• Korean Journal of Microbiology
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• v.45 no.4
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• pp.318-323
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• 2009

The aim of this work was to investigate the antibacterial effect of the food-poisoning bacterium, Salmonella enteritidis JK-15 exposed to rose extracts. Initially, the isolate S. enteritidis JK-15 was enriched and isolated from stale food. BIOLOG and 16S rRNA analyses revealed that strain S. enteritidis JK-15 was 98% similar to the S. enteritidis species cluster; therefore we have designated this strain as S. enteritidis JK-15. Bactericidal effects of S. enteritidis JK-15 exposed to rose extracts ranging from 5 mg/ml to 100 mg/ml were monitored, and complete bactericidal effects were achieved within 6 h at 100 mg/ml and 12 h at 50 mg/ml, respectively. SDSPAGE with silver staining revealed that the amount of lipopolysaccharides increased or decreased in the strain S. enteritidis JK-15 treated to different concentrations and exposing periods of rose extracts in exponentially growing cultures. Scanning electron microscopic analysis, demonstrated the presence of irregular rod shapes with umbilicated surfaces for cells treated with rose extracts.

• Korean Journal of Veterinary Service
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• v.24 no.1
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• pp.69-82
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• 2001

The result of studying the pathogenicity of Salmonella typhimurium and S enteritidis isolated from domestic animals in Gyeongbuk province were summarized as follows. In Congo-red binding test, S typhimurium had much more rough types than S enteritidis. In colicin production test, 4 strains of S typhimurium were positive but all of S enteritidis were negative. In hemolysin production test, all of S typhimurium and S enteritidis were negative. In Guinea pig serum resistant test, all of S typhimurium and S enteritidis were positive. As a result of pathogenicity test to mice, 54.4% of mice were died. Therefore, S typhimurium and S enteritidis were considered as highly pathogenic. S typhimurium DT104 and S enteritidis PT4 were more pathogenic to mice than other phage types of same serovar. S typhimurium and S enteritidis were considered not so pathogenic for 6-day-old chickens. The recovery rates of Salmonella stains from mice and chickens inoculated were 96.8%, and 54%, respectively. In chickens, proportional to the time from 2 weeks after challenge inoculation, the recovery rates were noticeably decreased.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1519-1528
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• 2017

Foodborne contamination and salmonellosis caused by Salmonella Enteritidis (S. Enteritidis) are a significant threat to human health and poultry enterprises. Outer membrane vesicles (OMVs), which are naturally secreted by gram-negative bacteria, could be a good vaccine option because they have many biologically active substances, including lipopolysaccharides (LPS), outer membrane proteins (OMPs), and phospholipids, as well as periplasmic components. In the present study, we purified OMVs derived from S. Enteritidis and analyzed their characteristics through silver staining and sodium dodecyl sulfate polyacrylamide gel electrophoresis. In total, 108 proteins were identified in S. Enteritidis OMVs through liquid chromatography tandem mass spectrometry analysis, and OMPs, periplasmic proteins, and extracellular proteins (49.9% of total proteins) were found to be enriched in the OMVs compared with bacterial cells. Furthermore, native OMVs used in immunizations by either the intranasal route or the intraperitoneal route could elicit significant humoral and mucosal immune responses and provide strong protective efficiency against a lethal dose (~100-fold $LD_{50}$) of the wild-type S. Enteritidis infection. These results indicated that S. Enteritidis OMVs might be an ideal vaccine strategy for preventing S. Enteritidis diseases.

