• 한국동물위생학회지
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• 제32권2호
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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.

• 한국환경보건학회지
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• 제39권3호
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• pp.239-246
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• 2013

Objectives: Antimicrobial resistance and multidrug resistance patterns have been studied with a total of 189 samples of Salmonella Enteritidis and Salmonella Typhimurium isolated from diarrhea patients in Incheon from 2008 to 2012. Methods: Antimicrobial resistance tests were determined by Disc Diffusion method. Results: The serological distribution of Salmonella spp. showed 108 strains (30.1%) of S. Enteritidis, 81 strains (22.6%) of S. Typhimirium, eight strains (8.0%) of S. Typhi, 11 strains ( 3.1% ) of S. Paratyphi, and the 151 other strains (42.1%). The separation rate of Salmonella spp. by year showed 14.5% (52 strains) in 2008, 13.6% (49 strains) in 2009, 22.8% (82 strains) in 2010, 25.3% (91 strains) in 2011, and 23.7% (85 strains) in 2012. Additionally, the separation rate of S. Enteritidis and S. Typhimirium in 2010 was the highest. The Salmonella spp. isolated from diarrhea patients showed significant differences according to age (p<0.05), gender (p<0.01) and medical institution (p<0.05). The highest resistance was found to the following antimicrobial agents: imipenem 77 strains, ampicillin 47 strains, ciprofloxacin 34 strains, nalidixic acid 29 strains for S. Enteritidis, and ampicillin 45 strains, nalidixic acid 45 strains for S. Typhimurium. Separated S. Enteritidis and S. Typhimurium resistance to the antibiotics by the year showed significant differences (p<0.05). The patterns of multidrug resistance rates were 43.1% (47 strains) for one drug, 8.3% (9 strains) for two drugs, 11.0% (12 strains) for three drugs, 15.62% (17 strains) for four drugs, and 13.7% (15 strains) for five or more drugs for S. Enteritidis. For S. Tyhpimurium, the rates were 15.0% (12 strains) for one drug, 10.0% (8 strains) for two drugs, 6.3% (five strains) for three drugs, 18.7% (15 strains) for four drugs, and 23.8% (19 strains) for five or more drugs. Conclusion: The antibiotic resistance issue is directly related to people's lives. Thus, the usage of antibiotics should be reduced in order to manage antibiotic resistance.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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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.

• 한국식품위생안전성학회지
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• 제15권3호
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• pp.262-266
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• 2000

우유에 포함된 Salmonella enteritidis를 효과적으로 분리하는 방법을 찾고 이를 이용하여 우유속의 S. enteritidis의 량을 추정하는 방법을 개발하였다. 일정량의 S. enteritidis를 접종한 우유로부터 guanidine thiocyanate/phenol/chloroform을 이용하여 DNA를 추출한 후 중합효소반응으로 S. enteritidis 섬모항원 유전자를 선택적으로 검출함으로써 우유 1ml당 200 colony forming unit까지 검출이 가능하였고 전체 과정의 수행에 단지 5시간 정도 걸렸다. S. enteritidis 섬모항원 유전자를 cloning한 pGem-4-Sef B(-) DNA와 인위적으로 접종된 우유로부터 추출한 Salmonella DNA를 함께 중합효소반응으로 증폭한 후 제한효소로 잘라 전기영동을 행하여 band의 강도를 비교함으로써 Salmonella DNA copy수를 추정하는 것이 가능하였다.

• Journal of Dairy Science and Biotechnology
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• 제33권4호
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• pp.271-275
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• 2015

Colloidal semiconductor CdSe-ZnS core-shell nanocrystal quantum dot (Qdot) are luminescent inorganic fluorophores that show potential to overcome some of the functional limitations encountered with organic dyes in fluorescence labeling applications. Salmonella Enteritidis has emerged as a major cause of human salmonellosis worldwide since the 1980s. A rapid, specific, and sensitive method for the detection of Salmonella Enteritidis was developed using Qdot as a fluorescence marker coupled with immunomagnetic separation. Magnetic beads coated with anti-Salmonella Enteritidis antibodies were employed to selectively capture the target bacteria, and biotin-conjugated anti-Salmonella antibodies were added to form sandwich immune complexes. After magnetic separation, the immune complexes were labeled with Qdot via biotin-streptavidin conjugation, and fluorescence measurement was carried out using a fluorescence measurement system. The detection limit of the Qdot method was a Salmonella Enteritidis concentration of $10^3$ colony-forming units (CFU)/mL, whereas the conventional fluorescein isothiocyanate-based method required over $10^5CFU/mL$. The total detection time was within 2 h. In addition to the potential for general nanotechnology development, these results suggest a new rapid detection method of various pathogenic bacteria from a complex food matrix.

• Journal of Biosystems Engineering
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• 제35권2호
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• pp.116-123
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• 2010

Rapid detection of foodborne pathogens has been a major challenge for the food industry. Salmonella contamination is well known in all foods including pasteurised milk. The possibility of specific detection of Salmonella Enteritidis by surface plasmon resonance (SPR) biosensor was explored using a commercially available portable SPR sensor. Self assembly technique was adopted to immobilize anti-Salmonella antibodies on the gold sensing surface of the SPR sensor. The concentration of polyclonal antibody for use in the SPR biosensor was chosen to 1.0 mg/mL. Experiments were conducted at near real-time with results obtained for one SPR biosensor assay within 1 hour. The limit of detection for Salmonella Enteritidis was determined to be $10^6$ CFU/mL in both PBS buffer and milk samples. The assay sensitivity was not significantly affected by milk matrix. Our results showed that it would be possible for employing the SPR biosensor to detect Salmonella Enteritidis in near real-time.

