Impact of the Population of Spoilage Microflora on the Growth of Listeria monocytogenes on Frankfurters

2006 ◽  
Vol 69 (3) ◽  
pp. 679-681 ◽  
Author(s):  
DRAGOSLAVA RADIN ◽  
STEVEN E. NIEBUHR ◽  
JAMES S. DICKSON
Keyword(s):  
Growth Rate ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Storage Period ◽  
Processed Meat ◽  
Time Intervals ◽  
Mesophilic Bacteria ◽  
Entire Storage Period ◽  
Spoilage Microflora

Approximately 100 CFU/cm2 of a five-strain mixture of Listeria monocytogenes was coinoculated onto frankfurters with three different concentrations (102, 104, and 106 CFU/cm2) of an undefined spoilage microflora derived from commercial frankfurters. The frankfurters were vacuum packaged and stored at 10°C for up to 48 days. The populations of L. monocyto-genes, aerobic mesophilic bacteria, lactic acid bacteria, and Enterobacteriaceae were determined at various time intervals during storage. After 14 days, the population of L. monocytogenes was highest when grown with a spoilage microflora population of 102 CFU/cm2, and this trend continued until 48 days. Throughout the entire storage period, the populations of L. monocytogenes at any concentration of inoculated spoilage microflora rarely differed by more than 0.5 log CFU/cm2, and the maximum observed difference as 1.1 log CFU/cm2 at 40 days. The growth rate of L. monocytogenes was approximately the same at all concentrations of the inoculated spoilage microflora. These results suggest that the concentration of spoilage microflora present on the original processed meat may have a slight impact on the growth of L. monocytogenes in the package.

Effect of Single or Sequential Hot Water and Lactic Acid Decontamination Treatments on the Survival and Growth of Listeria monocytogenes and Spoilage Microflora during Aerobic Storage of Fresh Beef at 4, 10, and 25°C

2004 ◽  
Vol 67 (12) ◽  
pp. 2703-2711 ◽  
Author(s):  
KONSTANTINOS P. KOUTSOUMANIS ◽  
LAURA V. ASHTON ◽  
IFIGENIA GEORNARAS ◽  
KEITH E. BELK ◽  
JOHN A. SCANGA ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Hot Water ◽  
Microbial Profile ◽  
Spoilage Bacteria ◽  
Brochothrix Thermosphacta ◽  
Survival And Growth ◽  
Spoilage Microflora ◽  
Storage Temperatures

The survival and growth of Listeria monocytogenes and spoilage microflora during storage of fresh beef subjected to different decontamination treatments was studied. Fresh beef inoculated with a five-strain mixture of L. monocytogenes (5.18 log CFU/cm2) was left untreated (control) or was immersed (30 s) in hot water (HW; 75°C), 2% lactic acid (LA; 55°C), hot water followed by lactic acid (HW-LA), or lactic acid followed by hot water (LA-HW) and then stored aerobically at 4, 10, and 25°C for 25, 17, and 5 days, respectively. Initial populations of L. monocytogenes were reduced by 0.82 (HW), 1.43 (LA), 2.73 (HW-LA), and 2.68 (LA-HW) log CFU/cm2. During storage, the pathogen grew at higher rates in HW than in control samples at all storage temperatures. Acid decontamination treatments (LA, HW-LA, and LA-HW) resulted in a weaker inhibition of L. monocytogenes (P < 0.05) at 25°C than at 4 and 10°C. In general, the order of effectiveness of treatments was HW-LA > LA > LA-HW > HW > control at all storage temperatures tested. In untreated samples, the spoilage microflora was dominated by pseudomonads, while lactic acid bacteria, Enterobacteriaceae, and yeasts remained at lower concentrations during storage. Brochothrix thermosphacta was detected periodically in only a limited number of samples. Although decontamination with HW did not affect the above spoilage microbial profile, acid treatments shifted the predominant microflora in the direction of yeasts and gram-positive bacteria (lactic acid bacteria). Overall, the results of the present study indicate that decontamination with LA and combinations of LA and HW could limit growth of L. monocytogenes and inhibit pseudomonads, which are the main spoilage bacteria of fresh beef stored under aerobic conditions. However, to optimize the efficacy of such treatments, they must be applied in the appropriate sequence and followed by effective temperature control.

scholarly journals Spoilage microflora of vacuum packaged frankfurters and influence on the growth of Listeria monocytogenes

2007 ◽  
Vol 23 (5-6-2) ◽  
pp. 103-112 ◽  
Author(s):  
D. Radin ◽  
S.E. Niebuhr ◽  
J.S. Dickson
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Reference Sample ◽  
Aerobic Bacteria ◽  
Lag Phase ◽  
Processed Meat ◽  
Post Processing ◽  
Initial Concentration ◽  
Final Population ◽  
Spoilage Microflora

