• 대한수의학회지
• /
• 제51권2호
• /
• pp.123-128
• /
• 2011

Salmonella spp. is an important pathogen to both public and swine industry. The aim of this study was to investigate the distribution of Salmonella serovar and antibiotics susceptibility of the isolates from Korean swine producing systems. A total of 63 (5.28%) Salmonella spp. was isolated from 1,194 samples (977 fecal materials and 67 organ samples). The predominant Salmonella (S.) enterica serotype and serovar was group B (69.8%) and S. Typhimurium (47.6%), S. Derby (20.6%) and S. Heidelberg (1.6%). But S. Cholerasuis which is characterized host specific by septicemia and enteritis to pigs was not isolated. Antimicrobial susceptibility of the isolates varies as follows: Norfloxacine (75%), Ciprofloxacin (67.5%), Amikacin (60%), Colistin (60%), Enrofloxacin (55%). All of isolates were resistant to Erythromycin, Penicillin, Tetracycline and Lincomycin. The results of this study provided useful information regarding antimicrobial susceptibility and resistance patterns to treat salmonellosis and to prevent emergence of multidrug resistance Salmonella.

• 한국식품위생안전성학회지
• /
• 제17권2호
• /
• pp.71-78
• /
• 2002

항생제 및 항균 물질 등의 오, 남용으로 인하여 항생제 내성균들이 등장, 사회적으로 큰 문제가 되고 있으며, 최근에는 식물이나 probiotics 등과 같이 항생제를 대체할 수 있는 물질에 대한 연구가 활발히 진행되고 있다. 이에 본 연구에서는 국내에서 오래 전부터 민간 요법으로 사용되어 오던 백련초 (Opuntia ficus-indica var. saboten)를 이용하여 in vitro와 in vivo에서 Salmonella enteyica serova. Enteritidis (S. enteritidis), S. enterica serova. Typhimurium (S. Typhimurium) DT104 및 Escherichia coli O157:H7에 대한 항균능을 평가하였다 백련초의 수용액이 포함된 Moulter Hinton agar에 Salmonella spp. 및 S. coli O157:H7를 접종한 결과 이들 균에 대한 억제능(inhibitory activity)을 확인할 수 있었다. 백련초 제제를 경구투여한 군에서 분변으로 배출되는 S.typhimurium DT104의 수가 급격히 감소하였고, 낀 후에는 더 이상 분변으로 균이 배출되지 않았으며, intestinal IgA가 유의적으로 증가함이 확인되었다. 본 연구를 통하여 백련초가 in vitro에서 S. enteritis, S. Typhimurium DT104와 E. coli O157:H7대한 항균력을 나타낼 뿐만 아니라 마우스의 gastrointestinal tract에서 역시 Salmonella에 대한 항균력을 보임을 확인할 수 있었다. 본 연구를 통해 백련초 및 그 성분을 이용한 병원성 세균의 제거 및 면역 증진 효과 등과 같은 연구의 필요성이 확인되었고, 그 응용 가능성도 매우 높을 것으로 사료된다.

• 한국축산식품학회지
• /
• 제37권1호
• /
• pp.134-138
• /
• 2017

Salmonella enterica infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target Salmonella envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for Salmonella envelope stress, we examined the transcription of the S. enterica serovar typhimurium spy gene, the ortholog of which in Escherichia coli encodes Spy (${\underline{s}}pheroplast$ ${\underline{p}}rotein$ ${\underline{y}}$). Spy is a chaperone protein expressed and localized in the periplasm of E. coli during spheroplast formation, or by exposure to protein denaturing conditions. spy expression in S. typhimurium was examined by constructing a spy-gfp transcriptional fusion. S. typhimurium spy transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, spy induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring spy transcription may be useful to determine whether a molecule particularly cause envelope stress in Salmonella.

