Population-Sequencing as a Biomarker of Burkholderia mallei and Burkholderia pseudomallei Evolution through Microbial Forensic Analysis

Table 2

Pipeline B alignment-based mapping statistics for threat agents and our Bg calibrant for comparison to nonalignment 𝑍 values.

Organism	𝑧-score; nonmapping	Nonreference; base fraction; (mapped reads)	Mapped read fraction	Unmapped reference bases	SNP calls
B.mallei	3.06	0.025	0.94	166,439	431
B.pseudomallei	2.87	0.027	0.98	859	365
B.globigii*	0.02	0.018	0.99	0	0

The 𝑍 values for Burkholderia are reflective of the higher fraction of non-reference-matching base calls in these samples and is indicative of greater population diversity compared to the Bg calibrant sample. The larger unmapped base counts along the reference genomes (column 5) for Bm are due to insertion elements that are highly mobile within these genomes and promote re-arrangements. BFAST default parameters for assigning candidate locations to reads when there is a high multiplicity of candidate alignments across the reference genome resulted in these gaps. Representative mapping statistics: 10,000,000 Illumina reads, 100 bp. *Calibrant.