Bacteriocins for Control of Listeria spp. in Food

1996 ◽  
Vol 59 (13) ◽  
pp. 54-63 ◽  
Author(s):  
PETER M. MURIANA

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.

2020 ◽  
Vol 83 (6) ◽  
pp. 1010-1019 ◽  
Author(s):  
CATHERINE A. GENSLER ◽  
STEPHANIE R. B. BROWN ◽  
SULAIMAN F. ALJASIR ◽  
DENNIS J. D'AMICO

ABSTRACT The documented survival of pathogenic bacteria, including Listeria monocytogenes (LM), Shiga toxin–producing Escherichia coli (STEC), and Salmonella during the manufacture and aging of some cheeses highlights the need for additional interventions to enhance food safety. Unfortunately, few interventions are compliant with the Standards of Identity for cheese. Protective bacterial cultures (PCs) represent actionable, natural interventions. However, supportive data for commercially produced PCs regarding their efficacy against pathogens and potential antagonism with each other and cheesemaking cultures are scant, thereby impeding their potential use by the cheese industry. The overall objective of this study was to identify commercially produced PCs that exert antimicrobial activity toward pathogens with minimal impact on beneficial cheese microbes. Direct antagonism and agar well diffusion assays were used to determine the impact of 10 commercially produced PCs on the growth of starter cultures and cultures of ripening bacteria and fungi. Deferred antagonism was used to evaluate the potential for antimicrobial effects against LM, STEC, and Salmonella. PCs and starter cultures were cocultured in ultrahigh-temperature-processed milk to determine the effects of coculture on starter acidification profiles when incubated according to a simulated cheesemaking temperature profile (4 h at 35°C followed by 20 h at 20°C). Compatibility assays suggest that PC antagonism is microbe and strain specific. Only one PC negatively impacted the acidification of the starters tested. PC antagonism of ripening bacteria and fungi growth varied but was consistent within species. All PCs displayed deferred inhibition of LM, STEC, and Salmonella growth, but to varying degrees. These data identify commercial PCs with potential for the control of pathogens and characterize their compatibility with cheesemaking cultures for future use by cheesemakers and investigations of their efficacy in the production of cheese. HIGHLIGHTS


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 671
Author(s):  
Federica Giacometti ◽  
Hesamaddin Shirzad-Aski ◽  
Susana Ferreira

Antimicrobial resistance (AMR) is a global problem and there has been growing concern associated with its widespread along the animal–human–environment interface. The farm-to-fork continuum was highlighted as a possible reservoir of AMR, and a hotspot for the emergence and spread of AMR. However, the extent of the role of non-antibiotic antimicrobials and other food-related stresses as selective factors is still in need of clarification. This review addresses the use of non-antibiotic stressors, such as antimicrobials, food-processing treatments, or even novel approaches to ensure food safety, as potential drivers for resistance to clinically relevant antibiotics. The co-selection and cross-adaptation events are covered, which may induce a decreased susceptibility of foodborne bacteria to antibiotics. Although the available studies address the complexity involved in these phenomena, further studies are needed to help better understand the real risk of using food-chain-related stressors, and possibly to allow the establishment of early warnings of potential resistance mechanisms.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 355
Author(s):  
Arícia Possas ◽  
Olga María Bonilla-Luque ◽  
Antonio Valero

Cheeses are traditional products widely consumed throughout the world that have been frequently implicated in foodborne outbreaks. Predictive microbiology models are relevant tools to estimate microbial behavior in these products. The objective of this study was to conduct a review on the available modeling approaches developed in cheeses, and to identify the main microbial targets of concern and the factors affecting microbial behavior in these products. Listeria monocytogenes has been identified as the main hazard evaluated in modelling studies. The pH, aw, lactic acid concentration and temperature have been the main factors contemplated as independent variables in models. Other aspects such as the use of raw or pasteurized milk, starter cultures, and factors inherent to the contaminating pathogen have also been evaluated. In general, depending on the production process, storage conditions, and physicochemical characteristics, microorganisms can grow or die-off in cheeses. The classical two-step modeling has been the most common approach performed to develop predictive models. Other modeling approaches, including microbial interaction, growth boundary, response surface methodology, and neural networks, have also been performed. Validated models have been integrated into user-friendly software tools to be used to obtain estimates of microbial behavior in a quick and easy manner. Future studies should investigate the fate of other target bacterial pathogens, such as spore-forming bacteria, and the dynamic character of the production process of cheeses, among other aspects. The information compiled in this study helps to deepen the knowledge on the predictive microbiology field in the context of cheese production and storage.


2012 ◽  
Vol 3 (1) ◽  
pp. 23-32 ◽  
Author(s):  
A. Do Carmo ◽  
M. De Oliveira ◽  
D. Da Silva ◽  
S. Castro ◽  
A. Borges ◽  
...  

