Comparative Resistance of Bacterial Foodborne Pathogens to Non-thermal Technologies for Food Preservation

ABSTRACTHigh-pressure processing is a nonthermal method of food preservation that uses pressure to inactivate microorganisms. To ensure the effective validation of process parameters, it is important that the design of challenge protocols consider the potential for resistance in a particular species. Herein, the responses of 99 diverseSalmonella entericastrains to high pressure are reported. Members of this population belonged to 24 serovars and were isolated from various Canadian sources over a period of 26 years. When cells were exposed to 600 MPa for 3 min, the average reduction in cell numbers for this population was 5.6 log10CFU/ml, with a range of 0.9 log10CFU/ml to 6 log10CFU/ml. Eleven strains, from 5 serovars, with variable levels of pressure resistance were selected for further study. The membrane characteristics (propidium iodide uptake during and after pressure treatment, sensitivity to membrane-active agents, and membrane fatty acid composition) and responses to stressors (heat, nutrient deprivation, desiccation, and acid) for this panel suggested potential roles for the cell membrane and the RpoS regulon in mediating pressure resistance inS. enterica. The data indicate heterogeneous and multifactorial responses to high pressure that cannot be predicted for individualS. entericastrains.IMPORTANCEThe responses of foodborne pathogens to increasingly popular minimal food decontamination methods are not understood and therefore are difficult to predict. This report shows that the responses ofSalmonella entericastrains to high-pressure processing are diverse. The magnitude of inactivation does not depend on how closely related the strains are or where they were isolated. Moreover, strains that are resistant to high pressure do not behave similarly to other stresses, suggesting that more than one mechanism might be responsible for resistance to high pressure and the mechanisms used may vary from one strain to another.

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Characterization and Application of Enterocin RM6, a Bacteriocin fromEnterococcus faecalis

BioMed Research International ◽

10.1155/2013/206917 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 14

Author(s):

En Huang ◽

Liwen Zhang ◽

Yoon-Kyung Chung ◽

Zuoxing Zheng ◽

Ahmed E. Yousef

Keyword(s):

Mass Spectrometry ◽

Foodborne Pathogens ◽

High Performance ◽

Cyclic Peptide ◽

Food Preservation ◽

Peptide Sequence ◽

Cottage Cheese ◽

Log Reduction ◽

Gram Positive Bacteria ◽

Potential Applications

Use of bacteriocins in food preservation has received great attention in recent years. The goal of this study is to characterize enterocin RM6 fromEnterococcus faecalisOSY-RM6 and investigate its efficacy againstListeria monocytogenesin cottage cheese. Enterocin RM6 was purified fromE. faecalisculture supernatant using ion exchange column, multiple C18-silica cartridges, followed by reverse-phase high-performance liquid chromatography. The molecular weight of enterocin RM6 is 7145.0823 as determined by mass spectrometry (MS). Tandem mass spectrometry (MS/MS) analysis revealed that enterocin RM6 is a 70-residue cyclic peptide with a head-to-tail linkage between methionine and tryptophan residues. The peptide sequence of enterocin RM6 was further confirmed by sequencing the structural gene of the peptide. Enterocin RM6 is active against Gram-positive bacteria, includingL. monocytogenes,Bacillus cereus,and methicillin-resistantStaphylococcus aureus(MRSA). Enterocin RM6 (final concentration in cottage cheese, 80 AU/mL) caused a 4-log reduction in population ofL. monocytogenesinoculated in cottage cheese within 30 min of treatment. Therefore, enterocin RM6 has potential applications as a potent antimicrobial peptide against foodborne pathogens in food.

