• 한국동물위생학회지
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• 제40권1호
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• pp.27-33
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• 2017

Salmonella enterica subsp. enterica is a common microbial flora in pet turtles, which could opportunistically become pathogenic to human. Their possession of aminoglycoside resistance genes has important significance both in humans and animal medicine. In this study, twenty-one Salmonella enterica subsp. enterica were isolated from thirty-five individual turtles purchased from pet shops and online markets in Korea. In order to characterize the aminoglycoside susceptibility patterns, antimicrobial susceptibility tests were performed against gentamicin, amikacin and kanamycin of aminoglycoside antimicrobial group. Each of the isolates showed susceptibility to all tested aminoglycosides in disk diffusion and minimum inhibitory concentration (MIC) tests. PCR assay was carried out to determine aminoglycoside resistance genes, integron and integron mediated aminoglycoside genes. None of the isolates showed aac(3)-IIa, aac-(6')-Ib, armA, aphAI-IAB aminoglycoside resistance genes. Only, five isolates (24%) harbored class 1 integron related IntI1 integrase gene. The results suggest that Salmonella enterica subsp. enterica strains isolated from pet turtles are less resistance to aminoglycosides and don't harbor any aminoglycosides resistance genes.

• 한국가금학회지
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• 제49권4호
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• pp.281-286
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• 2022

최근 산업동물에서도 동물복지의 관심이 높아짐에 따라 복지 사육방식을 채택한 농가의 수가 점점 늘어나고 있다. 본 연구는 복지농장과 일반농장 간의 살모넬라 검출율을 확인하였다. 각 농가에서 얻어진 샘플들을 이용하여 비교한 결과, 산란계와 육계농장 모두 복지농장이 일반농장에 비해 높은 검출율을 나타냈다. 산란계 농장의 경우 통계학적 유의차는 없었으나(P value, 1.00), 일반 농장 5개 농가에서는 살모넬라가 검출되지 않았으며 복지 농장 5개 농가에서 채취된 130개 샘플 중에서 1개 샘플에서 Salmonella enterica subsp. Enteritidis(SE)가 검출되었다. 육계 농장의 경우, 일반농장 10개 농가의 200개 샘플 중에 5개 농가의 7개 샘플에서 살모넬라가 검출되었으며, 복지농장 5개 농가의 200개 샘플 중 4개 농가의 21개 샘플에서 검출되었으며, 일반농장과 복지농장의 살모넬라 검출율간 통계학적 유의차를 보였다(P value, 0.0057). 일반농장의 2개 분리주는 Salmonella enterica subsp. Senftenberg, SE로 혈청형이 확인되었고 복지농장의 2개 분리주는 Salmonella enterica subsp. Grampian, Salmonella enterica subsp. Virchow로 혈청형이 확인되었다. 앞으로 국내에서 사육방식의 차이에 따른 지속적인 연구와 복지농장에서의 미생물 모니터링이 필요하며, 계사내 적절한 방역대책도 필요하다고 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권11호
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• pp.1797-1808
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• 2020

Objective: This study assessed the effects of probiotics on cecal microbiota, gene expression of intestinal tight junction proteins, and immune response in the cecal tonsil of broiler chickens challenged with Salmonella enterica subsp. enterica. Methods: One-day-old broiler chickens (n = 240) were randomly allocated to four treatments: negative control (Cont), multi-strain probiotic-treated group (Pro), Salmonella-infected group (Sal), and multi-strain probiotic-treated and Salmonella-infected group (ProSal). All chickens except those in the Cont and Pro groups were gavaged with 1×10⁸ cfu/mL of S. enterica subsp. enterica 4 days after hatching. Results: Our results indicated that body weight, weight gain, and feed conversion ratio of birds were significantly reduced (p<0.05) by Salmonella challenge. Chickens challenged with Salmonella decreased cecal microbial diversity. Chickens in the Sal group exhibited abundant Proteobacteria than those in the Cont, Pro, and ProSal groups. Salmonella infection downregulated gene expression of Occludin, zonula occludens-1 (ZO1), and Mucin 2 in the jejunum and Occludin and Claudin in the ileum. Moreover, the Sal group increased gene expression of interferon-γ (IFN-γ), interleukin-6 (IL-6), IL-1β, and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITAF) and reduced levels of transforming growth factor-β4 and IL-10 compared with the other groups (p<0.05). However, chickens receiving probiotic diets increased Lactobacillaceae abundance and reduced Enterobacteriaceae abundance in the ceca. Moreover, supplementation with probiotics increased the mRNA expression of Occludin, ZO1, and Mucin 2 in the ileum (p<0.05). In addition, probiotic supplementation downregulated the mRNA levels of IFN-γ (p<0.05) and LITAF (p = 0.075) and upregulated IL-10 (p = 0.084) expression in the cecal tonsil. Conclusion: The administration of multi-strain probiotics modulated intestinal microbiota, gene expression of tight junction proteins, and immunomodulatory activity in broiler chickens.

