• 대한약학회:학술대회논문집
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• 대한약학회 2005년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.231-232
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• 2005

Bacteria of Shigella spp. are responsible for shigellosis in humans, a disease characterized by destruction of the colonic epithelium that is induced by the inflammatory response elicited by invasive bacteria. They use a type III secretion system injecting effector proteins into host cells to induce their entry into epithelial cells and triggers apoptosis in macrophages. We present evidence that the effector OspG is a protein kinase that binds various ubiquitinylated ubiquitin-conjugating enzymes (E2s) and blocks degradation of phospho-$I{\kappa}B{\alpha}$ induced upon entry of bacteria into epithelial cells. Transfection experiments confirmed that OspG interferes with the $NF-{\kappa}B$ activation patway by preventing phospho-$I{\kappa}B{\alpha}$ degradation, suggesting that OspG inactivates a component of the $SCF^{{\beta}-TrCP}$ ubiquitin ligase complex (E3) involved in phospho-$I{\kappa}B{\alpha}$ ubiquitination. Upon infection of ileal loops in rabbits, the ospG mutant induced a stronger inflammatory response compared with the wild-type strain, indicating that OspG down-regulates the host innate response induced by invasive bacteria.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.171-178
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• 2017

A series of novel effector molecules secreted by the type three secretion system (T3SS) of Shigella spp. have been reported in recent years. In this study, a proteomic approach was applied to study T3SS effectors systematically. First, proteins secreted by the S. flexneri wild-type strain after Congo Red induction were separated and identified using two-dimensional electrophoresis to display the relative abundance of all kinds of early effectors for the first time. Then, a gene deletion mutant of known virulence repressor (OspD1) and a gene overexpressed mutant of two known virulence activators (MxiE and IpgC) were constructed and analyzed to discover potential late effectors. Furthermore, the supernatant proteins of gene deletion mutants of two known translocators (IpaB and IpaD), which would constantly secrete effectors, were also analyzed. Among all of the secreted proteins identified in our study, IpaH1.4, IpaH_5, and IpaH_7 have not been reported before. These proteomics data of the secreted effectors will be valuable to understand the pathogenesis of S. flexneri.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.106-113
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• 2002

One-hundred and twenty-four trimethoprim-resistant Shigella sonnei isolates extracted in Korea during the last two decades were investigated for their epidemiological relationship and mechanisms of resistance to trimethoprim. The S. sonnei isolates were distributed into two groups by three different epidemiological tools: biotyping, antibiogram, and pulsed-field gel electrophoresis. One group contained the isolates from the 1980s and the other group included the isolates from the 1990s. The geometric mean MICs of trimethoprim in S. sonnei isolates from the 1980s and 1990s were found to be $672.9{\mu}g/ml\;and\;>2,048{\mu}g/ml$, respectively. Trimethoprim resistance was associated with dfrA5, dfrA12, and dfrA13 genes in the isolates from the 1980s, dfrA1, dfrA5, and dfrA12 in the isolates from 1991, and dfrA1 and dfrA12 in the isolates from 1992 to 1999. The dfrA1 gene was located downstream of the intI2 gene in Tn7, which was located on chromosome. Some dfrA12 genes were found as gene cassettes in the class 1 integron. The dfrA5 and dfrA13 genes were located on conjugative plasmids. These results suggested that a clonal change occurred in S. sonnei isolates in Korea during the last two decades and that dfr genes located on different transposable genetic elements had gradually changed.

• Journal of Preventive Medicine and Public Health
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• 제38권4호
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• pp.420-424
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• 2005

Objectives : A few culture-confirmed cases of S. sonnei have been notified from Korean hospitals. The source of epidemic can't be firmly determined in such cases because of the rarity of this illness in the local communities and the timing of the outbreaks. The objective of this study is to estimate the source of epidemic by investigating the patients' lifestyles. Methods : Alibi verification was used to access the presumed source of the epidemic. PCR (Polymerase Chain Reaction) was used to rapidly detect the genes of Shigella in water specimens. Results : The common lifestyle trait among the Shigella infected patients was connected with Mt. Martyr in J city, Korea. The first patient's son had gone on a pilgrimage to Mt. Martyr with 41 friends and he had only eaten rice cakes on April 5th; the second patients had visited Mt. Martyr with their mother for a picnic on April 12th; the third patient had visited Mt. Martyr with 22 friends for a pilgrimage and the patient had only drunk holy water on April 13th. Therefore, the holy water of Mt. Martyr was reckoned to be the source of the epidemic. PCR detected the genes of Shigella two days before the S. sonnei was confirmed. Conclusion : The patients' lifestyles for 7 days before the onset of symptoms should be determined in terms of time, place and contacted people to find the source of infection when cases with food poisoning are seen in the hospital setting.