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Bacteriocins for Control of Listeria spp. in Food

Journal of Food Protection ◽

10.4315/0362-028x-59.13.54 ◽

1996 ◽

Vol 59 (13) ◽

pp. 54-63 ◽

Cited By ~ 98

Author(s):

PETER M. MURIANA

Keyword(s):

Foodborne Pathogens ◽

Food Processing ◽

Wide Distribution ◽

Food Preservation ◽

Starter Cultures ◽

Public Consciousness ◽

History Of ◽

Foodborne Outbreaks ◽

Novel Approaches ◽

Potential Use

ABSTRACT Foodborne outbreaks of listeriosis caused by Listeria monocytogenes have contributed to public consciousness about bacterial pathogens involved with foodborne disease. Major concerns with L. monocytogenes are its high mortality rate, wide distribution on raw products, growth at low temperatures, and its ability to establish itself in various food-processing environments. These concerns have prompted the examination of novel approaches, including the use of antimicrobial peptides, or bacteriocins, to combat its survival in foods. Bacteriocins from lactic acid bacteria have received much attention because these microorganisms have a long history of safe use in foods either as starter cultures or as indigenous contaminants. Some bacteriocins are inhibitory to foodborne pathogens, including Listeria spp., a substantial reason for investigating their potential use in novel food preservation applications. Nisin is currently accepted worldwide and in the U.S.; however, numerous other bacteriocins also have potential use in similar applications. Recent examples suggest that bacteriocins may contribute an additional barrier in the “hurdle” concept of food safety.

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Temperature Effects on the Antimicrobial Efficacy of Condensed Smoke and Lauric Arginate against Listeria and Salmonella

Journal of Food Protection ◽

10.4315/0362-028x.jfp-13-459 ◽

2014 ◽

Vol 77 (6) ◽

pp. 934-940 ◽

Cited By ~ 6

Author(s):

JODY M. LINGBECK ◽

PAOLA CORDERO ◽

CORLISS A. O'BRYAN ◽

MICHAEL G. JOHNSON ◽

STEVEN C. RICKE ◽

...

Keyword(s):

Foodborne Pathogens ◽

Salmonella Enterica ◽

Storage Temperature ◽

Antimicrobial Properties ◽

Food Preservation ◽

Lauric Arginate ◽

Serovar Typhimurium ◽

Serotype 1 ◽

Serotype 4B ◽

Incubation Temperatures

Condensed smoke or liquid smoke (LS) and lauric arginate (LAE) are antimicrobials used in food preservation. They have demonstrated abilities to reduce or inhibit pathogenic and spoilage organisms. Few studies, however, have reported on the effectiveness of LS or LAE over the range of temperatures typically encountered in food marketing channels. Therefore, the effects of temperature on the antimicrobial properties of two commercial LS fractions, an LS derived from pecan shells, and LAE against two common foodborne pathogens, Listeria and Salmonella, were investigated. The MICs of the three LS samples and LAE were measured at 4, 10, and 37°C for Listeria monocytogenes strains 2045 (Scott A, serotype 4b) and 10403S (serotype 1/2a) and two strains of Listeria innocua, a well-established surrogate, and at 10, 25, and 37°C for Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Heidelberg. The MICs for LS against Listeria ranged from 3 to 48% (vol/vol), with higher MICs seen with lower temperatures. The MICs for LS on Salmonella ranged from 3 to 24%. Values for LAE ranged between 0.004 and 0.07% for both pathogens, and like LS, higher MICs were always associated with lower incubation temperatures. Understanding how storage temperature affects the efficacy of antimicrobials is an important factor that can contribute to lowering the hurdles of use levels and costs of antimicrobials and ultimately improve food safety for the consumer.

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Inhibiting foodborne pathogens Vibrio parahaemolyticus and Listeria monocytogenes using extracts from traditional medicine: Chinese gallnut, pomegranate peel, Baikal skullcap root and forsythia fruit

Open Agriculture ◽

10.1515/opag-2018-0017 ◽

2018 ◽

Vol 3 (1) ◽

pp. 163-170 ◽

Cited By ~ 2

Author(s):

Jian Wu ◽

Katheryn M. Goodrich ◽

Joseph D. Eifert ◽

Michael L. Jahncke ◽

Sean F. O’Keefe ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Foodborne Pathogens ◽

