• 대한의생명과학회지
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• 제2권1호
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• pp.31-40
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• 1996

비뇨기계 병원성 대장균의 중요한 병원성 인자 중의 하나로 인정되고 있는p-fimbriae의 subtype의 분포를 확인하기 위하여 요로감염증으로 확진된 환자의 혈청을 이용하여 immunoblotting 을 실시하였고, 이와 동시에 효소면역 측정법을 실시하여 p-fimbriae특이 항체 보유를 확인하였다. Immunoblotting 결과 우리나라 요로감염증환자에서 높은 빈도로 확인되는 p-fimbriae subtype의 분포는 $F7_1$34(56.7%), $F7_2$28(46.7%), F13 30(50%)등이 높게 나타났으며, 이와 같은 결과는 효소면역측정법에서도 동일하게 나타났다. 그러나 P-pili를 순수분리하지 않고 whole cell을 이용한 효소면역 측정법은 교차반응 때문에 비뇨기 감염증의 혈청학적인 진단에 적합하지 않는 것으로 나타났다. 또 우리 나라의 요로감염 환자에서 항체 양성율이 높은 $F7_1$, $F7_2$, F13만을 혼합하여 항원으로 이용한 효소면역측정법의 특이도와 민감도가 각각 92.6%, 90%로 나타나, 이와 같은 방법을 임상진단에 응용할 수 있을 것으로 판단되었다.

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.283-292
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• 2022

Colibactins (clb) and Cytotoxic Necrotizing Factors (cnf) are virulence factors that impact cell cycle through cellular differentiation, proliferation, and apoptosis. Urinary tract infections (UTIs) are the most common among type of infection among outpatients, with a lifetime incidence of about 60-65% in adult females. Here, we sought to isolate uropathogenic Escherichia coli (UPCE) from urine specimens and investigates the prevalence of clb A, B and cnf 1, 2 genes among these isolates. A total of 110 E. coli isolates were collected from patients with UTIs. All the isolates were examined for their hemolytic activity and only 46 isolates showed a halo zone of hemolysis on blood agar. The collected UPEC isolates were screened for the existence of clb A, B and cnf genes. The results revealed that out of 110 isolates, 28 harbored the clbA gene, 40 harbored clb B, and 24 isolates harboured cnf1. 13 isolates harbored clbA, clbB, and cnf1 genes, while no cnf2 gene was detected among isolates. The molecular detection revealed that 8 out of 28 hemolytic isolates carrying the clbA, 11 out of 40 were carrying clbB, 1 out of 24 were carrying cnf 1, and 5 out of 9 carrying clbA+clbB. Furthermore, 7 out of 13 isolates were hemolytic and carrying clbA, clbB, and cnf1 genes. Finally, we investigated the cytotoxicity of E. coli harboring clb and cnf genes, eukaryotic REF cells were exposed to E. coli producing colibactin, which induces DNA damage and leads to cell cycle arrest, senescence and death.

• Biomolecules & Therapeutics
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• 제11권3호
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• pp.157-162
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• 2003

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 ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimHIctxa2b 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 western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was analyzed. 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/CTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of CTXB. This study also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin/CTXA2B chimeric protein might be a potential antigen for oral immunization against UPEC.

• 대한의생명과학회지
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• 제18권2호
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• pp.146-151
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• 2012

Urinary tract infection (UTI) is one of the most common bacterial infections and is predominantly caused by uropathogenic Escherichia coli (UPEC). UPEC strains generally possess several genes encoding virulent factors, which are mostly adhesins, toxins, bacteriocin and siderophores. E. coli is composed of four main phylogenetic group (A, B1, B2, D) and virulent extra-intestinal strains mainly belong to groups B2 and D. Prescription of ciprofloxacin, a kind of fluoroquinolone group antibiotics, is increasing now a days, but resistance to this drug is also increasing. A total of 188 strains of E. coli were collected. Thirteen strains were collected from healthy students in 2011 and 175 strains from patients with urinary tract infection in 2010. Virulence factor genes (papC, fimG/H, sfaD/E, hlyA, cnf1, and usp) were amplified by polymerase chain reaction (PCR) methods for phylogenetic group (A, B1, B2, D) detection. Ciprofloxacin susceptibility test was performed by disk diffusion method. The identified virulence factors (VFs), phylogenetic groups and ciprofloxacin resistance in 13 E. coli strains isolated from healthy students were papC (15.4%), fimG/H (76.9%), sfaD/E (30.8%), hlyA (23.1%), cnf1 (23.1%), usp (7.7%), phylogenetic group A (23%), B1 (8%), B2 (46%), D (23%) and ciprofloxacin resistance (7.7%), while those of in 175 E. coli strains isolated from patients with UTI were papC (41.1%), fimG/H (92.5%), sfaD/E (30.3%), hlyA (10.3%), cnf1 (30.3%), usp (27.4%), phylogenetic group A (9.1%), B1 (5.1%), B2 (60.6%), D (25.1%) and ciprofloxacin resistance (29.7%). In this study, 10 out of 13 E. coli strains (76.9%) from healthy students were found to possess more than one virulence factor associated with adhesion. In addition, one E. coli strain isolated from healthy students who had never been infected with UPEC showed ciprofloxacin resistance. According to these results between the virulence factors and phylogenetic groups it was closely associated, and UPEC strains isolated from patients showed high level of ciprofloxacin resistance.

