Growth and Survival of Listeria monocytogenes in Vacuum-Packaged Ground Beef Inoculated with Lactobacillus alimentarius FloraCarn L-2

1998 ◽  
Vol 61 (5) ◽  
pp. 551-556 ◽  
Author(s):  
BENJAMIN J. JUVEN ◽  
SUSAN F. BAREFOOT ◽  
MERLE D. PIERSON ◽  
LINDA H. McCASKILL ◽  
BRIAN SMITH
Keyword(s):  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Resistant Mutant ◽  
Antibiotic Resistant ◽  
Growth And Survival ◽  
Ca 50 ◽  
Psychrotrophic Strain

A culture of the psychrotrophic strain FloraCarn L-2 of Lactobacillus alimentarius was added to ground beef (pH 5.4) inoculated with two isolates of Listeria monocytogenes able to grow in refrigerated ground beef. The ground beef was vacuum-packaged and stored for 9 weeks at 4°C. Populations of inoculated L. monocytogenes initially were 6.3 to 6.4 log10 CFU/g and increased to 7.4 log10 CFU/g in ground beef with no added lactobacilli. Addition of L. alimentarius L-2 or its antibiotic-resistant mutant SRL-2 reduced the final populations of L. monocytogenes to 4.3 or 4.1 log10 CFU/g, respectively. L. alimentarius L-2 did not produce bacteriocins or hydrogen peroxide in vitro. The antilisterial effect of L. alimentarius observed in laboratory media and ground beef is attiibuted to lactic acid (ca. 50 mM) produced by growing cultures.

Inhibition of Listeria monocytogenes by Milk Culture Filtrates from Lactobacillus delbrueckii subsp. lactis

1992 ◽  
Vol 55 (7) ◽  
pp. 542-544 ◽  
Author(s):  
GEORGE THARRINGTON ◽  
KENT M. SORRELLS
Keyword(s):  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Causative Factor ◽  
Lactobacillus Delbrueckii ◽  
Culture Filtrates ◽  
In Vitro Inhibition ◽  
Lactobacillus Delbrueckii Subsp

Milk culture filtrates from Lactobacillus delbrueckii subsp. lactis were found to be inhibitory to test strains of Listeria monocytogenes. Effective in vitro inhibition was found in broth cultures and well diffusion assays. The causative factor(s) of inhibition was lactic acid and hydrogen peroxide.

Effect of pH, Acidulant, Time, and Temperature on the Growth and Survival of Listeria monocytogenes

1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Malic Acid ◽  
Incubation Temperature ◽  
Growth And Survival ◽  
Ph Values

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).

Inactivation of Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, and Listeria monocytogenes on Lettuce by Hydrogen Peroxide and Lactic Acid and by Hydrogen Peroxide with Mild Heat

2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
CHIA-MIN LIN ◽  
SARAH S. MOON ◽  
MICHAEL P. DOYLE ◽  
KAY H. McWATTERS
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Sensory Characteristics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.

Growth, Inhibition, and Survival of Listeria monocytogenes as Affected by Acidic Conditions

1990 ◽  
Vol 53 (8) ◽  
pp. 652-655 ◽  
Author(s):  
DONALD E. CONNER ◽  
VIRGINIA N. SCOTT ◽  
DANE T. BERNARD
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Growth Inhibition ◽  
Propionic Acid ◽  
Cell Populations ◽  
Growth And Survival ◽  
Viable Cells ◽  
Acidic Conditions ◽  
Ph Range ◽  
Lactic Acids

Growth and survival of four strains of Listeria monocytogenes under acidic conditions were investigated. Tryptic soy broth with yeast extract (TSBYE) was acidified with acetic, citric, hydrochloric, lactic, or propionic acid to pH 4.0–6.0, inoculated with L. monocytogenes and incubated at 30 or 4°C. The minimum test pH at which L. monocytogenes did not grow (inhibitory pH) was determined for each acid. In the pH range tested, this inhibitory pH was 5.0 for propionic acid, 4.5 for acetic and lactic acids, and 4.0 for citric and hydrochloric acids. All four strains gave similar results. Subsequent studies were conducted at 10 and 30°C to determine changes in cell populations in TSBYE adjusted to each inhibitory pH. Initial populations of viable cells (104 CFU/ml) were reduced to <10 CFU/ml within 1–3 weeks at 30°C, whereas at 10°C, L. monocytogenes survived for 11–12 weeks in acetic, citric, or propionic acid-adjusted media and for 6 weeks in media adjusted with hydrochloric or lactic acid. The concentration of undissociated lactic acid was 0.002 M at pH 4.5.

