Assay of Enterocin AS-48 for Inhibition of Foodborne Pathogens in Desserts

2009 ◽  
Vol 72 (8) ◽  
pp. 1654-1659 ◽  
Author(s):  
PILAR MARTINEZ VIEDMA ◽  
HIKMATE ABRIOUEL ◽  
NABIL BEN OMAR ◽  
ROSARIO LUCAS LÓPEZ ◽  
EVA VALDIVIA ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Proteolytic Activity ◽  
Foodborne Pathogens ◽  
Viable Cell ◽  
Inoculum Size ◽  
Cell Counts

Enterocin AS-48 was tested against Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes in different kinds of desserts. The highest activity against S. aureus was detected in baker cream. However, in yogurt-type soy-based desserts and in gelatin pudding, AS-48 (175 arbitrary units [AU]/g) reduced viable cell counts of S. aureus by only 1.5 to 1.8 log units at most. The efficacy of AS-48 in puddings greatly depended on inoculum size, and viable S. aureus counts decreased below detection levels within 24 h for inocula lower than 4 to 5.5 log CFU/g. For L. monocytogenes, bacteriocin concentrations of 52.5 to 87.5 AU/g reduced viable counts below detection levels and avoided regrowth of survivors. The lowest activity was detected in yogurt-type desserts. For B. cereus, viable cell counts were reduced below detection levels for bacteriocin concentrations of 52.5 AU/g in instant pudding without soy or by 175 AU/g in the soy pudding. In gelatin pudding, AS-48 (175 AU/g) reduced viable cell counts of B. cereus below detection levels after 8 h at 10°C or after 48 h at 22°C. Bacteriocin addition also inhibited gelatin liquefaction caused by the proteolytic activity of B. cereus.

Growth Inhibitory Effects of Kimchi (Korean Traditional Fermented Vegetable Product) against Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus

2008 ◽  
Vol 71 (2) ◽  
pp. 325-332 ◽  
Author(s):  
YONG-SUK KIM ◽  
ZIAN-BIN ZHENG ◽  
DONG-HWA SHIN
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Control Group ◽  
Growth Inhibitory ◽  
Side Dish ◽  
Pepper Powder ◽  
And Staphylococcus Aureus ◽  
Vegetable Product

Kimchi is a unique Korean traditional vegetable product that is fermented by lactic acid bacteria (LAB) and is mainly consumed as a side dish with boiled rice. Its main ingredients are brined Chinese cabbage, red pepper powder, and fermented fish sauce, and these are combined with many spices such as garlic, green onion, ginger, and some seaweed. The relationship between the concentration of LAB or the pH and the growth of three gram-positive foodborne pathogens (Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus) was evaluated. Heat treatment (HT; 85°C for 15 min) or neutralization treatment (NT; pH 7.0) was conducted on day 0 (0-D group) and day 3 (3-D group) of incubation. The pH in the control group and the NT group dropped sharply to 4.12 to 4.30 after 2 days of incubation and slightly decreased thereafter, whereas the pH in the control group and HT group stayed at 7.0 during incubation. LAB were not detected in the HT kimchi during incubation. B. cereus in the NT-0-D, NT-3-D, and HT-3-D groups was reduced by 1.5 to 3.1 log CFU/ml but increased slightly in the HT-0-D group. L. monocytogenes in HT-3-D and NT-3-D groups disappeared after 5 days of incubation, and S. aureus in the NT-0-D group disappeared after 4 days. These findings indicate that growth of all the foodborne pathogens was inhibited by NT-0-D, HT-3-D, and NT-3-D, but B. cereus was not inhibited by HT-0-D. Thus, growth of LAB in kimchi is an important factor in the control of foodborne pathogens.

scholarly journals Complete genome of the barotolerant Listeria monocytogenes RO15 strain and comparison with other strains isolated from food and food processing environments

2020 ◽  
Author(s):  
Ilhan Cem Duru ◽  
Margarita Andreevskaya ◽  
Pia Laine ◽  
Tone Mari Rode ◽  
Anne Ylinen ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Genome Analysis ◽  
Food Processing ◽  
Viable Cell ◽  
High Pressure Processing ◽  
Genome Comparison ◽  
Cell Counts ◽  
Reference Type ◽  
Pressure Tolerance

