• Korean Journal of Veterinary Service
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• v.37 no.4
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• pp.225-231
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• 2014

In this study, 185 cefotaxime-resistant Escherichia coli were isolated from different stages of a wastewater treatment plant (WWTP) in Daegu in Korea. Among them, 99.5% (184 isolates) originated from raw sewage and 0.5% (1 isolates) from the final effluent. Cefotaxime-resistant E. coli were high resistant to ampicillin, piperacillin, cefazolin, cephalothin, cefachlor and cefamandole (99.5~100%). About 93% of the cefotaxime-resistant E. coli were extended-spectrum ${\beta}$-lactamases (ESBL)-producing E. coli. The $bla_{TEM+CTX}$ gene was the most predominant of the ESBL genes (72.5%), followed by $bla_{CTX-M}$ (16.2%), $bla_{TEM}$ (8.7%), $bla_{TEM+CTX+SHV}$ (1.1%), $bla_{TEM+SHV}$, $bla_{TEM+OXA}$, and $bla_{TEM+CTX+SHV}$ (respectvely 0.5%). Class 1 and 2 integron were found in 49.7% and class 3 integron was not found. All of integron positive isolates were multiresistant (i.e. resistant to four or more antibiotics). Our findings showed WWTP is contaminated with antibiotic resistant bacteria with resistance genes.

• KSBB Journal
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• v.13 no.2
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• pp.168-173
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• 1998

Gamma irradiated and non-irradiated Agrimonia pilosa Ledebour were extracted by 70% ethanol. The combined effects of the Agrimonia pilosa Ledebour extract and NaCl on survival of Escherichia coli O157:H7 in tryptic soy broth were investigated. E. coli O157:H7 decreased ca 1 log cycle by the addition of 2% sample extract, and the anthbacterial activity was increased as the concentration of sample extract was increased. The irradiation effect of the sample on antibacterial activity was not observed. On the treatment of NaCl alone, E. coli O157:H7 was inactivated (ca 3~4 log cycle reduction within 48 hr) in more than 7% NaCl. The higher inactivation(ca 5 log cycle reduction within 48 hr) occurred in the presence of 2% sample extract and 5% NaCl than in the addition of each alone. The extracted antibacterial substance was stable in the pH range of 4.0 to 7.0, heat treatment at 121$^\circ C$ for 15 min, and freezing at -18$^\circ C$ and thawing at 37$^\circ C$. There fore, the sample extract, would substantially increase the food-safety in terms of E. coli O157:H7.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.550-553
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• 2003

This paper was shown water properly conversion and removal characteristic of escherichia coli for discharge tube with $ZrO_2$ beads. At the result of the removal characteristic experiments of escherichia coli using the discharge tube with $ZrO_2$ beads, because the electric field is also increased when input voltage is increased, the removal characteristic of escherichia coli was appeared relation connection to input voltage. And if a passing number of test water in discharge tube with $ZrO_2$ beads is increased, the removal ratio of escherichia coli is to be increased because passing number of electric field section is increased. And if diameter of $ZrO_2$ beads is increased, the removal time of escherichia coli is to be decreased because dielectric polalization of $ZrO_2$ beads. Also, the removal ratio of escherichia coli of the discharge tube with $ZrO_2$ beads. is appeared higher than the removal ratio of the discharge tube without $ZrO_2$ beads. And a salutation point of ozone and $H_2O_2$ generation density inner water was appeared near 60[min].

• Journal of agriculture & life science
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• v.46 no.2
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• pp.107-114
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• 2012

The present study evaluated the potential use of immunoglobulin prepared from egg yolk of chickens immunized with Escherichia coli K88 (IgY-Ec) in the control of E. coli K88 infection in RAW 264.7 murine macrophage. The binding activity of IgY-Ec against E. coli K88 surface protein was more specific and increased than control IgY. In infection assay of E. coli in macrophage, the specific IgY-Ec to E. coli K88 remarkably inhibited the phagocytic activity comparing to nonspecific IgY (p<0.001). In adherence assay, bacterial adhesion on macrophage cells was definitely reduced by preincubation of IgY-Ec compared with nonspecific IgY (p<0.05). These findings suggested that IgY-Ec have the protective effects against pathogens and IgY-based diets may have potential benefits for preventing or treating various infections in domestic animals.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.461-464
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• 2021

Escherichia coli normally colonizes the lower intestine of animals and humans, but some serotypes are foodborne pathogens. The Escherichia coli K_EC180 was isolated from swine feces that were collected from a weaner pig. In this genome announcement, E. coli K_EC180 was sequenced using PacBio RS II and Illumina NextSeq 500 platforms. The complete chromosome of E. coli K_EC180 is composed of one circular chromosome (5,017,281 bp) with 50.4% of guanine + cytosine (G + C) content, 4,935 of coding sequence (CDS), 88 of tRNA, and 22 of rRNA genes. The complete genome of E. coli K_EC180 contains the toxin genes such as shiga-like toxins (stxA and stxB).