Spoilage microflora present on vacuum packaged frankfurters is in most cases, result of post processing contamination, at the same time this is the primary cause of contamination with Listeria monocytogenes. Since spoilage organisms are present in the same environment as a pathogen, the aim was to determine their microbial interference. Approximately 100 CFU/cm2 of a five-strain mixture of L. monocytogenes was co inoculated onto frankfurters with different concentrations (103 and 106 CFU/cm2) of spoilage microflora (bacteria from genera Lactobacillus, Bacillus, Micrococcus, and Hafnia). The frankfurters were vacuum packaged and stored at 10?C for up to 48 days. The spoilage microflora that developed during storage consisted predominantly of lactic acid bacteria. The growth of mesophilic aerobic bacteria and LAB was very similar, with populations reaching 8.0 log CFU/cm2 within 24 days and final population of >9 log CFU/cm2 within 48 days. The presence of spoilage microflora extended the lag phase of L. monocytogenes until 24 days and significantly decreased pathogen level to 4 and 3 log CFU/cm2, in samples inoculated with initial concentration 103 CFU/cm2 and 106 CFU/cm2 of spoilage microflora, respectively. L. monocytogenes populations were significantly higher (P<0.05) in the reference sample (no spoilage microflora) and reached a maximum population of 5.9 log CFU/cm2 after 34 days. These results imply that competing microorganisms present on the processed meat may inhibit the growth of L. monocytogenes in the package.

Chemical Composition of and Listeria monocytogenesSurvival in White Pickled Cheese

1993 ◽  
Vol 56 (10) ◽  
pp. 841-846 ◽  
Author(s):  
O. M. ABDALLA ◽  
G. L. CHRISTEN ◽  
P. M. DAVIDSON
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Chemical Composition ◽  
Lactic Acid Bacteria ◽  
Cheese Whey ◽  
Storage Period ◽  
Pasteurized Milk ◽  
Total Solids ◽  
Produce Acid

White pickled cheese was made from pasteurized milk with 8% salt and preserved in the whey at 4°C. About 5.0 log10 CFU/ml cells of Listeria monocytogenes were inoculated into milk, and the survival of the pathogen was studied during the storage period. The chemical composition of the cheese was also determined. L. monocytogenes were not inhibited by 8% salt, but lactic acid bacteria were unable to grow and produce acid to inhibit L. monocytogenes. During ripening, the pH never decreased below 6.0. While fat, protein, total solids, and ash contents decreased in curd during ripening, the acidity and salt did not change. In cheese whey, fat, protein, acidity, and salt showed a slight increase, while total solids and ash contents were unchanged.

Effect of Antimicrobial Spice and Herb Extract Combinations on Listeria monocytogenes, Staphylococcus aureus, and Spoilage Microflora Growth on Cooked Ready-to-Eat Vacuum-Packaged Shrimp

2011 ◽  
Vol 74 (7) ◽  
pp. 1119-1125 ◽  
Author(s):  
NIMSHA S. WEERAKKODY ◽  
NOLA CAFFIN ◽  
GARY A. DYKES ◽  
MARK S. TURNER
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Lipid Oxidation ◽  
Aerobic Bacteria ◽  
Rosemary Extract ◽  
Spoilage Microflora ◽  
And Staphylococcus Aureus ◽  
Herb Extract

Two spice and herb extract combinations from galangal (Alpinia galanga), rosemary (Rosmarinus officinalis), and lemon iron bark (Eucalyptus staigerana) were evaluated for their ability to inhibit the growth of inoculated Listeria monocytogenes and Staphylococcus aureus and naturally present spoilage microflora on cooked ready-to-eat shrimp stored for 16 days at 4 or 8°C. A combination of galangal, rosemary, and lemon iron bark significantly reduced (P &lt; 0.05) levels of aerobic bacteria and lactic acid bacteria at 4°C on day 12 by 1.6 and 1.59 log CFU/g, respectively. By day 16, levels of these bacteria were equivalent to those of controls. The shrimp treated with this spice and herb extract combination had significantly lower (P &lt; 0.05) lipid oxidation from day 4 to day 16. Similarly, a combination of galangal and rosemary extract significantly reduced (P &lt; 0.05) levels of aerobic bacteria and lactic acid bacteria at 8°C on day 8 by 2.82 and 2.61 log CFU/g, respectively. By days 12 and 16, levels of these bacteria were equivalent to those of controls. The shrimp treated with this spice and herb combination had significantly lower (P &lt; 0.05) lipid oxidation on days 4 and 16. None of the spice and herb extract combinations had an effect on levels of L. monocytogenes or S. aureus or changed the color or pH of the shrimp during storage. The results of this study indicate that combinations of galangal, rosemary, and lemon iron bark extracts can be used to control the growth of spoilage microflora on ready-to-eat shrimp.

