Inhibitory Effects of Combinations of Chemicals on Escherichia coli, Bacillus cereus, and Staphylococcus aureus Biofilms during the Clean-in-Place Process at an Experimental Dairy Plant

2020 ◽  
Vol 83 (8) ◽  
pp. 1302-1306
Author(s):  
EUN-SEON LEE ◽  
JONG-HUI KIM ◽  
MI-HWA OH

ABSTRACT In dairy plants, clean-in-place (CIP) equipment cannot be disassembled, making it difficult to clean the inner surface of pipes. In this study, the inhibitory effects of chemical agents on biofilms formed by three foodborne pathogens, Bacillus cereus, Escherichia coli, and Staphylococcus aureus, was evaluated in a dairy CIP system. The experiment was conducted on a laboratory scale. Each of the three bacteria (200 μL) was inoculated onto stainless steel (SS) chips (25 by 25 mm), and the effect of single cleaning agents was evaluated. Individual treatments with NaClO (30, 50, 100, and 200 ppm), NaOH (0.005, 0.01, 0.05, and 0.1%), citric acid (1, 3, 5, and 7%), and nisin (5, 10, 25, 50, 100, and 200 ppm) were used to clean the SS chip for 10 min. The most effective concentration of each solution was selected for further testing in a commercial plant. Simultaneous cleaning with 200 ppm of NaClO (10 min) and 7% citric acid (10 min) reduced the biofilms of B. cereus, E. coli, and S. aureus by 6.9, 7.0, and 8.0 log CFU/cm2, respectively. Both 7% citric acid and 0.1% NaOH were optimal treatments for E. coli. NaClO and citric acid are approved for use as food additives in the Republic of Korea. Our results revealed that a combined treatment with NaClO and citric acid is the most effective approach for reducing biofilms formed by common foodborne pathogens on CIP equipment. These findings can contribute to the production of safe dairy products. HIGHLIGHTS

1979 ◽  
Vol 42 (6) ◽  
pp. 464-469 ◽  
Author(s):  
M. E. STILES ◽  
L.-K. NG

Ham and chopped ham from two manufacturers were contaminated with five enteropathogens: Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, at time of slicing and vacuum-packaging, to simulate contamination by manufacturer. Subsequent treatment of the samples, representing sound and undesirable retail handling and consumer use conditions, indicated marked differences in the fate of the pathogens between these products and within product type between the two manufacturers. Greatest differences were observed between the chopped ham products. All pathogens, except C. perfringens, grew actively in fresh ham and chopped ham with abusive holding at 30 and 21 C. After storage at 4 or 10 C for 30 days, B. cereus and C. perfringens were no longer detected, even after subsequent holding at 30 or 21 C for 24 h. E. coli survival and growth was variable, S. typhimurium survived well and grew under some conditions and S. aureus was generally inhibited at high levels of competition.


2005 ◽  
Vol 60 (9-10) ◽  
pp. 693-700 ◽  
Author(s):  
Simone M. de Souza ◽  
Franco Delle Monache ◽  
Artur Smânia

Abstract The antibacterial activity of coumarin per se and other 45 coumarin derivatives was tested against strains of Bacillus cereus MIP 96016, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Staphylococcus aureus ATCC 25923. The inhibitory effects of coumarins were affected by their substitution patterns. Osthenol (44) showed the most effective antibacterial activity against Gram-positive bacteria with MIC values ranging between 125 and 62.5 μg/ml. These results suggested that the prenyl chain of 44 at position 8 and the presence of OH at position 7 of the benzenic ring are required for the antibacterial activity against these strains.


2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).


