scholarly journals Effects of Bacteriophage, Ultraviolet Light, and Organic Acid Applications on STEC O157:H7 and the “Big Six” in Beef Packaged Under Vacuum and Aerobic Conditions

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
E. L. Shebs ◽  
F. M. Giotto ◽  
M. J. Lukov ◽  
S. T. Laidler ◽  
A. S. De Mello
Keyword(s):  
Organic Acids ◽  
Ultraviolet Light ◽  
Antimicrobial Effect ◽  
Sodium Chlorite ◽  
Aerobic Conditions ◽  
Log Reduction ◽  
Bacterial Enumeration ◽  
Contrast Analysis ◽  
Antimicrobial Treatments ◽  
And Control

ObjectivesBeef primals produced during high event periods (HEP) can also be affected by STEC contamination requiring microbial assessment. Commonly, primals are retreated with antimicrobials after removal from vacuum bags, then repackaged and tested for STEC. In this study, we evaluated the efficiency of bacteriophage, ultraviolet light, and organic acids on contaminated beef kept under vacuum and aerobic conditions.Materials and MethodsThe effects of antimicrobial interventions Peroxyacetic acid (PAA, 400 PPM), Ultraviolet light (UV, 30 s at 2.5 ± 0.3 cm height), Acidified Sodium Chlorite (ASC, 1200 ppm), and bacteriophage (P, 7 MS phages at 108 PFU/ml) against STEC (O157:H7 and O145, O121, O111, O103, O45, O26) were evaluated on beef. Fresh m. cutaneous trunci was fabricated into 100 cm2 samples (n = 154), which were randomly assigned to 11 treatments including Control, P, UV, ASC, PAA, and combinations P+UV, P+PAA, P+ASC, UV+PAA, UV+ASC, PAA+ASC. Treatments were tested under vacuum and aerobic conditions. Samples were inoculated with a STEC cocktail comprised of 7 strains to yield 3 log CFU/cm2. Samples were vacuumed or overwrapped with oxygen permeable film. Samples were unpackaged and treated with buffered peptone water (BPW, Control) or individual or combined antimicrobial treatments prior to re-packaging. After 1 h at 7°C, samples were swabbed, homogenized in 1 mL of BPW, serially diluted and spread-plated for bacterial enumeration. Data was analyzed using SAS as a completely randomized design.ResultsOverall, treatments including MS phages significantly decreased STEC populations in beef under vacuum and aerobic conditions (P < 0.0001). Under vacuum, individual phage application, combinations between phage and UV, ASC, and PAA plus UV+ASC provided optimal STEC reduction on beef surface. Phage and PAA combination led to the lowest STEC load (1.49 log reduction). When analyzing contrasts, treatments with phage significantly decreased STEC loads when compared to other treatments (P < 0.0001) and control (P < 0.0001). STEC loads recovered from treatments without phage and control were statistically similar at P = 0.32. Under aerobic conditions, individual treatments UV and ASC and combinations including UV+PAA, and PAA+ASC were statistically similar to the control. Inclusion of phage in treatments gradually decreased STEC loads when combined with ASC, PAA, and UV. Phage and UV combination led to the lowest STEC load (1.46 log reduction). Contrast analysis showed that treatments with phage significantly decreased STEC loads when compared to other treatments (P < 0.0001) and control (P < 0.0001). STEC loads recovered from treatments without phage and control were statistically similar at P = 0.07.ConclusionIndividual or combined applications of MS phages on beef surface contaminated with STEC provided optimal antimicrobial effect under vacuum or aerobic conditions. Although organic acids and UV combinations did reduce STEC populations, treatments that included phage yielded the lowest STEC loads. Only phage interventions gave optimal reduction effects under vacuum conditions. Antimicrobial treatments based on individual phage cocktails and their combinations with ASC, UV, and PAA significantly reduce STEC when treating primals produced during HEP.

