Compatibility of Commercially Produced Protective Cultures with Common Cheesemaking Cultures and Their Antagonistic Effect on Foodborne Pathogens

2020 ◽  
Vol 83 (6) ◽  
pp. 1010-1019 ◽  
Author(s):  
CATHERINE A. GENSLER ◽  
STEPHANIE R. B. BROWN ◽  
SULAIMAN F. ALJASIR ◽  
DENNIS J. D'AMICO
Keyword(s):  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Antagonistic Effect ◽  
Starter Cultures ◽  
Minimal Impact ◽  
Cheese Industry ◽  
Ultrahigh Temperature ◽  
Bacteria And Fungi ◽  
The Impact ◽  
Potential Use

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

Bacteriocins for Control of Listeria spp. in Food

1996 ◽  
Vol 59 (13) ◽  
pp. 54-63 ◽  
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.

scholarly journals Bacitracin Methylene Disalicylate Improves Intestinal Health by Modulating Its Development and Microbiota in Weaned Rabbits

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Chen ◽  
Shuaishuai Hu ◽  
Jiali Li ◽  
Bohao Zhao ◽  
Naisu Yang ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Nitrogen Concentration ◽  
Basal Diet ◽  
Ammonia Nitrogen ◽  
Antagonistic Effect ◽  
Polymerase Chain Reaction Test ◽  
Control Group ◽  
Intestinal Health ◽  
Intestinal Environment ◽  
The Impact

Intestinal infections are a major cause of morbidity and mortality in humans and agricultural animals, especially newborns and weaned animals. Preventive treatments that help weaned animals maintain homeostasis and balance the hindgut microbial populations are desirable. The present study aimed to explore the impact of bacitracin methylene disalicylate (BMD) on the intestinal health by analyzing the intestinal environment, morphology, expression of peptidoglycan recognition proteins (PGRPs), and flora of weaned rabbits. A total of 300 New Zealand weaned rabbits were randomly divided into the following five treatment groups for a 35-day feed trial: control group (basal diet), bacitracin zinc (BZ) group (50 mg/kg BZ), BMDa group (100 mg/kg BMD), BMDb group (50 mg/kg BMD), and BMDc group (rabbits fed a basal diet supplemented with 25 mg/kg BMD). In each treatment group, 28 rabbits were slaughtered for experimental analysis. The results showed that the supplementation of BMD increased the environmental acidity of the cecum of the weaned rabbits and reduced the ammonia-nitrogen concentration, which was beneficial to the survival of useful bacteria in the intestine. The morphology analysis of the duodenum using hematoxylin and eosin staining revealed that the villus length, villus/crypt ratio, and intestinal wall thickness increased in the BMD group, thereby improving the structure of the duodenum and the absorption capacity of the small intestine. Moreover, real-time polymerase chain reaction test showed that PGRPs (especially PGLYRP-1 and PGLYRP-2) in the intestinal had an antagonistic effect with BMD in the process of inhibiting pathogenic bacteria, resulting in their decreased expression (P < 0.05). Furthermore, through 16S rRNA sequencing in the cecal content, the abundance of the predominant phyla in the BMDa and BZ groups was found to be the closest. The abundance of the genera Lachnospira, Erysipelotrichaceae (p-75-a5), Paraprevotellaceae (YRC22), Mogibacterium, Peptococcaceae (rc4-4), Anaerovibrio, Succinivibrio, and Sphaerochaeta increased in the BMDa and BZ groups (P < 0.05). The relative abundance of Alistipes, Sedimentibacter, and Dorea significantly increased only in the BMDa group (P < 0.05). Conclusively, BMD, as well as microbes, improved the intestinal environment and structure to maintain the intestinal health of weaned rabbits.

ANTAGONISTIC EFFECT OF MONOCULTURES OF MILK-OXIDE BACTERIA AND THEIR CONSORTIUM WITH YEASTS ON PATHOGENIC BACTERIA AND FUNGI

2021 ◽  
Vol 1 (19) ◽  
pp. 365-367
Author(s):  
E.F. Semenova ◽  
L.M Teplitskaya ◽  
G.P. Zaitsev ◽  
I.E. Tsokalo ◽  
A.V. Omelchenko ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Microbial Consortium ◽  
Culture Fluid ◽  
Antagonistic Effect ◽  
Maximum Effect ◽  
Bacteria And Fungi

The efficiency of the consortium of lactic oxide bacteria and yeast is shown to suppress phytophotogenic bacteria and micromicets, conditionally pathogenic bacteria in vitro conditions. It has been shown that 1.0% of the solution of the culture fluid of the microbial consortium has the maximum effect in reducing the infestation of seed cereals.

scholarly journals Effect of Lactobacillus sp. isolates supernatant on Escherichia coli O157:H7 enhances the role of organic acids production as a factor for pathogen control

2015 ◽  
Vol 35 (4) ◽  
pp. 353-359 ◽  
Author(s):  
Larissa B. Poppi ◽  
Javier D. Rivaldi ◽  
Thais S. Coutinho ◽  
Claudete S. Astolfi-Ferreira ◽  
Antonio J. Piantino Ferreira ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Foodborne Pathogens ◽  
Pathogenic Bacteria ◽  
Inhibitory Effect ◽  
Antagonistic Effect ◽  
Pure Cultures ◽  
Pathogen Control ◽  
The Individual

Many attempts have been made to establish the control of foodborne pathogens through Lactobacillus isolates and their metabolism products with success being obtained in several situations. The aim of this study was to investigate the antagonistic effect of eight Lactobacillusisolates, including L. caseisubsp. pseudoplantarum,L. plantarum, L. reuteri and L. delbrueckii subsp. delbrueckii, on the pathogenic Escherichia colistrain O157:H7. The inhibitory effect of pure cultures and two pooled cultures supernatants of Lactobacillus on the growth of pathogenic bacteria was evaluated by the spot agar method and by monitoring turbidity. Antimicrobial activity was confirmed for L. reuteri and L. delbrueckii subsp. delbrueckii and for a pool of lactic acid bacteria. The neutralized supernatant of the pool exerted a higher antimicrobial activity than that of the individual strains. Furthermore, D-lactic acid and acetic acid were produced during growth of the Lactobacillus isolates studied.