Vibrio Parahaemolyticus ◽

Punica Granatum ◽

Antibacterial Activities ◽

The United States ◽

Inhibitory Effect ◽

Food Preservation ◽

Pomegranate Peel ◽

Forsythia Suspensa

Abstract Foodborne illnesses have been a heavy burden in the United States and globally. Many medicinal herbs have been cultivated in the US and many of which contain antimicrobial compounds with the potential to be used for food preservation. Methanol/water extracts of pomegranate peel (“PP”, Punica Granatum L.), Chinese gallnut (“CG”, Galla chinensis), Forsythia fruit (“FF”, Forsythia suspensa) and Baikal skullcap root (“BS”, Scutellaria baicalensis) were tested for antimicrobial activity using the agar diffusion assay on tryptic soy agar (TSA) and microdilution assay in tryptic soy broth (TSB). CG and PP extracts showed good to excellent inhibitory effect against Vibrio parahaemolyticus and Listeria monocytogenes in both assays, with a minimum inhibitory concentration (MIC) range from 0.04 to 5 mg/mL. BS had moderate inhibitory effects against V. parahaemolyticus with an MIC of 5 mg/mL in TSB, and against L. monocytogenes with an MIC of 20 mg/mL on TSA. CG was analyzed using LC-MS and fractionated using HPLC. The major components were identified as gallic acid, digallic acid, methyl gallate, and gallotannins (oligo-galloyl-D-glucose, nGG, n = 1~10). Six fractions (I - VI) were collected and their antibacterial activities were tested against L. monocytogenes, and V. parahaemolyticus both on TSA and in TSB. On TSA, fraction III, IV and V inhibited V. parahaemolyticus but no fraction inhibited L. monocytogenes. In TSB, all fractions inhibited V. parahaemolyticus and fractions II - V inhibited L. monocytogenes. Future studies are needed to investigate the effects of medicinal plants on food products.

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Safety and Quality of Fish and Game Meats Prepared by First Nations Communities in British Columbia, Canada

Journal of Food Protection ◽

10.4315/jfp-19-492 ◽

2020 ◽

Vol 83 (5) ◽

pp. 896-901

Author(s):

PATRICIA HINGSTON ◽

KEELY JOHNSON ◽

DAVID KITTS ◽

SIYUN WANG

Keyword(s):

British Columbia ◽

Food Security ◽

First Nations ◽

Foodborne Pathogens ◽

Well Being ◽

Food Preservation ◽

Culture Methods ◽

E Coli ◽

Preservation Methods

ABSTRACT Canadian First Nations communities rely on traditional preservation methods such as the smoking, drying, and canning of fish and game meats to ensure long-term food security. Unlike commercial food production, there are no recognized official standards for these methods, rendering their efficacy in producing microbiologically safe foods relatively unknown. In this study, 81 fresh or processed fish and game samples obtained from four British Columbia First Nations communities were analyzed for quality indicator microbes, foodborne pathogens, and mineral levels. Aerobic counts, coliforms (CC), Escherichia coli (EC), lactic acid bacteria, Staphylococcus aureus (STA), and yeast and molds (YM) were enumerated using the TEMPO, whereas the presence of E. coli O157:H7, Listeria monocytogenes, and Salmonella were detected using the VIDAS immunoassay system. The opportunistic pathogens Enterococcus faecalis and Enterococcus faecium were additionally detected using culture methods with subsequent PCR confirmation, and minerals (Ca, Cu, K, Mg, Mn, Na, and Zn) were detected using mass spectrometry. With the exception of STA, microbial loads were significantly (P < 0.05) higher in processed fish and meat samples compared with unprocessed samples, and game samples contained higher microbial levels than fish; however, differences were only significant (P < 0.05) for coliforms, E. coli, and STA. E. coli O157:H7 was detected in one smoked moose sample, and E. faecalis and E. faecium were isolated from 21 and 2 samples, respectively. Although smoked samples contained significantly higher Na levels, they were effective in reducing microbial levels. These results indicate that current food preservation methods practiced by British Columbia First Nations communities are infrequently effective at reducing microbial populations, and in many cases, resulted in increased microbial loads. More efforts should be made to improve the dissemination of safe food handling and processing knowledge to ensure long-term food security and well-being. HIGHLIGHTS

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Veronica Plants—Drifting from Farm to Traditional Healing, Food Application, and Phytopharmacology

Molecules ◽

10.3390/molecules24132454 ◽

2019 ◽

Vol 24 (13) ◽

pp. 2454 ◽

Cited By ~ 9

Author(s):

Bahare Salehi ◽

Mangalpady Shivaprasad Shetty ◽

Nanjangud V. Anil Kumar ◽

Jelena Živković ◽

Daniela Calina ◽

...

