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.

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 CULTIVO PILOTO DE MACROALGAS ROJAS (RHODOPHYTA) EN BAHÍA PORTETE, LA GUAJIRA, COLOMBIA

2016 ◽  
Vol 37 (2) ◽  
Author(s):  
Oscar Delgadillo Garzón ◽  
Federico Newmark
Keyword(s):  
Culture Conditions ◽  
Complete Characterization ◽  
Hypnea Musciformis ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Culture Techniques ◽  
High Loss ◽  
Upwelling Event ◽  
Biomass Increase

A seaweed pilot culture was developed in Portete bay, La Guajira, Colombia, between July 2005 and June 2006. The aim of this study was to evaluate the potential of this activity as a productive alternative to coastal communities thriving in the region. One hundred fourteen kilograms of the red algae Gracilaria cervicornis, Hydropuntia cornea, Hypnea musciformis and Grateloupia sp. were attached to polypropylene ropes and cylindrical meshes, at two sites of the bay. Gracilaria cervicornis had relative growth rates (RGR) between 0.1 % day-1 and 1.22 % day-1, with a mean of 0.44 % day-1, strong epiphytism and high loss rates. Hydropuntia cornea had a mean RGR of 0.91 % day-1 varying between 0.02 % day-1 and 3.5 % day-1 at site one, while at site two it had an average RGR of 0.97 % day-1 with a range between 0.03 % day-1 to 4.1 % day-1 with the maximum value recorded in February 2006. Small sized fragments exhibited the best RGR and biomass increase in comparison to larger fragments. Hypnea musciformis and Grateloupia sp. did not fare well under culture conditions due to their fragility. Environmental factors such as temperature and salinity had great variation in time, but no correlation was evident with RGR. The greatest RGR and epiphytism reduction were observed during the dry season where minimum temperatures were registered and there was an increase in nutrient availability due to a seasonal upwelling event. Different factors, such as water motion, nutrient concentration, temperature, salinity, herbivory, and epiphytism, exert some influence on seaweed growth, although is necessary to perform a complete characterization of physicochemical parameters in order to assess the bay’s productivity. It is also necessary to develop experiments aimed at reducing the incidence of different factors in the cultures. The RGR of some local algae species reported in this study suggest that Portete bay has adequate conditions to develop seaweed culture but, in order to do so, it is necessary to improve some of the culture techniques.

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.

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.

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.

Diversity Assessment of Heat Resistance of Listeria monocytogenes Strains in a Continuous-Flow Heating System

2009 ◽  
Vol 72 (5) ◽  
pp. 999-1004 ◽  
Author(s):  
STIJN van der VEEN ◽  
ARJEN WAGENDORP ◽  
TJAKKO ABEE ◽  
MARJON H. J. WELLS-BENNIK
Keyword(s):  
High Temperature ◽  
Listeria Monocytogenes ◽  
Continuous Flow ◽  
Foodborne Pathogen ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Heat Resistant ◽  
High Temperature Short Time ◽  
Diversity Assessment ◽  
Short Time

Listeria monocytogenes is a foodborne pathogen that has the ability to survive relatively high temperatures compared with other nonsporulating foodborne pathogens. This study was performed to determine whether L. monocytogenes strains with relatively high heat resistances are adequately inactivated in a high-temperature, short-time pasteurization process (72°C for 15 s). To obtain heat-resistant strains, 48 strains were exposed to 55°C for up to 3 h. The energy of activation constant and inactivation constant of strains that survived best (strains 1E and NV8) were subsequently determined in a continuous-flow-through system. Strain Scott A was taken along as a reference. The 3 strains were cultured in whole milk and in brain heart infusion broth at 30 and 7°C. Strains 1E and NV8 were significantly more heat resistant than was strain Scott A after growth in brain heart infusion broth at 30°C and after growth in milk at 7°C. From the inactivation parameters, it was calculated that exposure to high-temperature, short-time pasteurization (72°C for 15 s) will result in 12.1-, 14.2-, and 87.5-log reductions for the strains 1E, NV8, and Scott A, respectively. These results demonstrate that industrial pasteurization conditions suffice to inactivate the most heat-resistant L. monocytogenes strains tested in this study.

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.

A Measure of Economic Growth in East and in West Pakistan

1961 ◽  
Vol 1 (2) ◽  
pp. 49-54
Author(s):  
S. U. Khan
Keyword(s):  
Regional Planning ◽  
National Income ◽  
Future Planning ◽  
Correct Evaluation ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
National Planning ◽  
Income Data ◽  
Regional Basis ◽  
The Difference

It is sometimes said that "national planning will simply have no meaning if it completely ignores the economic disparities between the two wings and fails to evolve a sensible pattern of regional planning"2. The lack of much essential data on a regional basis, however, renders any precise estimate of the relative growth rates almost impossible. Data either are not available or are inadequate on such important variables as production, income, consumption and trade, so that even a correct evaluation of past development efforts is not possible. The implications of such a situation for future planning are not difficult to understand. In this article an attempt is made to estimate the absorption of specified commodities in East and West Pakistan separately3. This will indicate the pattern of consumption and also give a rough idea about the growth rate of the two wings. With this purpose in view, quantity indices of absorption are prepared for each wing separately, taking data on availability of goods and prices from the Institute's monograph on Inflation. The quantity indi¬ces, however, are not of course strictly comparable with national income estimates because of the difference in coverage of the two series. National income data include government, services, trade, etc., while the quantity indices cover only specified goods available for each region.

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