Abstract Background: High pressure processing (HPP; i.e. 100 - 600 MPa pressure depending on product) is a non-thermal preservation technique adopted by the food industry to decrease significantly foodborne pathogens, including Listeria monocytogenes, from food. However, susceptibility towards pressure differs among diverse strains of L. monocytogenes and it is unclear if this is related to their genomic content. Here, we tested the barotolerance of 10 different L. monocytogenes strains, from food and food processing environments and widely used reference type strains, to pressure treatments with 400 and 600 MPa. Genome sequencing and genome comparison of the tested L. monocytogenes strains were performed to investigate the relation between genomic profile and pressure tolerance.Results: None of the tested strains were tolerant to 600 MPa. A reduction of more than 5 log10 was observed for all strains after 1 minute 600 MPa pressure treatment. L. monocytogenes strain RO15 showed no significant reduction in viable cell counts after 400 MPa for 1 minute and was therefore defined as barotolerant. Genome analysis of so far unsequenced L. monocytogenes strain RO15, 2HF33, MB5, AB199, AB120, C7, and RO4 allowed us to compare the gene content of all strains tested. This revealed that the three most pressure tolerant strains had more than one CRISPR system with self-targeting spacers. Furthermore, several anti-CRISPR genes were detected in these strains. Pan-genome analysis showed that 10 prophage genes were significantly associated with the three most barotolerant strains.Conclusions: L. monocytogenes strain RO15 was the most pressure tolerant among the selected strains. Genome comparison suggests that there might be a relationship between prophages and pressure tolerance in L. monocytogenes.

Potential for Growth from Spores of Bacillus cereus and Clostridium botulinum and Vegetative Cells of Staphylococcus aureus, Listeria monocytogenes, and Salmonella Serotypes in Cooked Ground Beef during Cooling†

1997 ◽  
Vol 60 (3) ◽  
pp. 272-275 ◽  
Author(s):  
VIJAY K. JUNEJA ◽  
OSCAR P. SNYDER ◽  
BENNE S. MARMER
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Clostridium Botulinum ◽  
Ground Beef ◽  
Type B ◽  
Vegetative Cells ◽  
Safety Hazard ◽  
Salmonella Serotypes

The ability of 16 foodborne pathogens, representative of 5 different species, to grow during cooling of previously sterilized cooked beef was studied to determine a safe cooling rate. Auto-claved ground beef samples (3 g) were inoculated with heat-shocked spores of Bacillus cereus (strain BH 86) or Clostridium botulinum (nonproteolytic type B strains CBW 25, 17B, and KAP B5 and type E strains Whitefish, Saratoga, and Alaska) or vegetative cells of Listeria monocytogenes (strains HO-VJ-S, V-7, and Scott A), Staphylococcus aureus (strains 196E, B121, and B 124), or Salmonella serotypes (S. dublin, S. enteritidis, and S. typhimurium), vacuum-packaged, and cooked in a stirred water bath to an internal temperature of 60°C in I h. In some experiments combinations of C. botulinum and B. cereus spores or S. aureus and salmonellae vegetative cells were used. Heated samples were cooled through the temperature range of 54.4 to 7.2°C at rates varying from 6 to 21 h. Samples were removed at various times during cooling to determine if growth of the pathogens had occurred. No growth was observed with cooling periods of up to 21h. This study with the model meat system (3 g autoclaved ground beef inoculated with selected pathogens and then pasteurized) indicated that cooling from 52.4 to 7.2°C in up to 21 h would not pose a food safety hazard from growth of these pathogens.

scholarly journals Antimicrobial Activity of Six International Artisanal Kefirs against Bacillus cereus, Listeria monocytogenes, Salmonella enterica Serovar Enteritidis, and Staphylococcus aureus

2020 ◽  
Vol 8 (6) ◽  
pp. 849 ◽  
Author(s):  
Abrar Sindi ◽  
Md. Bahadur Badsha ◽  
Barbara Nielsen ◽  
Gülhan Ünlü
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Antimicrobial Activities ◽  
Negative Control ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Bacterial Indicator

Kefir, a fermented dairy beverage, exhibits antimicrobial activity due to many metabolic products, including bacteriocins, generated by lactic acid bacteria. In this study, the antimicrobial activities of artisanal kefir products from Fusion Tea (A), Britain (B), Ireland (I), Lithuania (L), the Caucuses region (C), and South Korea (K) were investigated against select foodborne pathogens. Listeria monocytogenes CWD 1198, Salmonella enterica serovar Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579 were inhibited by artisanal kefirs made with kefir grains from diverse origins. Kefirs A, B, and I inhibited all bacterial indicator strains examined at varying levels, except Escherichia coli ATCC 12435 (non-pathogenic, negative control). Kefirs K, L, and C inhibited all indicator strains, except S. aureus ATCC 25923 and E. coli ATCC 12435. Bacteriocins present in artisanal kefirs were determined to be the main antimicrobials in all kefirs examined. Kefir-based antimicrobials are being proposed as promising natural biopreservatives as per the results of the study.

