• Journal of the Korean Dietetic Association
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• v.13 no.4
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• pp.389-406
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• 2007

This study was conducted to estimate the safety level of non-cooking and cooking processed foods to propose the sanitary management of foods donated to foodbanks. The time and temperature were measured and the microbial levels of aerobic plate counts (APC), coliforms, E. coli, Salmonella spp., S. aureus, B. cereus, and E. coli O157:H7 were analyzed on ten food items donated to seven foodbanks. The amount of cooked foods donated to each foodbank was about 10 to 40 servings. All foodbanks hired a supervisor and had at least one refrigerator/freezer and one temperature-controlled vehicle, but only four foodbanks had the separate offices to manage the foodbank operation. The flow of donated foods was gone through the steps; production, meal service and holding at donator, collection by foodbank, transport (or holding after transport) and distribution to recipients. After production, the levels of APC of both non-cooking and cooking processed foods were complied with the standards by Ministry of Education & Human Resources Development, and were not increased till distribution. Only the level of coliforms in dried squid & cucumber salad (1.5×$10^3$ CFU/g) was not met the standards. E. coli and other pathogens were not detected in all tested samples. The microbial levels of delivery vessels and work tables were satisfactory, but the APC levels of two of four tested serving tables (6.9×$10^3$ and 5.3×$10^3$ CFU/100$cm^2$) and the coliforms level of one (1.1×$10^3$ CFU/100$cm^2$) were over the standards. The air-borne microflora level in serving room was estimated as satisfactory. It took about 3.0 to 6.5 hours from after-production to distribution and the temperatures of donated foods were exposed mostly to temperature danger zone, which had a high potential of microbial growth. These results imply that a checklist to monitor time and temperature in each step should be provided and the employees involving foodbank operation should be properly educated to ensure the safety of donated foods.

• Journal of Convergence for Information Technology
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• v.11 no.6
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• pp.198-205
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• 2021

Objectives: Antibiotics help treat Vaginitis, and prolonged usage of antibiotics can lead to resistance. Methods: This study investigates the antimicrobial activity of two types of lactic acid bacteria using essential oils. After cultivation by adding grapefruit seed extract (GSE), eucalyptus, tea tree, clove bud, cinnamon, lemongrass, thyme, and ginger oils in a specific ratio, pathogenic microorganisms, namely E. coli, C. albicans, and lactic acid bacteria were released. The number of bacteria was measured using a medium suitable for the strains. Results: The essential oils and GSE inhibited pathogenic microorganisms, and the inhibitory concentration of GSE against pathogenic bacteria (E. coli, C. albicans) was confirmed. The non-inhibitory mixing ratio was also confirmed (50 μl of eucalyptus globulus (EG) oil and 50 μl of melaleuca alternifolia oil (tea tree oil, TTO) at 200 ppm GSE (pH 5.0, 5.5, 6.0)). Conclusion: Essential oils can be considered as an alternative to antibiotics because of their antibacterial properties. They are useful as auxiliary antibacterial agents for patients under long-term antibiotic treatment.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.190-190
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• 2003

• Korean Journal of Veterinary Service
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• v.37 no.1
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• pp.19-27
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• 2014

This study was conducted to investigate the antimicrobial resistance, presence of ${\beta}$-lactamase genes and integrons in 83 ESBL-producing Escherichia coli isolated from Nakdong river and Geumho river in Daegu. Among the ${\beta}$-lactam antimicrobials, all isolates were resistant to ampicillin, cephalothin, cefamandole and cefotaxime, followed by piperacillin (98.8%), ampicillin/sulbactam (86.7%), aztreonam (60.2%) and cefepime (59.0%), whereas resistance to piperacillin/tazobacram, ticarcillin/clavulanic acid and cefoxitin was less than 30%. Many of the ESBL-producing Escherichia coli were also resistant to non-${\beta}$-lactams antimicrobials such as nalidixic acid (83.1%), sulfonamides (72.3%), ciprofloxacin (62.7%) and gentamicin (38.6%). All isolates showed resistance to seven or more antimicrobial agents. The most frequently detected gene was $bla_{TEM+CTX-M}$ (49.4%), followed by $bla_{CTX-M}$ (27.7%), $bla_{TEM}$ (6.0%) and $bla_{OXA}$ (1.2%). But $bla_{SHV}$ was not found. Class 1 integrons were found in 61.4% (51 isolates) of isolates, however, class 2 and 3 integrons were not detected. The results showed water from Nakdong river and Geumho river is contaminated with ESBL-producing E. coli isolates. These results suggest the need for further investigation of antibiotic resistant bacteria to prevent public health impacts in the water environment.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.68-74
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• 2020

This study investigated the inactivation and synergistic efficacy of combined low-temperature heating (LT) and atmospheric plasma (AP) against Escherichia coli in red pepper powder. A cocktail of two strains of E. coli (ATCC 11229, KCCM 11234) was inoculated onto red pepper powder and then treated with LT (60℃ for 5-20 min) and AP (atmospheric plasma for 5-20 min). The counts of E. coli in the red pepper powder were significantly (P<0.05) reduced with the increase in treatment time using LT and AP. The reduction of E. coli levels in red pepper powder when treated with LT alone for 5, 10, 15, and 20-min were 0.25, 1.45, 2.54, and 2.85 log₁₀ CFU/g, respectively. Also, the reduced levels of E. coli on red pepper powder when treated with AP alone for 5, 10, 15, and 20 min were 0.19, 0.32, 0.54, and 0.96 log₁₀ CFU/g, respectively. The synergistic effects were not dependent on the treatment time with AP, but were dependent on the LT treatment time. Synergistic reduction values for combined LT and AP treatment against E. coli in red pepper powder were -0.13 to 2.91 log₁₀ CFU/mL, respectively. Especially, the largest synergistic values (2.91-2.82 log₁₀ CFU/mL) of E. coli in red pepper powder were revealed by the combination of a 20-min treatment with LT and a 15-20-min treatment with AP. All sensory parameters (color, off-odor, taste, texture, and overall acceptability) were not significantly (P>0.05) different between non-treated and all combination-treated samples. Therefore, these results suggest that the combination of LT and AP can be potentially utilized in the food industry to effectively inactivate E. coli without incurring quality deterioration in red pepper powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.4
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• pp.577-584
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• 2016