Experimental Study of the Impact of Alisma plantago-aquatica Secretions on Pathogenic Bacteria

2014 ◽  
Vol 1 (3) ◽  
pp. 3-7
Author(s):  
O. Zhukorskyy ◽  
O. Hulay
Keyword(s):  
Pathogenic Bacteria ◽  
Initial Density ◽  
Biologically Active ◽  
Erysipelothrix Rhusiopathiae ◽  
Natural Focus ◽  
Test Species ◽  
Popula Tions ◽  
And Control ◽  
The Impact

Aim. To estimate the impact of in vivo secretions of water plantain (Alisma plantago-aquatica) on the popula- tions of pathogenic bacteria Erysipelothrix rhusiopathiae. Methods. The plants were isolated from their natural conditions, the roots were washed from the substrate residues and cultivated in laboratory conditions for 10 days to heal the damage. Then the water was changed; seven days later the selected samples were sterilized using fi lters with 0.2 μm pore diameter. The dilution of water plantain root diffusates in the experimental samples was 1:10–1:10,000. The initial density of E. rhusiopathiae bacteria populations was the same for both experimental and control samples. The estimation of the results was conducted 48 hours later. Results. When the dilution of root diffusates was 1:10, the density of erysipelothrixes in the experimental samples was 11.26 times higher than that of the control, on average, the dilution of 1:100 − 6.16 times higher, 1:1000 – 3.22 times higher, 1:10,000 – 1.81 times higher, respectively. Conclusions. The plants of A. plantago-aquatica species are capable of affecting the populations of E. rhusiopathiae pathogenic bacteria via the secretion of biologically active substances into the environment. The consequences of this interaction are positive for the abovementioned bacteria, which is demon- strated by the increase in the density of their populations in the experiment compared to the control. The intensity of the stimulating effect on the populations of E. rhusiopathiae in the root diffusates of A. plantago-aquatica is re- ciprocally dependent on the degree of their dilution. The investigated impact of water plantain on erysipelothrixes should be related to the topical type of biocenotic connections, the formation of which between the test species in the ecosystems might promote maintaining the potential of natural focus of rabies. Keywords: Alisma plantago-aquatica, in vivo secretions, Erysipelothrix rhusiopathiae, population density, topical type of connections.

Development of Strategies for Glycopeptide Synthesis: An Overview on the Glycosidic Linkage

2020 ◽  
Vol 24 (21) ◽  
pp. 2475-2497
Author(s):  
Andrea Verónica Rodríguez-Mayor ◽  
German Jesid Peralta-Camacho ◽  
Karen Johanna Cárdenas-Martínez ◽  
Javier Eduardo García-Castañeda
Keyword(s):  
Chemical Synthesis ◽  
Solid Phase ◽  
Building Blocks ◽  
Heterogeneous Environments ◽  
Phase Synthesis ◽  
Low Concentrations ◽  
Biological Sources ◽  
Synthetic Routes ◽  
The Impact ◽  
Potential Use

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.

scholarly journals AMPK activates Parkin independent autophagy and improves post sepsis immune defense against secondary bacterial lung infections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathaniel B. Bone ◽  
Eugene J. Becker ◽  
Maroof Husain ◽  
Shaoning Jiang ◽  
Anna A. Zmijewska ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Inflammatory Responses ◽  
Abdominal Sepsis ◽  
Immune Defense ◽  
Bacterial Killing ◽  
Lung Infections ◽  
Sepsis Survivors ◽  
The Impact

AbstractMetabolic and bioenergetic plasticity of immune cells is essential for optimal responses to bacterial infections. AMPK and Parkin ubiquitin ligase are known to regulate mitochondrial quality control mitophagy that prevents unwanted inflammatory responses. However, it is not known if this evolutionarily conserved mechanism has been coopted by the host immune defense to eradicate bacterial pathogens and influence post-sepsis immunosuppression. Parkin, AMPK levels, and the effects of AMPK activators were investigated in human leukocytes from sepsis survivors as well as wild type and Park2−/− murine macrophages. In vivo, the impact of AMPK and Parkin was determined in mice subjected to polymicrobial intra-abdominal sepsis and secondary lung bacterial infections. Mice were treated with metformin during established immunosuppression. We showed that bacteria and mitochondria share mechanisms of autophagic killing/clearance triggered by sentinel events that involve depolarization of mitochondria and recruitment of Parkin in macrophages. Parkin-deficient mice/macrophages fail to form phagolysosomes and kill bacteria. This impairment of host defense is seen in the context of sepsis-induced immunosuppression with decreased levels of Parkin. AMPK activators, including metformin, stimulate Parkin-independent autophagy and bacterial killing in leukocytes from post-shock patients and in lungs of sepsis-immunosuppressed mice. Our results support a dual role of Parkin and AMPK in the clearance of dysfunctional mitochondria and killing of pathogenic bacteria, and explain the immunosuppressive phenotype associated Parkin and AMPK deficiency. AMPK activation appeared to be a crucial therapeutic target for the macrophage immunosuppressive phenotype and to reduce severity of secondary bacterial lung infections and respiratory failure.

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