Functional analysis of Salmonella Typhi adaptation to survival in water

Abstract

SummaryContaminated water is a major risk factor associated with the transmission of Salmonella enterica serovar Typhi (S. Typhi), the aetiological agent of human typhoid. However, little is known about how this pathogen adapts to living in the aqueous environment. We used transcriptome analysis (RNA‐seq) and transposon mutagenesis (TraDIS) to characterize these adaptive changes and identify multiple genes that contribute to survival. Over half of the genes in the S. Typhi genome altered expression level within the first 24 h following transfer from broth culture to water, although relatively few did so in the first 30 min. Genes linked to central metabolism, stress associated with arrested proton motive force and respiratory chain factors changed expression levels. Additionally, motility and chemotaxis genes increased expression, consistent with a scavenging lifestyle. The viaB‐associated gene tviC encoding a glcNAc epimerase that is required for Vi polysaccharide biosynthesis was, along with several other genes, shown to contribute to survival in water. Thus, we define regulatory adaptation operating in S. Typhi that facilitates survival in water.

The Contribution of Wastewater to the Transmission of Antimicrobial Resistance in the Environment: Implications of Mass Gathering Settings

“…These environments can provide an ideal platform allowing the transfer of ARGs among the bacterial populations either before or after being discharged into the environment. This is alarming considering that many clinically relevant bacterial species, including enterotoxigenic E. coli and typhoidal and non-typhoidal serotypes of Salmonella, have been shown to be able to persist in the environmental water for relatively long times [113][114][115].…”

Genetic Markers in S. Paratyphi C Reveal Primary Adaptation to Pigs

“…Lists of disrupted genes were overlaid onto the metabolic pathway overview of the S. Typhi CT18 pathway/genome database [31] to identify disrupted pathways and transport reactions. Disrupted pathways were compared between the 5 Salmonella to produce an UpSet plot [32].…”

Functional analysis of colonization factor antigen I positive enterotoxigenic Escherichia coli identifies genes implicated in survival in water and host colonization

“…Importantly, hldE has previously been shown to be associated with reduced expression of CFA/I and flagellae, therefore impairing its ability to bind Caco2-cells [49]. Interestingly, genes involved in polysaccharide biosynthesis were also recently identified in a screen for survival in water of another human-adapted enteric pathogen, Salmonella enterica serovar Typhi [50].…”

“…S . Typhi is notoriously difficult to culture from the environment [50]. A VBNC state may be mediated by transcriptional switching, potentially involving alternative sigma factors.…”