계란의 비열살균기술을 개발하고자 생성기체를 달리한 감압방전플라즈마(low-pressure discharge plasma, LPDP)처리에 의한 Salmonella Typhimurium 살균패턴을 조사하였고 이를 활용한 계란의 위생성 향상기법을 모색하였다. 플라즈마 생성기체를 달리하여 생성한 LPDP 처리 시 S.Typhimurium 살균력은 공기플라즈마가 가장 우수하였으며, 산소플라즈마, 질소플라즈마 순으로 낮아졌다. 공기를 사용한 LPDP의 처리시간별 S. Typhimurium의 살균효과는 2분, 5분, 10분 처리에 의해 각각 4, 6, 6.5 log 정도로 나타났다. 계란껍질의 S. Typhimurium에 대한 살균효과도 공기플라즈마가 가장 양호하였으며, 살균효과는 유리표면에 비해 약간 저하되어 5분 처리에 의해 3 log 정도 감소하였다. LPDP 처리 시 계란표면의 온도상승은 10oC 이하로 미미하였으며, 계란의 흰자와 노른자 모두 변성되지 않았다. 이러한 결과로부터 LPDP는 계란의 품질을 저하하지 않으면서 안전성 을 향상하는 비가열살균기술로 활용 가능함을 확인하였다.

Salmonellosis is a widespread bacterial zoonosis that commonly causes enterocolitis and foodborne poisoning leading to an extensive economic loss in domestic animal industry. Considerably, the emergence of multidrug resistant strains of Salmonella spp. induces further severe problems affecting public health. The present report was designated to investigate the antibacterial efficacies of three common disinfectants including an oxidizing compound disinfectant (OXC), a triple salt (TS) and a quaternary ammonium compound (QAC) against Salmonella typhimurium subjected to the preliminary changes of drug temperature. All solutions of three disinfectants were pre-incubated at different temperature (22, 37 and 63°C) for 1 h prior to exposure to bacteria. The disinfectants and bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OMS) according to treatment condition. Under the DW condition, the disinfectant efficacy of the QAC at 63°C was higher than that of 22°C. Furthermore, under HW diluent the disinfectant efficacy of the TS pre-warmed at both of 37 and 63°C were increased compared to that of 22°C. Considerably, the efficacy of pre-warmed QAC at both of 37 and 63°C under the OMS diluent were higher than that of 22°C. Conclusively, prewarming at higher temperatures have positive effects on the stability of the antibacterial efficacies of TS and QAC.

This study was performed to compared the effectiveness of individual treatments (electrolyzed water: EW, organic acid, and ultrasound) and their combination on reducing foodborne pathogens from perilla leaves. Perilla leaves were innoculated with a cocktail of Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus. Inoculated perilla leaves were treated with EW combined with different concentration of acetic acid (0.5%, 1.0%, 1.5%, 2.0%) for 1 min at room temperature. Treatment of 3 pathogens on perilla leaves with electrolyzed water combined with ultrasound (25 kHz) and 0.5% acetic acid was also performed for 1 min. While the numbers of S. Typhimurium and B. cereus showed reduced with increasing acetic acid concentration, there is no difference in the number of S. aureus treated with EW containing 0.5% to 1.5% acetic acid. Discoloration was observed the perilla leaves treated with EW combined with more than 1.0% acetic acid. For all three pathogens, the combined treatment of EW and ultrasound resulted in additional 0.42 to 0.72 log10 CFU/g. The maxium reductions of S. Typhimurium and B. cereus were 0.95, 1.23 log10 CFU/g after treatment with EW combined with 0.5% acetic acid and ultrasound simultaneously. The results suggest that the treatment of EW combined with 0.5% acetic acid and ultrasound increased pathogens reduction compared to individual treatment.

