Effect of Iron on Cytolysin A Expression in Salmonella enterica serovar Typhi

Jinghua Cui,Honghua Piao,Shen Jin,나희삼,홍영진,최현일,류필열 한국미생물학회 2009 The journal of microbiology Vol.47 No.4

Previously, a novel protein ClyA (Cytolysin A) has been identified in Escherichia coli K-12, Salmonella enterica serovars Typhi and Paratyphi A and Shigella. Salmonella spp. synthesize substantial amounts of ClyA upon infection of the human host, although the mechanism by which ClyA is induced in vivo is unclear. Since environmental signals could control the expression of virulence determinants, ClyA expression in S. Typhi Ty2 was tested by Western blotting in the presence of normal pooled human serum (NPS). The level of ClyA expression increased in the presence of NPS in a concentration-dependent manner. RPMI 1640 medium similarly induced ClyA expression. ClyA expression was inversely proportional to the concentration of iron in RPMI medium. Therefore, we speculated that iron inhibited the expression of ClyA in S. Typhi Ty2, and free iron depletion may be one of the causes of S. Typhi-mediated induction of ClyA in vivo. Transcription from a clyA-lacZ fusion gene decreased as iron concentration increased, but not as significantly as the ClyA protein expression. It is concluded that the regulatory effect of iron on clyA expression is mainly at translational level.

김진의 음악활동에 대한 사회학적 고찰

박경화 ( Jinghua Piao ),최옥화 ( Yuhua Cui ) 민족음악학회 2017 음악과 민족 Vol.0 No.53

Jin Zhen, a gayageum sanjo performer, has played a very important role in the field of Korean music in South and North Korea as well as in China. He has not only made a great contribution to the development of the Korean music, but also left a precious national musical legacy for the young generation of China`s Korean ethnic people in the field of gayageum playing and its theory. Without great passion and love for the Korean traditional folk music, Jin Zhen could have never risked his life to do such great performance and research in a rough political and social environment of forbidding traditional music study. And withouthis strong obligation and his anticipation to the development and the future of the folk music, all these could never happen. As a founder of the China`s Korean gayageum sanjo, Jin Zhen committed all his life to the development of Korean music education and the study of ethnic music theory. Meanwhile, He is admired and respected not only because of his noble character, broad mind and his loyalty to ethnic group, but also because of his love for his faculty and his students. In a word, the foundation of his life and his musical achievement is the coexistence of his passion for the national tradition, the spirit of seeking truth practically, and his persistence of cultural philosophical thinking. First of all, Jin Zhen has been a famous gayageum sanjo performer in North-Korea. He used to be a student of An Qiyu, a famous composer, in Pyongyang Music College. He developed a good friendship with An Qiyu who had given him a great influence on most musical activities and performance. Particularly, the development of the gayageum musical art in YanBian Universty and the development of traditional folk music education has been inseparable with the support of An Qiyu and other people. And as a gayageum sanjo educator, Jin Zhen paid much attention to the solution of the educational targets and emphasized in the yield of the gayageum talent training. Meanwhile, his clear view of education and his obligation has lay great foundation within developing new teaching materials. In addition, as a folk music theorist, Jin Zhen has left us so many articles and papers such as music criticism, music papers, travelling writings of music and so on. Jin Zhen is the only man who has disseminated gayageum sanjo to China. Besides, he has also played an important role in gayageum sanjo cultural exchanges between China and South Korea. He has made a great contribution to the talent training of the China`s Korean gayageum sanjo. He has also been confirmed as an An Qiyu`s gayageum sanjo disseminator, a folk musician and a contributor to the modern development of gayageum music in China. Meanwhile, Jin Zhen has inherited and continued An Qiyu`s gayageum sanjo as a vital yield in south-north musical exchange activities. He has showed a profound preoccupation with the folk music. Therefore, with preservation and development of the gayageum sanjo, the achievement of Jin Zhen will be a precious social cultural inheritance.

