Quantitative method for measuring the proportion of bacterial cells expressing phase 1 or 2 of flagellin of Salmonella enterica serovar Typhimurium.

Salmonella enterica subsp. enterica is a major pathogen that causes zoonotic foodborne diseases worldwide. Some Salmonella serovars possess two antigenic phases for flagellin: phase 1 and 2. In Salmonella enterica serovar Typhimurium (S. Typhimurium), the flagellin is antigenically divided into "Hi" as phase 1 and "H1 or H2" as phase 2. Flagellin phase variation is regulated by inversion of hin gene. We focused on the inversion of hin and developed a real-time PCR system to quantitatively measure the proportion of bacterial cells expressing each phase of flagellin. In this study, we demonstrated that our newly developed real-time PCR system shows high quantitative accuracy and aligns with flagellin expression status. Furthermore, the newly developed real-time PCR system was applicable to various S. Typhimurium laboratory and field strains. This newly developed real-time PCR system has the potential to become a powerful tool for analyzing flagellin phase variation.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Momoko Nakayama reports financial support was provided by General Incorporated Foundation Kieikai Research Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)