Heidie Hornstra, Talima Pearson, Shalamar Georgia, Andrew Liguori, Julia Dale, Erin Price, Matthew O’Neill, David DeShazer, Ghulam Muhammad, Muhammad Saqib, Abeera Naureen, and Paul Keim
Author affiliations: Northern Arizona University, Flagstaff, Arizona, USA (H. Hornstra, T. Pearson, S. Georgia, A. Liguori, J. Dale, M. O’Neill, P. Keim); The Translational Genomics Research Institute, Phoenix, Arizona (E. Price, P. Keim); US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, USA (D. DeShazer); University of Agriculture, Faisalabad, Pakistan (G. Muhammad, M. Saqib); Veterinary Research Center, Sultanate of Oman (M. Saqib); University of Veterinary and Animal Sciences, Lahore, Pakistan (A. Naureen)
Figure 1. Unrooted neighbor-joining tree based on 23 variable number tandem repeat loci demonstrating that the Punjab isolates (black text and PRL-20) are genetically distinct from and less diverse than available whole genome sequences (WGS, red text) (8). Statistical supports for branches based on 1,000 bootstrap iterations are shown. Sample PRL-20 is shown in red text because it is also available as a whole genome sequence; therefore, it was used in all 3 situations where an average pairwise distance (APD) was calculated. Among 10 WGS, the average pairwise distance was 0.607; between 10 WGS and Punjab isolates, average pairwise distance was 0.627; and among 15 Punjab isolates, average pairwise distance was 0.312. These results indicate that the Punjab isolates are more closely related to each other than to the sequenced strains because the APD among Punjab isolates is 2× lower than the APD calculated in the other 2 situations.
The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.