Comparison of swab types for collection and analysis of microorganisms

The human microbiome is an emerging tool for forensic investigations, but its use could be hindered by improper collection at crime scenes. Here, we show that flocked swabs outperform cotton, dissolvable, and dental applicators in their ability to collect and releaseProteus mirabilis DNA for analysis. Therefore, the ubiquitous use of cotton swabs for biological sample collection should be re-evaluated. AbstractThe human microbiome has begun to emerge as a potential forensic tool, with varied applications ranging from unique identification to investigative leads that link individuals and/or locations. The relative abundance of the combined DNA of the microbiome, compared to human nuclear DNA, may expand potential sources of biological evidence, especially in cases with transfer or low-copy number DNA samples. This work sought to determine the optimal swab type for the collection and analysis of microorganisms. A bacterium (Proteus mirabilis) was deposited by pipette onto four swab types (cotton, flocked, dental applicators, and dissolvable), and extraction and real-time PCR quantitation of the bacterial DNA were performed, which allowed for absolute microbial DNA recovery and comparison of yields across the four sampling substrates. Flocked swabs had the highest yield (~1240  ng) compared to the cotton swabs (~184 ng), dental applicators (~533 ng), and dissolvable swabs (~430 ng). The collection efficiency was further evaluated for cotton and flocked swabs using dried micr...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: COMMENTARY Source Type: research