Validation of the Use of Organic Acids and Acidified Sodium Chlorite To Reduce Escherichia coli O157 and Salmonella Typhimurium in Beef Trim and Ground Beef in a Simulated Processing Environment

2006 ◽  
Vol 69 (8) ◽  
pp. 1802-1807 ◽  
Author(s):  
K. HARRIS ◽  
M. F. MILLER ◽  
G. H. LONERAGAN ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Frozen Storage ◽  
Ground Beef ◽  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
Refrigerated Storage ◽  
E Coli ◽  
Log Reduction ◽  
Antimicrobial Treatments

A study was conducted to determine if acidified sodium chlorite (1,200 ppm) and acetic and lactic acids (2 and 4%) were effective in reducing foodborne pathogens in beef trim prior to grinding in a simulated processing environment. The reduction of Salmonella Typhimurium and Escherichia coli O157:H7 at high (4.0 log CFU/g) and low (1.0 log CFU/g) inoculation doses was evaluated at various processing steps, including the following: (i) in trim just after treatment application, (ii) in ground beef just after grinding, (iii) in ground beef 24 h after refrigerated storage, (iv) in ground beef 5 days after refrigerated storage, and (v) in ground beef 30 days after frozen storage. All antimicrobial treatments reduced the pathogens on the trim inoculated with the lower inoculation dose to nondetectable numbers in the trim and in the ground beef. There were significant reductions of both pathogens in the trim and in the ground beef inoculated with the high inoculation doses. On the trim itself, E. coli O157:H7 and Salmonella Typhimurium were reduced by 1.5 to 2.0 log cycles, with no differences among all treatments. In the ground beef, the organic acids were more effective in reducing both pathogens than the acidified sodium chlorite immediately after grinding, but after 1 day of storage, there were no differences among treatments. Overall, in the ground beef, there was a 2.5-log reduction of E. coli O157:H7 and a 1.5-log reduction of Salmonella Typhimurium that was sustained over time in refrigerated and frozen storage. Very few sensory differences between the control samples and the treated samples were detected by a consumer panel. Thus, antimicrobial treatments did not cause serious adverse sensory changes. Use of these antimicrobial treatments can be a promising intervention available to ground beef processors who currently have few interventions in their process.

scholarly journals Efficiency of Commercial Bacteriophages on Stec O157:H7 Populations in Beef Kept Under Vacuum and Aerobic Conditions

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
E. L. Shebs ◽  
M. J. Lukov ◽  
F. M. Giotto ◽  
E. S. Torres ◽  
A. S. De Mello
Keyword(s):  
Organic Acids ◽  
Fixed Effects ◽  
Antimicrobial Treatment ◽  
Aerobic Conditions ◽  
Bacterial Enumeration ◽  
Peptone Water ◽  
Industry Practice ◽  
Elevated Rate ◽  
Meat Samples

ObjectivesHigh event period (HEP) is a specific time length when processing facilities experience an elevated rate of STEC contamination. STEC contamination during beef fabrication is assessed by sampling trim combos usually using N60, N60 plus, or CSD cloth methods. However, beef primals produced during high event periods can also be affected and must be assessed. A common industry practice consists in reworking primals by removing them from vacuum sealed bags, treating with antimicrobials, repackaging, and then test for STEC. In this study, we evaluated the efficiency of bacteriophage and organic acid applications on contaminated beef kept under vacuum and aerobic conditions.Materials and MethodsAntimicrobials used in this study included: PhageGuard E (PGE, 108 PFU/ml, Bacteriophage solution from Micreos Food Safety BV), peroxyacetic acid (PAA, 400 PPM), and lactic acid (LA, 4.5% at 50°C). STEC O157:H7 strains included: ATCC® 35150 (stx1 and stx2 positive), ATCC® 43895 (stx1 and stx2 positive), ATCC® 43894 (stx1 and stx2 positive), and Micreos 128. Bacteriophage killing efficiency was determined for individual strains in vitro. Fresh rose meat (Cutaneous trunci) was cut into 100 cm2 and stored at 7°C. Meat samples (n = 160, 5 reps, 2 experimental units per rep) were randomly assigned to a 4×2×2 factorial whereas fixed effects were antimicrobial treatment (Control, PGE, PAA, and LA), packaging (V- vacuum and NV– aerobic), and lysing time (30 min and 6 h). Samples were inoculated with 500 ML of a STEC cocktail containing all 4 strains and after 30 min at 7°C under vacuum or wrapped in permeable film, samples were treated with 500 μL PGE, sterile buffered peptone water (BPW, Control), LA, or PAA. Samples were then re-vacuumed or re-wrapped with oxygen permeable film and kept either for 30 min or 6h at 7°C. After refrigeration, samples were swabbed and homogenized in 1mL of BPW. The swab content was serially diluted and spread-plated onto LB agar plates for bacterial enumeration. Data were analyzed using SAS as a completely randomized design.ResultsIn vitro killing efficiency was 98.3%, 96.7%, 97.2%, and 98.2% for Micreos 128, ATCC® 43894, ATCC® 43895, and ATCC® 35150 strains, respectively. When analyzing the effects of antimicrobials, packaging, and lysing time, a three-way interaction was observed (P = 0.035). Under aerobic conditions for 30 min, PGE reduced STEC in beef by approximately 1.4 log CFU/cm2 whereas organic acids reduced by 0.5 log. Similar results were observed when samples were kept for 6 h. Under vacuum conditions for 30 min, PGE significantly reduced STEC by 1 log, whereas no significant effects were observed when treating beef with PAA and LA. Under vacuum conditions for 6h, PGE significantly reduced STEC loads by 1.4 log, whereas LA reduced by 0.6 log and no differences were observed between control and PAA treatments.ConclusionBacteriophage applications on beef contaminated with STEC yielded the lowest counts when compared to PAA and LA. Although organic acids led to a significant decrease of STEC loads in beef kept under aerobic conditions, bacteriophage application led to the lowest counts. Similar to reworking and testing primals produced during a HEP, while under vacuum conditions, bacteriophage significantly reduced STEC loads whereas no or minimal effects of organic acids were observed.