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.1-5
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• 2010

The present study was evaluated the antibacterial effect of the combination of Coptidis rhizoma, Lonicerae Flos, and Paeonia japonica (1:1:1) extracts (CLP1000). Also, the effectiveness of CLP1000, dioctahedral smectite (DHS), and the combination of CLP1000 and DHS (CLPS1000) against E. coli O157:H7 infection was studied using ICR female mice. During the incubation period, the dose of 10% and 20% CLP1000 were inhibited the growth of E. coli O157:H7 by 30% and 47%, respectively. For 7 days after single challenge with E. coli O157:H7, forty female ICR mice were divided into four experimental groups which were orally administered with saline, 10% CLP1000, 10% DHS, and 10% CLPS1000, respectively. On the 3rd day, the number of E. coli O157:H7 in mouse feces was significantly decreased by administration of CLP1000 (p < 0.05), DHS (p < 0.05) and CLPS1000 (p < 0.001). On the 7th day, CLP1000 (p < 0.05) and CLPS1000 p < 0.001) administration significantly decreased the number of E. coli O157:H7. According to the results of the present study, administration of CLPS1000 to mice can reduce the severity of E. coli O157:H7 infection. Also, it is suggested that CLPS100 represents a good candidate for the treatment of enteric infections in domestic animals.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.234-240
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• 2013

This test was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). In preliminary tests, both E. coli and S. typhimurium working culture suspension number (N value) was $4.0{\times}10^8$ CFU/mL. And all of the colony numbers on the carriers exposed the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of bacteria recovered on the control-carriers (T value) was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the reduction number of S. typhimurium and E. coli (d value) was 5.26 and 5.64 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results of this study, Fumagari OPP$^{(R)}$ has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.176-180
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• 1989

There are three pseudourdine ($Psi$)bases in the E. coli $tRNA^{phe}$ In order to study the function of the pseudouridine bases in the $tRNA^{phe}$, changes of bases $tRNA^{phe}$ gene to other bases were undertaken by the site-specific mutagenesis. Site-specific mutagenesis of T in the pheW gene, a $tRNA^{phe}$ gene of E. coli, corresponding to the baseat the No.32 position to C and also T corresponding to the base at the No.39 position to C were performed using Kunkel's uracil-containing template method. Identification of mutants were undertaken by the KNA sequencing techniques of the mutated pheW genes and activities of the mutated pheW genes complementing to E. coli NP37 mutant($pheS^{-ts}$) using the recombinant plasmid containing the mutated genes. Neither NP37 harboring pheW gene mutated at No.32 position nor NP37 harboring pheW gene mutated at No.39 position can be grown at non-permissive temperature. The result means that both mutated pheW genes can not complement to E. coli NP37, and that the pseudouridine bases are essential to the activity of the E. coli $tRNA^{phe}$ in vivo.

• The Korean Journal of Community Living Science
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• v.18 no.2
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• pp.293-300
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• 2007

The antimicrobial activity of 10 different traditional medicinal herbs extracts against E. coli was determined using paper disc method. Caesalpinia sappan and Rhus javanica, extracts in 5 mg/ml, and Paeonia suffruticosa and Seutellaria baicalensis extracts in 10 mg/ml showed significant antimicrobial activity against E. coli. Minimum inhibitory concentrations of medicinal herbs extracts were in the range of $1.4{\sim}8mg/ml\;and\;1.2{\sim}12mg/ml$, for MeOH extracts and EtOH extracts, respectively. In addition, the antimicrobial activity of each solvent fraction was most significant with the EtOAc layer. Optical density at 620nm after 24 hours incubation of E. coli in the presence of 100, 300 or 500 ppm of Caesalpinia sappan extract ranged from 0.02 to 0.1 compared to 0.6 in the absence of Caesalpinia sappan extract, indicating that growth of E. coli was significantly inhibited within 24 hours by the addition of at least 300 ppm of Caesalpinia sappan extract. Optical density at 620 nm after 24 hours incubation of E. coli in the presence of 300 ppm of Rhus javanica extract ranged from 0.02 to 0.2 compared to 0.5 in the absence of Rhus javanica extract, indicating that growth of E. coli was also significantly inhibited within 24 hours by the addition of at least 500 ppm of Rhus javanica extract. In conclusion, these findings suggest that extracts from medicinal herbs may play important roles in antimicrobial activities against E. coli.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1063-1068
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• 2010

This study compared UV and UV/$H_2O_2$ inactivation of E.coli, a possible indicator microorganism for fecal contamination of water, and $Q{\ss}$ phage, an indicator for pathogenic viruses. UV inactivation of $Q{\ss}$, T4 and lambda phages in actual secondary effluent was investigated, too. As a result, similar inactivation efficiency between $Q{\ss}$ phage and E.coli was observed during UV treatment, while $Q{\ss}$ phage showed higher resistance to UV/$H_2O_2$ than E.coli. $Q{\ss}$ phage resistance to UV or UV/$H_2O_2$ does not reflect those of all pathogenic viruses. However, the result tells that the use of E.coli inactivation efficiency in evaluating microbiological safety of water could not always ensure the sufficient safety from pathogenic viruses. Meanwhile, $Q{\ss}$ phage showed less resistance to UV than T4 and lambda phages, indicating that the use of $Q{\ss}$ phage as an indicator virus may bring insufficient disinfection effectiveness by causing the introduction of lower UV dose than required. Consequently, it can be thought that T4 or lambda phages would be more desirable indicators in ensuring the sufficient disinfection effectiveness for various pathogenic viruses.