Multiplex enumeration of Escherichia coli and Salmonella enteritidis in a passive capillary microfluidic chip

2020 ◽  
Vol 12 (30) ◽  
pp. 3788-3796
Author(s):  
Üzeyir Dogan ◽  
Esin Nagihan Kasap ◽  
Ferah Sucularlı ◽  
Ender Yildirim ◽  
Ugur Tamer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fluorescence Detection ◽  
Microfluidic Chip ◽  
Salmonella Enteritidis ◽  
E Coli

The concept of a capillary driven microfluidic chip to carry out the immunoassay for fluorescence detection of two target bacteria, namely Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis) in less than 60 min.

Screening of Commercial and Pecan Shell–Extracted Liquid Smoke Agents as Natural Antimicrobials against Foodborne Pathogens

2012 ◽  
Vol 75 (6) ◽  
pp. 1148-1152 ◽  
Author(s):  
ELLEN J. VAN LOO ◽  
D. BABU ◽  
PHILIP G. CRANDALL ◽  
STEVEN C. RICKE
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Antioxidant Properties ◽  
Inhibitory Effects ◽  
Natural Antimicrobials ◽  
E Coli ◽  
Liquid Smoke ◽  
Water Based ◽  
Smoke Sample

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.

Inactivation of Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, and Listeria monocytogenes on Lettuce by Hydrogen Peroxide and Lactic Acid and by Hydrogen Peroxide with Mild Heat

2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
CHIA-MIN LIN ◽  
SARAH S. MOON ◽  
MICHAEL P. DOYLE ◽  
KAY H. McWATTERS
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Sensory Characteristics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.

Inactivation of Escherichia Coli 0157:H7 and Salmonella Enteritidis in Liquid Egg Using Continuous Pulsed Electric Field System

2006 ◽  
Vol 1 (5) ◽  
Author(s):  
Malek Amiali ◽  
Michael Ngadi ◽  
James P. Smith ◽  
Vijaya Raghavan
Keyword(s):  
Escherichia Coli ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Salmonella Enteritidis ◽  
Processing Temperature ◽  
Bacterial Inactivation ◽  
E Coli ◽  
Liquid Whole Egg ◽  
Whole Egg

This study sought to evaluate the effect of PEF parameters such as electric field intensity and number of pulses on the inactivation of Escherichia coli O157:H7 and Salmonella Enteritidis suspended in liquid whole egg. The medium was inoculated with 108 CFU ml-1 of E. coli O157:H7 or S. Enteritidis and was treated continuously at 10, 20 or 30°C using electric field intensity of either 20 or 30 kV cm-1. A biphasic instant reversal PEF waveform with up to 105 pulses of 2 µs in width was applied. Bacterial inactivation increased with increasing applied electric field intensity, number of pulses and processing temperature. Maximum reductions of 3.9 and 3.6 log cycles were obtained for E. coli O157:H7 and S. Enteritidis, respectively. The maximum input energies required to inactivate E. coli O157:H7 and S. Enteritidis were 538 and 914 J, respectively. The higher kinetic value was obtained for S. Enteritidis (0.043 µs-1) representing the more heat–PEF sensitive bacteria compared to E. coli O157:H7.

Survival of Escherichia coli O157:H7, Salmonella Enteritidis, Staphylococcus aureus, and Listeria monocytogenes in Kimchi

2004 ◽  
Vol 67 (7) ◽  
pp. 1497-1500 ◽  
Author(s):  
Y. INATSU ◽  
M. L. BARI ◽  
S. KAWASAKI ◽  
K. ISSHIKI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Incubation Period ◽  
Salmonella Enteritidis ◽  
Detectable Level ◽  
Escherichia Coli O157 ◽  
Inoculum Level ◽  
Initial Inoculum ◽  
E Coli