• 대한미생물학회지
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• 제21권1호
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• pp.33-45
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• 1986

On hundred and forty stains of shigella cultures isolated from the twelve hygiene laboratories of cities and provincial general hospital laboratories in 1983 were tested for their resistance to thirteen antimicrobial drugs and their R-plasmid transfer. Antimicrobial drugs were used amikacin, ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, nalidixic acid, rifampicin, streptamycin, tetracycline, tobramycin, cefoperazone and piperacillin. All strains were resistant to one or more of thirteen antimicrobial drugs but 94.3% were susceptible to amikacin, gentamicin and tobramycin of total isolated. The most strains commonly found resistance was to chloramphenicol (94%) followed by streptamycin (93%), tetracyline (92%) piperacillin (90%) ampicillin (83%), cefoperazone (42%), nalidixic acid (14%), cephalothin (17%), rifampicin (22%) and kanamycin (6%), sixty percent of strains among 140 were resistance to ampicillin, chloramphenicol, streptomycin, tetracycline at the same time. The transfer of drug resistance by conjugation was tested and ninety four strains (94.3%) were resistant to one or more drugs were found to transfer their drug resistance of E. coli. percentage of transfer frequency by conjugation was one strains (54%), the transfer frequency of drug resistance varied by donor strains and recipients, but not by selecting drugs. Resistance to nalidixic acid was not transferred by conjugation to recipients. Percentage of plasmid curing after the treatment of acriflavine, acridine orange was about 8%. Among strains cured two strains were tested compare original strains with them in biochemical properties in arginine dihydrolase and arabinose fermentation reaction. It was found to growth curves of No.2 shigella flexneri, serotype 1b, and its derivatives cured with acriflavine in $M{\ddot{u}}ller$ Hinton broth medium (pH 7.4, $38^{\circ}C$) by temperature Gradient Biophoto Recorder TN-1120 (Tokyo, Japan).

• 대한미생물학회지
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• 제14권1호
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• pp.17-25
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• 1979

Bacteriologic diagnosis of enteric infection remains to be an important role of clinical laboratory because of the prevalence of the infection. Often the determination of etiologic agent and its susceptibility to antibiotics are of vital importance for a proper management of the infection. In our previous paper, an analysis of the isolation of enteric pathogens for the years 1969-73 was reported to clarify the status of those years. The present analysis was made based on the data obtained during the years 1974-78, to see if any change of the status was rendered. 1. During the 5-year period, from the cultures of 7,308 stool or rectal specimens 833 patients yielded enteric pathogens: 468 Shigella, 295 Salmonella, 30 Vibrio parahaemolyticus and 40 enteropathogenic Escherichia coli(EPEC). 2. Of the 295 Salmonella, 271 were S. typhi Isolation of 12 S.paratyphi-A, 1 Salmonella group B, 4 group C, 5 group D and 2 group E meant a definite increase of these sero-groups, S. typhi was most frequently isolated in August and in December, and from 30- to 39-year-old patients. 3. Of the 468 Shigella, 10 were subgroup A, 338 subgroup B, 3 subgroup C and 117 subgroup D. Most of the subgroup B belonged to type 1,2, or 3. The proportion of S. sonnei decreased from 31.3% in 1974 to 18.2% in 1978. In foreign patients, S. sonnei remained to be the frequntly isolated species. Shigella isolation was frequent in August and in 2- to 5-year-old patients. 4. V. parahaemolyticus was isolated from 30 and EPEC from 40 patients. 5. Ninty-nine per cent and 99.5% of the S. typhi isolates were susceptible to chloramphenicol and to ampicillin respectively. 92.8% of S sonnei were susceptible to ampicillin. S. flexneri type 2 was notable for their markedely decreased proportion being susceptible to ampicillin: 84.4% in 1974 and 25.6% in 1978.