• Korean Journal of Veterinary Service
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• v.23 no.3
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• pp.227-233
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• 2000

Salmonella enteritidis is the most prevalent etiologic agents of foodborne acute gastroenteritis. Direct isolation and identification of S enteritidis are time consuming work and not so highly sensitive. This study was conducted to develop for the specific detection of S enteritidis using polymerase chain reaction(PCR). PCR primers were selected to amplify a 351-base pair(bp) DNA fragment from the salmonella plasmid virulence A(spv A) gene of S enteritidis. With the primers, 351 bp DNA products were amplified from S enteritidis but not from other B, D, Cl serogroup Salmonella spp. It was sensitive to detect up to 40 pg of template DNA by agarose gel electrophoresis. This PCR assay is very rapid and specific method and less time consuming than the standard bacteriological methods.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.342-348
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• 2016

The objective of this study was to compare the change of S. Enteritidis with S. Typhimurium populations in liquid egg products. S. Enteritidis or S. Typhimurium was inoculated into egg white and egg yolk and stored at 8, 10, 15, 25, and $35^{\circ}C$, respectively. In egg white, no growth of S. Enteritidis and S. Typhimurium was observed at 8, 10, 15, and $35^{\circ}C$, while both S. Enteritidis and S. Typhimurium in egg white stored grew more than 1 log CFU/ml after 50 hours storage at $25^{\circ}C$. In egg yolk, there was no growth of S. Enteritidis and S. Typhimurium at $8^{\circ}C$ but growth of both strains was observed at 10, 15, 25, and $35^{\circ}C$. Since growth of S. Enteritidis and S. Typhimurium was only observed in egg yolk, primary growth models for both strains were developed using modified Gompertz equation and then secondary models for lag time (LT), specific growth rate (SGR), and maximum population density (MPD) were developed as a function of temperature. At all temperatures, more rapid growth of S. Enteritidis than S. Typhimurium was observed in egg yolk, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products. In conclusion, the results indicate that temperature control less than $8^{\circ}C$ is very important to ensure safety of liquid egg products, especially liquid egg yolk.

• Journal of Life Science
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• v.11 no.3
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• pp.266-272
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• 2001

A total of 79 Salmonella spp. were isolated from Pusan area in 2000. The serotypes of 79 Salmonella isolates were classified as 42 strains of S. typhi(53.1%), 24 strains of S. enteritidis(30.4%), 9 strains of S. montevideo(11.4%), 2 strains of S. typhimurium(2.5%), 1 strain of S. infantis(1.3%) and 1 strain of S. indiana(1.3%) strains(16.5%) of Salmonella sp. were isolated at May July, respectively. The isolates of S. typhi were sensitive to most sntibiotics except streptomycin. All isolates of S. typhi were especially sensitive to tobramycin, gentamicin, colistin, kanamycin, samikacin, sulfamethozazole/ trimethoprim, cefriaxone, ceftazdime, cifrofloxacin, cefoxitin and cefotaxime. Isolates of S. enteritidis wer presented higher resistance than isolates of S. typhi. Twenty-four strains of S. enteritidis were sensitive to kanamycin, amikacin cifrofloxacin, cefoxitin and cefotaxime, however 13 strains(54.2%) of S. enteritidis were resistant to carbenicillin, ampicillin and ticarcillin. Nine strains of S. montevideo were sensitive to most antibiotics except carbenicillin and streptomycin. Each 1 stain of S. indiana and S. infantis was sensitive to most antibiotics used in this study except streptomycin. Three kinds of resistant pattern (CB, SM, TE, AM, TC). In the case of S. enteritidis isolates, 9 kinds resistant pattern were detected. Most frequent resistant pattern of S. enteritidis isolates was CB, AM, TC type(16.7%)

• Journal of the East Asian Society of Dietary Life
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• v.27 no.1
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• pp.78-87
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• 2017