2012 ◽  
Vol 75 (6) ◽  
pp. 1148-1152 ◽  
Author(s):  
ELLEN J. VAN LOO ◽  
D. BABU ◽  
PHILIP G. CRANDALL ◽  
STEVEN C. RICKE

Liquid smoke extracts have traditionally been used as flavoring agents, are known to possess antioxidant properties, and serve as natural alternatives to conventional antimicrobials. The antimicrobial efficacies of commercial liquid smoke samples may vary depending on their source and composition and the methods used to extract and concentrate the smoke. We investigated the MICs of eight commercial liquid smoke samples against Salmonella Enteritidis, Staphylococcus aureus, and Escherichia coli. The commercial liquid smoke samples purchased were supplied by the manufacturer as water-based or concentrated extracts of smoke from different wood sources. The MICs of the commercial smokes to inhibit the growth of foodborne pathogens ranged from 0.5 to 6.0% for E. coli, 0.5 to 8.0% for Salmonella, and 0.38 to 6% for S. aureus. The MIC for each liquid smoke sample was similar in its effect on both E. coli and Salmonella. Solvent-extracted antimicrobials prepared using pecan shells displayed significant differences between their inhibitory concentrations depending on the type of solvent used for extraction. The results indicated that the liquid smoke samples tested in this study could serve as effective natural antimicrobials and that their inhibitory effects depended more on the solvents used for extraction than the wood source.


1981 ◽  
Vol 44 (6) ◽  
pp. 430-434 ◽  
Author(s):  
JAMES E. STEELE ◽  
MICHAEL E. STILES

Ham sandwiches inoculated with a mixture of five enteropathogenic bacteria, Bacillus cereus, Clostridium perfringens. Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, were held at 30, 21 and 4 C for up to 24 h. Food poisoning potential was judged by the growth and survival of the inoculated pathogens. Major differences were observed between new and old (30 days of storage at 4 C) ham samples. On new ham, all enteropathogens were able to grow except C. perfringens, whereas on old ham, with high microbial competition. the pathogens survived but did not grow. Severe storage temperature abuse was necessary to develop a food poisoning potential in new ham samples. The safety of old ham was attributed to the competitive microflora that grew in the ham during storage at 4 C for 30 days. Infective pathogens, E. coli and S. typhimurium, either survived or increased in numbers under all test conditions. The safety of vacuum packaged sliced ham for use in sandwiches, in its present market form, was indicated by these studies.


2008 ◽  
Vol 71 (2) ◽  
pp. 325-332 ◽  
Author(s):  
YONG-SUK KIM ◽  
ZIAN-BIN ZHENG ◽  
DONG-HWA SHIN

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.


2003 ◽  
Vol 9 (5) ◽  
pp. 353-358 ◽  
Author(s):  
O. Sagdic ◽  
A. G. Karahan ◽  
M. Ozcan ◽  
G. Ozkan

Eighteen extracts of spices commonly consumed worldwide and grown naturally in Turkey were tested against twenty three bacterial strains to compare their antibacterial effects with eleven antibiotics. Eight pathogens and fifteen lactobacilli isolated from chick intestine were used as the test microorganisms. Pathogens (six different Staphylococcus aureus strains, Escherichia coli ATCC 25922 and Yersinia enterocolitica ATCC 1501) were grown in Nutrient broth and lactobacilli in MRS broth. Hop extracts formed inhibition zones against S. aureus strains of upto 36 mm. Inhibitory effects of hop extracts against S. aureuswere generally higher than that of erythromycin as antibiotic. Helichrysum compactum extract produced an inhibition zone of 23mm to E. coli ATCC 25922 and 26mm to Y. enterocolitica ATCC 1501. Helichrysum compactum extract inhibited the growth of Y. enterocolitica ATCC 1501 more than other spice extracts. While inhibition zones of these extracts against lactobacilli were found smaller than on S. aureus strains, inhibition zones of the same extracts against lactobacilli were found similar to those of E. coli ATCC 25922 and Y. enterocolitica ATCC 1501.


Author(s):  
Sukhuntha Osiriphun ◽  
Phichaya Poonlarp ◽  
Danai Boonyakiat ◽  
Patcharin Raviyan

