Resistance of Listeria monocytogenes F2365 Cells to Synthetic Gastric Fluid Is Greater following Growth on Ready-to-Eat Deli Turkey Meat Than in Brain Heart Infusion Broth

2007 ◽  
Vol 70 (11) ◽  
pp. 2589-2595 ◽  
Author(s):  
LUKE D. PETERSON ◽  
NANCY G. FAITH ◽  
CHARLES J. CZUPRYNSKI
Keyword(s):  
Listeria Monocytogenes ◽  
Gastrointestinal Tract ◽  
High Risk ◽  
Stationary Phase ◽  
Brain Heart Infusion ◽  
Gastric Fluid ◽  
Brain Heart Infusion Broth ◽  
Early Stationary Phase ◽  
Turkey Meat ◽  
Enhanced Resistance

Ready-to-eat (RTE) deli meats have been categorized as high-risk foods for contraction of foodborne listeriosis. Several recent listeriosis outbreaks have been associated with the consumption of RTE deli turkey meat. In this study, we examined whether the growth of Listeria monocytogenes F2365 on commercially prepared RTE deli turkey meat causes listerial cells to become more resistant to inactivation by synthetic gastric fluid (SGF). Listerial cells grown on turkey meat to late logarithmic–early stationary phase were significantly more resistant to SGF at pH 7.0, 5.0, or 3.5 than listerial cells grown in brain heart infusion (BHI) broth. The pH was lower in the fluid in packages of turkey meat than in BHI broth (6.5 versus 7.5). However, listerial cells grown in BHI broth adjusted to a lower pH (6.0) did not exhibit enhanced resistance to SGF. The lesser resistance to SGF of listerial cells grown in BHI broth may be due, in part, to the presence of glucose (0.2%). This study indicates the environment presented by the growth of L. monocytogenes on deli turkey meat affects its ability to survive conditions it encounters in the gastrointestinal tract.

Effects of Suspension in Emulsified Wiener or Incubation in Wiener Packages on the Virulence of Listeria monocytogenes Scott A in Intragastrically Inoculated A/J Mice†

2005 ◽  
Vol 68 (3) ◽  
pp. 597-601 ◽  
Author(s):  
NANCY G. FAITH ◽  
MARK L. TAMPLIN ◽  
DARRELL BAYLES ◽  
JOHN B. LUCHANSKY ◽  
CHARLES J. CZUPRYNSKI
Keyword(s):  
Listeria Monocytogenes ◽  
Gastrointestinal Tract ◽  
Meat Products ◽  
Brain Heart Infusion ◽  
Systemic Infection ◽  
Brain Heart Infusion Broth ◽  
Harsh Environment ◽  
Meat Matrix

Several outbreaks of listeriosis have been associated with contamination of wieners and other ready-to-eat meat products. In this study, we addressed the question of whether emulsification in, or growth on, wieners triggers a response in the listerial cells that makes them more virulent or protects them against the harsh environment of the gastrointestinal tract in mice. Our results indicate that Listeria monocytogenes Scott A grows poorly, if at all, in one brand of commercially prepared wieners inoculated with 5 × 103 to 5 × 106 CFU per package and incubated at 15°C. Neither L. monocytogenes Scott A emulsified in a slurry of homogenized wieners nor recovered from wiener package fluid after a 7-day incubation at 15°C were more virulent when inoculated into the stomachs of A/J mice than L. monocytogenes Scott A grown in brain heart infusion broth. These findings suggest that the ability of L. monocytogenes Scott A to cause systemic infection following introduction into the gastrointestinal tract was not improved by incubation with wieners or suspension in a meat matrix.

scholarly journals Listeria monocytogenes Grown at 7°C Shows Reduced Acid Survival and an Altered Transcriptional Response to Acid Shock Compared to L. monocytogenes Grown at 37°C

2012 ◽  
Vol 78 (11) ◽  
pp. 3824-3836 ◽  
Author(s):  
R. A. Ivy ◽  
M. Wiedmann ◽  
K. J. Boor
Keyword(s):  
Listeria Monocytogenes ◽  
Stationary Phase ◽  
Growth Phase ◽  
Transcriptional Response ◽  
Brain Heart Infusion ◽  
Gastric Fluid ◽  
Food Storage ◽  
Content Type ◽  
Acid Shock ◽  
Temperature And Growth

