• Molecules and Cells
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• 제43권12호
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• pp.989-1001
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• 2020

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular pathogen that causes salmonellosis and mortality worldwide. S. Typhimurium infects macrophages and survives within phagosomes by avoiding the phagosome-lysosome fusion system. Phagosomes sequentially acquire different Rab GTPases during maturation and eventually fuse with acidic lysosomes. Lysophosphatidylcholine (LPC) is a bioactive lipid that is associated with the generation of chemoattractants and reactive oxygen species (ROS). In our previous study, LPC controlled the intracellular growth of Mycobacterium tuberculosis by promoting phagosome maturation. In this study, to verify whether LPC enhances phagosome maturation and regulates the intracellular growth of S. Typhimurium, macrophages were infected with S. Typhimurium. LPC decreased the intracellular bacterial burden, but it did not induce cytotoxicity in S. Typhimurium-infected cells. In addition, combined administration of LPC and antibiotic significantly reduced the bacterial burden in the spleen and the liver. The ratios of the colocalization of intracellular S. Typhimurium with phagosome maturation markers, such as early endosome antigen 1 (EEA1) and lysosome-associated membrane protein 1 (LAMP-1), were significantly increased in LPC-treated cells. The expression level of cleaved cathepsin D was rapidly increased in LPC-treated cells during S. Typhimurium infection. Treatment with LPC enhanced ROS production, but it did not affect nitric oxide production in S. Typhimurium-infected cells. LPC also rapidly triggered the phosphorylation of IκBα during S. Typhimurium infection. These results suggest that LPC can improve phagosome maturation via ROS-induced activation of NF-κB pathway and thus may be developed as a therapeutic agent to control S. Typhimurium growth.

• Journal of Animal Science and Technology
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• 제64권6호
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• pp.1144-1172
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• 2022

Salmonella enterica serovar Typhimurium isolate HJL777 is a virulent bacterial strain in pigs. The high rate of salmonella infection are at high risk of non-typhoidal salmonella gastroenteritis development. Salmonellosis is most common in young pigs. We investigated changes in gut microbiota and biological function in piglets infected with salmonella via analysis of rectal fecal metagenome and intestinal transcriptome using 16S rRNA and RNA sequencing. We identified a decrease in Bacteroides and increase in harmful bacteria such as Spirochaetes and Proteobacteria by microbial community analysis. We predicted that reduction of Bacteroides by salmonella infection causes proliferation of salmonella and harmful bacteria that can cause an intestinal inflammatory response. Functional profiling of microbial communities in piglets with salmonella infection showed increasing lipid metabolism associated with proliferation of harmful bacteria and inflammatory responses. Transcriptome analysis identified 31 differentially expressed genes. Using gene ontology and Innate Immune Database analysis, we identified that BGN, DCN, ZFPM2 and BPI genes were involved in extracellular and immune mechanisms, specifically salmonella adhesion to host cells and inflammatory responses during infection. We confirmed alterations in gut microbiota and biological function during salmonella infection in piglets. Our findings will help prevent disease and improve productivity in the swine industry.

• Pediatric Infection and Vaccine
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• 제28권3호
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• pp.160-167
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• 2021

비장티푸스 살모넬라균에 의한 화농성 척추염은 면역이 정상인 소아청소년에서는 매우 드문 질환으로, 주로 면역저하자나 낫적혈구병과 같은 혈색소병을 가진 환자들이 이 질환의 위험군으로 알려져 있다. 본 증례는 발열과 우상복부 통증으로 내원한 정상 면역을 가진 건강한 13세 청소년에서 대변 배양 검사를 통하여 비장티푸스 살모넬라균을 확인하고, 지속된 발열에 대하여 추가 영상 검사를 통하여 화농성 척추염이 합병되었음을 확인한 증례로, 불명열의 검사로 배양 검사의 중요성을 인식하게 하고, 일반적이지 않은 살모넬라증의 임상경과를 보이는 경우에는 장외 국소감염의 합병증에 대하여 철저하게 조사하는 것이 중요함을 보여준다.

