Stress Response and Adaptation of Listeria monocytogenes 08-5923 Exposed to a Sublethal Dose of Carnocyclin A

Abstract

Carnocyclin A (CCLA) is an antimicrobial peptide produced by Carnobacterium maltaromaticum ATCC PTA-5313, which can be used to control the growth of Listeria monocytogenes in ready-to-eat meat products. The aim of this research was to elucidate the cellular responses of L. monocytogenes 08-5923 exposed to a sublethal dose of CCLA. Microarray, quantitative reverse transcription-PCR, tandem mass spectrometry, and electron microscopy were used to investigate the alteration in gene expression, protein production, and morphological changes in cells of Listeria following treatment with CCLA. The genes involved in metabolism (baiE, trn, and pykA), cell wall synthesis (murZ and dacB2), and cell division (clpE and divIVA) were upregulated following a 15-min exposure to CCLA as a result of stress responses. Genes involved in cell division, cell wall synthesis, flagellar synthesis, and metabolism were downregulated after 4 h as a result of adaptation. Analysis of total soluble proteins confirmed the downregulation of pykA and gnd after 4 h of exposure to CCLA. The absence of flagella was observed in L. monocytogenes following 30 h of exposure to CCLA. A sublethal dose of CCLA induced adaptation in L. monocytogenes 08-5923 by inhibition of expression of genes and proteins critical for synthesis of cell wall structures and maintaining metabolic functions. Both the mannose-and cellobiose-specific phosphotransferase systems could be targets for CCLA.

Sodium chloride-induced filamentation and alternative gene expression offts,murZ,andgndinListeria monocytogenes08-5923 on vacuum-packaged ham

“…Primers targeting four genes (ftsX, murZ, pykA, and gnd; Table 1) were designed using PRIMER3 (http://frodo.wi.mit.edu/primer3/). These genes were selected as they were previously involved in a stress response to sublethal dose of bacteriocins (Liu et al, 2014). All qRT-PCR experiments were performed on a 7500 Fast Real-Time PCR system (Applied Biosystems) using QuantiFast â SYBR â Green PCR Kit (Qiagen).…”

The Effect of Carbohydrates and Bacteriocins on the Growth Kinetics and Resistance of Listeria monocytogenes

“…For class IIa bacteriocins, concentrations exceeding the MIC 5- to 1,000-fold can induce resistance in L. monocytogenes ( Duffes et al, 2000 ; Kaur et al, 2011 ). Although others have reported inhibition of L. monocytogenes in the presence of carnocyclin A ( Gong et al, 2009 ; Liu et al, 2014 ), to the best of our knowledge this is the first report of resistance to carnocyclin A in strains of L. monocytogenes . In the current study, all of the strains used were able to grow in the presence of carnocyclin A, although the growth rate and lag phase were impacted by carbohydrate.…”

"Molecular mechanisms adopted by abiotic stress tolerant Pseudomonas fluorescens (NBAII-PFDWD) in response to in vitro osmotic stress"

“…Ribosome profiling provides an insight to its role in expression of bacterial proteins under environmental fluctuations (Starosta et al, 2014). Expression of 30s ribosomal proteins were found to be down regulated in carnocyclin treated Listeria monocytogenes (Liu et al, 2014). DNA repair mechanisms play a pivotal role in altering stressed genes for a normal functioning of a cell.…”