Stress Response of Campylobacter spp. and its Role in Food Processing

Campylobacter jejuni is the most frequent cause of bacterial gastrointestinal food-borne infection worldwide. The transmission of Campylobacter and Arcobacter-like species is often made possible by their ability to adhere to various abiotic surfaces. This study is focused on monitoring the biofilm ability of 69 strains of Campylobacter spp. and lesser described species of the Arcobacteraceae family isolated from food, water, and clinical samples within the Czech Republic. Biofilm formation was monitored and evaluated under an aerobic/microaerophilic atmosphere after cultivation for 24 or 72 h depending on the surface material. An overall higher adhesion ability was observed in arcobacters. A chi-squared test showed no association between the origin of the strains and biofilm activity (p > 0.05). Arcobacter-like species are able to form biofilms under microaerophilic and aerobic conditions; however, they prefer microaerophilic environments. Biofilm formation has already been demonstrated at refrigerator temperatures (5 °C). Arcobacters also showed higher biofilm formation ability at the temperature of 30 °C. This is in contrast to Campylobacter jejuni NP 2896, which showed higher biofilm formation ability at temperatures of 5–30 °C. Overall, the results demonstrated the biofilm formation ability of many strains, which poses a considerable risk to the food industry, medical practice, and human health.

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Legal aspects and microbiological criteria for Campylobacter spp. in the food processing chain

Campylobacter ◽

10.1016/b978-0-12-803623-5.00007-1 ◽

2017 ◽

pp. 131-142

Author(s):

Felix Reich ◽

Günter Klein

Keyword(s):

Food Processing ◽

Legal Aspects ◽

Processing Chain ◽

Microbiological Criteria ◽

Campylobacter Spp

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The Response to Oxidative Stress in Listeria monocytogenes Is Temperature Dependent

Microorganisms ◽

10.3390/microorganisms8040521 ◽

2020 ◽

Vol 8 (4) ◽

pp. 521 ◽

Cited By ~ 1

Author(s):

Beatriz Manso ◽

Beatriz Melero ◽

Beatrix Stessl ◽

Isabel Jaime ◽

Martin Wagner ◽

...

Keyword(s):

Oxidative Stress ◽

Listeria Monocytogenes ◽

Stress Response ◽

Food Processing ◽

Molecular Mechanisms ◽

Cumene Hydroperoxide ◽

Oxidative Stress Response ◽

Survival Strategies ◽

Processing Plants ◽

Dairy Plant

The stress response of 11 strains of Listeria monocytogenes to oxidative stress was studied. The strains included ST1, ST5, ST7, ST6, ST9, ST87, ST199 and ST321 and were isolated from diverse food processing environments (a meat factory, a dairy plant and a seafood company) and sample types (floor, wall, drain, boxes, food products and water machine). Isolates were exposed to two oxidizing agents: 13.8 mM cumene hydroperoxide (CHP) and 100 mM hydrogen peroxide (H2O2) at 10 °C and 37 °C. Temperature affected the oxidative stress response as cells treated at 10 °C survived better than those treated at 37 °C. H2O2 at 37 °C was the condition tested resulting in poorest L. monocytogenes survival. Strains belonging to STs of Lineage I (ST5, ST6, ST87, ST1) were more resistant to oxidative stress than those of Lineage II (ST7, ST9, ST199 and ST321), with the exception of ST7 that showed tolerance to H2O2 at 10 °C. Isolates of each ST5 and ST9 from different food industry origins showed differences in oxidative stress response. The gene expression of two relevant virulence (hly) and stress (clpC) genes was studied in representative isolates in the stressful conditions. hly and clpC were upregulated during oxidative stress at low temperature. Our results indicate that conditions prevalent in food industries may allow L. monocytogenes to develop survival strategies: these include activating molecular mechanisms based on cross protection that can promote virulence, possibly increasing the risk of virulent strains persisting in food processing plants.