Egg yolk immunoglobulin (IgY) is the antibody in egg yolk and can be produced in egg yolk by immunizing hens with antigens. IgY is functionally equivalent to mammalian IgG. It is found in the serum of the chicken and is passed from the mother chicken to the embryo via the egg yolk, a process that results in a high concentration of IgY in the egg yolk. The objective of this study was to evaluate the efficacy of specific IgY against enterotoxigenic Escherichia coli (ETEC) K99, Salmonella Typhimurium and Salmonella Choleraesuis that cause porcine bacterial diseases. To prepare specific IgY, Hy-Line Brown chickens were vaccinated with killed vaccine complex including E. coli K99, S. Typhimurium and S. Choleraesuis. The chicken egg yolk antibodies were purified from egg yolk by ammonium sulfate precipitation and the quality of the final preparation was confirmed by sodium dodecyl sulfate polyacrylamide gel electro-phoresis (SDS-PAGE). Titres of specific IgY in final preparations were measured by an enzyme-linked immunosorbent assay (ELISA). Antibody titers peaked at 3 weeks regardless the bacterial types and the similar patterns of immune response were observed for respective pathogens. In growth inhibitor test, specific IgY showed inhibitory effect on bacterial growth. After 0, 3, 6 and 12 hour of incubation with specific IgY (100 ㎍/㎖, 250 ㎍/㎖, 500 ㎍/㎖), there was a significant decrease in the growth (A 600nm ) of E. coli K99, S. Typhimurium and S. Choleraesuis compared to nonspecific IgY and controls. In BALB/c mice, the effect of specific IgY (100 ㎎/㎏, 250 ㎎/㎏) on bacterial challenges was investigated by intramuscular injection and oral administration of bacteria. Mice treated with specific IgY showed high survival rate though there was no significant differences on blood biochemichal examinations between treated and untreated groups. These results indicate the potential of specific IgY for the treatment of porcine bacterial diseases caused by E. coli K99, S. Typhimurium and S. Choleraesuis.

Salmonella spp. and Brucella spp. have caused a considerable disease of farmed animals and economic loss in animal farming and food industry. In this study, the disinfection efficacy of Vital-Oxidel®, a commercial disinfectant, composed to chlorine dioxide, betaine hydrochloride, and propylene glycol was evaluated against S. typhimurium and Brucella ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at 4oC. Vital-Oixdel® and test bacteria were diluted with distilled water (DW), hard water (HW) or organic matter suspension (OM) according to treatment condition. On OM condition, the bactericidal activity of Vital-Oixdel® against S. typhimurium and Brucella ovis was lowered compared to that on HW condition. As Vital-Oxidel® possesses bactericidal efficacy against animal pathogenic bacteria such as S. typhimurium and Brucella ovis, this disinfectant solution can be used to control the spread of bacterial diseases.

A greening phenomenon has been observed in some plant foods such as chestnut, sweet potato,burdock, and others during processing. The formation of the pigments was postulated as reactions of primary amino compounds with chlorogenic acid or caffeic acid ester, yielding acridine derivatives. Acridine derivatives have been regarded as mutagenetic agents. For the reason, the bacterial reverse mutation test was carried out to evaluate the genotoxicity of green pigment using Salmonella typhimurium TA98 and TA100. Alanine, arginine, aspartic acid, glycine,lysine, and phenylalanine were reacted repectively with chlorogenic acid to synthesize model compound. Green pigment was extracted from sweet potato. Maximum concentration of 2 and 50 mg/plate was tested for the synthetic green pigments and extracted green pigment respectively, taking bacterial survival, solubility, and color intensity into consideration. There was no signigicant increase in the reverse mutation either with or without S9 activation system by any test material. Though further studies with other genotoxicity test system are necessary, both synthetic and sweet potato green pigments seemed not to cause mutation despite the acridine moiety in their structures.

Salmonellosis is a major bacterial zoonosis that causes self-limited enteritis to fatal infection in animals and food-borne infection and typhoid fever in humans. Multidrug-resistant strains of Salmonella spp. has increased over the last several decades and recently causes more serious problems in public health. The present study was investigated bacteriocidal effects of sodium chlorate, sodium azide, sodium cyanide, and sodium salts mixture containing sodium chlorate, sodium azide, and sodium cyanide on infection with S. typhimurium in macrophage RAW 264.7 cells, and antibacterial effects of sodium salts mixture for murine salmonellosis. In infection assay of S. typhimurium in RAW 264.7 cells, bacterial survival rates within macrophage in all treated groups was significantly reduced comparing to that of the control group with the passage of incubation time. Administration of sodium salts mixture showed a therapeutic effect for S. typhimurium infected ICR mice. The mortality of mice treated with sodium salts mixture was 70% until 12 days, while that of control mice was 100% until 9 days after S. typhimurium infection. The results of this study strongly indicate that sodium salts mixture has a potency treatment for murine salmonellosis.