The survival of gram-positive and gram-negative foodborne pathogens in both commercial and laboratory-prepared kimchi (a traditional fermented food widely consumed in Japan) was investigated. It was found that Escherichia coli O157:H7, Salmonella Enteritidis, Staphylococcus aureus, and Listeria monocytogenes could survive in both commercial and laboratory-prepared kimchi inoculated with these pathogens and incubated at 10°C for 7 days. However, when incubation was prolonged, the S. aureus level decreased rapidly from the initial inoculum level to the minimum detectable level within 12 days, whereas Salmonella Enteritidis and L. monocytogenes took 16 days to reach similar levels in commercial kimchi. On the other hand, E. coli O157:H7 remained at high levels throughout the incubation period. For laboratory-prepared kimchi, the S. aureus level decreased rapidly from the initial inoculum level to the minimum detectable level within 12 days, and L. monocytogenes took 20 days to reach a similar level. E. coli O157:H7 and Salmonella Enteritidis remained at high levels throughout the incubation period. The results of this study suggest that the contamination of kimchi with E. coli O157:H7, Salmonella Enteritidis, S. aureus, or L. monocytogenes at any stage of production or marketing could pose a potential risk.

scholarly journals Antimicrobial Activity of Wine in Relation to Bacterial Resistance to Medicinal Antibiotics

OENO One ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. 45-48
Author(s):  
Mladen Boban ◽  
Nataša Boban ◽  
Marija Tonkić ◽  
Mia Grga ◽  
Ana Marija Milat ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Salmonella Enteritidis ◽  
Bacterial Resistance ◽  
Bacterial Suspension ◽  
Antimicrobial Drugs ◽  
Principal Mechanism ◽  
E Coli ◽  
Resistance To Antibiotics ◽  
Time Kill

Although antimicrobial properties of wine have been extensively studied, antimicrobial effects of wine in relation to bacterial resistance to medicinal antibiotics have not been examined. Therefore, our aim was to determine whether bacterial resistance to antibiotics can be related to their resistance to red wine as an unspecific antimicrobial medium. The organisms studied were Salmonella enteritidis (ATCC 13076), Escherichia coli (ATCC 25922), and two clinical isolates which exhibited different resistance to antibiotics, ESBL - producing Escherichia coli UR 3612 and Salmonella enteritidis KK 962. The time-kill curves method was used. The minimal incubation time of the bacterial suspension with wine, necessary for prevention of bacterial growth, was 3 and 20 min for E. coli ATCC and ESBL E. coli respectively. This was associated with susceptibility testing in which E. coli ATCC proved highly sensitive in contrast to ESBL-producing E. coli, which exhibited resistance to a spectrum of antimicrobial drugs of different classes regarding their principal mechanism of action. In the case of S. enteritidis strains, they were similar in their susceptibility against test antibiotics and time-kill curves following exposure to wine. Bacterial resistance to wine is closely associated with bacterial resistance to antimicrobial drugs. The exact mechanisms of antimicrobial activity of wine are still a matter of debate. However, wine might be less susceptible to bacterial resistance development and may include mechanisms different from those of medicinal antibiotics. The present study represents an initial contribution to this important subject which has been practically unexplored.

scholarly journals Produção de itens de ensaio de proficiência contendo bactérias em matriz frango utilizando a técnica de liofilização

2021 ◽  
Vol 9 (2) ◽  
pp. 59-67
Author(s):  
Ingrid Camelo da Silva ◽  
◽  
Paula Vasconcelos Costa ◽  
Luiza Vasconcellos ◽  
Pablo Tavares Coimbra ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Salmonella Enteritidis ◽  
E Coli ◽  
Iso Guide 35