• 대한미생물학회지
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• 제14권1호
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• pp.1-9
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• 1979

A bacteriological survey was carried out to get hold of the distribution of pathogenic enteric bacteria in Korea. The total number of 2,013 specimens were obtained from various sources; 1,407 specimens from marine products circulated in the markets, sewage, and 606 rectal swabs from persons. All the specimens were collected in Seoul, Chumunjin(Kangwondo), and Gwangcheon(Chungcheongnam-do) during 1978. The isolation and identification of enteric pathogens from the specimens were performed by means of bacteriological studies. 1. The isolation rates of the pathogenic enterobacteria among the total 2,013 specimens are as follows: Salmonella species 0.05%(1 strain), Shigella species 0.50%(10 strains), and Vibrio parahaemolyticus 0.35%(7 strains). 2. One salmonella strain was isolated from marine products circulated in the market in Seoul. Its serotype was identified as group $C_1$. 3. Ten shigella strains were isolated from various sources: 0.45% from natural environments and 0.05% from rectal swabs. The distribution of shigella serotype was identified as Sh. boydii 90%(9 strains), Sh. sonnei 10%(1 strain). 4. Seven strains of V. parahaemolyticus were isolated from natural environments. In addition, 40 strains of halophilic vibrios nontypable with anti-K antisera were also isolated. Of the 7 strains, the 2 strains were agglutinated with type K-32, each 1 strain of the others with K-17, K-19, K-36, K-39, K-56.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1457-1462
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• 2010

Three types of serotypically atypical Shigella flexneri isolates were collected between 2007 and 2008 from Korean patients at the Korea National Institute of Health (NIH). These atypical isolates were characterized and compared with serologically typical S. flexneri. The first grouping of 11 atypical isolates displayed agglutination only with polyB antiserum and exhibited no reaction with any typing or grouping sera (PolyB:un). The second group of 3 isolates displayed reactions with typing sera IV, but also did not bind with any grouping sera (IV:un). The third group of 14 isolates exhibited a plural agglutination pattern, reacting with typing sera II, and two grouping sera (II:(3)4,7(8)). Amongst these atypical isolates, isolates belonging to IV:un and II:(3)4,7(8) exhibited greater antibiotic resistance, in particular to ampicillin, streptomycin, and trimethoprim-sulfamethoxazole, than typical S. flexneri strains. Furthermore, all II:(3)4,7(8) strains harbored integrons. This study suggests that these multiple antibiotic-resistant atypical S. flexneri are new subserotypes of S. flexneri that await further serological classification.

• 동아시아식생활학회지
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• 제21권2호
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• pp.272-276
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• 2011

본 연구에서는 과거부터 민간이나 한방에서 널리 사용되어져 온 백작약의 식중독 유발 세균에 대한 항균 활성을 조사해 보고자하였다. 백작약을petroleum ether. chloroform, ethylacetate 및 methanol의 4가지 유기용매 및 열수에 추출하고, Gram(+)세균인 Staphylococcus. aureus 및 Staphylococcus. epidermidis와Gram(-)세균인 Salmonella typhimirium, Salmonella paratyphimirium, Shigella dysenteriae, Shigella flexneri, Shigella sonnei 및 Pseudomonas aeruginosa에 대한 성장 억제 실험을 해 본 바, 백작약의 methanol 추출물이 10 mg/mL 농도에서 Salmonella typhimurium에 대해 가장 높은 항균력을 나타내었다. Staphylococcus aureus에 대한 항균력은 백작약의 ethylacetate 추출물이 5 mg/mL에서 가장 큰 항균 효과를 보였으며, 액체 배지에 배양한 경우 5~10 mg/mL 농도에서 18시간까지 성장 억제 효과가 나타났다.

• 한국자원식물학회지
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• 제18권1호
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• pp.198-206
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• 2005

애완견의 털에 부착되어 있는 세균을 분리 동정한 후, 이 분리 세균들에 대한 항세균효과가 있는 생약재 추출물을 탐색하였다. 애완견의 털에서 76개의 세균을 분리한 결과, Staphylococcus속이 41균주로 가장 많았으며 그 다음으로 Micrococcus속이 21균 주, Enterococcus속이 8균주, Bacillus속이 3균주, Exiguobacterium속 of 2균주, Shigella속과 Zoogloea속이 각각 1균주씩으로 동정되었다. 이러한 결과는 개의 털에 존재하는 세균들이 사람에게 감염을 일으킬 수 있는 원인이 될 수 있음을 시사한다. 분리균주들에 대한 항생제 저항성과 생약재 추출물의 항세균 활성은 디스크 확산법으로 확인하였다. 황금의 추출물이 애완견의 털로부터 분리한 세균들에 대해 높은 항세균 활성을 나타내어 항생제 저항성이 있는 세균들에 대한 새로운 항미생물제로 사용학 수 있을 것으로 기대된다.