scholarly journals Application of Neutral Electrolyzed Water on pork chops and its impact on meat quality

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Erwin Torres-Rosales ◽  
Andres Rivera-Garcia ◽  
Patricia Janet Rosario-Perez ◽  
Juan Carlos Ramirez-Orejel ◽  
David Paez-Esquiliano ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Color Change ◽  
Thiobarbituric Acid ◽  
Physicochemical Analysis ◽  
Pork Meat ◽  
Electrolyzed Water ◽  
All Solutions ◽  
New Treatment

AbstractPhysicochemical and microbiological properties of pork chops sprayed with Neutral Electrolyzed Water (NEW) were evaluated during storage at refrigeration temperature. Pork chops were randomly allocated into three groups and were artificially contaminated with an inoculum of 106 CFU/mL of Listeria monocytogenes. Each group was treated with either NEW (58 ppm), NaClO (35 ppm), or saline solution (SS). Subsequently, recovered bacteria were plated on TSA petri dishes and the reduction percentage of Listeria monocytogenes was calculated 24 h and 8 days after treatment. Physicochemical analysis [pH, content of lactic acid, thiobarbituric acid reactive substances (TBARS) and total volatile base nitrogen (TVBN)] were performed to evaluate the effect of all solutions used on pork meat kept at 4 °C for 19 days. In vitro NEW reduced L. monocytogenes titers by > 99.98% and 80.19% and 90.35% in artificially contaminated pork 24 h and 8 days after NEW treatment, respectively. Compared to the SS treatment, NEW and NaClO solutions caused a 0.67 Log UFC/g and 0.65 Log UFC/g reduction respectively. After eight days post-treatment, NEW and NaClO bacterial titers were below the SS treatment. NEW caused little color change in treated meat. It helped to reduce the formation of lactic acid and TVB-N when pork chops are kept at 4 °C for 19 days. Therefore, NEW could be considered as a new alternative to sanitize and preserve pork meat.

scholarly journals Impact of Hydrogen Peroxide on Growth and Survival ofListeria MonocytogenesBiofilms

2010 ◽  
Vol 7 (3) ◽  
pp. 1008-1012
Author(s):  
Farhan Zameer ◽  
Shubha Gopal
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Listeria Monocytogenes ◽  
Stationary Phase ◽  
Adaptive Behavior ◽  
Potential Risk ◽  
Growth Cycle ◽  
Food Preservation ◽  
Survival Strategies ◽  
Growth And Survival

The present study aimed to understand the survival strategies adapted byListeria monocytogenesto combat oxidative stress in planktonic and biofilm cells with response to hydrogen peroxide (H2O2). The sensitivity ofL. monocytogenesto H2O2(oxidative stress) was found to vary in growth cycle. Early log phase cells were found to be sensitive to 100 μM H2O2when compared to stationary phase. Biofilm population was found to be resistant to the oxidative stress induced at 4% of H2O2when compared to their planktonic counterpart at 3.5%. This adaptive behavior allows the pathogen to overcome food preservation and safety barriers, which pose a potential risk to human health. The overall results suggest that, H2O2at a concentration of 6% could be used as a potent sanitizer for the elimination of listerial biofilms.

scholarly journals Impact of Probiotic on the Number of Lactic Acid Rods Forming Hydrogen Peroxide Isolated From Porkers and on Changes in Drug Resistance of Selected Escherichia Coli Isolates

2012 ◽  
Vol 56 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Marek Selwet ◽  
Mariola Galbas ◽  
Piotr Dullin
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Drug Resistance ◽  
Lactic Acid ◽  
Control Group ◽  
Large White ◽  
E Coli ◽  
Probiotic Preparation ◽  
Hydrogen Oxide