Keyword(s):

Foodborne Pathogens ◽

Food Systems ◽

Biological Activities ◽

Wide Spectrum ◽

Iridoid Glycosides ◽

Traditional Healing ◽

Food Preservation ◽

Food Ingredients

The Veronica genus, with more than 200 species, belongs to the Plantaginaceae family and is distributed over most of the Northern Hemisphere and in many parts of Southern Hemisphere. These plants are traditionally used in medicine for wound healing, in the treatment of rheumatism, and in different human diseases. This paper reviews the chemical composition of some valuable Veronica species, the possibilities Veronica extracts have in food preservation and as food ingredients, and their functional properties. Veronica species represent a valuable source of biological active secondary metabolites, including iridoid glycosides and phenolic compounds. In particular, due to presence of these phytochemicals, Veronica species exhibit a wide spectrum of biological activities, including antimicrobial and antioxidant. In fact, some studies suggest that some Veronica extracts can inhibit foodborne pathogens, such as Listeria monocytogenes, but only a few of them were performed in food systems. Moreover, anticancer, anti-inflammatory, and other bioactivities were reported in vitro and in vivo. The bioactivity of Veronica plants was demonstrated, but further studies in food systems and in humans are required.

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Relationship between Consumer Food Safety Knowledge and Reported Behavior among Students from Health Sciences in One Region of Spain

Journal of Food Protection ◽

10.4315/0362-028x-68.12.2631 ◽

2005 ◽

Vol 68 (12) ◽

pp. 2631-2636 ◽

Cited By ~ 33

Author(s):

RONCESVALLES GARAYOA ◽

MARÍA CÓRDOBA ◽

ISABEL GARCÍA-JALÓN ◽

ALMUDENA SANCHEZ-VILLEGAS ◽

ANA ISABEL VITAS

Keyword(s):

Food Safety ◽

Foodborne Pathogens ◽

Storage Temperature ◽

Foodborne Pathogen ◽

Health Sciences ◽

Food Preservation ◽

Cross Contamination ◽

Food Handling ◽

Accurate Knowledge ◽

Home Based

A survey was conducted to investigate the relationship between knowledge about food safety and actual food handling practices among Spanish university students (mainly from the health sciences disciplines) who usually prepare meals at home. Based on level of education in food safety topics, students were divided in three groups: high, which included students from Food Science and Nutrition; medium, which included students from other health sciences; and low, which included students from non–health-related studies. More than two thirds of the 562 people selected had an accurate knowledge of the eight foodborne pathogens included in the survey, but only 5.2% were able to identify Staphylococcus aureus as a foodborne pathogen. Significant differences in responses were found depending on educational level concerning the food safety topic. For food handling, up to 60% of the responses reflected accurate knowledge of proper storage of prepared meals and washing of hands and materials to avoid cross-contamination. However, with the exception of questions related to storage temperature, there was considerable difference between knowledge and reported behavior. Although 98.6% of the participants recognized the importance of hand washing before and during food preparation, only one quarter (24.4%) affirmed that they washed their hands with soap and water. On questions concerning food practices, more accurate answers were given by the older students. Women answered questions regarding cross-contamination more accurately, whereas men were more accurate in response to questions concerning temperature and food preservation. In general, students with more knowledge of food hygiene had better reported practices, but even these students reported some high-risk behaviors. These results confirm the need to improve educational programs, ensuring that the acquired knowledge actually modifies consumer behavior.

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Combinational Antibacterial Activity of Nisin and 3-Phenyllactic Acid and Their Co-production by Engineered Lactococcus lactis

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.612105 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jiaheng Liu ◽

Rongrong Huang ◽

Qianqian Song ◽

Hui Xiong ◽

Juan Ma ◽

...

