Scientific Publications by FDA Staff

J Microbiol Methods 2017 Feb;133:55-61

Molecular characterization of Salmonella Typhimurium isolated in Brazil by CRISPR-MVLST.

Almeida F, Medeiros MI, Rodrigues DD, Allard MW, Falcao JP

CRISPR- multi-locus virulence sequence typing (CRISPR-MVLST) was performed to type 92S. Typhimurium strains isolated from humans and food sources between 1983 and 2013 in Brazil and assess the suitability of this methodology comparing it with PFGE already used for subtyping the same strains. Among the 92S. Typhimurium strains studied, we identified 25 CRISPR1 alleles, 27 CRISPR2 alleles, 2 fimH alleles and 3 sseL alleles showing that the genetic variability is much higher in the CRISPRs loci than in the virulence genes. The CRISPR-MVLST analysis provided similar results to the PFGE previously published used to type the same set of strains, demonstrating that CRISPR-MVLST is a very efficient approach for subtyping S. Typhimurium serovar and can be used to complement and validate results obtained by the PFGE methodology.