• 한국식품위생안전성학회지
• /
• 제34권4호
• /
• pp.374-379
• /
• 2019

본 연구에서는 대표적인 신선 잎채소류인 상추의 세척 단계에서 초음파 (37 kHz) 와 염소 (100~300 ppm) 의 병용처리 후 냉장 ~ 실온저장 ($10{\sim}25^{\circ}C$)에 따른 이 식품 중의 Salmonella Typhimurium의 성장예측모델을 개발하였다. 1 차 모델 개발을 위해 Gompertz 방정식을 활용하여 각기 다른 실험 조건에서의 S. Typhimurium의 생육도 (SGR 과 LT)를 조사했다. 본 방정식에 의한 1 차 모델 개발시 $R^2$가 0.92 이상으로 우수하게 나타났으며 저장온도가 낮을수록 초음파에 사용된 염소의 농도가 높을수록 SGR 값은 감소하였고 LT 값은 증가하였다. 이를 바탕으로 2 차 polynomial 모델을 개발하여 다양한 통계적 지표 ($R^2$, MSE, $A_f$ 및 $B_f$)를 통해 분석한 결과 개발된 모델의 적합성을 확인할 수 있었다. 따라서 개발된 모델이 초음파와 염소의 병용 세척에 따른 저장 중 상추에 대한 S. Typhimurium의 성장예측모델로 사용 가능하다고 판단되어지며, 신선 잎채소류에서의 식중독을 예방하고 미생물학적 위생관리기준을 설정하는데 기초자료로 활용될 수 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
• /
• 제19권10호
• /
• pp.1271-1279
• /
• 2009

To develop low endotoxic and multi-immunogenic outer membrane vesicles (OMVs), a deletion mutant of the msbB gene in Salmonella enterica serovar Typhimurium (S. Typhimurium) was used as a source of low endotoxic OMV, and an expression vector of the canine parvovirus (CPV) VP2 epitope fused to the bacterial OmpA protein was constructed and transformed into the Salmonella ${\Delta}msbB$ mutant. In a lethality test, BALB/c mice injected intraperitoneally with the Salmonella ${\Delta}msbB$ mutant survived for 7 days, whereas mice injected intraperitoneally with the wild type survived for 3 days. Moreover, all mice inoculated orally with the ${\Delta}msbB$ mutant survived for 30 days, but 80% of mice inoculated orally with the wild type survived. The OmpA::CPV VP2 epitope fusion protein was expressed successfully and associated with the outer membrane and OMV fractions from the mutant S. Typhimurium transformed with the fusion protein-expressing vector. In immunogenicity tests, sera obtained from the mice immunized with either the Salmonella msbB mutant or its OMVs containing the OmpA::CPV VP2 epitope showed bactericidal activities against wild-type S. Typhimurium and contained specific antibodies to the CPV VP2 epitope. In the hemagglutination inhibition (HI) assay as a measurement of CPV-neutralizing activity in the immune sera, there was an 8-fold increase of HI titer in the OMV-immunized group compared with the control. These results suggested that the CPV-neutralizing antibody response was raised by immunization with OMV containing the OmpA::CPV VP2 epitope, as well as the protective immune response against S. Typhimurium in BALB/c mice.

• 한국동물위생학회지
• /
• 제39권1호
• /
• pp.51-57
• /
• 2016

Fifty and forty two Salmonella enterica subspecies enterica serovar 52 Typhimurium (ST) strains were isolated from chicken and pigs, respectively, collected from markets throughout Korea from 2008 to 2011. The isolates were investigated for the presence of antimicrobial resistance and multi-drug patterns. All 50 ST isolates from chicken and 42 ST isolates from pigs were resistant to at least one of 13 antibiotics used in this study, 92.0% of ST isolates from chicken and 88.1% of ST isolates from pigs were resistant to three or more antimicrobials. As many as 3 isolates of ST isolates from chicken were resistant to 11 of 13 antimicrobials tested in this study. Only one isolate of ST isolates from pigs was resistant to 10 of 13 antimicrobials. The ACSSuT resistance phenotype was observed in 34% of the 50 isolates and 23.8% of the 42 isolates. Especially, 1 isolate from pigs had the ACSSuTAu. The high rate of antimicrobial-resist and multi-drug resistant (MDR) ST isolation may give rise to crucial public health problems. Therefore, control of antimicrobial use, and continuous monitoring of antimicrobial resistance and MDR patterns among Salmonella isolates in chicken and pig farms is necessary to ensure public health.