• 한국동물위생학회지
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• 제46권3호
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• pp.211-218
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• 2023

This study was carried out to investigate the prevalence and antimicrobial resistance of Salmonella serotypes in duck farms of Jeollanam-do Province, South Korea. A total of 1112 samples (breeder ducks, 286; broiler ducks, 826) were collected from 196 duck farms (breeder duck farms, 25; broiler duck farms, 171) between January 2018 and November 2019. The total prevalence of Salmonella serotypes was 45.4% (89/196) in the duck farms, with no significant difference between prevalence in breeder and broiler duck farms (48% and 45%, respectively; P>0.05). The most prevalent serotype among the 127 Salmonella isolates was Salmonella Typhimurium (20.5%) followed by Salmonella Albany (17.3%), Salmonella Hadar (15.7%), and Salmonella Enteritidis (11.8%). Maximum resistance was observed against penicillin (78.74%), followed by tetracycline (68.50%), and kanamycin (65.35%). Of the 127 isolates, 117 (92.13%) were resistant to ≥3 antimicrobials and 2 to all 18 antimicrobials. Our results demonstrate the presence of Salmonella strains and their resistance to multiple antimicrobials, thus indicating a public health concern in South Korea. The emergence of Salmonella stains that are resistant to multiple drugs highlight the need for careful use of antimicrobials in duck farms.

• 한국동물위생학회지
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• 제46권4호
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• pp.303-314
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• 2023

Protective efficacy of trivalent Salmonella inactivated vaccine containing Chlorhexidine-inactivated S. Enterltidis (SE), S. Typhimurium (ST), and S. Gallinarum (SG) strains, was evaluated in this study. A total of 70 brown nick layers were divided into 7 groups, A to G, containing 10 hens per group. All hens in groups B to D were intramuscularly immunized with approximately 7×10⁸ cells (3×10⁸ cells of SE+1×10⁸ SE+1×10⁸ cells of ST+3×10⁸ cells of SG) of the trivalent vaccine in 0.5 mL of PBS. All chickens in groups E to G were injected with sterile PBS. All hens of groups B and E, groups C and F, and groups D and G were orally challenged with approximately 2 ×10⁹ CFU of wild-type SE, ST, and SG, respectively. Serum IgG titers and CD3⁺CD4⁺ T-cells, and CD3⁺CD8⁺ T-cells levels of groups B to D significantly higher than those of group A. In addition, all animals in groups A to C, E and F showed no clinical symptoms and survived after the virulent challenges, whereas one chicken in group D died and all chickens in group G died following the challenge. The protection against wild-type SE and ST in liver, spleen, cecum, and cloaca of groups B and C chickens was significant effective as compared with those in groups E and F. These indicate that the trivalent inactivated vaccine can be an effective tool for prevention of Salmonella infections by inducing robustly protective immune responses and cellular immune response in chickens.

• Journal of Veterinary Science
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• 제25권1호
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• pp.4.1-4.14
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• 2024

Background: Lawsonia intracellularis is the causative agent of proliferative enteropathy and is associated with several outbreaks, causing substantial economic loss to the porcine industry. Objectives: In this study, we focused on demonstrating the protective effect in the mouse model through the immunological bases of two vaccine strains against porcine proliferative enteritis. Methods: We used live-attenuated Salmonella Typhimurium (ST) secreting two selected immunogenic LI antigens (Lawsonia autotransporter A epitopes and flagellin [FliC]-peptidoglycan-associated lipoprotein-FliC) as the vaccine carrier. The constructs were cloned into a Salmonella expression vector (pJHL65) and transformed into the ST strain (JOL912). The expression of immunogenic proteins within Salmonella was evaluated via immunoblotting. Results: Immunizing BALB/c mice orally and subcutaneously induced high levels of LI-specific systemic immunoglobulin G and mucosal secretory immunoglobulin A. In immunized mice, there was significant upregulation of interferon-γ and interleukin-4 cytokine mRNA and an increase in the subpopulations of cluster of differentiation (CD) 4⁺ and CD 8⁺ T lymphocytes upon splenocytes re-stimulation with LI antigens. We observed significant protection in C57BL/6 mice against challenge with 10^6.9 times the median tissue culture infectious dose of LI or 2 × 10⁹ colony-forming units of the virulent ST strain. Immunizing mice with either individual vaccine strains or co-mixture inhibited bacterial proliferation, with a marked reduction in the percentage of mice shedding Lawsonia in their feces. Conclusions: Salmonella-mediated LI gene delivery induces robust humoral and cellular immune reactions, leading to significant protection against LI and salmonellosis.