ABSTRACTSurvival of the food-borne pathogenListeria monocytogenesin acidic environments (e.g., in the human stomach) is vital to its transmission. Refrigerated, ready-to-eat foods have been sources of listeriosis outbreaks. The purpose of this study was to determine whether growth at a low temperature (i.e., 7°C) affectsL. monocytogenessurvival or gene transcription after exposure to a simulated gastric environment (i.e., acid shock at 37°C).L. monocytogenescells grown at 7°C were less resistant to artificial gastric fluid (AGF) or acidified brain heart infusion broth (ABHI) than bacteria grown at higher temperatures (i.e., 30°C or 37°C). ForL. monocytogenesgrown at 7°C, stationary-phase cells were more resistant to ABHI than log-phase cells, indicating that both temperature and growth phase affect acid survival. Microarray transcriptomic analysis revealed that the number and functional categories of genes differentially expressed after acid shock differed according to both growth temperature and growth phase. The acid response ofL. monocytogenesgrown to log phase at 37°C involved stress-related transcriptional regulators (i.e., σB, σH, CtsR, and HrcA), some of which have been implicated in adaptation to the intracellular environment. In contrast, for bacteria grown at 7°C to stationary phase, acid exposure did not result in differential expression of the stress regulons examined. However, two large operons encoding bacteriophage-like proteins were induced, suggesting lysogenic prophage induction. The adaptive transcriptional response observed in 37°C-grown cells was largely absent in 7°C-grown cells, suggesting that temperatures commonly encountered during food storage and distribution affect the ability ofL. monocytogenesto survive gastric passage and ultimately cause disease.

Survival of Listeria monocytogenes Strain H7762 and Resistance to Simulated Gastric Fluid following Exposure to Frankfurter Exudate†

2004 ◽  
Vol 67 (6) ◽  
pp. 1170-1176 ◽  
Author(s):  
LAURA D. WONDERLING ◽  
DARRELL O. BAYLES
Keyword(s):  
Listeria Monocytogenes ◽  
Brain Heart Infusion ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Time Of Death ◽  
Nonlinear Regression Analysis ◽  
Underlying Distribution ◽  
Acid Sensitivity ◽  
The Mean ◽  
Mean Time

Listeria monocytogenes strain H7762, a frankfurter isolate, was tested to determine whether it was able to survive at 4°C in frankfurter pack fluid (exudate) and to determine whether food exposure affects its acid sensitivity. Cultures were sampled and tested for acid sensitivity by challenge with simulated gastric fluid (SGF). SGF challenges performed immediately after inoculation revealed that between 20 and 26% of the cells survived the full 30 min of SGF challenge regardless of whether the cells were inoculated into brain heart infusion broth (BHI) or exudate. After 2 days of incubation, cells exposed to both exudate and BHI had significantly decreased SGF resistance; however, the cells exposed to exudate were significantly more SGF resistant than cells exposed to BHI (after 15 min of SGF treatment, 33% of the exudate-exposed cells survived and 12% of the BHI-exposed cells survived). L. monocytogenes exposed to exudate had greater SGF resistance at all challenge times compared with BHI-exposed cells from day 2 through day 4. From days 8 to 15, exudate-exposed cells continued to have greater SGF resistance than BHI-exposed cells up to 10 min of SGF challenge but were as sensitive as the BHI-exposed cells at 20 to 30 min of challenge. By day 25, cells exposed to exudate were significantly more sensitive to SGF challenge than BHI-exposed cells. The survivor data generated from SGF challenges were modeled by a nonlinear regression analysis to calculate the underlying distribution of SGF resistance found in the challenged populations. These analyses indicated that L. monocytogenes exposed to exudate at 48C had a broader distribution of resistance to SGF compared with cells exposed to BHI at 4°C. In addition, the mean time of death during SGF treatment was greater after exposure to exudate, indicating that cells exposed to exudate were more resistant to killing by SGF. These data suggest that exposure to frankfurter exudate might render L. monocytogenes more able to survive the stomach environment during the initial stages of infection.