• Pediatric Infection and Vaccine
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• 제22권3호
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• pp.194-200
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• 2015

목적: 요로감염은 소아에서 흔한 세균 감염이며, Escherichia coli가 주요 원인균이다. 본 연구는 우리나라에서 소아 요로감염을 일으키는 E. coli의 계통 분류와 독성인자를 분석하고자 하였다. 방법: 2010년 10월부터 2013년 4월까지 요로감염으로 입원한 33명의 소아 환자로부터 검출된 E. coli균주를 대상으로 하였다. 중합효소연쇄반응을 통해 E. coli의 계통 분류 및 5가지 독성인자(fimH, sfa, papA, hylA, and cnf1)를 조사하였다. E. coli의 분자유전학적 특징을 환자의 임상적 진단과 동반된 방광요관 역류에 따라 분석하였다. 결과: 대부분의 요로병원성 E. coli 는 계통 분류에서 B2군(84.8%)에 속했으며, 나머지는 모두 D군(15.2%)에 해당되었다. 독성인자는 fimH (100%), sfa (100%), hylA (63.6%), cnfI (63.6%), 그리고 papA (36.4%)의 분포를 보였다. 임상 진단에 따른 계통 분류에서 급성 신우신염의 경우 B2군이 92.3%, D군이 7.7%를 나타냈으며, 방광염에서는 B2군에서 57.1%, D2군은 42.9%였다. 독성인자는 양 군에서 비슷하게 분포하였다. 급성 신우신염에서 방광요관 역류의 유무에 따른 계통 분류의 분포에는 차이가 없었으나, 독성인자의 경우 papA 유전자가 방광요관 역류가 동반되지 않은 군에서보다 방광요관 역류 군에서 적게 나타났다(43.8% vs. 20.0%, P=0.399). 결론: 본 연구는 국내 소아 요로감염의 원인 E. coli 균주의 분자유전학적 역학 자료를 제시하였으며, 이 결과는 향후 소아 요로감염의 발생 기전을 이해하는 데 기초가 될 것으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1643-1649
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• 2016

The aims of this study were to characterize the molecular epidemiological profiles of CTX-M-producing uropathogenic Escherichia coli isolates from a tertiary hospital in Daejeon, Korea, and to investigate the genetic diversity and compare the prevalence of sequence types (STs) in different areas. Extended spectrum β-lactamase-producing E. coli strains isolated from urine were analyzed for CTX-M, integrons, and insertion sequence common regions (ISCRs) by PCR and sequencing. Multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), phylogenetic analysis, and rep-PCR were also used for molecular typing of the isolates. Of 80 CTX-M producers, 31 and 46 expressed CTX-M-15 and CTX-M-14, respectively. MLST analysis indicated that the most prevalent ST was ST131 (n = 34, 42.5%), followed by ST38 (n = 22, 27.5%), ST405 (n = 8, 10.0%), and ST69 (n = 6, 7.5%). Most CTX-M producers harbored class 1 integrons. ST131 strains belonged to phylogenetic group B2 and showed identical rep-PCR patterns, whereas ST69, ST38, and ST405 strains belonged to phylogenetic group D; the ST38 and ST405 strains displayed the same rep-PCR pattern, respectively. ST131 and ST38 isolates showed 21 and 19 distinct types, respectively, by PFGE. In Daejeon, D-ST38 CTX-M-14 producers were relatively more prevalent than in other countries and Korean cities. Our results indicate that CTX-M-producing E. coli isolates belonged mostly to ST131 or ST38 and were more related to hospital-onset than to community-onset infections and that the bla_CTX-M gene may vary according to the ST.

• 대한임상검사과학회지
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• 제52권4호
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• pp.342-348
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• 2020

전 세계적으로 요로감염은 사람에서 가장 흔한 감염 질환 중 하나로, 요로병인성 E. coli는 요로감염의 주요 원인균이다. 요로병인성 E. coli는 많은 항균제에 대한 내성이 점차 증가하고 있어, 최근 요로감염의 항균제 치료에 큰 우려를 낳고 있는 실정이다. 본 연구는 2017년 3월부터 12월까지, 대전지역의 요로감염 환자에서 분리된 요로병인성 E. coli 84 균주를 대상으로 역학관계와 항균제 내성 양상을 조사하였다. 역학 관계를 확인하기 위해 다좌위 서열 형별분석(MLST)를 실시하였고, 항균제 감수성 시험은 E-test법으로 확인하였다. 본 연구 결과, 요로감염은 남성(26.2%)보다 여성(73.8%)에서 더 흔한 분포를 보였고, 70대가 가장 높은 분포의 연령대로 확인되었다. 84 균주의 요로병인성 E. coli 중, 59 균주(70.2%)가 다제내성이었으며, 주요 seqeunce type은 ST131 (44 균주, 52.4%)임을 확인하였다. 흥미롭게도, non-ST131에서 다제내성의 비율(72.5%)이 ST131 (68.2%)보다 더 높은 결과를 확인하였다. 이러한 연구결과는 non-ST131에서의 다제내성의 발달과 확산 가능성을 의미하는 것으로 해석된다. 다제내성 non-ST131의 출현과 국제적인 확산을 예방하기 위해, 전 세계적으로 효과적인 감시 체계와 지속적인 연구가 수행되어야 할 것으로 사료된다.