Salmonellosis is the commonest zoonosis worldwide that generally causes enterocolitis and foodborne poisoning which represents a considerable public health burden. Salmonella spp. are potential enteric pathogens and intracellularly replicates in host cells resulting in chronic infections. The medical treatments for salmonellosis have been difficult yet and had a serious problem including the increasing emergence of antibiotic resistance. The present report was designated to investigate the antibacterial effects of Saururus chinensis Baill ethanol extract (SCEE) on pure culture and infection with Salmonella enterica serovar Typhimurium (S. typhimurium) in murine derived macrophage RAW 264.7 cells. In determination of antibacterial activity of SCEE against S. typhimurium, bacterial viability was markedly decreased compared to the control. Also, SCEE significantly induced morphological change (p<0.05) of RAW 264.7 cells. In infection assay of S. typhimurium in RAW 264.7 cells pretreated with 100㎍/㎖ of SCEE, which is a non-cytotoxic concentration, bacterial uptake ability of macrophage was increased corresponding with morphological change, whereas bacterial survival rates within macrophage were markedly reduced compared with untreated control. Furthermore, nitric oxide (NO) production in SCEE-treated cells was slightly increased until 2 h but showed a tendency of decrease after 4 h until 24 h post infection compared with untreated control with S. typhimurium infection. Taken together, these findings demonstrated that SCEE has the antibacterial activity for S. typhimurium and the protective effects against S. typhimurium infection through activating murine macrophage independent on NO, suggesting that SCEE may be beneficial on the disease caused by intracellularly replicating pathogens as a safe alternatives of conventional chemotherapies.

살모넬라증은 대표적인 인수공통전염병의 하나로서 세포내 기생하며 질병을 유발하며 장염과 식중독 등을 유발하여 공중보건학적으로 심각한 문제를 야기하고 있다. 본 연구는 삼백초의 수용성 추출물을 (SCWE) 이용하여 숙주세포에 대한 안전성, S. typhimurium 균에 대한 항균효과 및 대식세포 내 균 증 식억제 기능을 규명하였다. 본 실험을 통하여 SCWE 1, 10 및 100 μg/ml 농도로 첨가한 배지에서 RAW 264.7 체포와 24 시간 반응 후 평가해본 결과 세포독성이 인정되지 않았으며, S. typhimurium 균에 대하여 시간 경과에 따라 항균효과가 증가되는 것을 확인하였고, SCWE 처리에 의해 대식세포의 형태적 변화가 증가되는 것으로 나타났으며 (p<0.05), 살모넬라균의 탐식능력 및 대식세포 내 균 증식 억제 능 력이 비 처리군에 비해 현저히 증가되는 것이 확인되었다. 또한 SCWE 처리 한 대식세포에 살모넬라균 감염을 수행하였을 때 대식세포의 nitric oxide (NO) 산생능력이 비 처리 군에 비해 저하되는 것으로 나타나, 살모넬라균에 의한 대식세포의 세포독성을 억제하는 것으로 나타났다. 종합적으로 SCWE의 숙 주세포에 대한 안전성, 살모넬라균에 대한 항균효과 및 대식세포 내 균 증식 억제 효과가 있는 것으로 나타나 SCWE를 이용한 세포내 기생세균의 치료제 개발이 가능할 것으로 판단된다.