Effectiveness of Trisodium Phosphate, Acidified Sodium Chlorite, Citric Acid, and Peroxyacids against Pathogenic Bacteria on Poultry during Refrigerated Storage

2007 ◽  
Vol 70 (9) ◽  
pp. 2063-2071 ◽  
Author(s):  
ELENA del RÍO ◽  
REBECA MURIENTE ◽  
MIGUEL PRIETO ◽  
CARLOS ALONSO-CALLEJA ◽  
ROSA CAPITA
Keyword(s):  
Citric Acid ◽  
Salmonella Enteritidis ◽  
Pathogenic Bacteria ◽  
Trisodium Phosphate ◽  
Sodium Chlorite ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Microbial Group ◽  
And Control

The effects of dipping treatments (15 min) in potable water or in solutions (wt/vol) of 12% trisodium phosphate (TSP), 1,200 ppm acidified sodium chlorite (ASC), 2% citric acid (CA), and 220 ppm peroxyacids (PA) on inoculated pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Salmonella Enteritidis, Escherichia coli, and Yersinia enterocolitica) and skin pH were investigated throughout storage of chicken legs (days 0, 1, 3, and 5) at 3 ± 1°C. All chemical solutions reduced microbial populations (P &lt; 0.001) as compared with the control (untreated) samples. Similar bacterial loads (P &gt; 0.05) were observed on water-dipped and control legs. Type of treatment, microbial group, and sampling day influenced microbial counts (P &lt; 0.001). Average reductions with regard to control samples were 0.28 to 2.41 log CFU/g with TSP, 0.33 to 3.15 log CFU/g with ASC, 0.82 to 1.97 log CFU/g with CA, and 0.07 to 0.96 log CFU/g with PA. Average reductions were lower (P &lt; 0.001) for gram-positive (0.96 log CFU/g) than for gram-negative (1.33 log CFU/g) bacteria. CA and ASC were the most effective antimicrobial compounds against gram-positive and gram-negative bacteria, respectively. TSP was the second most effective compound for both bacterial groups. Average microbial reductions per gram of skin were 0.87 log CFU/g with TSP, 0.86 log CFU/g with ASC, 1.39 log CFU/g with CA, and 0.74 log CFU/g with PA for gram-positive bacteria, and 1.28 log CFU/g with TSP, 2.03 log CFU/g with ASC, 1.23 log CFU/g with CA, and 0.78 log CFU/g with PA for gram-negative bacteria. With only a few exceptions, microbial reductions in TSP- and ASC-treated samples decreased and those in samples treated with CA increased throughout storage. Samples treated with TSP and samples dipped in CA and ASC had the highest and lowest pH values, respectively, after treatment. The pH of the treated legs tended to return to normal (6.3 to 6.6) during storage. However, at the end of storage, the pH of legs treated with TSP remained higher and that of legs treated with CA remained lower than normal.

scholarly journals Effects of Ultraviolet Light, Organic Acids, and Bacteriophage Interventions on Salmonella Populations in Ground Beef

