Expression and secretion pattern of FljB of Salmonella enterica serovar Typhi in different culture conditions

•Flagellin of Salmonella is highly immunogenic and is a key protein recognized by the host immune system.•SPI-1 inducing condition increases the secretion but not the expression level of FljB.•SPI-2 inducing condition shut down the expression and consequential secretion of FljB.•Salmonella may subvert the host's innate immune system through regulation of the expression and secretion of Flagellin.