Abstract The presented investigations were conducted on a group of 60 porkers of crossbreed Polish Landrace x Large White Polish. The animals were divided into two equal experimental groups. The control group (K) was fed diets without supplementation with probiotics, group (P) - diets with the addition of probiotic (0.2 kg t-1 feed). The aim of the study was to determine the effect of probiotic preparation on total numberof lactic acid rods from the Lactobacillus genus and those forming hydrogen oxide. The second part of experiment concerned the influence of probiotic preparation on the number, haemolytic ability and changes in drug resistance of Escherichia coli isolated from animal faeces. The significantly highest number of Lactobacillus sp. were determined in the saliva of porkers fed diets with the addition of probiotic, while the lowest in the control group. Lactobacillus sp. rods capable of forming hydrogen peroxide were isolated from 17 animals in group K and from three animals in group P. E. coli was determined in each examined sample of faeces. In groups K and P, counts of these bacteria were similar and did not differ statistically. High numbers of haemolytic isolates (haemolysis β) were found in faeces of animals fed diets with the addition of probiotic. Number and proportions of resistant isolates in groups K and P were different. Gentamicin was characterised by exceptionally high in vitro effectiveness. The used probiotic increased drug resistance of E. coli and increased frequency of incidence of haemolysis β.

scholarly journals In vitro evaluation of bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated during traditional Sicilian cheese making

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Giusi Macaluso ◽  
Gerlando Fiorenza ◽  
Raimondo Gaglio ◽  
Isabella Mancuso ◽  
Maria Luisa Scatassa
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Salmonella Enteritidis ◽  
Raw Milk ◽  
Starter Cultures ◽  
Proteinase K ◽  
Alternative Methods ◽  
Diffusion Assay

Bacteriocins are antimicrobial proteins produced by bacteria that inhibit with a bactericidal or bacteriostatic mode of action, the growth of other bacteria. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognized as safe (GRAS) and useful to control the frequent development of pathogens and spoilage microorganisms; for this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances (BLIS), by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the <em>spot on the lawn</em> and the <em>well-diffusion assay</em> and the sensitivity to proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes. The indicator strains used were: <em>Listeria monocytogenes</em>, <em>Staphylococcus aureus</em>, <em>E. coli</em>, <em>Salmonella enteritidis</em>. A total of 223 strains (belonged to the species <em>Enterococcus</em> spp., <em>Lactobacillus</em> spp., <em>Pediococcus</em> spp., <em>Streptococcus</em> spp., <em>Leuconostoc</em> spp. and <em>Lactococcus lactis</em>) were found to inhibit the growth of <em>Listeria monocytogenes</em> by using the <em>spot on the lawn</em> method; only 37 of these were confirmed by using the well-diffusion assay. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product.

Inactivation of Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on Apples, Oranges, and Tomatoes by Lactic Acid with Hydrogen Peroxide

2002 ◽  
Vol 65 (1) ◽  
pp. 100-105 ◽  
Author(s):  
KUMAR S. VENKITANARAYANAN ◽  
CHIA-MIN LIN ◽  
HANNALORE BAILEY ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Chemical Treatment ◽  
Salmonella Enteritidis ◽  
Deionized Water ◽  
Wash Water ◽  
Escherichia Coli O157 ◽  
E Coli

The objective of this study was to develop a practical and effective method for inactivating or substantially reducing Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on apples, oranges, and tomatoes. Apples, oranges, and tomatoes were spot-inoculated with five-strain mixtures of E. coli O157:H7, Salmonella Enteritidis, and L. monocytogenes near the stem end and were submerged in sterile deionized water containing 1.5% lactic acid plus 1.5% hydrogen peroxide for 15 min at 40°C. Inoculated samples treated with sterile deionized water at the same temperature and for the same duration served as controls. The bacterial pathogens on fruits subjected to the chemical treatment were reduced by &gt;5.0 log10 CFU per fruit, whereas washing in deionized water decreased the pathogens by only 1.5 to 2.0 log10 CFU per fruit. Furthermore, substantial populations of the pathogens survived in the control wash water, whereas no E. coli O157:H7, Salmonella Enteritidis, or L. monocytogenes cells were detected in the chemical treatment solution. The sensory and qualitative characteristics of apples treated with the chemical wash solution were not adversely affected by the treatment. It was found that the treatment developed in this study could effectively be used to kill E. coli O157:H7, Salmonella Enteritidis, and L. monocytogenes on apples, oranges, and tomatoes at the processing or packaging level.

Sign in / Sign up

Export Citation Format

Share Document