• 한국식품영양과학회지
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• 제39권4호
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• pp.595-601
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• 2010

본 연구는 국내 주요 식중독 원인균인 Staphylococcus aureus, Salmonella enterica subsp., Vibrio parahaemolyticus를 동시에 검출 및 동정할 수 있는 simultaneous multiplex PCR방법을 개발하고자 하였다. S. aureus의 23s rRNA 유전자(482 bp), V. Parahaemolyticus의 toxR 유전자(368 bp), S. enterica subsp.의 invA 유전자(284 bp)를 특이적으로 검출 및 동정할 수 있는 3개 primer set 즉, STA-5F/STA-5R, ToxR-F/ToxR-R, 139/141을 구축하였으며, 그 결과 정제되어진 각 식중독 원인균의 genomic DNA를 template로 하여 세 균주 모두 10 pg까지 다중동시검출이 가능하였다. 생균수(CFU)와 상응되는 검출한계 결과로써 $10^1\sim10^2$ CFU/reaction의 검출한계를 보였으며 이는 즉, S. aureus $6.0\times10^4$ CFU/mL, S. enterica subsp. $9.5\times10^4$ CFU/mL, V. parahaemolyticus $6.1\times10^5$ CFU/mL의 검출한계를 나타내었다. 균체회수부터 agarose gel 상에서 검출 및 동정까지 3~4 hr의 시간 소요로 single tube 반응으로 세 식중독 원인균의 다중동시검출이 가능하였다. 또한 추가적인 연구를 통하여 세 식중독 원인균주의 검출을 위한 향상된 민감도를 가지는 multiplex PCR법 및 real time PCR을 이용한 다중동시검출법 개발을 위한 기초자료로서 활용 가능할 것이라 사료된다.

• Journal of Microbiology and Biotechnology
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• 제32권12호
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• pp.1605-1614
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• 2022

The strains associated with foodborne Salmonella enterica Thompson outbreaks in Korea have not been identified. Therefore, we characterized S. Thompson strains isolated from chocolate cakes linked to foodborne outbreaks in Korea. A total of 56 strains were isolated from preserved cake products, products in the supply chain distribution, the manufacturer's apparatus, and egg white liquid products used for cream preparation. Subsequently, serological typing, pathogenic gene-targeted polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome multi-locus sequence typing (wgMLST) were performed to characterize these isolates. The antigen formula of all isolates was 7:k:1,5, namely Salmonella enterica subsp. enterica Serovar Thompson. All 56 isolates harbored invA, his, hin, and stn, and were negative for sefA and spvC based on gene-targeted PCR analyses. Based on PFGE results, these isolates were classified into one group based on the same SP6X01.011 pattern with 100% similarity. We selected 19 strains based on the region and sample type, which were subjected to wgMLST. Although the examined strains showed 100% similarity, they were classified into seven clusters based on allelic differences. According to our findings, the cause of these outbreaks was chocolate cake manufactured with egg white liquid contaminated with the same Salmonella Thompson. Additionally, comparative analysis of wgMLST on domestic isolates of S. Thompson from the three outbreaks showed genetic similarities of over 99.6%. Based on the results, the PFGE and wgMLST combination can provide highly resolved phylogeny and reliable evidence during Salmonella outbreak investigations.

• 대한수의학회지
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• 제56권2호
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• pp.129-131
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• 2016

Five eastern great egrets with a history of ataxia, wry neck, and wet feathers were submitted to the Veterinary Diagnostic Center for pathologic examination. Slightly enlarged livers with diffuse white-grayish nodules were observed. Microscopically, the hepatic and lung parenchyma contained granulomatous lesions consisting of central necrosis. Some hearts showed myofiber necrosis with infiltration of histiocytes and heterophils. Partial 16SrRNA and gyrB gene sequences of all isolates showed high similarities (99-100%) to those of Salmonella (S.) enterica subsp. enterica. Based on pathological and molecular biological results, S. enterica subsp. enterica systemic infections were diagnosed in eastern great egrets of Korea.