• 대한수의학회지
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• 제40권3호
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• pp.505-514
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• 2000

This study was conducted to investigate the isolation prequency, serotypes, and related epidemiological properties of 341 Salmonella spp from domestic poultry and environmental samples during the period 1993-1995. A total of 1,918 samples was collected during the three years period in nationwide. Most of Salmonella spp were isolated from the intestinal contents of poultry, especially cecal(46.0%) and rectal(35.8%) contents. Among the tested samples, rat(28.5 %) was the most predominant Salmonella reservoirs and followed by duck(24.8%), broiler(18.8%), layer(14.8%) and feed(7.1%), in order. More than twelve Salmonella serovars were identified among the 341 Salmonella isolates. The most prevalent serotypes isolated from non-human sources were S enteritidis (22.3%) and S pullorum (21.9%), S muenchen (13.9%), S typhimurium (12.6%), S gallinarum, S meleagridis, S heidelberg, and S senftenberg were followed, in order. In layer chickens, S pullorum (26.0%) was the most predominant serotype but S muenchen (33.0%) was in broiler chickens, S enteritidis (28.4%) was in ducks, and S typhimurium (60.0%) was in rats, respectively. As a results, S enteritidis was identified as the most prevalent serotype in non-human Salmonella isolates in Korea during the period 1993-1995. A preliminary study on the phage typing of 19 S enteritidis selected from the nationwide scale was shown that S enteritidis phage type(PT) 4 was the most predominant PT, and SEPT 1, SEPT 6a, SEPT 7 and SEPT 7a variant were also found in the same period.

• 한국식품위생안전성학회지
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• 제31권5호
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• pp.342-348
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• 2016

본 연구는 계란을 난백과 난황으로 분리하여, 액란 상태에서 8, 10, 15, 25, $35^{\circ}C$의 보관온도가 S. Enteritidis와 S. Typhimurium 두 혈청 형의 증식 또는 사멸패턴에 미치는 영향을 비교 분석하였다. 난백에서는 8, 10, 15, $35^{\circ}C$에서 두 혈청 형 모두 감소하였으나 $25^{\circ}C$에서는 두 혈청 형 모두 증식 하여 상온에서의 관리에 대한 주의가 필요한 것으로 나타났다. 반면 10, 15, 25, $35^{\circ}C$ 난황에서는 두 혈청 형 모두 성장하였으나 $8^{\circ}C$에서는 감소하여 유통 판매시 난황으로 준비된 액란을 냉장온도로 철저하게 관리해야 할 것으로 판단된다. 난황에서 증식한 S. Enteritidis와 S. Typhimurium의 성장곡선을 Modified Gompertz model에 적용하여 산출된 유도기(LT)와 최대증식속도(SGR) 및 최대개체군밀도(MPD)값을 Davey model과 Square-root model 및 Polynomial second order model을 이용하여 각각 온도의 영향을 나타내는 2차 모델을 개발하였다. 모든 온도에서 S. Enteritidis가 S. Typhimurium보다 유도기가 짧고 최대증식속도가 빠르게 나타나 액란 제품에서의 S. Enteritidis에 대한 위험성이 더 큰 것으로 나타났다.

• 한국동물위생학회지
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• 제34권3호
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• pp.217-226
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• 2011

Salmonella spp. is of increasing public health concern as causative pathogens of food poisoning. The aim of this study was to investigate the serotypes and antimicrobial resistance pattern of Salmonella spp. isolated from duck farms in Daegu-Gyeongbuk province. Also, S. Enteritidis and S. Typhimurium isolates were further examined for plasmid analysis, phage typing and pulsed-field gel electrophoresis (PFGE). A total of 34 Salmonella spp. (16.4%) were isolated from duck farms and ten serotypes were identified. The predominant serotypes were S. Typhimurium (23.5%) S. Fyris (17.6%) and S. Haardt (11.8%), S. Agona and S. Enteritidis (respectively 8.8%). Of 34 Salmonella isolates, 15 (44.1%) isolates were resistant to at least one antimicrobial agent and multiple resistance (resistance to more than 4 drugs) was observed in 9 strains (26.5%). The high resistance was found to streptomycin (32.4%), tetracycline (29.4%), ampicillin, kanamycin and nalidixic acid (respectively, 26.5%), all Salmonella isolates were susceptible to cefoxitin, cefotaxime, gentamicin, amikacin and ciprofloxacin. All S. Enteritidis and S. Typhimurium isolates were found to contain only one plasmid (ca. 54 or 55kb, respectively). Among the S. Enteritidis isolates, two phage types were found, PT32a and PT1c, respectively, one isolates did not react with any of the phages used. Whereas, all S. Typhimurium isolates were RDNC (reacts but does not conform). PFGE showed to be a useful typing method better than plasmid analysis and phage typing for discrimination of isolates especially, S. Typhimurium isolates. Our results indicated that the serotypes of Salmonella isolates are widely distributed in duck farms, further epidemiological studies should be carried out.

• 미생물학회지
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• 제54권2호
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• pp.164-166
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• 2018

본 연구에서는 2014년 국내에서 식중독 원인식품인 김밥으로부터 분리된 Salmonella Enteritidis의 유전체 분석을 수행하였다. Salmonella Enteritidis MFDS1004839는 한 개의 chromosome (4,679,649 bp)과 plasmid (96,994 bp)로 구성되어있고, 각각의 G + C contents는 52.2%와 49.3%로 확인되었다. chromosome와 plasmid DNA에 예측된 유전자의 총 수는 4,482개의 단백질 코딩유전자와 84개 tRNA, 그리고 22개의 rRNA였다.