• 대한미생물학회지
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• 제22권3호
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• pp.241-250
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• 1987

A total 64 strains of Escherichia coli including 38 strains of urinary tract infection and 26 strains from other clincal sources were studied for several properties related to the virulence markers of organisms. Urinary isolates(76.3%) showed higher frequency of mannose resistant hemagglutination(MRHA) wi th human erythrocytes(A type, $Rh^+$) than the strains of control group isolated from other sources(34.6%). Seventeen strains(44.4%) of urinary isolates and 2 strains(7.7%) of control group showed hemolysis on blood agar plate. There was no significant difference in MIC's of 23 drugs between both groups of urinary isolates and control group. But they showed high frequency of resistance to ampicillin, carbenicillin, piperacillin, kanamycin, and trimethoprim, but were very susceptible to cefotaxime, moxalactam, ceftizidime, imipenem, and norfloxacine. Fourteen strains(36.8%) of urinary isolates and 10 strains(38.5%) of control group showed conjugally transferable resistance conferred to R plasmids. The urinary isolates carried one or more to 6(mean 3.4) plasmids of approximate molecular weight ranged 3.1 to 94 megadalton(Mdal) and strains of control group carried 2 to 5(mean 3.8) plasm ids of size ranged 3.6 to 130 Mdal. The size of conjugally transferable R plasmid identified with transconjugants ranged 32 to 130 Mdal.

• 대한의생명과학회지
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• 제19권3호
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• pp.275-279
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• 2013

Etiological agents of extended spectrum ${\beta}$-lactamase (ESBL) producing uropathogenic Escherichia coli (UPEC) have become a major problem in urinary tract infections. The purpose of this study was to compare the molecular characteristics of ESBL producing UPEC strains isolated from 1989 and 2010. A total of 301 strains of UPEC clinical isolates was collected from Korean healthcare facility in 1989 (126 strains) and in 2010 (175 strains). UPEC clinical isolates were analyzed by multiplex polymerase chain reaction method (ESBL related bla genes and phylogenetic groups) and amplified fragment length polymorphism (AFLP). Among 301 isolates, ESBL producing UPEC were 8 strains (6.3%) in 1989 isolates and 35 strains (20%) in 2010 isolates. The rate of bla genes in ESBL producing UPEC from 1989 isolates and 2010 isolates were $bla_{TEM}$ (75% and 85.7%), $bla_{CTX-M}$ (0% and 91.4%), $bla_{OXA}$ (25% and 20%), $bla_{PER}$ (0% and 2.9%). The distribution of phylogenetic groups in 1989 isolates and 2010 isolates were A (37.5% and 11.4%), B2 (12.5% and 51.4%), and D (50% and 37.1%). The most prevalent ESBL related bla gene and phylogenetic group were $bla_{CTX-M}$ (91.4%) and B2 (51.4%) in 2010 isolates, while $bla_{CTX-M}$ was not detected in 1989 isolates. Among 43 ESBL producing UPEC were grouped into 12 clusters up to 76% of genetic similarities by AFLP analysis. During past twenty one years, the rate of the ESBL producing UPEC strains in 2010 isolates was increased than that of in 1989 isolates. Also, the most prevalent ESBL related bla gene has been changed from $bla_{TEM}$ to $bla_{CTX-M}$.

• Preventive Nutrition and Food Science
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• 제9권1호
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• pp.29-33
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• 2004

Cranberries have long been used by lay people to relieve the symptoms of urinary tract infections. Recent research has determined that the component of cranberry called proanthocyanidin (PAC) is the primary mechanism for inhibiting P-fimbriated E.coli adhesion to uroepithelial cells in vitro. A series of experiments were performed to determine the effects of PAC on growth and adhesion of uropathogenic E. coli and Staphylococcus aureus to urinary catheter material. The results showed that PAC-inhibited binding of Gram positive S. aureus to collagen coated surfaces and significantly decreased the growth of these bacteria. P-fimbriated E.coli did not bind well to the biomaterial and their growth was unaffected by the cranberry extract with the exception of some loss in viability at 1000 $\mu\textrm{g}$/mL after 5 to 18 hours of exposure. This is the first report of the potential for cranberries to interfere with the adhesion and growth of S. aureus, a multi-drug resistant organisms responsible for morbidity and mortality especially in hospitalized patients.