• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.135-135
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• 2005

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.226.2-226.2
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• 2003

The FimH subunit of type 1-fimbriated Escherichia coli has been determined as a major cause of urinary tract infection. To produce a possible vaccine antigen against urinary tract infection, the fimH gene was genetically linked to the Itxa2b gene, which was then cloned into the pMAL -p2E expression vector. The chimaeric construction of pMALfimH/Itxa2b was transformed into Escherichia coli TB1 and its N-terminal amino acid sequence was analyzed. (omitted)

• 한국환경보건학회지
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• 제42권4호
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• pp.255-265
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• 2016

Objectives: Mobile phones have become one of the most essential accessories in daily life. However, they may act as reservoir of infectious pathogens if they are used without hygienic practices in their handling. Therefore, this study aimed to isolate food-borne pathogens from mobile phones and investigate the characteristics of toxin genes and antibiotic susceptibility patterns. Methods: A total of 146 mobile phones were collected from 83 middle- and 63 high-school students in Busan. The surfaces of the mobile phones were aseptically swabbed. Results: Among the food-borne pathogens, Staphylococcus aureus, Bacillus cereus and Escherichia coli were detected in 26 (17.8%), 20 (13.7%) and four (2.7%) samples, respectively. There were no statistically significant differences according to school level, gender or phone type. None of four E. coli strains had pathogenic toxic genes. All of the B. cereus strains carried at least three different toxin genes among the nine enterotoxin and emetic toxin genes. Three out of 20 B. cereus strains (15%) possessed emetic toxin genes, which are rarely detected in food-poisoning cases in Korea. Among the 26 strains of S. aureus, the detection rate of staphylococcal enterotoxin genes, toxic shock syndrome toxin (tsst) and factors essential for methicillin resistance (femA) were 84.6%, 7.7% and 100%, respectively. In the antibiotic susceptibility test, there was no methicillin-resistant S. aureus (MRSA) or vancomycin-resistant S. aureus (VRSA). Conclusion: The results show that students' mobile phones in Busan were contaminated by food-borne pathogens which carried various toxic genes. Therefore, regular phone disinfection and hand hygiene is important in order to reduce cross-contamination.

• Biomolecules & Therapeutics
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• 제13권2호
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• pp.101-106
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• 2005

The generation of secretory IgA antibodies (Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the heat-labile Escherichia coli enterotoxin A2B (ltxa2b) gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ltxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and westem blotting using antibodies to the maltose binding protein (MBP) or the heat labile E. coli subunit B (LTXB), plus the N-terminal amino acid sequence was analyzedd. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/LTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of LTXB. thisstudy also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA (sIgA) and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked LTXA2B acts as a useful mucosal adjuvant, and that adhesin/LTXA2A chimeric protein might be a potential antigen for oral immunization against UPEC.

• 한국식품위생안전성학회지
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• 제14권4호
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• pp.327-332
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• 1999

1996년 3월부터 1998년 10월간에 경남지방 시판 냉장육 888건, 냉동포장육 222건 및 수입 냉동육 117건의 시료로부터 식중독관련 병원균의 분포와 혈청형을 조사하였다. 식중독균의 분리률은 Staphylocorcus aureus. Campylobarter jejuni/coli, Listeria monocytogenes 및 Salmonella spp 순으로 높았고, Escherichia coli O157:H7은 전시료를 통해서 분리되지 않았다. C. jejuni /coli는 냉장육에서 높은 오염률을 나타내고, 냉동포장육에서는 거의 분리되지 않는데 반해서 L. monocytogenes는 냉장육에 이해서 냉동포장 계육에서 높은 분리율을 나타낸 것은 매우 흥미로운 일이다. 분리균의 혈청형 분포는 Sta. aureus의 경우 대부분이 enterotoxin type C와 D였고, Salmonella spp는 돈육유래균에서 모두 A group이었으며, 계육유래균은 대부분 B와 D group이었다. L. monocytogenes는 계육유래균의 대부분이 type 1 이었고, type 4는 소수로 분리되었다.