Keyword(s):

Antibacterial Activity ◽

Lactococcus Lactis ◽

Foodborne Pathogens ◽

Antimicrobial Agents ◽

Cost Effective ◽

Food Preservation ◽

Phenyllactic Acid ◽

Nisin Z ◽

Effective Performance ◽

Microbial Analysis

Nisin produced by certain Lactococcus lactis strains is commercially used in meat and dairy industries because of its effective antibacterial activity and food safety characteristics. It has been proved that the antibacterial activity could be enhanced when combined with other antimicrobial agents. In this study, we demonstrated that nisin and 3-phenyllactic acid (PLA) in combination displayed excellent combinational antibacterial activity against foodborne pathogens including S. xylosus and M. luteus. The potential application in food preservation was further verified via microbial analysis during the storage of meat and milk, and determination of strawberry rot rate. Scanning electron microscopy observation indicated a distinct mode of PLA with nisin, which may target at the dividing cell, contributing to their combinational antibacterial effect of nisin and PLA. Considering the positive results, a nisin-PLA co-producing strain was constructed based on the food-grade strain L. lactis F44, a nisin Z producer. By the knockout of two L-lactate dehydrogenase (LDH) and overexpression of D-LDHY25A, the yield of PLA was significantly increased 1.77-fold in comparison with the wild type. Anti-bacterial assays demonstrated that the fermentation product of the recombinant strain performed highly effective antibacterial activity. These results provided a promising prospect for the nisin-PLA co-expressing L. lactis in food preservation on account of its considerable antibacterial activity and cost-effective performance.

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Isolation and Characterization of Fengycins Produced by Bacillus amyloliquefaciens JFL21 and Its Broad-Spectrum Antimicrobial Potential Against Multidrug-Resistant Foodborne Pathogens

Frontiers in Microbiology ◽

10.3389/fmicb.2020.579621 ◽

2020 ◽

Vol 11 ◽

Author(s):

Long-Zhen Lin ◽

Qian-Wang Zheng ◽

Tao Wei ◽

Zi-Qian Zhang ◽

Chao-Fan Zhao ◽

...

Keyword(s):

Foodborne Pathogens ◽

Fungal Pathogens ◽

Proteolytic Enzymes ◽

Gel Filtration ◽

Antimicrobial Properties ◽

Multidrug Resistant ◽

Antimicrobial Activities ◽

Food Preservation ◽

Antimicrobial Substance ◽

Isolation And Characterization

The continuing emergence and development of pathogenic microorganisms that are resistant to antibiotics constitute an increasing global concern, and the effort in new antimicrobials discovery will remain relevant until a lasting solution is found. A new bacterial strain, designated JFL21, was isolated from seafood and identified as B. amyloliquefaciens. The antimicrobial substance produced by B. amyloliquefaciens JFL21 showed low toxicity to most probiotics but exhibited strong antimicrobial activities against multidrug-resistant foodborne pathogens. The partially purified antimicrobial substance, Anti-JFL21, was characterized to be a multiple lipopeptides mixture comprising the families of surfactin, fengycin, and iturin. Compared with commercially available polymyxin B and Nisin, Anti-JFL21 not only could exhibit a wider and stronger antibacterial activity toward Gram-positive pathogens but also inhibit the growth of a majority of fungal pathogens. After further separation through gel filtration chromatography (GFC), the family of surfactin, fengycin, and iturin were obtained, respectively. The results of the antimicrobial test pointed out that only fengycin family presented marked antimicrobial properties against the indicators of L. monocytogenes, A. hydrophila, and C. gloeosporioides, which demonstrated that fengycins might play a major role in the antibacterial and antifungal activity of Anti-JFL21. Additionally, the current study also showed that the fengycins produced by B. amyloliquefaciens JFL21 not only maintained stable anti-Listeria activity over a broad pH and temperature range, but also remained active after treatment with ultraviolet sterilization, chemical reagents, and proteolytic enzymes. Therefore, the results of this study suggest the new strain and its antimicrobials are potentially useful in food preservation for the biological control of the multidrug-resistant foodborne pathogens.

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