Fresh cut vegetables are a source of minerals, vitamins, and phytonutrients that are convenient foods for consumers which are following the global trend of inclination toward health food. In terms of food safety, contamination of vegetables with microorganisms can occur at multiple points along the supply chain. This study was conducted to investigate the risk factors of Escherichia coli and Staphylococcus aureus which contaminate freshly cut vegetables during production (receiving, washing, centrifuging, and packing areas) by using a statistical method for sensitivity analysis and an exposure assessment model complying with the @RiskTM software program. At washing step, the numbers of S. aureus found in the vegetables and water were 0.79 ±1.76 Log cfu/g and 0.68±1.52 Log cfu, respectively. For the equipment, the hand, and the table swabbing samples, the numbers of S. aureus were 0.48±1.07 Log cfu/25 cm2, 1.81±1.69 Log cfu/25 cm2 , and 0.54±1.21 Log cfu/25 cm2 , respectively. An amount of E. coli of 0.48±1.07 Log cfu/25 cm2 was found in the table swabbing samples at the packing area. E.coli and S. aureus were not found in any of the mixed fresh-cut salad samples; therefore, the product samples could be considered safe for consumers. The result of the sensitivity analysis showed that the temperature and pH of water samples were the important factors in the washing process. The suggested interventions included monitoring and maintaining the water temperature at 5°C; also, maintaining the pH of water between 6.5 and 7.5 could help to reduce pathogen contamination of freshly cut vegetables.


Biofilms ◽  
2004 ◽  
Vol 1 (1) ◽  
pp. 65-73 ◽  
Author(s):  
N. Oulahal ◽  
A. Martial-Gros ◽  
M. Bonneau ◽  
L. J. Blum

Two ultrasonic devices – flat (T1) and curved (T2) ultrasonic transducers – were developed to remove biofilms from opened and closed surfaces, respectively. The aim is to standardize biofilm removal for in situ sanitary control in the food industry. The biofilms studied in this work were model biofilms made with milk on stainless steel sheets. We have shown in a previous study that sonication could be employed to remove and resuspend biofilm consistently, with a good recovery rate, from opened surfaces. Plate counting was used to assess the efficiency of each treatment. A total removal of Escherichia coli and Staphylococcus aureus from model biofilms was obtained with T1: 10 s at 40 kHz. However, ultrasound applied with T2 (a patented curved transducer developed for closed surfaces: 10 s at 40 kHz) failed to completely remove these model biofilms: 30±7% and 66±10% for E. coli and S. aureus biofilms, respectively. In order to improve the biofilm removal from closed surfaces with T2, the effect of the application of ultrasound in combination with chelating agent preparations was investigated. The application of ultrasound with T2 in 0.05 mol EDTA or EGTA per litre dislodged the E. coli milk model biofilm, with 100±10% and 100±5% recovery yields, respectively. These results showed a synergism between ultrasonic waves and chelator preparations, i.e. the combination achieved three times the recovery rate of sonication alone (30%). However, when the same treatment was applied to the S. aureus milk model biofilm, the combined treatment with EDTA or EGTA did not significantly improve the recovery of the biofilm cells: 74±26% with EDTA at 0.025 mol/l and 41–47% with EGTA at 0.025 mol/l and 0.05 mol/l, respectively, compared with 66±10% for sonication alone. The combined treatment was in agreement with an industrial control, i.e. a good reproducible recovery of the biofilm in a few seconds (10 s) for E. coli milk biofilms but not for S. aureus biofilms.


2000 ◽  
Vol 55 (9-10) ◽  
pp. 778-784 ◽  
Author(s):  
Josep Serra Bonvehí ◽  
Francesc Ventura Coll

Abstract The composition, bacteriostatic and ROO• -scavenging potential activities of fifteen propolis samples from various botanic and geographic origins were determined to obtain objective information related to propolis quality. Variance analysis showed significant differences (p ≤ 0.05) in the contents of polyphenols, flavonoids and active components between fresh and aged propolis. The state of the product (fresh or aged) could be differentiate by using flavonoid pattern and biological activities. A minimum propolis concentration of 80 μg/ml was required inhibit Bacillus subtilis and Staphylococcus aureus while 800 μg/ml was required to inhibit Escherichia coli using fresh propolis. Aged propolis inhibit B. subtilis and S. aureus at concentration of 100 μg/ml and E. coli at 1000 μg/ml. A minimum flavonoids percentage of 18 g/100 g and a maximum ROO• -scavenging potential activity of 4.3 μg/ml were determined in fresh propolis. Flavonoids levels in aged propolis were approximately 20% lower than in fresh propolis. A maximum flavonoids percentage of 19.8 g/100 g and a ROO•-scavenging potential activity between 5.7 to 6.4 μg/ml in aged propolis were quantified. Another objective was to assess the use of ROO•-scavenging potential activity in propolis quality.


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