Phenotypic and genotypic characterization of Salmonella Typhimurium isolates from humans and foods in Brazil

Author(s):Show less -

Seribelli, Amanda Aparecida ^[1] ; Cruz, Marcelo Ferreira ^[1] ; Vilela, Felipe Pinheiro ^[1] ; Frazao, Miliane Rodrigues ^[1] ; Paziani, Mario H. ^[1] ; Almeida, Fernanda ^[1] ; Cazentini Medeiros, Marta Ines ^[2] ; Rodrigues, Dalia dos Prazeres ^[3] ; von Zeska Kress, Marcia R. ^[1] ; Allard, Marc W. ^[4] ; Falcao, Juliana Pfrimer ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Anal Clin Toxicol & Bromatol, Fac Ciencias Farmaceut Ribeirao Preto, Sao Paulo - Brazil

^[2] Inst Adolfo Lutz Ribeirao Preto, Sao Paulo - Brazil

^[3] Fundacao Oswaldo Cruz FIOCRUZ, Rio De Janeiro - Brazil

^[4] US FDA, College Pk, MD 20740 - USA

• Document type: Journal article
• Source: PLoS One; v. 15, n. 8 AUG 18 2020.
• Web of Science Citations: 2

Abstract

Salmonella entericasubsp.entericaserovar Typhimurium (S. Typhimurium) causes gastroenteritis in many countries. However, in Brazil there are few studies that have conducted a virulence characterization of this serovar. The aim of this study was to evaluate the virulence potential ofS. Typhimurium strains isolated in Brazil. FortyS. Typhimurium strains isolated from humans (n = 20) and food (n = 20) from Brazil were studied regarding their invasion and survival in human epithelial cells (Caco-2) and macrophages (U937). Their virulence potential was determined using theGalleria mellonellalarvae model combined with the analysis of virulence genes by whole genome sequencing (WGS). A total of 67.5% of theS. Typhimurium studied (32.5% isolated from humans and 35% isolated from food) invaded Caco-2 epithelial cells at levels similar to or greater than theS. Typhimurium SL1344 prototype strain. In addition, 37.5% of the studied strains (25% isolated from humans and 12.5% isolated from food) survived in U937 human macrophages at levels similar to or greater than SL1344.S. Typhimurium strains isolated from humans (40%) and food (25%) showed high or intermediate virulence inG.mellonellalarvae after seven days exposure. Approximately, 153 virulence genes of chromosomal and plasmidial origin were detected in the strains studied. In conclusion, the ability of theS. Typhimurium to invade Caco-2 epithelial cells was strain dependent and was not related to the source or the year of isolation. However,S. Typhimurium strains isolated from humans showed greater survival rates in U937 human macrophages, and presented higher proportion of isolates with a virulent profile inG.mellonellain comparison to strains isolated from food suggesting that this difference may be related to the higher frequency of human isolates which contained plasmid genes, such asspvABCDRoperon,pefABCDoperon,rckandmig-5. (AU)

• FAPESP's process: 16/24716-3 - Sequencing of the Genome, transcriptoma and phenotypic analysis of Campylobacter coli strains isolated from different sources in Brazil
• Grantee: Juliana Pfrimer Falcão
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/06633-6 - Comparative analysis of the genome, transcriptome and phenotypic characterization of Salmonella typhimurium strains isolated from humans and food in Brazil
• Grantee: Amanda Aparecida Seribelli
• Support Opportunities: Scholarships in Brazil - Doctorate