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Preadaptation to Cold Stress in Salmonella enterica Serovar Typhimurium Increases Survival during Subsequent Acid Stress Exposure

Applied and Environmental Microbiology ◽

10.1128/aem.02621-13 ◽

2013 ◽

Vol 79 (23) ◽

pp. 7281-7289 ◽

Cited By ~ 42

Author(s):

Jigna Shah ◽

Prerak T. Desai ◽

Dong Chen ◽

John R. Stevens ◽

Bart C. Weimer

Keyword(s):

Stress Response ◽

Cold Stress ◽

Food Processing ◽

Abiotic Stresses ◽

Acid Stress ◽

Aerobic Respiration ◽

Stress Exposure ◽

Content Type ◽

Repair Pathways ◽

Subsequent Acid

ABSTRACTSalmonellais an important cause of bacterial food-borne gastroenteritis.Salmonellaencounters multiple abiotic stresses during pathogen elimination methods used in food processing, and these stresses may influence its subsequent survivability within the host or in the environment. Upon ingestion,Salmonellais exposed to gastrointestinal acidity, a first line of the host innate defense system. This study tested the hypothesis that abiotic stresses encountered during food processing alter the metabolic mechanisms inSalmonellathat enable survival and persistence during subsequent exposure to the host gastrointestinal acidic environment. Out of the four different abiotic stresses tested,viz., cold, peroxide, osmotic, and acid, preadaptation of the log-phase culture to cold stress (5°C for 5 h) significantly enhanced survival during subsequent acid stress (pH 4.0 for 90 min). The gene expression profile ofSalmonellapreadapted to cold stress revealed induction of multiple genes associated with amino acid metabolism, oxidative stress, and DNA repair, while only a few of the genes in the above-mentioned stress response and repair pathways were induced upon exposure to acid stress alone. Preadaptation to cold stress decreased the NAD+/NADH ratio and hydroxyl (OH·) radical formation compared with those achieved with the exposure to acid stress alone, indicating alteration of aerobic respiration and the oxidative state of the bacteria. The results from this study suggest that preadaptation to cold stress rescuesSalmonellafrom the deleterious effect of subsequent acid stress exposure by induction of genes involved in stress response and repair pathways, by modification of aerobic respiration, and by redox modulation.

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CarR, a MarR-family regulator from Corynebacterium glutamicum, modulated antibiotic and aromatic compound resistance

Biochemical Journal ◽

10.1042/bcj20190320 ◽

2019 ◽

Vol 476 (21) ◽

pp. 3141-3159 ◽

Cited By ~ 2

Author(s):

Meiru Si ◽

Can Chen ◽

Zengfan Wei ◽

Zhijin Gong ◽

GuiZhi Li ◽

...

Keyword(s):

Stress Response ◽

Ligand Binding ◽

Corynebacterium Glutamicum ◽

Conformational Changes ◽

Cysteine Oxidation ◽

Transcriptional Regulatory ◽

Ligand Free ◽

Redox Sensing

Abstract MarR (multiple antibiotic resistance regulator) proteins are a family of transcriptional regulators that is prevalent in Corynebacterium glutamicum. Understanding the physiological and biochemical function of MarR homologs in C. glutamicum has focused on cysteine oxidation-based redox-sensing and substrate metabolism-involving regulators. In this study, we characterized the stress-related ligand-binding functions of the C. glutamicum MarR-type regulator CarR (C. glutamicum antibiotic-responding regulator). We demonstrate that CarR negatively regulates the expression of the carR (ncgl2886)–uspA (ncgl2887) operon and the adjacent, oppositely oriented gene ncgl2885, encoding the hypothetical deacylase DecE. We also show that CarR directly activates transcription of the ncgl2882–ncgl2884 operon, encoding the peptidoglycan synthesis operon (PSO) located upstream of carR in the opposite orientation. The addition of stress-associated ligands such as penicillin and streptomycin induced carR, uspA, decE, and PSO expression in vivo, as well as attenuated binding of CarR to operator DNA in vitro. Importantly, stress response-induced up-regulation of carR, uspA, and PSO gene expression correlated with cell resistance to β-lactam antibiotics and aromatic compounds. Six highly conserved residues in CarR were found to strongly influence its ligand binding and transcriptional regulatory properties. Collectively, the results indicate that the ligand binding of CarR induces its dissociation from the carR–uspA promoter to derepress carR and uspA transcription. Ligand-free CarR also activates PSO expression, which in turn contributes to C. glutamicum stress resistance. The outcomes indicate that the stress response mechanism of CarR in C. glutamicum occurs via ligand-induced conformational changes to the protein, not via cysteine oxidation-based thiol modifications.

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