The objective of this study was to investigate the effects of various washing waters on the quality and safety characteristics of eggs during storage. Eggs were washed with tap water, 100 ppm of sodium hypochlorite, or 30 ppm of slightly acidic electrolyzed water and stored at $10^{\circ}C$ and $20^{\circ}C$. Effects of various washing waters on reduction of Salmonella Enteritidis and aerobic plate counts and survival of S. Enteritidis on egg shells were also analyzed at $10^{\circ}C$ and $20^{\circ}C$ for 25 days. As an index of quality, haugh unit, weight reduction, and pHs of egg white and egg yolk were measured. Reduction percentages of haugh unit and weight were higher at $20^{\circ}C$ than at $10^{\circ}C$. Egg qualities were less affected by tap water, slightly acidic electrolyzed water, and sodium hypochlorite, regardless of storage temperature. The greatest reductions in aerobic plate counts and S. Enteritidis were observed with slightly acidic electrolyzed water. The level of S. Enteritidis on egg shells gradually decreased during 20 days of storage at both $10^{\circ}C$ and $20^{\circ}C$, whereas S. Enteritidis survived longer at $20^{\circ}C$ than at $10^{\circ}C$. S. Enteritidis was not detected in eggs at $10^{\circ}C$, 2.13 log CFU/g of S. Enteritidis was detected in eggs washed with sodium hypochlorite after 20 days of storage at $20^{\circ}C$, indicating that S. Enteritidis penetrated into the egg shell during storage at $20^{\circ}C$. In conclusion, slightly acidic electrolyzed water increased microbial reduction and least affected quality of washed eggs. Thus, slightly acidic electrolyzed water can be recommended for washing of graded eggs, at retail markets.

• Korean Journal of Veterinary Service
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• v.32 no.2
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• pp.147-153
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• 2009

Salmonella species are the most important etiologic agents of food-borne acute gastroenteritis. The most common serotypes isolated from humans are Salmonella enterica serotype Typhimurium (S. Typhimurium) and S. Enteritidis. Traditional detection methods for Salmonella are based on cultures using selective media and characterization of suspicious colonies by biochemical and serological tests. These methods are generally time-consuming and not so highly sensitive. Recently, the polymerase chain reaction (PCR) has been used as a highly sensitive, specific, and rapid test for the presence of pathogenic bacteria. In this study, a multiplex PCR (m-PCR) was used to detect S. Typhimurium and S. Enteritidis. We selected m-PCR target genes, which were the spv (virulence plasmid specific for S. Enteritidis) and sefA (S. Enteritidis fimbrial antigen) genes, fliC (H1-i antigen specific for S. Typhimurium) and a randomly cloned sequence specific for the genus Salmonella. With m-PCR, random sequence was detected from all strains of Salmonella spp, spv and sefA were detected from all strains of S. Enteritidis (100%), and fliC was detected from all strains of S. Typhimurium (100%). This assay indicate that the specificity of the m-PCR make them potentially valuable tools for detection of S. Typhimurium and S. Enteritidis.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.329-334
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• 2016

The inhibitory effect of epigallocatechin gallate (EGCG), one of the antioxidants in green tea (Camellia sinensis), against Salmonella Enteritidis was evaluated in commercial braised quail eggs at two temperatures (4 and $25^{\circ}C$). Although S. Enteritidis was dose-dependently suppressed by EGCG in pure culture at $25^{\circ}C$, it was not inhibited in the sauce or eggs at this temperature. At low temperature ($4^{\circ}C$), S. Enteritidis was inhibited in both the sauce and eggs by $400{\mu}g/mL$ EGCG. Thus, EGCG at an appropriate concentration could be a useful food additive for inhibiting S. Enteritidis in braised quail eggs at low temperatures.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.262-266
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• 2000

The polymerase chain reaction was used to selectively detect sequences within the fimbrial antigen of Salmonella enteritidis. Sterile milk was artificially inoculated with known amount of S. enteritidis and then DNA was extracted with guanidine thiocyanate/phenol/chloroform, followed by PCR. A detection limit of as few as 100 colony forming unit (cfu) per 0.5 ml milk was obtained with this method. For the whole procedure, it took only 5 h. A semi-quantitative polymerase chain reaction assay which allows an estimation of colony forming unit of S. enteritidis was developed. Known amount of standard plasmid pGem-4Z-Sef B(-) containing cloned S. enteritidis fimbrial antigen gene was co-amplified with Salmonella genomic DNA isolated from artificially inoculated milk. The same set of primers were used for the amplification and the products were cleaved with Bam HI. The concentration of the target DNA could be estimated by comparing the intensity of the two bands after electrophoresis. The PCR-based protocol described in this paper provides a rapid, simple, and sensitive method for detecting S. enteritidis in milk.