scholarly journals Microbiological and Chemical Properties of Chokeberry Juice Fermented by Novel Lactic Acid Bacteria with Potential Probiotic Properties during Fermentation at 4 °C for 4 Weeks

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 768
Author(s):  
Christos Bontsidis ◽  
Athanasios Mallouchos ◽  
Antonia Terpou ◽  
Anastasios Nikolaou ◽  
Georgia Batra ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Chemical Properties ◽  
Storage Period ◽  
Probiotic Strain ◽  
Physicochemical Characteristics ◽  
Probiotic Properties ◽  
Acid Fermentation ◽  
Chokeberry Juice ◽  
Fermented Juice

On the frame of this research survey, a novel potentially probiotic strain (Lactobacillus paracasei SP5) recently isolated from kefir grains was evaluated for chokeberry juice fermentation. Chokeberry juice was retrieved from the variety Aronia melanocarpa, a plant known to provide small, dark berries and to be one of the richest sources of antioxidants. The juice was subsequently fermented inoculating L. paracasei SP5 for 48 h at 30 °C. The fermented juices were left at 4 °C and tested regarding microbiological and physicochemical characteristics for 4 weeks. The potentially probiotic strain was proved capable of performing lactic acid fermentation at 30 °C. Cell viability of L. paracasei was detected in high levels during fermentation and the whole storage period, while the fermented juice showed higher levels of viability in juice with 40.3 g/L of initial sugar concentration. No ethanol was detected in the final fermented juice. Fermented chokeberry juice was characterized by aromatic desirable volatiles, which were retained in adequate levels for the whole storage period. Specifically, the occurrence of organic esters detected in fermented juices is considered as positive evidence of the provision of fruity and floral notes to the final product. During storage, total phenolics content and antioxidant activity were observed in higher levels in fermented chokeberry juice compared with non-fermented juice. Subsequently, fermentation of chokeberry juice by potentially probiotic lactic acid bacteria could provide high industrialization potential, providing the market with a nutritional beverage of good volatile quality with an enhanced shelf-life compared with an unfermented fresh juice.

scholarly journals Effect of lactic acid bacteria on Listeria monocytogenes infection and innate immunity in rabbits

2020 ◽  
Vol 65 (No. 1) ◽  
pp. 23-30 ◽  
Author(s):  
Heping Zhao ◽  
Feike Zhang ◽  
Jun Chai ◽  
Jianping Wang
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Positive Control ◽  
Negative Control ◽  
Listeriolysin O ◽  
Serum Iga ◽  
Probiotic Lactic Acid Bacteria ◽  
Spleen And Lymph Nodes ◽  
Proinflammatory Factors

The present study aimed to investigate the effect of probiotic lactic acid bacteria (LAB) addition on Listeria monocytogenes translocation and its toxin listeriolysin O (LLO), proinflammatory factors, immune organ indexes and serum immunoglobulins in farmed rabbits. Five treatments included negative control (NC), positive control (PC) with L. monocytogenes infection and supplemental LAB at 3.0 × 10<sup>6 </sup>(low-LAB, L-LAB), 3.0 × 10<sup>8</sup> (medium-LAB, M-LAB) and 3.0 × 10<sup>10 </sup>(high-LAB, H-LAB) CFU/kg of diet, respectively. The LAB was a mixture of equal amounts of Lactobacillus acidophilus (ACCC11073), Lactobacillus plantarum (CICC21863) and Enterococcus faecium (CICC20430). A total of 180 weaned rabbits (negative for L. monocytogenes) were randomly assigned to 5 groups with 6 replicates of 6 rabbits each in response to the 5 treatments. L. monocytogenes infection occurred on the first day of feeding trial and dietary LAB supplementation lasted for 14 days. The results showed that on days 7 and 14 post administration, L. monocytogenes in caecum, liver, spleen and lymph nodes was reduced in M-LAB and H-LAB compared to PC (P &lt; 0.05), and linear and quadratic reducing trends were found in liver on day 7 (P ≤ 0.002). On day 14, mucosa LLO mRNA expression and serum TNFα, IL1β and IFNγ were reduced in the three LAB treatments (P &lt; 0.05), and linear and quadratic trends were found on TNFα and IL1β (P ≤ 0.025); indexes of thymus and spleen, serum IgA and IgG were increased in the LAB treatments (P &lt; 0.05). It is concluded that LAB can be used to alleviate L. monocytogenes infection and to improve the immune function of farmed animals.