• 한국식품위생안전성학회지
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• 제18권2호
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• pp.79-86
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• 2003

대부분의 식중독은 단체 급식으로부터 발생하는 경우가 많으며, 특히 위생상태와 연관되어 식중독을 야기 시키는 병인 물질 중 포도상 구균은 많은 부분을 차지하고 있다 따라서 본 연구에서는 서부경남지역의 5개 초등학교 급식시설에서 총 98개의 샘플 중 A 급식소의 식수, D 급식소의 손, E 급식소의 냉장고와 앞치마에서 4개의 포도상 구균을 분리하였다. 분리된 균주들은 1개의 메티실린 저항성 혈장응고 효소 음성 황색포도상구균(Methicilline Resistant Coagulase Negative Staphylococcus aureus； MRCPS)과 3개의 메치실린 민감성 혈장응고효소 양성 황색포도상구균 (Methicilline sensitive Coagulase positive Staphylococcus aureus； MSCPS)으로 구분되었다. 한편 포도상 구균은 내열성 내독소로서, 이 중 가장 문제가 되는 내독소 B(enterotoxin B)를 검색하기 위한 PCR을 실시한 결과, A 장소의 식수, D 장소의 손, E 장소의 냉장고와 앞치마에서 분리된 균주로부터 477bp의 생성물을 갖는 sob gene을 확인할 수 있었다. 이들 분리된 황색포도상구균에 대한 항생제 민감성 실험에서는 ampicillin과 penicillin에 대하여 전체적으로 저항성을 가졌으며, 특히 A 식수에서 분리된 균주는 옥사실린 저항성(oxacilline resistant)균주로 나타나 MRSA(methicilline resistant staphylococcus aureus)균주로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.872-879
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• 2015

Many strains of Bacillus cereus cause gastrointestinal diseases, and the closely related insect pathogen Bacillus thuringiensis has also been involved in outbreaks of diarrhea. The diarrheal diseases are attributed to enterotoxins. Sixteen reference strains of B. cereus and nine commercial and 12 reference strains of B. thuringiensis were screened by PCR for the presence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, bceT, entFM, and entS), one emetogenic gene (ces), seven hemolytic genes (hlyA, hlyII, hlyIII, plcA, cerA, cerB, and cerO), and a pleiotropic transcriptional activator gene (plcR). These genes encode various enterotoxins and other virulence factors thought to play a role in infections of mammals. Amplicons were successfully generated from the strains of B. cereus and B. thuringiensis for each of these sequences, except the ces gene. Intriguingly, the majority of these B. cereus enterotoxin genes and other virulence factor genes appeared to be widespread among B. thuringiensis strains as well as B. cereus strains.

• Journal of Nutrition and Health
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• 제34권2호
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• pp.150-157
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• 2001

Intestinal absorption of dietary taurine is one of the regulatory component maintaining taurine homeostasis along with renal reabsorption, bile acid conjugation and secretion, and de nobo synthesis of taurine in mammals. Recent observations of decreased enterocytic levels of taurine in response to trauma, infection and surgical insults, postulate the possibility that intestinal taurine absorption might be impaired in such stressed conditions. The aim of the present study was to evaluate changes in enterocytic taurine transporter activity using the human intestinal colon carcinoma cell line, HT-29, in various stress-induced conditions. Pretreatment of the HT-29 cells with dexamethasone, a stress hormone(0.1,1,10 or 100$\mu$M) for 3 hrs, or with E coli heat-stable enterotoxin(10, 100, or 200nM) for 30 minutes in order to induce the condition of enterotoxigenic infection did not influence taurine uptake as compared to the value found in control cells. In contrast, pretreatment of the cells with cholera toxin(10, 100, 500, or 1000ng/ml)for 3hr or 24hr significantly decreased taurine uptake by HT-29 cells to 40~50% of the value found in untreated control cells. Kinetic studies of the taurine transporter activity were conducted in control and cholera toxin treated HT-29 cells with varying taurine concentrations(2~60$\mu$M) in the uptake medium. Pretreatment of the cells with cholera toxin(100ng/ml) for 3hr did not influence the Vmax, but resulted in a 55% increase in the Michaelis-Menten constant(Km) of the taurine transporter compared to those in control cells. These results suggest that cholera toxin-induced reduction in taurine transporter activity in HT-29 cells is associated with decreased affinity of the taurine transporter without altering the amount of transporter protein. Intestinal taurine absorption appears to be reduced in the condition of water-borne diseases caused by bacteria such as V. cholerae. This might influence the taurine status of infants and young children more readily, an age group in which the prevalence of intestinal infection is high and the role of intestinal absorption is crucial for maintaining the body taurine pool. (Korean J Nutrition 34(2) : 150-157, 2001)

