Journal Article

Comparison of inferred relatedness based on multilocus variable-number tandem-repeat analysis and whole genome sequencing of Vibrio cholerae O1

Sack, David A., Lindsay, Brianna R., Morris, J. Glenn, Azman, Andrew S., Almeida, Mathieu, Alam, Munirul, Huq, Anwar, Colwell, Rita R., Rashid, Mahamud-ur, Stine, O. Colin

2016

Overview

Vibrio cholerae causes cholera, a severe diarrheal disease. Understanding the local genetic diversity and transmission of V. cholerae will improve our ability to control cholera. Vibrio cholerae isolates clustered in genetically related groups (clonal complexes, CC) by multilocus variable tandem-repeat analysis (MLVA) were compared by whole genome sequencing (WGS). Isolates in CC1 had been isolated from two geographical locations. Isolates in a second genetically distinct group, CC2, were isolated only at one location. Using WGS, CC1 isolates from both locations revealed, on average, 43.8 nucleotide differences, while those strains comprising CC2 averaged 19.7 differences. Strains from both MLVA-CCs had an average difference of 106.6. Thus, isolates comprising CC1 were more closely related (P < 10−6) to each other than to isolates in CC2. Within a MLVA-CC, after removing all paralogs, alternative alleles were found in all possible combinations on separate chromosomes indicative of recombination within the core genome. Including recombination did not affect the distinctiveness of the MLVA-CCs when measured by WGS. We found that WGS generally reflected the same genetic relatedness of isolates as MLVA, indicating that isolates from the same MLVA-CC shared a more recent common ancestor than isolates from the same location that clustered in a distinct MLVA-CC. Genetic relatedness of Vibrio cholerae isolates from distinct locations was similar when measured by multilocus variable tandem-repeat analysis or whole genome sequencing.

• Publisher: Oxford University Press
• Subject: Analysis / Cholera / Cholera - microbiology / Cholera - transmission / Chromosomes / Diarrhea / Genetic diversity / Genetic Variation / Genetics / Genome, Bacterial / Genotype / High-Throughput Nucleotide Sequencing / Humans / Microbiology / Minisatellite Repeats / Molecular Typing - methods / Recombination, Genetic / Research Letter / Taxonomy & Systematics / Vibrio cholerae - classification / Vibrio cholerae - genetics / Vibrio cholerae O1 - classification / Vibrio cholerae O1 - genetics / Vibrio cholerae O1 - isolation & purification / Waterborne diseases