Introdução: A participação em ensaios de proficiência (EP) é utilizada para avaliar a competência de laboratórios de ensaio e calibração. Objetivo: Avaliar a viabilidade da técnica de liofilização na produção de seis lotes de itens de EP, dois contendo Escherichia coli, dois contendo Bacillus cereus e Staphylococcus aureus concomitantemente, e dois contendo Salmonella Enteritidis em matriz frango desfiado cozido. Método: Foram realizados testes de homogeneidade segundo o protocolo harmonizado e de estabilidade em longo prazo pelo modelo clássico e curto prazo pelo modelo isócrono segundo a ISO Guide 35. Resultados: Todos os lotes produzidos foram considerados suficientemente homogêneos. No estudo de estabilidade em longo prazo, todos os lotes se apresentaram suficientemente estáveis nas temperaturas de -80 ± 10ºC e -20 ± 4ºC, exceto o lote contendo B. cereus e S. aureus. Os outros lotes apresentaram estabilidade por pelo menos 126 dias a -80 ± 10ºC e 84 dias a -20 ± 4ºC. Na avaliação da estabilidade em curto prazo, foram analisados apenas os lotes suficientemente estáveis no estudo em longo prazo. Os lotes foram suficientemente estáveis nas temperaturas de 5 ± 3ºC e 35 ± 2ºC, com exceção do lote contendo Salmonella Enteritidis a 35 ± 2ºC, devido ao decréscimo significativo da concentração celular. Conclusões: A técnica de liofilização foi satisfatória para produção de itens de ensaio contendo E. coli e Salmonella Enteritidis em matriz frango viáveis para utilização em um EP, sendo que o lote contendo Salmonella Enteritidis deve ser transportado aos laboratórios participantes em temperatura ≤ 8ºC por até quatro dias. Lotes contendo S. aureus e B. cereus, simultaneamente, apresentaram estabilidade insuficiente, indicando que a produção de lotes individuais contendo cada bactéria individualmente é necessária.

scholarly journals Transference in vitro of the resistance to the antimicrobials between Escherichia coli, Lactobacillus spp. and Salmonella enteritidis isolated from chickens

2011 ◽  
Vol 63 (5) ◽  
pp. 1149-1153
Author(s):  
A.S Okamoto ◽  
R.L Andreatti Filho ◽  
T.S Rocha ◽  
E.L Milbradt
Keyword(s):  
Escherichia Coli ◽  
Standard Method ◽  
Salmonella Enteritidis ◽  
Clinical Laboratory ◽  
National Committee ◽  
E Coli ◽  
Normal Microbiota ◽  
Lactobacillus Spp

The objective of this work was to verify the possibility of transference of resistance to the antimicrobials between bacteria that are in the present normal microbiota of chickens and Salmonella Enteritidis. Samples of Lactobacillus spp. (L. spp.), Salmonella Enteritidis (SE) and Escherichia coli (E. coli) previously isolated from chickens, selected after the test of sensitivity antimicrobial in vitro according the standard method (National Committee for Clinical Laboratory Standards) utilizing those with resistance and sensibility to the antimicrobials inductors, named donor and receptor bacteria, respectively were used. Antimicrobials inductors were utilized to stimulate the transference of resistance to the antimicrobials between the bacteria. The possibility of transference was verified from the E. coli resistant to the SE and L. spp. Transference of a sample of L. spp resistant to the antimicrobials inductors to the SE was also verified. It was only possible to verify the transference of the resistance to the antimicrobials inductor when the donor bacteria was the E. coli and the bacteria receptor was SE. In the present study we conclude that the transference of resistance to the antimicrobials between bacteria is possible, however, not all bacteria participate in that trial, not transmitting and neither acquiring this resistance.

scholarly journals Efficacy of Electrolyzed Oxidizing Water for Inactivating Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes

1999 ◽  
Vol 65 (9) ◽  
pp. 4276-4279 ◽  
Author(s):  
Kumar S. Venkitanarayanan ◽  
Gabriel O. Ezeike ◽  
Yen-Con Hung ◽  
Michael P. Doyle
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Enteritidis ◽  
Sampling Time ◽  
Deionized Water ◽  
Escherichia Coli O157 ◽  
Water Control ◽  
E Coli ◽  
Complete Inactivation ◽  
Control Samples

