Transcriptome Analysis of Alkali Shock and Alkali Adaptation inListeria monocytogenes10403S

Abstract

Alkali stress is an important means of inactivating undesirable pathogens in a wide range of situations. Unfortunately, Listeria monocytogenes can launch an alkaline tolerance response, significantly increasing persistence of the pathogen in such environments. This study compared transcriptome patterns of alkali and nonalkalistressed L. monocytogenes 10403S cells, to elucidate the mechanisms by which Listeria adapts and=or grows during short-or long-term alkali stress. Transcription profiles associated with alkali shock (AS) were obtained by DNA microarray analysis of midexponential cells suspended in pH 9 media for 15, 30, or 60 min. Transcription profiles associated with alkali adaptation (AA) were obtained similarly from cells grown to midexponential phase at pH 9. Comparison of AS and AA transcription profiles with control cell profiles identified a high number of differentially regulated open-reading frames in all tested conditions. Rapid (15 min) changes in expression included upregulation of genes encoding for multiple metabolic pathways (including those associated with Na + =H + antiporters), ATP-binding cassette transporters of functional compatible solutes, motility, and virulence-associated genes as well as the s B controlled stress resistance network. Slower (30 min and more) responses to AS and adaptation during growth in alkaline conditions (AA) involved a different pattern of changes in mRNA concentrations, and genes involved in proton export.

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Growth on Vacuum-Packed Cold Smoked Salmon

“…A number of previous studies have analyzed the transcriptomes of foodborne pathogens under stress conditions commonly present on/in food matrices (including hyperosmotic stress, cold stress, hydrostatic pressure stress, antimicrobial stress, acid stress, and alkali stress), using laboratory media modified to simulate these conditions as a model (15)(16)(17)(18)(19)(20)(21)(22)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63). These laboratory media include BHI broth (18,20,21,59), BHI agar (19), Luria-Bertani broth (60,61), tryptic soy broth (62), M9-glucose (63), and Listeria minimal medium (22) as reference conditions.…”

The Contribution of Transcriptomic and Proteomic Analysis in Elucidating Stress Adaptation Responses ofListeria monocytogenes

“…Transcriptome analysis has revealed that as much as 390 gene transcripts in L. monocytogenes cells are differentially expressed in response to alkaline stress exposure. Genes mobilized for alkaline stress adaptation participate in general stress responses, solute transport, and various metabolic pathways (Giotis et al, 2010). In another study the proteome analysis of L. monocytogenes cells exposed to alkaline stress revealed the synthesis or over expression of a limited number of proteins as compared to the repressed expression of proportionally large number of proteins (Giotis et al, 2008b).…”

Recent transcriptomics advances and emerging applications in food science

“…The contamination of food-processing facilities and food products with this pathogen is of particular concern because it survives in extreme environmental conditions and has the ability to form resistant biofilms. Transcriptomics studies on L. monocytognes have generally been conducted in culture media under stress conditions frequently used in food processing and storage, including low and high temperatures [69], high hydrostatic pressure [70], acidic or alkali conditions [71], and organic acids [72]. In some studies, gene-expression microarrays have been employed to study transcriptional differences due to specific mutations that confer tolerance or susceptibility to a particular condition [73].…”