Changes in growth, rRNA content, and cell morphology of Listeria monocytogenes induced by CO2 up- and downshift

Jydegaard-Axelsen, Anne-Marie; Aaes‐Jørgensen, Anders; Koch, Anette Granly; Jensen, Jens S.; Knøchel, Susanne

doi:10.1016/j.ijfoodmicro.2004.05.019

Cited by 19 publications

(8 citation statements)

References 21 publications

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“…In addition, they seemed to lose their motility. Pronounced elongation of cells has previously been reported for Salmonella and Listeria monocytogenes cells stressed by gas (100% CO 2 ) or low water activity ( a w =0.93–0.98) within the temperature growth range (Jørgensen et al , 1995; Mattick et al , 2000; Nilsson et al , 2000; Jydegaard‐Axelsen et al , 2005). Brief elongation of C. jejuni at 37°C has also previously been observed in the transitional state from the exponential to stationary phase and again from the stationary to death phase (Thomas et al , 1999).…”

Section: Discussionmentioning

confidence: 77%

Survival ofCampylobacter jejuniin different gas mixtures

Boysen

Knøchel

Rosenquist³

2007

FEMS Microbiology Letters

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Campylobacter jejuni in fresh chilled chicken meat is known to be a major risk factor for human gastrointestinal disease. In the present study, the survival under chilled conditions of different C. jejuni strains exposed to different gas mixtures usually used for gas packaging of food was examined. Bolton broth and fresh, skinless chicken fillets were inoculated with six and four strains, respectively, and exposed to the gas mixtures 70/30% O(2)/CO(2), 70/30% N(2)/CO(2), and 100% N(2) (the latter only investigated in broth) at refrigeration temperature (4-5 degrees C). In broth culture, the strains survived significantly longer when exposed to 100% N(2) and 70/30% N(2)/CO(2) than in the oxygen-containing gas mixture, 70/30% O(2)/CO(2) (P<0.0001). For the two anaerobic gas mixtures, the reductions only reached 0.3-0.8 log(10) CFU mL(-1) within the same period. In the presence of oxygen, the numbers of C. jejuni were reduced by a minimum of 4.6 log(10) CFU mL(-1) over 21 days. When inoculated onto chicken fillets, the C. jejuni strains also died significantly faster in the oxygen-containing gas mixture, 70/30% O(2)/CO(2) (P<0.0001), reaching reductions of 2.0-2.6 log(10) CFU g(-1) after 8 days. In the gas mixture without oxygen (70/30% N(2)/CO(2)), no reductions were observed.

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Section: Discussionmentioning

confidence: 77%

Survival ofCampylobacter jejuniin different gas mixtures

Boysen

Knøchel

Rosenquist³

2007

FEMS Microbiology Letters

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“…As a consequence, the adaptation response may result in a modified expression of physiological and phenothypical characteristics. For example, authors refer that stress factors such as salinity, nutrient depletion, temperature, pH and atmosphere affect bacterial cell shape, suggesting that morphological changes are correlated to adaptive mechanisms that allow bacteria to prolong survival under adverse conditions (Mattick et al 2000(Mattick et al , 2003aEveris and Betts 2001;Alonso et al 2002;Shi and Xia 2003;Alterman et al 2004;Jydegaard-Axelsen et al 2005;Piuri et al 2005;McMahon et al 2007;Pianetti et al 2009). Furthermore, several studies report that pathogenic bacteria may modulate their virulence properties in response to stress conditions, therefore influencing the outcome of the infectious process in the host.…”

Section: Introductionmentioning

confidence: 99%

Changes in adhesion ability of Aeromonas hydrophila during long exposure to salt stress conditions

et al. 2012

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Aims Stressful environmental conditions influence both bacterial growth and expression of virulence factors. In the present study, we evaluated the influence of NaCl on Aeromonas hydrophila adhesiveness at two temperatures. This agent is often involved in clinical cases; however, its pathogenic potential is still not fully understood. Methods and Results Bacteria were grown in presence of 1·7%, 3·4%, 6·0% NaCl over a 188 day period and then reinoculated in fresh Nutrient Broth with incubation at 4 and 24°C. Bacterial adhesiveness was tested on Hep‐2 cells, and specimens were processed for light, scanning and transmission electron microscopy. Adhesive capacity decreased over time with an increase in reduction percentages depending on NaCl concentrations. At 1·7% NaCl, the reduction was apparently temporary and adhesiveness rapidly recovered in revitalized bacteria, while 3·4%, 6·0% NaCl seemed to be detrimental. Normal, elongated and filamentous bacteria retained adhesiveness capability, although with reduced expression, while in spherical cells, this property seemed to be lost or dramatically reduced. Conclusions Our study shows that high osmolarity plays a significant role in adhesion inhibition, therefore having possible implications in the pathogenesis of the infections by Aer. hydrophila. Significance and Impact of the Study This study intends to give a contribution to a better understanding of the pathogenic role of this bacterium whose pathogenicity is still under debate.

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“…2004) Pseudomonas (Shi and Xia 2003), Campylobacter (Alonso et al. 2002) Listeria (Jydegaard‐Axelsen et al. 2005), Escherichia coli (Mattick et al.…”

Section: Introductionmentioning

confidence: 99%