2017 ◽  
Vol 1 (3) ◽  
pp. 118-118
Author(s):  
Y. Yeh ◽  
F. de Moura ◽  
K. Van Den Broek ◽  
M. Fonseca ◽  
A. S. De Mello
Keyword(s):  
Organic Acids ◽  
Ultraviolet Light ◽  
Ground Beef

scholarly journals Inactivation of Multi-Drug Resistant Non-Typhoidal Salmonella and Wild-Type Escherichia coli STEC Using Organic Acids: A Potential Alternative to the Food Industry

Pathogens ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 849
Author(s):  
Vinicius Silva Castro ◽  
Yhan da Silva Mutz ◽  
Denes Kaic Alves Rosario ◽  
Adelino Cunha-Neto ◽  
Eduardo Eustáquio de Souza Figueiredo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Organic Acids ◽  
Sodium Hypochlorite ◽  
Bacterial Species ◽  
Disk Diffusion ◽  
Clinical Strains ◽  
Linear Pattern ◽  
E Coli ◽  
Log Reduction

Salmonella and Escherichia coli are the main bacterial species involved in food outbreaks worldwide. Recent reports showed that chemical sanitizers commonly used to control these pathogens could induce antibiotic resistance. Therefore, this study aimed to describe the efficiency of chemical sanitizers and organic acids when inactivating wild and clinical strains of Salmonella and E. coli, targeting a 4-log reduction. To achieve this goal, three methods were applied. (i) Disk-diffusion challenge for organic acids. (ii) Determination of MIC for two acids (acetic and lactic), as well as two sanitizers (quaternary compound and sodium hypochlorite). (iii) The development of inactivation models from the previously defined concentrations. In disk-diffusion, the results indicated that wild strains have higher resistance potential when compared to clinical strains. Regarding the models, quaternary ammonium and lactic acid showed a linear pattern of inactivation, while sodium hypochlorite had a linear pattern with tail dispersion, and acetic acid has Weibull dispersion to E. coli. The concentration to 4-log reduction differed from Salmonella and E. coli in acetic acid and sodium hypochlorite. The use of organic acids is an alternative method for antimicrobial control. Our study indicates the levels of organic acids and sanitizers to be used in the inactivation of emerging foodborne pathogens.

scholarly journals Antimicrobial Effect of Sodium Chlorite on Bacteria and Yeasts

1989 ◽  
Vol 30 (3) ◽  
pp. 240-249_1 ◽  
Author(s):  
Yukari HASEGAWA ◽  
Yumiko NAKAMURA ◽  
Yasuhide TONOGAI ◽  
Michiko KOBATAKE ◽  
Yoshio ITO
Keyword(s):  
Antimicrobial Effect ◽  
Sodium Chlorite

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XXXIII. AUTOMATIC pH CONTROL IN THE DISSIMILATION OF SUCROSE BY BACILLUS POLYMYXA

1949 ◽  
Vol 27f (12) ◽  
pp. 457-469
Author(s):  
R. W. Watson ◽  
Florence Tamboline ◽  
G. W. Harmsen
Keyword(s):  
Carbon Dioxide ◽  
Organic Acids ◽  
Sucrose Concentration ◽  
Marked Change ◽  
Ammonium Hydroxide ◽  
Carbon Dioxide Production ◽  
Ph Control ◽  
Invert Sugar ◽  
Aerobic Conditions ◽  
Chemical Balance

An electronic control circuit was used to maintain pH within ±0.02 units between successive additions of soluble alkali. Carbon balances show the effects of a series of pH levels and of a range of sucrose concentrations on the proportional yields of end products. There is a marked change in the chemical balance of this fermentation at about pH 7.0, correlated with a suppression of the acetoin enzyme system. Above pH 6.8 a sharp increase in acid production is correlated with decreased formation of diol and carbon dioxide: below pH 6.8 the yield of organic acids decreases steadily. Most efficient conversion to diol occurs from pH 6.0 to 6.4. Several reasons are advanced for selecting pH 6.2 as the optimum. Under anaerobic conditions the fermentation rate is increased over that under aerobic conditions. Diol yields increase and ethanol yields decrease steadily with increasing sucrose concentrations. The increases in diol are accompanied by decreasing yields of organic acids, and not by changes in carbon dioxide production, which remains relatively uniform. The sucrose concentration most efficient for conversion to diol is about 8%, which is dissimilated anaerobically in 30 hr. at pH 6.2 to yield 65 mM. (millimoles) of diol per 100 mM. of invert sugar fermented. Under aerobic conditions the diol–ethanol ratios show a marked increase, and reach a maximum of about 11 at 10% sucrose. This is due largely to increased acetoin and decreased ethanol formation. The dissimilation of 6% sucrose reaches 98% in 71 hr. under aerobic conditions and yields 82 mM. of diol plus acetoin per 100 mM. of invert sugar fermented. The use of either sodium or potassium hydroxide in place of ammonium hydroxide increases five times the period for complete dissimilation of 5% sucrose. Advantages of controlling the reaction by addition of ammonium hydroxide are reviewed.

