Lab Matters Summer 2018 - Page 59

APHL 2018 Annual Meeting Poster Abstracts Presenter: Colleen Courtney, PhD, Chief of Molecular Diagnostics, DC Public Health Laboratory, Washington, DC, Phone: 202.481.3533, Email: Whole Genome Sequence Analysis of Salmonella Montevideo Isolates from Multiple Outbreaks at a Restaurant Between 1997 and 2012 J. Wolfe 1 , S. Klish, M. Zahn 1 , J. Sevinsky 3 , L. Fink 3 , M. Cheung 2 , M. Crumpler 1 ; 1 Orange County Public Health Laboratory, Santa Ana, CA, 2 Orange County Health Care Agency, Santa Ana, CA, 3 Colorado Department of Public Health and Environment, Denver, CO Background: Multiple outbreaks of Salmonella Montevideo associated with a single restaurant located in Orange County, CA occurred from 1997 to 2012. A total of 48 cases were identified, including 30 patrons and 18 staff. Intense environmental investigation in 2012 identified multiple sites at the facility with S. Montevideo contamination. Pulsed-field gel electrophoresis (PFGE) was performed on 30 patient and 10 environmental isolates. Eight PFGE patterns with less than four band differences between them were identified. Results: The phylogenetic tree from lyve-SET hqSNP analysis identified 4 clades, with none of the isolates differing from any other by more than by 96 single-nucleotide polymorphisms (SNP). One clade contained isolates from 2000, the other three clades were from 2012 isolates. SNP differences between clades ranged from 13 to 68 SNPs. Conclusions: The three clades from 2012 all contained case, employee and environmental isolates, demonstrating that the restaurant contained at least three separate strains. The 2000 clade contained isolates which differed from 2012 isolates by as few as 13 SNPs, strongly suggesting that these Salmonella strains were residing in the restaurant and caused outbreaks for over 15 years. Molecular analysis of the case isolates alone may have suggested that the 2012 clades were unrelated, but careful epidemiological investigation clearly tied these clades together through employee and environmental isolates. Presenter: Julia Wolfe, MPH, Orange County Public Health Laboratory, Santa Ana, CA, Phone: 714.834.8277, Email: An Alternative to Liquid Handling Robots in Next-Generation Sequencing: Streamlin