Molecular Cloning and Characterization of clyA Genes in Various Serotypes of Salmonella enterica

Lan Ji Huang,Jinghua Cui,Hong Hua Piao,홍영진,최현일,류필열 한국미생물학회 2010 The journal of microbiology Vol.48 No.5

Cytolysin A (ClyA) is a pore-forming hemolytic protein encoded by the clyA gene. It has been identified in Salmonella enterica serovars Typhi and Paratyphi A. To identify and characterize the clyA genes in various Salmonella enterica strains, 21 different serotypes of strains isolated from clinical specimens were presently examined. Full-length clyA genes were found in S. enterica serovar Brandenburg, Indiana, Panama, and Schwarzengrund strains by polymerase chain reaction amplification. The ClyA proteins from these four strains showed >97% amino acid identity to that of S. enterica serovar Typhi. Although all four serovars expressed detectable levels of ClyA as determined by Western blot analysis, they did not show a strong hemolytic effect on blood agar, indicating that ClyA may not be efficiently expressed or secreted. Escherichia coli transformed with clyA genes from the four serovars enhanced production of ClyA proteins and hemolytic activities to a level similar to S. enterica serovar Typhi ClyA. The present results suggest that ClyA may play a role in the pathogenesis of S. enterica serovar Brandenburg, Indiana, Panama and Schwarzengrund.

Optimization of recombinant Zea mays transglutaminase production and its influence on the functional properties of yogurt

Hongbo Li,Yanhua Cui,Lanwei Zhang,Lili Zhang,Hui Liu,Jinghua Yu 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.3

The requirements for the production of optimized Zea mays transglutaminase (TGZo) using Pichia pastoris GS115 (pPIC9K-tgzo) were optimized in this study. Plackett–Burman design was used to screen variables that significantly influence TGZo production. Oleic acid, methanol, and loading volume were identified as the most significant parameters. Central composite design was employed to determine the optimal level of these three parameters for TGZo production. Results showed that 1078 mU/mL of TGZo activity and 7.6 mg/L of TGZo production were obtained under conditions of 0.07% oleic acid, 1.31% methanol, and 7.36% loading volume. To explore the functional characteristics of TGZo, it was used in yogurt. It was found that the addition of TGZo could produce yogurt with stronger acid gel and higher consistency, cohesiveness, index of viscosity, and apparent viscosity than the untreated product. Therefore, TGZo can be used as a substitute for microbial transglutaminase in the yogurt, even in the food industry.

Effects of Biofilm Formation on The Antimicrobial Susceptibility of Staphylococcus aureus

Cho, Kyung-Jin,Jin, Shen,Cui, Jinghua,Yoon, Taek-Rim,Ryu, Phil-Youl 대한미생물학회 2008 Journal of Bacteriology and Virology Vol.38 No.4

Staphylococcus aureus induces chronic infection in form of biofilm that exists in the host cells and arthroplastic prosthesis surface. In this study, the biofilm formation ability of S. aureus clinically isolated from bacteremia patients, biofilm processing and relationship of resistance to antibiotics, and difference of biofilm formation ability on different prosthetic material surfaces were studied. All of them formed biofilm and especially 6 strains of S. aureus had high ability of biofilm formation. In addition, it was found that some strains with higher biofilm formation ability make more higher polysaccharide layer production. When S. aureus ATCC 25923 forms biofilm, minimal bactericidal concentration (MBC) of biofilm bacteria is more increased than that of the planktonic state bacteria about one thousand folds. Especially, after 6 hours from starting on biofilm formation, the resistance to antibiotics was increased by more than $256{\mu}g/ml$ of MBC to every antibiotics and after 8 hours prominent increase (more than $4096{\mu}g/ml$) was noted. Biofilm formation after bacterial adherence to plastic cover-slip was increased with time-dependent manner. Microcolonies were formed after 5 hours from a point that bacteria adhere to plastic cover-slip surface and after 6 hours biofilm was diffusely formed on entire surface, and then after 8 hours very thick biofilm was formed. Thicker biofilm was found on cobalt-chromium than titanium surface. These results suggest that titanium alloy materials are better than cobalt-chromium to minimize S. aureus biofilm formation on the arthroplastic material surface. Also, when microcolonies are formed after adherence of S. aureus to the arthroplastic material surface, resistance to antibiotics is starting.