Effects of pH and Agitation on the Growth of Listeria monocytogenes Scott A in Brain Heart Infusion Broth Containing Combined Potassium Lactate and Sodium Diacetate during Storage at 4 or 10°C

2003 ◽  
Vol 66 (8) ◽  
pp. 1469-1473 ◽  
Author(s):  
K. S. YOON ◽  
C. N. BURNETTE ◽  
R. C. WHITING
Keyword(s):  
Listeria Monocytogenes ◽  
Brain Heart Infusion ◽  
Lag Time ◽  
Low Ph ◽  
Brain Heart Infusion Broth ◽  
Limited Effect ◽  
Potassium Lactate ◽  
Effects Of Ph ◽  
Sodium Diacetate ◽  
Kinetics Of

The objective of this study was to compare the effects of pH on the growth kinetics of Listeria monocytogenes Scott A in static and agitated broths stored at 4 and 10°C with and without a combination of 1.85% potassium lactate (PL) and 0.13% sodium diacetate (SDA) (3.3% of a 60% commercial solution, PURASAL P Opti.Form 4). The pH of brain heart infusion broth without (control) or with 1.85% PL + 0.13% SDA was adjusted to 5.5, 6.0, 6.5, and 7.5. L. monocytogenes Scott A was inoculated (at 102 CFU/ml) into pH-adjusted broth, which was stored at 4 or 10°C with or without agitation. At pH 5.5, a listeriostatic effect was observed for the broth containing 1.85% PL + 0.13% SDA at 4 and 10°C both with and without agitation. At pH 6.0, 1.85% PL + 0.13% SDA fully controlled the growth of L. monocytogenes Scott A in static broth at 4°C for up to 20 days and significantly slowed the growth of the pathogen in agitated broth. At 10°C, the growth of L. monocytogenes Scott A was significantly reduced by 1.85% PL + 0.13% SDA in agitated and unagitated broths. At pH 6.5, 1.85% PL + 0.13% SDA significantly suppressed the growth of L. monocytogenes Scott A at both 4°C (P < 0.001) and 10°C (P < 0.01). At pH 7.5, 1.85% PL + 0.13% SDA had a limited effect on the growth of L. monocytogenes Scott A in broth stored at 4 and 10°C. At 4°C, agitation decreased the lag time and increased the growth rate of L. monocytogenes Scott A at all tested pHs. A similar but less obvious trend was observed for broths stored at 10°C. These results indicate that lactate-diacetate combinations effectively acted with low pH and temperature to inhibit the growth of L. monocytogenes Scott A.

Inhibitory Effect of Select Nitrocompounds on Growth and Survivability of Listeria monocytogenes In Vitro†‡

2006 ◽  
Vol 69 (5) ◽  
pp. 1061-1065 ◽  
Author(s):  
M. DIMITRIJEVIC ◽  
R. C. ANDERSON ◽  
T. R. CALLAWAY ◽  
Y. S. JUNG ◽  
R. B. HARVEY ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Growth Rates ◽  
Specific Growth ◽  
Brain Heart Infusion ◽  
Inhibitory Effect ◽  
Brain Heart Infusion Broth ◽  
Anaerobic Culture ◽  
Aerobic Culture ◽  
Specific Growth Rates

We report the effects of 2-nitro-1-propanol (2NPOH), 2-nitroethanol (2NEOH), and nitroethane (NE) on growth and survivability of Listeria monocytogenes. In all cases, inhibition was greatest with 2NPOH and least with NE. For example, specific growth rates of L. monocytogenes strain 18 declined (P < 0.05) 76, 60, and 29% from controls during aerobic culture at 37°C in brain heart infusion broth containing 10 mM 2NPOH, 2NEOH, or NE, respectively. Mean specific growth rate for the controls incubated likewise without added nitrocompound was 0.62 ± 0.02 h−1. Specific growth rates of L. monocytogenes Scott A decreased (P < 0.05) 67, 45, and 11%, respectively, from controls (0.67 ± 0.02 h−1) when cultured similarly. Specific growth rates for L. monocytogenes strain 18 incubated similarly except at 30°C were reduced (P < 0.05) 76, 60, and 30%, respectively, and were reduced (P < 0.05) 78, 23, and 23% during anaerobic culture at 30°C in brain heart infusion broth containing 15 mM 2NPOH, 2NEOH, or NE (control rates ranged from 0.37 ± 0.07 to 0.74 ± 0.05 h−1). Survivability of L. monocytogenes strain 18 was reduced (P < 0.05) during aerobic storage (4 months at 4°C) in brain heart infusion broth containing 2NPOH or 2NEOH (by 7.8 and 1.9 log units, respectively) but not NE. The inhibitory effect of 2NPOH was approximately 20% greater during growth at pH 7.0 than at pH 5.6 or 8.0. These results demonstrate the differential inhibitory activity of 2NPOH, 2NEOH, and NE against L. monocytogenes in vitro.