• 한국식품저장유통학회지
• /
• 제15권5호
• /
• pp.736-742
• /
• 2008

전통 된장의 숙성기간 중 기능적 특성의 변화를 조사하기 위하여 상황버섯 추출물을 이용하여 된장을 담금하여 일정기간 숙성한 후, 된장의 protease 활성, 항돌연변이 활성, isoflavone 등을 측정하였다. Protease의 활성은 상황버섯 추출물을 이용한 실험구가 3.15 unit/mL로 대조구보다 높은 활성을 나타내었으며 tyrosinase의 저해 활성과 ACE 저해 활성은 실험구가 각각 45.78%와 55.18%로 대조구보다 약 20% 이상 높은 활성을 나타내었다. 항돌연변이 활성은 실험구가 S. enterica serovar Typhimurium TA100을 사용한 경우 변이원 MNNG와 NPD에 대한 항돌연변이 활성은 각각 90.42%와 82.57%, S. enterica serovar Typhimurium TA98을 사용한 경우 변이원 NPD와 NQO에 대한 항돌연변이 활성은 각각 60.28%와 50.33%로 대조구보다 높은 활성을 나타내었다. 수소 공여능은 실험구의 활성이 86.65%로 대조구의 61.69%보다 높게 나타났다. 상황버섯 추출물을 이용하여 제조한 된장의 isoflavon 중 glucoside인 daidzin은 실험구가 35.49 mg/kg높게 나타났으며 genistin은 실험구와 대조구 모두에서 검출되지 않았다. Aglycone인 daidzein과 genistein은 각각 263.01 mg/kg와 262.60 mg/kg로 대조구 보다 높은 함량을 나타내었다.

• Journal of Microbiology and Biotechnology
• /
• 제25권4호
• /
• pp.479-491
• /
• 2015

Lactobacillus species have been shown to enhance intestinal epithelial barrier function, modulate host immune responses, and suppress the growth of pathogenic bacteria, yeasts, molds, and viruses. Thus, lactobacilli have been used as probiotics for treating various diseases, including intestinal disorders, and as biological preservatives in the food and agricultural industries. However, the molecular mechanisms used by lactobacilli to suppress pathogenic bacterial infections have been poorly characterized. We previously isolated Lactobacillus plantarum JSA22 from buckwheat sokseongjang, a traditional Korean fermented soybean food, which possessed high enzymatic, fibrinolytic, and broad-spectrum antimicrobial activity against foodborne pathogens. In this study, we investigated the effects of L. plantarum JSA22 on the growth of S. Typhimurium and S. Typhimurium-induced cytotoxicity by stimulating the host immune response in intestinal epithelial cells. The results showed that coincubation of S. Typhimurium and L. plantarum JSA22 with intestinal epithelial cells suppressed S. Typhimurium infection, S. Typhimurium-induced NF-κB activation, and IL-8 production, and lowered the phosphorylation of both Akt and p38. These data indicated that L. plantarum JSA22 has probiotic properties, and can inhibit S. Typhimurium infection of intestinal epithelial cells. Our findings can be used to develop therapeutic and prophylactic agents against pathogenic bacteria.

• Journal of Microbiology and Biotechnology
• /
• 제17권4호
• /
• pp.644-649
• /
• 2007

Response surface model was developed for predicting the growth rates of Salmonella enterica sv. Typhimurium in tryptic soy broth (TSB) medium as a function of combined effects of temperature, pH, and NaCl. The TSB containing six different concentrations of NaCl (0, 2, 4, 6, 8, and 10%) was adjusted to an initial of six different pH levels (pH 4, 5, 6, 7, 8, 9, and 10) and incubated at 10 or $20^{\circ}C$. In all experimental variables, the primary growth curves were well $(r^2=0.900\;to\;0.996)$ fitted to a Gompertz equation to obtain growth rates. The secondary response surface model for natural logarithm transformations of growth rates as a function of combined effects of temperature, pH, and NaCl was obtained by SAS's general linear analysis. The predicted growth rates of the S. Typhimurium were generally decreased by basic (9, 10) or acidic (5, 6) pH levels or increase of NaCl concentrations (0-8%). Response surface model was identified as an appropriate secondary model for growth rates on the basis of coefficient determination $(r^2=0.960)$, mean square error (MSE=0.022), bias factor $(B_f=1.023)$, and accuracy factor $(A_f=1.164)$. Therefore, the developed secondary model proved reliable predictions of the combined effect of temperature, NaCl, and pH on growth rates for S. Typhimurium in TSB medium.

• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 2002년도 추계학술대회
• /
• pp.151-158
• /
• 2002