소아 설사환자에서 분리된 장병원성 대장균의 분자생물학적 특성

김선영,조태형,최정화,황란희,최영륜,류필열 대한감염학회 2005 감염과 화학요법 Vol.37 No.6

목적 : 대장균은 대부분 비병원성이지만 일부는 사람과 어린 동물에서 다양한 장 질병과 설사 증상을 유발하는데, 특히 장병원성대장균(EPEC)은 영유아의 설사의 주된 원인균이다. 본 연구에서는 광주지역에서 분리되는 EPEC의 분자생물학적 특성을 조사하고자 하였다. 재료 및 방법 : 2003년 5월부터 8월까지 310명의 소아설사환자로부터 설사의 원인균으로 의심되는 EPEC 균주를 37개 검체에서 분리하여 병원성 유전자의 특성과 HEp-2 세포주에 대한 부착능 및 항균제내성양상을 조사하였다. 결과 : 병원성 유전자 중 eae 유전자를 보유한 35주의 대장균에서 bfp 유전자의 PCR 반응이 양성으로 나온 균주가 14주, east-l 유전자를 보유한 균주가 6주였다. 또한 4개의 균주는 hemolysin를 생성하였다. EPEC의 전형적인 부착형태인 LA pattern을 보인 균주는 2주에서만 관찰되고 LAL pattern을 보인 균주는 13주(37.1%)이었으며 20주(57.1%)는 DA pattern을 보였다. 분리된 EPEC의 균주는 eaeγ tir_(α)-espA_(α)-espB_(α)의 유전자형을 가진 균주가 7주(20.0%)로 가장 많았으며, 다음으로는 eae_(β) tir_(β) espA_(β) espB_(β)형이 6주(17.1%), eae_(β) tir_(α), espA_(α) espB_(α)및 eae tir_(α) espA_(α) espB_(α)이 5주(14.3%)로 많았다. 분리균주 중 1가지 이상의 항생제에 대해 내성을 갖는 균주는 27주(70.2%)였다. 특히 8가지의 항생제에 대한 다제내성을 보인 균주는 2주, 6가지 및 5가지 항생제에 대한 다제내성을 보인 균주는 각각 1주, 4가지 항생제에 대한 내성을 보인 균주는 5주였으며, 3가지 항생제에 다제내성을 보인 균주는 7주였다. 결론 : 광주지역에서 분리된 EPEC는 분자역학적 특성에서는 eaeγ-tir_(α)-espA_(α)-espB_(α)이 가장 많았으며 Hep-2 세포에 대한 부착양상은 다양하였다. 분리균주 75%에서 한가지 이상의 항생제에 내성을 가지고 있었으며 4가지 이상의 약제에 대제내성을 보인 균주는 28%였다. Background : Enteropathgenic Escherichia coli (EPEC) commonly causes infantile diarrhea in the developing countries. This study aims to find out the phenotypic and genotypic characteristics of EPEC in children with diarrhea in Gwangju city. Methods : We isolated 35 strains from the stool obtained from diarrheal patients and investigated the presence of various virulence genes, adherence patterns, hemolysis, and antibiotic resistance patterns. Results : All isolates were negative for the EPEC adherence factor (EAF) plasmid, and 14 isolates were bfpA-positive by PCR. The eae, tir, espA, and espB genes were analyzed by multiplex PCR. When the results of the four multiplex PCRs were analysed, we observed that the rate of the presence of eae_(γ)-tir_(α)-espA_(α)-espB_(α) was highest. The incidence of enteroaggregative E. coli heat- stable enterotoxin (east) was 17.1%. Analysis of Hep-2 cell adherence showed three adherence patterns : the localized adherence pattern, the diffuse adherence pattern, the localized adherence-like pattern. In hemolysin assay, four isolates produced enterohemolysin. The resistance rate of isolates against tetracycline, streptomycin, ampicillin, and rifampin was 56%, 39%, 34%, and 34%, respectively. All isolates were susceptible to ciprofloxacin and colistin. Conclusion : In our study, the rate of the presence of eae_(γ)-tir_(α)-espA_(α)-espB_(α) was the highest. Analysis of Hep-2 cell adherence showed various adherence patterns. Seventy-five percent of isolates were resistant to at least one antibiotic and 28% were resistant to four or more antibiotics.

Effects of Biofilm Formation on The Antimicrobial Susceptibility of Staphylococcus aureus

Kyung Jin Cho,Shen Jin,Jinghua Cui,Taek Rim Yoon,Phil Youl Ryu 대한미생물학회 2008 Journal of Bacteriology and Virology Vol.38 No.4