Microbial Competition: Effect of Culture Conditions on the Suppression of Listeria monocytogenes Scott A by Carnobacterium piscicola†

1997 ◽  
Vol 60 (3) ◽  
pp. 254-261 ◽  
Author(s):  
ROBERT L. BUCHANAN ◽  
LORI K. BAGI
Keyword(s):  
Listeria Monocytogenes ◽  
Brain Heart Infusion ◽  
Oxygen Depletion ◽  
Culture Conditions ◽  
Brain Heart Infusion Broth ◽  
Microbial Competition ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Carnobacterium Piscicola ◽  
Effects Of Temperature

The effects of temperature (4,12, and 19°C), pH (5, 6, and 7), and NaCl (5, 25, and 45 g/liter) on the growth of Listeria monocytogenes Scott A in the presence of either Camobacterium piscicola LK5 or 2762 were studied quantitatively in brain heart infusion broth. Strain LK5 produces a bacteriocin that is released into the environment, whereas 2762 appears to produce a bacteriocin that remains cell associated. The primary effect of both C. piscicola strains was a suppression of the maximum population density (MPD) attained by L. monocytogenes. The extent of this depression was dependent on the three culture variables, and appeared to be a function of their influence on the relative growth rates of the two species. The effects were similar with both strains. However, two bacteriocin-negative strains, 2305 and 2818, also depressed the growth of L. monocytogenes. Little of the C. piscicola isolates' ability to suppress L. monocytogenes appeared attributable to bacteriocin production. The MPD-depressing activity of 2762 could not be attributed to peroxide, pH depression, or oxygen depletion. However, MPD suppression may involve nutrient depletion, since the extent of MPD suppression was decreased in a dose-related manner when the two species were cultured in 3 × and 6× brain heart infusion broth.

Listeria monocytogenes F5069 Thermal Death Times in Liquid Whole Egg1,2

1990 ◽  
Vol 53 (1) ◽  
pp. 6-8 ◽  
Author(s):  
P. M. FOEGEDING ◽  
N. W. STANLEY
Keyword(s):  
Listeria Monocytogenes ◽  
Safety Factor ◽  
Capillary Tube ◽  
Brain Heart Infusion ◽  
Heating Time ◽  
Brain Heart Infusion Broth ◽  
Initial Population ◽  
Thermal Death ◽  
Liquid Whole Egg ◽  
Whole Egg

Thermal death times (F-values) for L. monocytogenes F5069 inoculated into sterile liquid whole egg were determined between 62 and 73°C by a submerged capillary tube procedure. The initial population was 5 × 106 to 2 × 107 CFU/tube (0.05 ml). High populations intentionally were selected to build in a safety factor. At each temperature, F-values were determined to be the shortest heating time which did not permit recovery of L. monocytogenes from six or more replicate tubes. L. monocytogenes were recovered by incubating the entire contents of the capillary tube in brain heart infusion broth at 25°C for 2 weeks. At 62°C, F = 16 min and at 69°C, F = 1.6 min. The zF-value was 7.1°C. Minimal pasteurization of egg would not result in product free from L. monocytogenes if initial populations were large. Ultrapasteurization processes may be designed to produce product free from L. monocytogenes and appropriate for prolonged refrigeration.

scholarly journals Influence of Catalase and Superoxide Dismutase on Ozone Inactivation of Listeria monocytogenes