The present study was undertaken to estimate the antibacterial effect of a combination of C. rhizoma,L. Flos, and P. japonica (1:1:1) extracts (CLP1000) and a combination of the herbal extract mixture and dioctahedral smectite (CLPS1000) against murine salmonellosis. At the concentration of CLP1000 and CLPS10000.5 mg/ml, the antibacterial effect was not showed on Salmonella typhimurium (S. typhimurium). On the other hand,the antibacterial effect against S. typhimurium was observed at the concentration of CLP1000 and CLPS1000 1.0 mg/ml. Oral administration of Smectite, CLP1000, and CLPS1000 at the dose of 10 mg/ml showed a therapeutic effect for S. typhimurium infected BALB/c mice. The mortality of Smectite, CLP1000 and CLPS1000-treated mice was 90%,90%, and 70% at 12 days, respectively, while that of untreated mice was 100% at 9 days after a lethal dose of S. typhimurium infection. The results of our study strongly indicate that CLPS1000 has potential as an effective of salmonellosis.

Biological organisms require iron for optimal metabolism. Intracellular pathogens also must secure iron especially during infection of animal hosts expressing NRAMP(natural resistance-associated macrophage protein), a transporter protein sequestering metal ions from pathogens. This study shows that extracytoplasmic function sigma factor σE is required for Salmonella virulence in NRAMP1-expressing mice, and further shows that iron deprivation turns on σE expression of Salmonella. The virulence of σE -deficient Salmonella is completely attenuated in C3H/HeN mice while wild type Salmonella kills all mice. Addition of an iron-chelator DTPA(Diethylene triamine pentaacetic acid) to culture media induces σE expression of Salmonella, but iron supplementation abrogates this induction. These findings suggest that iron limitation in host macrophages can trigger σE -dependent virulence system of Salmonella that may include bacterial iron homeostasis.

국내산 과일 주스 4종을 준비하고 식중독 유발균인 Listeria monocytogenes와 Salmonella Typhimurium를 접종하여 14일 동안 4℃에서 보관하며 항균 효과를 살펴본 결과 다음과 같은 결론을 얻었다. L. monocytogenes 에서는 매실 주스가 가장 뛰어난 효과를 나타내어 보존 14일만에 생존하고 있는 균을 전혀 측정할 수 없었으며, 그 다음으로 키위가 3.0 log만큼 억제를 보이는 항균 효과를 나타내었다. 감귤의 경우 1.0 log만큼 억제하는데 그쳤다. 매실주스 10%를 다른 주스에 혼합하였을 때 L. monocytogenes는 키위 즙에서 더욱 향상된 항균 효과를 나타내어 14일 후 생존 균을 측정할 수 없었고, 감귤주스에서도 1.5 log 만큼의 향상된 항균 효과를 나타내었다. S. Typhimurium은 전반적으로 L. monocytogenes 보다 더 쉽게 억제되는 경향을 보였다. 키위 즙과 매실 주스에서 접종한 모든 균이 보존 14일 후 생존하지 않는 것으로 관찰되었으며, 감귤의 경우에는 1.4 log 만큼밖에 억제하지 못했다. 10%의 매실과 혼합된 주스에 S. Typhimurium을 접종한 결과 키위 즙에서는 접종한 전 균이, 감귤주스에서는 3.2 log 만큼의 증가된 억제효과를 나타내었다. 이상과 같은 결과로 볼 때, 매실은 식중독 유발균에 대한 강한 항균 활성을 가지고 있으며 다른 과실주스에서의 식중독을 예방하기 위한 식품 보존 첨가제로서 사용이 가능할 것으로 기대된다.

This study was carried out to evaluate the genotoxicity of the gamma-irradiated (0, 5 and 10 kGy) milk and ice cream. The Salmonella typhimurium reversion assay was performed using S. typhimurium TA98, TA100, TA102, TA1535 and TA1537 as tester strains. The number of revertant colonies were not increased in both milk and ice cream, compared with negative controls with or without metabolic activation. There were no significant differences among the irradiation doses. These results indicate that the gamma-irradiated milk and ice cream do not show any genotoxic effect under these experimental conditions, and that they may be safe genotoxically.