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.550-557
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• 2010

Escherichia coli (E. coli) heat-labile enterotoxin B subunit (LTB) was regarded as one of the most powerful mucosal immunoadjuvants eliciting strong immunoresponse to coadministered antigens. In the research, the high-level secretory expression of functional LTB was achieved in P. pastoris through high-density fermentation in a 5-1 fermentor. Meanwhile, the protein was expressed in E. coli by the way of inclusion body, although the gene was cloned from E. coli. Some positive yeast and E. coli transformants were obtained respectively by a series of screenings and identifications. Fusion proteins LTB-6$\times$His could be secreted into the supernatant of the medium after the recombinant P. pastoris was induced by 0.5% (v/v) methanol at $30^{\circ}C$, whereas E. coli transformants expressed target protein in inclusion body after being induced by 1 mM IPTG at $37^{\circ}C$. The expression level increased dramatically to 250-300 mg/l supernatant of fermentation in the former and 80-100 mg/l in the latter. The LTB-6$\times$His were purified to 95% purity by affinity chromatography and characterized by SDS-PAGE and Western blot. Adjuvant activity of target protein was analyzed by binding ability with GMI gangliosides. The MW of LTB-6$\times$His expressed in P. pastoris was greater than that in E. coli, which was equal to the expected 11 kDa, possibly resulted from glycosylation by P. pastoris that would enhance the immunogenicity of co-administered antigens. These data demonstrated that P. pastoris producing heterologous LTB has significant advantages in higher expression level and in adjuvant activity compared with the homologous E. coli system.

• 대한미생물학회지
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• 제19권1호
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• pp.65-71
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• 1984

The author attempted serological typing with the slide agglutination and the production of heat-labile enterotoxin (LT) and heat-stable enterotoxin (ST) by the enterotoxingenic eschenchia coli 446 strains isolated from diarrheal patients. The enterotoxingenic E.coli, producing LT and/or St, were detected by use of assays in the reversed passive hemagglutination(RPHA) and the suckling mouse method. The results obstained were as follows: 1. Of 446 strains isolated, 88 strains(19.73%) produced LT, while 224 strains(50.22%) produced ST, 134(30.05%) produced both LT-ST simultaneously. Serological typing were typed into 06, 08, 020, 025, 027, 0126, 0148 and 0159. Serotype 06 had the highest incidence of 26.46% followed by 0148(18.16%), 027(14.57%); 025(10.99%), 0159(4.03%), 0126(3.59%), 020(1.12%) and 08(0.45%). 2. Serotype 06, 08 and 025 almost always produced both LT and ST, whereas serotypes 020, 027 and 0148 almost always produced only ST. And serotypes 06, 025, 0126 and 0159 almost always produced LT or ST. 3. Of 134 LT-ST positive strains, 115 strains were serotype 06, 3 strains were 025, 2 strains were 08, and 14 strains were 0 untypable. 4. Of 224 ST positive strains, 65 strains were serotype 027, 81 strains were 0148, 16 strains were 0159, and 42 strains were 0 untypable. 5. Of 88 LT positive strains, 45 strains were serotype 025, 5 strains were 0126, 2 strains were 0159, and 42 strains were 0 untypable.