• 한국동물위생학회지
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• 제24권3호
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• pp.223-241
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• 2001

From September 1996 to September 1999, 419 Korean-native calves with diseases under 6-month old collected from Kyonggi, Chungcheong, Chonlla and Kyongsang were examined by clinical, microbiological, parasitic, hematologic and histopathological mean. Among them, 124 cases were tested about the neutralization antibodies against infectious bovine rhinotracheitis virus(IBRV), Parainfluenza-3 virus(PI-3V), bovine uiral diarrhea virus(BVDV), bovine ephemeral fever virus(BEFV). In calf diseases in the survey, enteric diseases(72.8%) were most frequently involved and the following orders were taken by respiratory(17.4%) and reproductive (5.0%) disorders. In the causative pathogens associated with calf diseases and motality, 48.4% was induced by bacteria origin and also 35.6% by viral agents. Calf mortality was up to 76.3% in the cae of bacterial diseases and 55.7% in viral diseases. In bacterial diseases, frequent disorders were composed of colibacillosis(52.7%), salmonellosis(13.8%), pasteurellosis(12.8%) and campylobacteriosis(3.9%) and their mortalities showed 73.8% in colibacillosis, 73.0% in pasteurellosis, 67.9% in salmonellosis and 50.0% in campylobacteriosis (50.0%). Among the outbreaks of viral diseases, there were BVD(22.8%), bovine rotavirus infection(20.8%), bovine coronavirus infection(16.8%), bovine respiratory syncytial virus infection(15.4%), IBR(15.4%). Akabane disease(4.7%) and Chuzan diseases(3.4%). Interesting results through this studies were obtained the first isolate to Chuzan virus and Ainovirus in Korea which could be promised the development for diagnostic method and vaccines soon. Calf mortality to Akabane and Chuzan diseases was 100%. Main parasitic diseases were occupied by coccidiosis and babesiosis and their mortality of babesiosis was 20.0%. Other diseases were abomasal impaction(6.7%) and toxicosis(4.5%). The mortality of abomasal impaction was 89.3%. In some causes with malformations(1.9%) were confirmed as anasarca, derodidymus, polymelia, humerus hypoplasia, and tracheal collapse. Calf diseases had mostly been occurred in one month old grout (52.5%) and its prevalence was 25.1% in two to three month old group and 22.4% in four to six month old group. In calf mortality by age, there were 37.9% in one month old group, 18.1% in two and three month old group, and 13.8% in four to six month old group, respectively. The older the age of calf, the less the prevalence of calf enteric diseases. Respiratory diseases in calves to be tested frequently occurred in one to two month old group (41.4%). In one month old calves, the prevalence of enteric disease was 80.0%(p<0.05) and that of reproductive and respiratory disease was 9.5% and 8.2%, respectively. In two month old and four to six month old, enteric disease was 65.7% and 63.8% and respiratory disease was 28.6% and 26.6%. Seasonal prevalence and mortality of Korean-native calf diseases were not a significant difference. Prevalence of calf diseases in summer(31.5%) frequently occurred to compare that in winter(20.3%). Abortion and malformation in calves frequently occurred in spring. Hematological values in 84 calves with clinical signs showed mild to marked leukocytosis. Also, there was slight increase in hematocrit, platelet, mean corpuscular volume and mean plasma volume, but all of those were included the higher level to normal ranges. Calves with respiratory signs showed slightly erythrocytosis. One hundred seventy three calves without clinical signs were not significant different to ill cases in hematological values, but number of platelets was in higher normal range. In 125 calves, 84.8% was taken the antibody to IBRV, but 72% with the antibody had recorded the titer level lower than log$_2$5. The neutralizing antibody levels of higher than $log_{2}5$ to PI-3V and BVD virus were 60.8% and 67.2% cases, respectively. There were the cases of 57.6% had the neutralizing antibody level lower than log$_2$5 to BEFV.