ABSTRACT The efficacy of electrolyzed oxidizing water for inactivatingEscherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes was evaluated. A five-strain mixture of E. coli O157:H7,S. enteritidis, or L. monocytogenes of approximately 108 CFU/ml was inoculated in 9 ml of electrolyzed oxidizing water (treatment) or 9 ml of sterile, deionized water (control) and incubated at 4 or 23°C for 0, 5, 10, and 15 min; at 35°C for 0, 2, 4, and 6 min; or at 45°C for 0, 1, 3, and 5 min. The surviving population of each pathogen at each sampling time was determined on tryptic soy agar. At 4 or 23°C, an exposure time of 5 min reduced the populations of all three pathogens in the treatment samples by approximately 7 log CFU/ml, with complete inactivation by 10 min of exposure. A reduction of ≥7 log CFU/ml in the levels of the three pathogens occurred in the treatment samples incubated for 1 min at 45°C or for 2 min at 35°C. The bacterial counts of all three pathogens in control samples remained the same throughout the incubation at all four temperatures. Results indicate that electrolyzed oxidizing water may be a useful disinfectant, but appropriate applications need to be validated.

Synergistic Effect of High Temperature and High pH on the Destruction of Salmonella enteritidis and Escherichia co1i O157:H7

1996 ◽  
Vol 59 (10) ◽  
pp. 1023-1030 ◽  
Author(s):  
YEOW-LIM TEO ◽  
TIMOTHY J. RAYNOR ◽  
KAMESWAR R. ELLAJOSYULA ◽  
STEPHEN J. KNABEL
Keyword(s):  
Escherichia Coli ◽  
High Temperature ◽  
Synergistic Effect ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Synergistic Interaction ◽  
Escherichia Coli O157 ◽  
Gram Negative ◽  
High Ph ◽  
E Coli

This study was undertaken to determine if high temperature and high pH interact synergistically to enhance the rate of destruction of two important gram-negative foodborne pathogens, Escherichia coli O157:H7 and Salmonella enteritidis. The rates of destruction in NaHCO3-NaOH buffers at pH 7.0, 10.0, and 11.0 were determined at 35, 40, 45, 50, 55, 60, and 65°C. Use of an improved heating protocol eliminated a “tailing effect” at longer exposure times. The present study demonstrated that the combination of high pH and high temperature resulted in a highly significant synergistic interaction (P > F = 0.0001), which caused rapid death of both E. coli O157:H7 and S. enteritidis. This “alka-therm” technology might be used commercially to destroy gram-negative foodborne pathogens on various raw agricultural commodities.

Inactivation of Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on Apples, Oranges, and Tomatoes by Lactic Acid with Hydrogen Peroxide

2002 ◽  
Vol 65 (1) ◽  
pp. 100-105 ◽  
Author(s):  
KUMAR S. VENKITANARAYANAN ◽  
CHIA-MIN LIN ◽  
HANNALORE BAILEY ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Chemical Treatment ◽  
Salmonella Enteritidis ◽  
Deionized Water ◽  
Wash Water ◽  
Escherichia Coli O157 ◽  
E Coli

The objective of this study was to develop a practical and effective method for inactivating or substantially reducing Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on apples, oranges, and tomatoes. Apples, oranges, and tomatoes were spot-inoculated with five-strain mixtures of E. coli O157:H7, Salmonella Enteritidis, and L. monocytogenes near the stem end and were submerged in sterile deionized water containing 1.5% lactic acid plus 1.5% hydrogen peroxide for 15 min at 40°C. Inoculated samples treated with sterile deionized water at the same temperature and for the same duration served as controls. The bacterial pathogens on fruits subjected to the chemical treatment were reduced by >5.0 log10 CFU per fruit, whereas washing in deionized water decreased the pathogens by only 1.5 to 2.0 log10 CFU per fruit. Furthermore, substantial populations of the pathogens survived in the control wash water, whereas no E. coli O157:H7, Salmonella Enteritidis, or L. monocytogenes cells were detected in the chemical treatment solution. The sensory and qualitative characteristics of apples treated with the chemical wash solution were not adversely affected by the treatment. It was found that the treatment developed in this study could effectively be used to kill E. coli O157:H7, Salmonella Enteritidis, and L. monocytogenes on apples, oranges, and tomatoes at the processing or packaging level.

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