Behavior of Listeria monocytogenes in Skim Milk during Fermentation with Mesophilic Lactic Starter Cultures

1988 ◽  
Vol 51 (8) ◽  
pp. 600-606 ◽  
Author(s):  
MICHELLE M. SCHAACK ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Starter Cultures ◽  
Plate Count ◽  
Inoculum Level ◽  
Plate Count Agar ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris

The ability of Listeria monocytogenes to grow and compete with mesophilic lactic acid bacteria was examined. Autoclaved skim milk was inoculated with 103 cells of L. monocytogenes (strain V7 or Ohio)/ml, and with 5.0, 1.0, 0.5 or 0.1% of a milk culture of either Streptococcus cremoris or Streptococcus lactis. Inoculated milks were fermented for 15 h at 21 or 30°C, followed by refrigeration at 4°C. Samples were plated on McBride Listeria Agar to enumerate L. monocytogenes and on either APT Agar or plate count agar to enumerate lactic acid bacteria. L. monocytogenes survived in all fermentations, and commonly also grew to some extent. Incubation at 30°C with 5% S. lactis as inoculum appeared to be the most inhibitory combination for strain V7, causing 100% inhibition in growth based on maximum population attained. S. cremoris at the 5.0% and 0.1% inoculum levels, was slightly less inhibitory to L. monocytogenes at 37°C, but it was slightly more inhibitory to L. monocytogenes at the 1.0% inoculum level than was S. lactis. In general, S. lactis reduced the pH of fermented milks more than did S. cremoris. The population of L. monocytogenes began to decrease before 15 h in only one test combination, which was use of a 5.0% inoculum of S. cremoris and 30°C incubation. In most instances, growth of the pathogen appeared to be completely inhibited when the pH dropped below 4.75.

Modeling and Predicting the Growth of Lactic Acid Bacteria in Lightly Preserved Seafood and Their Inhibiting Effect on Listeria monocytogenes

2007 ◽  
Vol 70 (11) ◽  
pp. 2485-2497 ◽  
Author(s):  
OLE MEJLHOLM ◽  
PAW DALGAARD
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Chemical Characterization ◽  
Effect Of Temperature ◽  
Inhibiting Effect ◽  
Smoked Salmon ◽  
Boundary Model ◽  
Parameter Values ◽  
Separate Product

A cardinal parameter model was developed to predict the effect of diacetate, lactate, CO2, smoke components (phenol), pH, NaCl, temperature, and the interactions between all parameters on the growth of lactic acid bacteria (LAB) in lightly preserved seafood. A product-oriented approach based on careful chemical characterization and growth of bacteria in ready-to-eat seafoods was used to develop this new LAB growth model. Initially, cardinal parameter values for the inhibiting effect of diacetate, lactate, CO2, pH, and NaCl–water activity were determined experimentally for a mixture of LAB isolates or were obtained from the literature. Next, these values and a cardinal parameter model were used to model the effect of temperature (Tmin) and smoke components (Pmax). The cardinal parameter model was fitted to data for growth of LAB (μmax values) in lightly preserved seafood including cold-smoked and marinated products with different concentrations of naturally occurring and added organic acids. Separate product validation studies of the LAB model resulted in average bias and accuracy factor values of 1.2 and 1.5, respectively, for growth of LAB (μmax values) in lightly preserved seafood. Interaction between LAB and Listeria monocytogenes was predicted by combining the developed LAB model and an existing growth and growth boundary model for the pathogen (O. Mejlholm and P. Dalgaard, J. Food Prot. 70:70–84). The performance of the existing L. monocytogenes model was improved by taking into account the effect of microbial interaction with LAB. The observed and predicted maximum population densities of L. monocytogenes in inoculated lightly preserved seafoods were 4.7 and 4.1 log CFU g−1, respectively, whereas for naturally contaminated vacuum-packed cold-smoked salmon the corresponding values were 0.7 and 0.6 log CFU g−1 when a relative lag time of 4.5 was used for the pathogen.

Incidence of Listeria monocytogenes in Silage and Its Subsequent Control by Specific and Nonspecific Antagonism

1990 ◽  
Vol 53 (8) ◽  
pp. 642-647 ◽  
Author(s):  
CURTT M. PERRY ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Dairy Farms ◽  
Listeria Innocua ◽  
Listeria Species

Silage samples representing approximately 10% of Vermont's dairy farms were tested for the presence of Listeria species. Listeria innocua was isolated from 15.3% of the silage samples, while Listeria monocytogenes was isolated from 2.9% of the examined samples. As silage pH increased, the incidence of Listeria increased concomitantly. Seventy-eight mesophilic lactic acid bacteria, indigenous to silage, were screened for specific and nonspecific antagonism against four L. monocytogenes indicator strains. Most of the silage isolates demonstrated nonspecific inhibition via lactic acid production against the L. monocytogenes indicator strains. None of the indigenous silage isolates tested in this survey demonstrated specific antagonism via production of bacteriocinogenic compounds.

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