任何可能局限性。为实现这一目标，将臭虫分别喂食仅人类男性血液或人类混合（女性：男性）血液30分钟，随后在采血后（PBM）以12小时的间隔进行收集，直至108小时。无论血餐类型和采血后时间如何，从DNA分离后剩余的臭虫尸体中进行RSID™血液检测均获得成功。在采血后<60小时的臭虫中生成了完整的Y-STR图谱。随着采血后时间增加，DNA数量减少，而降解指数增加。在犯罪现场收集臭虫可为Y STR分型提供宝贵的人类血液来源，并用于将个人与犯罪现场联系起来或排除潜在男性嫌疑人。未来的研究应考虑用更多数量的臭虫、更多样化的献血者和额外的STR分型试剂盒来重复这项概念验证研究的结果。