scholarly journals Simultaneous Control of Staphylococcus aureus and Bacillus cereus Using a Hybrid Endolysin LysB4EAD-LysSA11

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 906
Author(s):  
Bokyung Son ◽  
Minsuk Kong ◽  
Yoyeon Cha ◽  
Jaewoo Bai ◽  
Sangryeol Ryu
Keyword(s):  
Thermal Stability ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antimicrobial Agent ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Lytic Activity ◽  
Antimicrobial Spectrum ◽  
Hybrid Proteins ◽  
Simultaneous Control

Bacteriophage endolysins have attracted attention as promising alternatives to antibiotics, and their modular structure facilitates endolysin engineering to develop novel endolysins with enhanced versatility. Here, we constructed hybrid proteins consisting of two different endolysins for simultaneous control of two critical foodborne pathogens, Staphylococcus aureus and Bacillus cereus. The full-length or enzymatically active domain (EAD) of LysB4, an endolysin from the B. cereus-infecting phage B4, was fused to LysSA11, an endolysin of the S. aureus-infecting phage SA11, via a helical linker in both orientations. The hybrid proteins maintained the lytic activity of their parental endolysins against both S. aureus and B. cereus, but they showed an extended antimicrobial spectrum. Among them, the EAD of LysB4 fused with LysSA11 (LysB4EAD-LyaSA11) showed significantly increased thermal stability compared to its parental endolysins. LysB4EAD-LysSA11 exhibited high lytic activity at pH 8.0–9.0 against S. aureus and at pH 5.0–10.0 against B. cereus, but the lytic activity of the protein decreased in the presence of NaCl. In boiled rice, treatment with 3.0 µM of LysB4EAD-LysSA11 reduced the number of S. aureus and B. cereus to undetectable levels within 2 h and also showed superior antimicrobial activity to LyB4EAD and LysSA11 in combination. These results suggest that LysB4EAD-LysSA11 could be a potent antimicrobial agent for simultaneous control of S. aureus and B. cereus.

scholarly journals Response of Listeria monocytogenes to Disinfection Stress at the Single-Cell and Population Levels as Monitored by Intracellular pH Measurements and Viable-Cell Counts

2009 ◽  
Vol 75 (13) ◽  
pp. 4550-4556 ◽  
Author(s):  
Vicky G. Kastbjerg ◽  
Dennis S. Nielsen ◽  
Nils Arneborg ◽  
Lone Gram
Keyword(s):  
Listeria Monocytogenes ◽  
Single Cell ◽  
Intracellular Ph ◽  
Bacterial Population ◽  
Single Cells ◽  
Viable Cell ◽  
Population Subdivision ◽  
Single Cell Level ◽  
Cell Level ◽  
Cell Counts

ABSTRACT Listeria monocytogenes has a remarkable ability to survive and persist in food production environments. The purpose of the present study was to determine if cells in a population of L. monocytogenes differ in sensitivity to disinfection agents as this could be a factor explaining persistence of the bacterium. In situ analyses of Listeria monocytogenes single cells were performed during exposure to different concentrations of the disinfectant Incimaxx DES to study a possible population subdivision. Bacterial survival was quantified with plate counting and disinfection stress at the single-cell level by measuring intracellular pH (pHi) over time by fluorescence ratio imaging microscopy. pHi values were initially 7 to 7.5 and decreased in both attached and planktonic L. monocytogenes cells during exposure to sublethal and lethal concentrations of Incimaxx DES. The response of the bacterial population was homogenous; hence, subpopulations were not detected. However, pregrowth with NaCl protected the planktonic bacterial cells during disinfection with Incimaxx (0.0015%) since pHi was higher (6 to 6.5) for the bacterial population pregrown with NaCl than for cells grown without NaCl (pHi 5 to 5.5) (P < 0.05). The protective effect of NaCl was reflected by viable-cell counts at a higher concentration of Incimaxx (0.0031%), where the salt-grown population survived better than the population grown without NaCl (P < 0.05). NaCl protected attached cells through drying but not during disinfection. This study indicates that a population of L. monocytogenes cells, whether planktonic or attached, is homogenous with respect to sensitivity to an acidic disinfectant studied on the single-cell level. Hence a major subpopulation more tolerant to disinfectants, and hence more persistent, does not appear to be present.