• 미생물학회지
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• 제54권2호
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• pp.155-157
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• 2018

Salmonella enterica subsp. enterica serovar Thompson strain MFDS1004024 는 2014 년 한국에서 발생한 식중독 사고의 게맛살에서 분리되었다. 본 연구에서는 4,742,942 bp 의 크기와 약 52%의 G + C 함량을 가진 MFDS1004024 균주의 완전한 유전체 염기서열을 분석하였다. 이 유전체에는 4,373 개의 코딩 서열, 22 개의 리보솜 RNA 유전자 및 84 개의 전사 RNA 유전자가 존재한다. 또한 유전체 분석 결과를 통해 살모넬라 감염과 베타락탐계 항생제 내성에 관련이 있는 유전자를 발견하였다.

• Journal of Microbiology and Biotechnology
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• 제18권10호
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• pp.1689-1694
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• 2008

The ability to detect Salmonella spp. is essential in the prevention of foodborne illness. This study examined a Salmonella spp. detection method involving the application of immunomagnetic separation and immunoliposomes (IMS/IL) encapsulating sulforhodamine B (SRB), a fluorescent dye. A quantitative assay was conducted by measuring the fluorescence intensity of SRB that was produced from an immunomagnetic bead-Salmonella spp.-immunoliposome complex. The results indicated detection limits of $2.7{\times}10^{5}$ and $5.2{\times}10^{3}$ CFU/ml for Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) and Salmonella enterka subsp. enterka serovar Typhimurium (S. Typhimurium), respectivley. The signal/noise ratio was improved by using 4% skim milk as a wash solution rather than 2% BSA. In addition, higher fluorescence intensity was obtained by increasing the liposome size. Compared with the conventional plating method, which takes 3-4 days for the isolation and identification of Salmonella spp., the total assay time of to h only including 6 h of culture enrichment was necessary for the Salmonella detection by IMS/IL. These results indicate that the IMS/ IL has great potential as an alternative rapid method for Salmonella detection.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.1983-1993
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• 2017

Salmonella enterica subsp. enterica serovar Typhimurium, one of the most common foodborne pathogens, is transmitted mainly through contaminated food derived from infected animals. In this study, S. Typhimurium ST1120, an isolate from pig feces in Korea, was subjected to whole-genome analysis to understand its genomic features associated with virulence. The genome of ST1120 was found to have a circular chromosome of 4,855,001 bp (GC content 52.2%) and a plasmid of 6,863 bp (GC content 46.0%). This chromosome was predicted to have 4,558 open reading frames (ORFs), 17 pseudogenes, 22 rRNA genes, and 86 tRNA genes. Its plasmid was predicted to have three ORFs. Comparative genome analysis revealed that ST1120 was phylogenetically close to S. Typhimurium U288, a critical isolate in piggery farms and food chains in Europe. In silico functional analysis predicted that the ST1120 genome harbored multiple genes associated with virulence and stress resistance, including Salmonella pathogenicity islands (SPIs containing SPI-1 to SPI-5, SPI-13, and SPI-14), C63PI locus, ST104 prophage locus, and various antibiotic resistance genes. In accordance with these analysis results, ST1120 showed competence in invasion and survival abilities when it was added to host cells. It also exhibited robust resistance against antibiotics in comparison with other S. Typhimurium strains. This is the first report of the complete genome sequence of S. Typhimurium isolated from swine in Korea. Comparative genome analysis between ST1120 and other Salmonella strains would provide fruitful information toward understanding Salmonella host specificity and developing control measures against S. Typhimurium infection.

• 한국식품위생안전성학회지
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• 제35권6호
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• pp.602-606
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• 2020

본 연구는 다양한 항생제 내성을 갖는 Salmonella enterica subsp. enterica serovar Typhimurium ATCC 19585 (STWT), S. Typhimurium KCCM 40253 (STKCCM), ciprofloxacininduced S. Typhimurium ATCC 19585 strains (STCIP), and S. Typhimurium CCARM 8009 (STCCARM)에 대한 phage의 흡착 및 용균 특성을 평가하였다. PBST-10, PBST-13, PBST-32, PBST-35, P-22, P-22 B1 phages는 narrow host range를 보였다. 숙주인 STWT, STKCCM, STCIP에 대한 phage의 흡착률은 각각 47-85%, 58-95%, 61-93%였지만, STCCARM에 대한 phage의 흡착률은 14-36%의 낮은 수준을 보였다. STWT, STKCCM, STCIP, STCCARM에 대한 phage burst size는 각각 43-350, 37-530, 66-500, 24-500 plaque-forming unit(PFU)으로 다양하게 관찰되었다. P-22 B1을 제외한 모든 phage는 배양 초기에 STCIP숙주를 효과적으로 저해하였다. 이러한 결과는 항생제 내성균을 저해하기 위해 phage control system 개발에 유용한 정보로 활용될 것이다.