The objectives of this study were I) to compare the acid resistance (AR) of seven non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups, including O26, O45, O103, O111, O121, O145, and O157:H7 STEC isolated from various sources, in 400 mM acetic acid solution (AAS) at pH 3.2 and $30^{\circ}C$ for 25 min with or without glutamic acid and II) to determine strain survival upon exposure to simulated gastric fluid (SGF, pH 1.5) at $37^{\circ}C$ for 2 h after acid adaptation in apple, pineapple, orange, and strawberry juices at pH 3.8, $4^{\circ}C$ and $20^{\circ}C$. Results show that the O111 serogroup strains had the strongest AR (0.12 log reduction CFU/mL) which was very similar to that of O157:H7 STEC (P>0.05), compared to other serogroups in AAS without glutamic acid, whereas O26 serogroup strains showed the most sensitive AR. However, there was no significant (P>0.05) difference of AR among seven serogroups in AAS with glutamic acid. In the SGF study, 05-6545 (O45:H2), 08023 (O121:H19), and 03-4669 (O145:NM) strains adapted in fruit juices at $4^{\circ}C$ and $20^{\circ}C$ displayed enhanced survival with exposure to SGF for 60 min compared to 06E0218 (O157:H7) strains (P<0.05). In addition, 4 STEC strains adapted in pineapple juice at $4^{\circ}C$ showed enhanced survival with exposure to SGF for 60 min compared to those strains acid-adapted in the other fruit juices. Generally, adaptation at $4^{\circ}C$ in fruit juices resulted in significantly enhanced survival levels compared to acid-adapted at $20^{\circ}C$ and non-adapted conditions. The AR caused by adaptation in fruit juices at low temperature may thus increase survival of non-O157 STEC strain in acidic environments such as the gastrointestinal tract. These results suggest that more careful strategies should be provided to protect against risk of foodborne illness by non-O157 STEC.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.355-356
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• 2000

Three 'stress probe' plasmids were constructed and characterized which utilize a green fluorescent protein (CFP) as a non-invasive reporter to elucidate Escherichia coli cellular stress responses in quiescent or 'resting' cells. Facile detection of cellular stress levels was achieved by fusion of three heat shock stress protein promoter elements, those of the heat shock transcription factor ${\sigma}^{32}$, pretense subunit ClpB, and chaperone DnaK, to the reporter gene $gfp_{uv}$. When perturbed by chemical or physical stress (such as heat shock, nutrient (amino acid) limitation, addition of IPTG, acetic acid, ethanol, phenol, antifoam, and salt (osmotic shock), the E. coli cells produced GFPuv which was easily detected from within the cells as emitted green fluorescence. A temporal and amplitudinal mapping of these responses was performed, demonstrating regions where quantitative delineation of cell stress was afforded.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.323-325
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• 2004

To model the behavior of expanded beds with aqueous feed streams containing different amounts of glycerol, we previously developed a modified Stokes expression that correlates the terminal settling velocity of a particle of a solution with the properties of the particle (particle diameter and density) and the solution (density and viscosity). Two empirical parameters, the effective diameter of the poly-disperse resins for protein adsorption and an exponent of non-unity for $(\rho_{P}-\rho)/\mu$ term, are introduced in the modified Stokes expression. We applied the same type of the modified Stokes expression in combination with the Richardson-Zaki correlation to the published results [1], and found that the expansions of the beds with feed streams containing different amounts of E. coli homogenates can also be successfully described.

• Korean Journal of Microbiology
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• v.19 no.3
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• pp.103-107
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• 1981

Increasing the concentration of the nonionic surfactants the solubility of methyl paraben was increased. This is called the solubilization phenomenon and caused inactivation of the preservatives used. The MICs(minimum inhibitory concentrations) on E. coli were increased at the same time. So the relation between the solubility and the mic could be expressed as $S-S_0=R^{\prime}/R^{\prime\prime}\;(M-M_0)$ and in this case $R^{\prime}/R^{\prime\prime}$ was about 2.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1183-1189
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• 2021

Autodisplay of a multimeric protein complex on a cell surface is limited by intrinsic factors such as the types and orientations of anchor modules. Moreover, improper folding of proteins to be displayed often hinders functional cell surface display. While overcoming these drawbacks, we ultimately extended the applicability of the autodisplay platform to the display of a protein complex. We designed and constructed a cell surface attachment (CSA) system that uses a non-covalent protein-protein interaction. We employed the high-affinity interaction mediated by an orthogonal cohesin-dockerin (Coh-Doc) pair from Archaeoglobus fulgidus to build the CSA system. Then, we validated the orthogonal Coh-Doc binding by attaching a monomeric red fluorescent protein to the cell surface. In addition, we evaluated the functional anchoring of proteins fused with the Doc module to the autodisplayed Coh module on the surface of Escherichia coli. The designed CSA system was applied to create a functional attachment of dimeric α-neoagarobiose hydrolase to the surface of E. coli cells.