동결 건조된 죽력을 물 또는 50% ethanol에 각각 용해시킨 시료(1 mg eq./disc)에 대하여 항세균 활성을 측정한 결과, 물에 용해시킨 죽력은 gram 양성균의 경우 L. monocytogenes이 15 mm의 저해환으로 가장 활성이 강하였고 B. subtilis는 활성이 전혀 나타나지 않았으며 Gram 음성균의 경우는 S. dysenteriae가 저해환이 22 mm로 가장 강한 활성을 보였다. 50% ethanol에 용해시킨 죽력은 gram 양성균의 경우 L. monocytodenes, 가 가장 강한 활성을 보였으나 B. subtilis는 활성이 전혀 없던 물에 용해시킨 경우에 비하여 활성이 크게 나타났다. Gram 음성균의 경우, S. dysenteriae가 23 mm저해 환으로 가장 강한 활성을 보였고 V. parahaemolyticus, V. vulnificus, E. coli O157:H7는 16 mm로 상대적으로 약한 활성을 보였다. 젖산균 2종의 경우는 물 또는 50% ethanol에 용해시킨 경우 모두 전혀 활성을 나타내지 않았다. 최소저해농도는 L. monocytogenes는 50% ethanol에 녹인 경우 MIC가 0.6 mg/disc로 가장 낮았고 물에 용해시킨 죽력의 경우 S. epidermides, S. dysenteriae, L. monocytogenes, Sal. typhimurium, V. parahaemolyticus가 각각 0.8 mg/disc의 MIC값을 나타내 50% ethanol에 용해시킨 경우에 비하여 MIC값이 높은 경향을 보였으며 다른 세균들은 1.0 mg/disc의 거의 유사한 MIC값을 보였다. Model food system에서의 저해활성은 물에 용해시킨 죽력 보다 50%, ethanol에 용해시킨 죽력이 대조구에 비하여 생육을 강하게 저해하였고 MIC가 낮은 이들 4가지 공시균주들이 모두 model food system상에서 상당히 강한 저해활성을 나타내 50% ethanol에 용해시킨 죽력은 적절한 농도에서 부패세균들의 생육 억제제로 사용 가능할 것으로 사료되었다.

In order to investigate the MDR gene by plasmid profile, multiplex-PCR and PFGE analysis, it was examined 20 Salmonella Typhimurium isolated from patients stool from 1999 to 2002. The plasmid profile analysis was shown one to five kinds of plasmid in 600bp~150Kb sized. Especially, PT104 isolates obtained has 3 plasmid identically. According to the result of multiplex-PCR, all PT104 isolates amplified only tet(G) and pse1, but aadA2 was not specialized. PFGE analysis of the fragments restricted by XbaⅠ evidently discriminated plasmid DNA among phage types.

To investigate antimicrobial susceptibility and relationships of the multidrug resistance and phage types of 49 Salmonella enterica serovar Typhimurium isolated from diarrhea patients in Seoul between 1999 and 2002, we analyed stranis by serotyping, antimicrobial susceptibility test and phage typing. Out of 2,705 samples examined for the causative agent from diarrhea patients, total of 512 isolates were confirmed to be genus Salmonella. Out of 512 isolates, 49 isolates(9.6%) were identified as S. Typhimurium. All of the S. Typhimurium strains represented 100% susceptibility to ceftriaxone, cefoxitin, amikacin and ciprofloxacin and were over 90% susceptibility to gentamicin, cephalothin and kanamycin, but were resistant to tetracycline(75.5%), streptomycin(59.2%), sulfonamides(55.1%), ticarcillin(36.7%), ampicillin( 28.6%), and chloramphenicol(20.4%). Out of 49 S. Typhimurium, only 3 isolates(20.4%) were resistant to one drug, 6 isolates(12.2%) to two drugs and 12 isolates(24.5%) to 3 drugs, 1 isolate(2.0%) to 4 drugs, 2 isolates (4.1%) to 5 drugs, and 6 isolates(12.2%) to 6 drugs and 5 isolates (10.2%) to 7 drugs. Out of 49 S. Typhimurium, 10 isolates(20.4%) were DT195, 5 isolates(10.2%) were DT193 and DT206, 4 isolates(8.2%) were DT104L, DT146, DT203 and RDNC, respectively. Phage types observed the resistant patterns of more than 6 drugs were DT104L, DT193, DT194, DT195 and DT67, but those of 3 drugs representing S-S3-TE type was DT195.