• 농촌의학ㆍ지역보건
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• 제39권4호
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• pp.222-229
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• 2014

지금까지 다른 고위험군들에 비해 상대적으로 양돈 종사자에 대한 연구가 드물었고, 돼지가 인수공통감염병의 주요 병원소로 국내에서도 돼지와 관련된 인수공통감염병이 지속적으로 발생하고 있는 상황에서 이번 연구는 양돈 종사자들을 대상으로 인수공통감염병에 대한 인지도를 파악해 보고자 진행하였다. 2012년도에 경상남도 권역, 경상북도 권역, 전라남도 권역, 충청남도 권역 등 4개 권역의 양돈협회 자체교육에 참여한 양돈 종사자 중 278명을 대상으로 자체 개발하여 농업기술원의 전문가 23명을 대상으로 타당성 조사를 마친 설문지를 활용하여 일 대 일 면접방식으로 설문조사를 진행하였다. 인수공통감염병의 인지율은 살모넬라증 89.6%, 결핵 87.8%, 브루셀라증 85.6% 등의 순으로 개별 인수공통감염병에 대해서는 80% 이상 인지하고 있었지만 인수공통감염병 자체에 대한 인지율은 52.9%이었고, 돼지의 질병이 사람에게 감염될 수 있다고 응답한 대상자는 46.9%에 불과하였다. 연구 대상자들의 개별 특성 및 양돈 작업관련 특성 중 인수공통감염병 인지율에 미치는 영향을 파악해 본 결과 대학 졸업이상의 학력을 가진 대상자들이 중학교 졸업 이하의 학력을 가진 대상자들에 비해 인수공통감염병 자체는 3.1배, 살모넬라증은 6.0배 더 잘 인지하고 있었다. 또한 양돈업에 10년 미만 종사한 대상자들에 비해 30년 이상과 20-29년 종사한 대상자들이 각각 6.2배와 7.9배 더 잘 살모넬라증을 인지하고 있었다. 이처럼 국내의 양돈 종사자들은 브루셀라증, 살모넬라증, 결핵 등 각각의 인수공통감염병에 대해서는 잘 인지하고 있었지만 인수공통감염병이라는 용어 자체와 돼지의 질병이 사람에게도 감염될 수 있다는 특성은 절반 정도만이 인지하고 있었다. 이번 연구에서 고학력일수록, 양돈업에 종사기간이 길수록 인수공통감염병 및 살모넬라증을 더 잘 인지한다고 밝혀진 것처럼, 교육 및 관련 정보에의 노출이 인지율을 높일 수 있는 가장 좋은 방법일 것이다. 돼지는 다양한 인수공통감염병의 주요한 병원소인 만큼, 향후 양돈 종사자들을 대상으로 인수공통감염병의 개념 및 감염경로를 포함하는 체계적인 교육과 정보제공이 지속적으로 이루어져야 할 것이다.