Impact of Aluminum Oxide and Silica Oxide Nanocomposite on Foodborne Pathogens in Chicken Fillets

2019 ◽  
pp. 152-162 ◽  
Author(s):  
Alaa G. Osman ◽  
Ahmed I. El-Desouky ◽  
Mohamed K. Morsy ◽  
Ahmed A. Aboud ◽  
Mahmoud H. Mohamed
Keyword(s):  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Agricultural Research ◽  
Control Sample ◽  
Storage Period ◽  
Edible Films ◽  
Innovative Technology ◽  
Al2o3 Nps

Nanotechnology is an innovative technology for improving food quality and safety. Aims: The aim of this study was to evaluate the efficacy of hydroxy propyl methyl cellulose (HPMC) films containing nanoparticles against three foodborne pathogens.        Design of the Study: *This study was designed using two nanoparticles i.e. (Al2O3-NPs and SiO2-NPs), edible film (HPMC), and three foodborne pathogens i.e. Bacillus cereus, Staphylococcus aureus, and Salmonella Typhimurium. Both nanoparticles were evaluated against foodborne pathogens as well applied in chicken fillets.     Place and Duration: All experiments were done in the Food Technology Department, Benha University, Egypt; Nanomaterial Laboratory, Beni-Suef University, Egypt; and Agricultural Research Center, Egypt and were done within three months.        Methodology: The preparation of edible films, the antimicrobial activity, mode of antimicrobial action, challenge study, and scanning electron microscopy had been carried out in different laboratories. As well the mechanical properties of the HPMC films were evaluated.                                                                                                    Results: The results obtained from this study showed that the nanoparticles (~80 nm) at 80 ppm were active against Bacillus cereus, Staphylococcus aureus, and Salmonella Typhimurium compared with 20 and 40 ppm. The HPMC films including Al2O3-NPs were active against B. cereus than S. aureus and S. typhimurium, while the SiO2-NPs were more effective against S. typhimurium and B. cereus compared with S. aureus. In challenge studies, HPMC films including Al2O3-NPs and SiO2-NPs at 80 ppm decreased the viability of the three-foodborne pathogens associated with chicken fillets stored at 4±1°C for 15 days, as compared with the control sample. HPMC films incorporated with nanoparticles inhibited the microbial population ~ 2-3 log10 CFU/cm2 over the chicken fillets during storage period.                                                   Conclusion: This work indicated that, HPMC films incorporated with Al2O3-NPs and SiO2-NPs (~80 nm) at 80 ppm could be reduce the microbiological loads of the refrigerated chicken fillets.

scholarly journals Growth inhibition of foodborne pathogens in camel milk: Staphylococcus aureus, Listeria monocytogenes, Salmonella spp. and E. coli O157:H7

2017 ◽  
Vol 35 (No. 4) ◽  
pp. 311-320 ◽  
Author(s):  
Abusheliabi Aisha ◽  
Al-Holy Murad A ◽  
Al-Rumaithi Hind ◽  
Al-Khaldi Sufian ◽  
Al-Nabulsi Anas A ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Growth Inhibition ◽  
Foodborne Pathogens ◽  
Bovine Milk ◽  
Growth Patterns ◽  
Camel Milk ◽  
Salmonella Spp ◽  
E Coli ◽  
Milk Samples

The growth behaviour of foodborne pathogens (Staphylococcus aureus, Listeria monocytogenes, E. coli O157:H7 and Salmonella spp.) was investigated in pasteurised camel milk and compared with pasteurised bovine milk at different incubation temperatures. This study also aimed to compare the growth patterns of these four foodborne pathogens in pasteurised and raw camel milk. Pasteurised or raw camel milk and pasteurised bovine milk were separately inoculated with a cocktail of three strains of each foodborne pathogen. The inoculated milk samples were incubated at 10, 25, and 37°C. The total bacterial count (TBC) in raw milk and the total thermoduric bacteria count (TDB) in pasteurised milk samples were monitored. Greater growth inhibition rates of four pathogens were obtained for the pasteurised camel milk compared to the pasteurised bovine milk. Raw and pasteurised camel milk exerted bacteriostatic effect against all tested pathogens, particularly for the first 8 h of incubation in milk at the different temperatures. Pasteurised camel milk exerted an inhibitory activity that was equivalent to that of raw camel milk.

Sign in / Sign up

Export Citation Format

Share Document