There are three main reasons for using lactic acid bacteria (LAB) as starter cultures in industrial food fermentation processes: food preservation due to lactic acid production; flavour formation due to a range of organic molecules derived from sugar, lipid and protein catabolism; and probiotic properties attributed to some strains of LAB, mainly of lactobacilli. The aim of this study was to identify some genes involved in lactose metabolism of the probiotic Lactobacillus delbrueckii UFV H2b20, and analyse its organic acid production during growth in skimmed milk. The following genes were identified, encoding the respective enzymes: ldh – lactate dehydrogenase, adhE – Ldb1707 acetaldehyde dehydrogenase, and ccpA-pepR1 – catabolite control protein A. It was observed that L. delbrueckii UFV H2b20 cultivated in different media has the unexpected ability to catabolyse galactose, and to produce high amounts of succinic acid, which was absent in the beginning, raising doubts about the subspecies in question. The phylogenetic analyses showed that this strain can be compared physiologically to L. delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis, which are able to degrade lactose and can grow in milk. L. delbrueckii UFV H2b20 sequences have grouped with L. delbrueckii subsp. bulgaricus ATCC 11842 and L. delbrueckii subsp. bulgaricus ATCC BAA-365, strengthening the classification of this probiotic strain in the NCFM group proposed by a previous study. Additionally, L. delbrueckii UFV H2b20 presented an evolutionary pattern closer to that of probiotic Lactobacillus acidophilus NCFM, corroborating the suggestion that this strain might be considered as a new and unusual subspecies among L. delbrueckii subspecies, the first one identified as a probiotic. In addition, its unusual ability to metabolise galactose, which was significantly consumed in the fermentation medium, might be exploited to produce low-browning probiotic Mozzarella cheeses, a desirable property for pizza cheeses.


2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Sandeep Tamber

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.


Author(s):  
Dão Pedro de Carvalho Neto ◽  
Gilberto Vinícius de Melo Pereira ◽  
Susan Grace Karp ◽  
Carlos Ricardo Soccol

1979 ◽  
Vol 42 (2) ◽  
pp. 180-182
Author(s):  
BOYD T. MARSH

A brief review of the history of food-caused illness in humans and those categories or areas in a foodservice operations that are considered critical by public health personnel are discussed. The role of the foodservice manager is examined with respect to foodborne outbreaks. Some issues divergent from basic sanitation, but nevertheless, important to the foodservice manager and to public health personnel, are presented.


2021 ◽  
pp. 174-184
Author(s):  
Andrey V. Melnikov ◽  

The article is devoted to the source features of a unique documentary complex – the correspondence of two major Russian historians S.F. Platonov (1860–1933) and M.M. Bogoslovsky (1867–1929). The epistolary dialogue of scientists is of considerable interest not only in terms of studying their life and work. The confidential correspondence reflects significant events in the scientific and social life of Russia, Moscow, Petersburg-Petrograd-Leningrad. Correspondence is a valuable historical and historiographic source not only for understanding the development of historical science in Russia, the formation of Moscow and St. Petersburg historical schools, but also for studying the public consciousness of the Russian humanitarian intelligentsia at the end of the 19th — first third of the 20th centuries, in-depth knowledge of the culture of a turning point in the history of Russia. The letters contain valuable information about the everyday life and life of the professors, the organization of scientific life at the Academy of Sciences, the Archaeographic commission, at Moscow university and the Moscow theological academy, at the Moscow higher courses for women, at the Institute of history of the RANION, the Historical Museum, other higher educational institutions and scientific societies two capitals, they reflect the international ties of domestic historical science with scientists from Great Britain, Germany, France, USA, Czech Republic.


2020 ◽  
Vol 83 (9) ◽  
pp. 1480-1487
Author(s):  
WON CHOI ◽  
SANG-SOON KIM

ABSTRACT Bacillus cereus has been reported as a foodborne pathogen worldwide. Although food processing technologies to inactivate the pathogen have been developed for decades, foodborne outbreaks related to B. cereus have occurred. In the present review, foodborne outbreaks, germination, inactivation, and detection of B. cereus are discussed, along with inactivation mechanisms. B. cereus outbreaks from 2003 to 2016 are reported based on food commodity, number of cases, and consequent illnesses. Germination before sporicidal treatments is highlighted as an effective way to inactivate B. cereus, because the resistance of the pathogen increases significantly following sporulation. Several germinants used for B. cereus are listed, and their efficacies are compared. Finally, recently used interventions with sporicidal mechanisms are identified, and rapid detection methods that have been developed are discussed. Combining two or more interventions, known as the hurdle technology concept, is suggested to maximize the sporicidal effect. Further study is needed to ensure food safety and to understand germination mechanisms and sporicidal resistance of B. cereus. HIGHLIGHTS


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