• 한국식품위생안전성학회지
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• 제30권3호
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• pp.217-226
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• 2015

본 연구는 국내 식품안전보건지표의 개발과정을 정립하기위해 수행되었다. 이를 위해 국내 식품안전보건지표의 개발과정을 제안하고, 제안된 과정에 대해 시뮬레이션을 함으로서 타당성 검사를 실시하고, 개발된 지표의 활용방안을 제시하였다. 국내 식품안전보건지표 개발과정은 국내 환경보건지표 개발과정을 주로 참고하여 설계되었으며, DPSEEA 모형을 적용하였다. 제안된 식품안전보건지표를 개발과정은 크게 개발단계와 운용단계로 나뉜다. 개발단계는 초기지표 제안, 후보지표 선정, 자료 현황 조사, 실행가능성 평가, 파일럿 스터디, 최종 지표 선정의 6단계로 구성되며, 운용단계는 주기적인 지표의 산출과 공표로 구성된다. 개발의 6개 단계는 전반적인 식품안전보건지표 개발을 총괄하는 Task Force팀과 각 개발 단계에서 제안된 지표를 검토 및 평가하는 자문위원회(최소 학계 4명, 연구계 2명, 식약처 관련부서 전문가 4명)의 단계적 역할분배를 통해 운영되도록 하였다. 제안된 과정의 타당성검토를 위해 시뮬레이션을 시행한 결과 제안된 45개의 초기지표 중 최종적으로 4개의 지표(세부지표 17개)가 선정되었다: '국산 과일 채소류 내 잔류농약/제초제 잔류랑 적합판정비율', '식품매개질환사고(outbreak) 발생 수', '식품매개(food-borne) 법정전염병의 발생률', '살모넬라 식중독(Salmonellosis) 발생률'. 선정된 지표는 지수화를 통해 효과적으로 활용될 수 있다. 2010~2012년의 지표를 토대로 비율차를 적용한 통합식품안전보건지수를 산출한 결과 2010년 대비 2011년, 2011년 대비 2012년의 통합식품안전보건지수로 10.37과 9.87이 산출되었다. 이는 식품안전보건상태가 2010년에 비하여 2011년에 10.37%, 2011년에 비해 2012년에 9.87% 호전되었음을 의미한다. 또한, 개별지표의 변화를 살펴봄으로서 변화율에 기여도가 큰 지표를 파악할 수 있으며, 통합식품안전보건지수를 도식화함으로서 대중과 정책입안자의 이해를 높일 수 있다. 이와 같이 식품안전보건지표는 다방면으로 효율적으로 활용될 수 있기 때문에 앞으로 더욱 큰 관심과 함께 법안의 제정과 활발한 연구가 필요하다.

• 한국동물위생학회지
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• 제31권4호
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• pp.521-532
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• 2008

The prevalence of major calf disease was investigated in 117 Holstein dairy calves in Chonnam area. All of them were moved in the College experimental farm which is operated in intensive units. clinical signs were daily examined throughout two months after the introduction of the College farm. Among calves, 92 cases(78.6%) died in the two months after the introduction in it. Outbreaks of respiratory and alimentary diseases were their main causes of their fatality. The incidence of respiratory disorders during the full period of the experiment was up to 42.8%, and the alimentary diseases were occurred 35.9% of the herd. Most of the mortality was related with respiratory(59.9%) and alimentary(52.1%) pathogens. Also calf mortality by combined infection claimed 6.6% among 100 morbidity cases. Principle pathogens to cause mortality were Pasteurella spp(44.4%), E coli(29.9%), bovine viral diarrhea virus(16.2%), IBRV(12.0%), respectively. Viruses also played as an important role in increasing calf morbidity to secondary respiratory bacterial pathogens. Pasteurella infection combined with infectious bovine rhinotracheitis virus(11 cases), parainfluenza virus type-3(9 cases), or bovine respiratory syncytial virus(7 cases) was appeared as major pattern to mortality. colibacillosis in causing enteritis was concurrently infected with BVD(19 cases), bovine coronavirus infection(14 cases), salmonellosis(5 cases), coccidiosis(5 cases) and clostridial infection(4 cases). Ninty-two cases to death were appeared to have 100% neutralizing antibodies to BCV; Among them, 73.8% had the neutralizing antibody level higher than 64. Calves with neutralizing antibodies higher than 16 to BVDV were 50%. The cases with neutralizing antibody level lower than 8 to BEFV were 89.4% that means the necessity of appropriate vaccination.