2000 ◽  
Vol 66 (4) ◽  
pp. 1405-1409 ◽  
Author(s):  
Christopher W. Fisher ◽  
Dongha Lee ◽  
Beth-Anne Dodge ◽  
Kristen M. Hamman ◽  
Justin B. Robbins ◽  
...  
Keyword(s):  
Cell Death ◽  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Stationary Phase ◽  
Distilled Water ◽  
Late Stationary Phase ◽  
Early Stationary Phase ◽  
Phosphate Buffered Saline

ABSTRACT The effects of ozone at 0.25, 0.40, and 1.00 ppm on Listeria monocytogenes were evaluated in distilled water and phosphate-buffered saline. Differences in sensitivity to ozone were found to exist among the six strains examined. Greater cell death was found following exposure at lower temperatures. Early stationary-phase cells were less sensitive to ozone than mid-exponential- and late stationary-phase cells. Ozonation at 1.00 ppm of cabbage inoculated with L. monocytogenes effectively inactivated all cells after 5 min. The abilities of in vivo catalase and superoxide dismutase to protect the cells from ozone were also examined. Three listerial test strains were inactivated rapidly upon exposure to ozone. Both catalase and superoxide dismutase were found to protect listerial cells from ozone attack, with superoxide dismutase being more important than catalase in this protection.

Growth, Injury, and Survival Potential of Yersinia enterocolitica. Listeria monocytogenes, and Staphylococcus aureus in Brine Chiller Conditions†

1997 ◽  
Vol 60 (11) ◽  
pp. 1334-1340 ◽  
Author(s):  
ARTHUR J. MILLER ◽  
JEFFREY E. CALL ◽  
B. SHAWN EBLEN
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Yersinia Enterocolitica ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Processed Foods ◽  
Survival Potential ◽  
And Staphylococcus Aureus ◽  
Significant Injury

A model brine system was used to evaluate growth, injury, and survival potential of Yersinia enterocolitica. Listeria monocytogenes, and Staphylococcus aureus. Each strain was incubated for up to 30 days at −12 to 28°C in brain heart infusion broth containing 0.5 to 20% NaCl. Samples were enumerated on a dual agar plating system to assess growth and injury. Y. enterocolitica grew at −2°C in 0.5% brine and at 5°C in 5% NaCl. L. monocytogenes grew at 5°C in 5% NaCl and at 12°C in 9% NaCl. S. aureus grew at 12°C in 5% NaCl. Significant injury was observed for two of the pathogens, but not for L. monocytogenes. Bacteriostatic or lethal conditions were maintained for the three organisms at −2°C and 9% NaCl. While lethal NaCl and temperature combinations were defined for Y. enterocolitica and S. aureus. L. monocytogenes survived for 30 days at −12°C in 20% NaCl. This study provides safety criteria and recommendations for use in the operation of recycle brine systems for cooling processed foods.

Effect of Benzalkonium Chloride on Viability and Energy Metabolism in Exponential- and Stationary-Growth-Phase Cells of Listeria monocytogenes

2001 ◽  
Vol 64 (4) ◽  
pp. 476-482 ◽  
Author(s):  
S. B. I. LUPPENS ◽  
T. ABEE ◽  
J. OOSTEROM
Keyword(s):  
Listeria Monocytogenes ◽  
Stationary Phase ◽  
Growth Phase ◽  
Benzalkonium Chloride ◽  
Brain Heart Infusion ◽  
Viable Cell ◽  
Exponential Phase ◽  
Similar Reduction ◽  
The Difference ◽  
Unit Reduction

The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter−1), a similar reduction in viable cell numbers was observed for stationary-phase cells and exponential-phase cells (an approximately 0.22–log unit reduction), although their membrane potential and pH gradient were dissipated. However, at higher concentrations of BAC, exponential-phase cells were more susceptible than stationary-phase cells. At 25 mg liter−1, the difference in survival on plates was more than 3 log units. For both types of cells, killing, i.e., more than 1–log unit reduction in survival on plates, coincided with complete inhibition of acidification and respiration and total depletion of ATP pools. Killing efficiency was not influenced by the presence of glucose, brain heart infusion medium, or oxygen. Our results suggest that growth phase is one of the major factors that determine the susceptibility of L. monocytogenes to BAC.

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