scholarly journals Antimicrobial Efficacy of Low Concentration PVP-Silver Nanoparticles Deposited on DBD Plasma-Treated Polyamide 6,6 Fabric

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 581 ◽  
Author(s):  
Ana Isabel Ribeiro ◽  
Dilara Senturk ◽  
Késia Karina Silva ◽  
Martina Modic ◽  
Uros Cvelbar ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Low Cost ◽  
Antimicrobial Effect ◽  
Bactericidal Effect ◽  
Dbd Plasma ◽  
Low Concentration ◽  
Log Reduction ◽  
Spray Method ◽  
Antibacterial Textiles ◽  
Fabric Surface

In this study, a low concentration (10 μg·mL−1) of poly(N-vinylpyrrolidone) (PVP)-coated silver nanoparticles (AgNPs) were deposited by spray and exhaustion (30, 70 and 100 °C) methods onto untreated and dielectric barrier discharge (DBD) plasma-treated polyamide 6,6 (PA66) fabric. DBD plasma-treated samples showed higher AgNP deposition than untreated ones for all methods. After five washing cycles, only DBD plasma-treated samples displayed AgNPs on the fabric surface. The best-performing method was exhaustion at 30 °C, which exhibited less agglomeration and the best antibacterial efficacy against S. aureus (4 log reduction). For E. coli, the antimicrobial effect showed good results in all the exhaustion samples (5 log reduction). Considering the spray method, only the DBD plasma-treated samples showed some bacteriostatic activity for both strains, but the AgNP concentration was not enough to have a bactericidal effect. Our results suggest DBD plasma may be a low cost and chemical-free method for the preparation of antibacterial textiles, allowing for the immobilization of a very low—but effective—concentration of AgNPs.

EFFECT OF MULTI-WALLED CARBON NANOTUBES ON VIABILITY AND SUPEROXIDE DISMUTASE EXPRESSION IN HUMAN WOUND PATHOGENS

2009 ◽  
Vol 08 (04n05) ◽  
pp. 415-423
Author(s):  
SANJAI SAXENA ◽  
CHARU GOMBER ◽  
K. K. RAINA
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Superoxide Dismutase ◽  
Chronic Wound ◽  
Antimicrobial Effect ◽  
Bacterial Count ◽  
Burn Wound ◽  
Antimicrobial Drugs ◽  
Sod Activity ◽  
Log Reduction ◽  
Multi Walled Carbon Nanotubes

Recently, a wide variety of bionanocomposites and biocomposites are being developed to be used as extracellular matrix for chronic wound healing. Majority of the chronic wound situations arise due to infections caused by drug-resistant microbes like Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. In particular S. aureus has become refractory to the current armamentarium of antimicrobial drugs. Therefore, it is imperative while designing nanobiocomposites for use as extracellular matrices to profile their antimicrobial activity. MWNT (multi-wall carbon nanotube) has been exploited previously in designing biocompatible nanocomposite for medical applications. Keeping in view, we studied the antimicrobial effect of MWNT on human clinical burn/wound pathogens, which were Methicillin-resistant Staphylococci and one Vancomycin intermediate Staphylococcus isolate. We also studied E. coli NCTC 10418 and Pseudomonas aeruginosa NCTC 10662, two surrogate gram negative microbes to understand their behavior in the presence of MWNT. Apart from reduction in viable counts of the test panel, organism's extracellular expression of the enzyme Superoxide dismutase (SOD) was also taken into account as this is the probable mechanism adopted by bacteria in general to survive and sustain under nutritional and other stress situation including pathogenesis. The present study indicated that all Staphylococcal isolates were susceptible to MWNT which reduced the bacterial count between 3–9 logs barring Sau G19 which only exhibited 1 log reduction. Sau G17, Sau G18, and Sau G19 expressed a higher SOD activity, Sau G9 exhibited a lower SOD expression and in Sau G16, the SOD expression was nearly the same as compared to control. Thus, from this study, it could be inferred that MWNT, apart from being antimicrobial, induces oxidative stress on S. aureus.

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