• Biomolecules & Therapeutics
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• v.13 no.2
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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.

• Biomolecules & Therapeutics
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• v.11 no.3
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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.

• Korean Journal of Microbiology
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• v.29 no.3
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• pp.199-202
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• 1991

The O serotypes of uropathogenic Escherichia coli isolated in Korea were studied using a complete set of rabbit O antisera raised with reference O antigen type strains of E. coli. The distribution of "O" serotypes found in this survey was grossly similar with the prevalence of "O" types observed in other parts of the world, and some differences were also noted. A total of 31 "O" serotypes were identified and the most frequent serotype associated with urinary tract infections was O75(11.5%), which was followed by O6(7.4%), O10 and O40(5.7%, respectively).0 and O40(5.7%, respectively).

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.552-559
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• 2003

The FimH subunit of type 1-fimbriated Escherichiu coli (E. coli) has been determined as a major cause for urinary tract infections. Thus, to produce a possible vaccine antigen against urinary tract infections, the fimIH gene was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. A fusion protein, based on fusing adhesin to the cholera toxin subunit A2B (CTXA2B), was induced with 0.01 mM isopropyl-${\beta}-D-thiogalactoside$ (IPTG) for 4 h at $37^{\circ}C$ to yield a soluble fusion protein. The fusion protein was then purified by affinity chromatography. The expressed fusion 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 also analyzed. The orderly-assembled fusion protein was confirmed by a modified $G_{Ml}-ganglioside$ ELISA, using antibodies to adhesin. The results indicated that the purified fusion protein was an adhesin/CTXA2B protein containing E. coli adhesin and the $G_{Ml}-ganglioside$ binding activity of CTXB. Accordingly, this adhesin/CTXA2B protein may be a potential antigen for oral immunization against uropathogenic E. coli.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.2
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• pp.105-110
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• 2021

Objective: Uropathogenic Escherichia coli is known to cause urinary tract infections, and the endotoxin (lipopolysaccharide [LPS]) of this bacterium may cause deficiencies of sperm quality and morphology. In the present study, the effects of LPS on mouse sperm were studied, and the levels of interleukin (IL)-17A and possible changes in testis tissue were evaluated. Methods: LPS of uropathogenic E. coli was extracted using the methanol-chloroform method, followed confirmation using sodium dodecyl sulfate-polyacrylamide electrophoresis. Purified LPS (100 ㎍/kg) or phosphate-buffered saline was injected intraperitoneally into BALB/c mice for 7 days consecutively in the test and control groups, mice were sacrificed on days 3, 7, and 42 after the first injection. Blood was tested for levels of IL-17A using the enzyme-linked immunosorbent assay method. Testis tissue and sperm were collected from each mouse and were studied according to standard protocols. Results: The mean sperm count and motility significantly decreased (p=0.03) at 3, 7, and 42 days after the injections. The level of IL-17A in the test groups increased, but not significantly (p=0.8, p=0.11, and p=0.15, respectively). Microscopic studies showed no obvious changes in the morphology of the testis tissue; however, significant changes were observed in the cellular parenchyma on day 42. Conclusion: LPS can stimulate the immune system to produce proinflammatory cytokines, resulting in an immune response in the testis and ultimately leading to deficiency in sperm parameters and testis tissue damage. In addition, the presence of LPS could significantly impair sperm parameters, as shown by the finding of decreased motility.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.137-142
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• 2015

Trimethoprim-sulfamethoxazole (TMP-SMX) has been used for the treatment of urinary tract infections, but increasing resistance to TMP-SMX has been reported. In this study, we analyzed TMP-SMX resistance genes and their relatedness with integrons and insertion sequence common regions (ISCRs) in uropathogenic gram-negative bacilli. Consecutive nonduplicate TMP-SMX nonsusceptible clinical isolates of E. coli, K. pneumoniae, Acinetobacter spp., and P. aeruginosa were collected from urine. The minimal inhibitory concentration was determined by Etest. TMP-SMX resistance genes (sul and dfr), integrons, and ISCRs were analyzed by PCR and sequencing. A total of 45 E. coli (37.8%), 15 K. pneumoniae (18.5%), 12 Acinetobacter spp. (70.6%), and 9 Pseudomonas aeruginosa (30.0%) isolates were found to be resistant to TMP-SMX. Their MICs were all over 640. In E. coli and K. pneumoniae, sul1 and dfr genes were highly prevalent in relation with integron1. The sul3 gene was detected in E. coli. However, in P. aeruginosa and Acinetobacter spp., only sul1 was prevalent in relation with class 1 integron; however, dfr was not detected and sul2 was less prevalent than in Enterobacteriaceae. ISCR1 and/or ISCR2 were detected in E. coli, K. pneumoniae, and Acinetobacter spp. but the relatedness with TMP-SMX resistance genes was not prominent. ISCR14 was detected in six isolates of E. coli. In conclusion, resistance mechanisms for TMP-SMX were different between Enterobacteriaceae and glucose non-fermenting gram-negative bacilli. Class 1 integron was widely disseminated in uropathogenic gram-negative baciili, so the adoption of prudent use of antimicrobial agents and the establishment of a surveillance system are needed.

• Biomedical Science Letters
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• v.28 no.2
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• pp.127-136
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• 2022

Uropathogenic Escherichia coli (UPEC) is main causative agent of urinary tract infections. They are classified based on various types of O antigen. UPEC strains commonly possess many genes encoding virulece-associated factors. E. coli strains are generally divided into four main phylogenetic groups. The virulence factor (VF) profiles of UPEC are related with their O-serogroups in each strains. A total of 681 strains of UPEC clinical isolates were collected from Korean healthcare facility (1989: 123 strains and 2010-2014: 558 strains). The UPEC clinical isolates were analyzed by polymerase chain reaction (PCR) methods. A total of 14 O-serotypes (O1, O2, O4, O6, O7, O8, O15, O16, O18, O21, O22, O25, O75 and O83), 6 virulence factors (papC, fimG/H, sfaD/E, hly1, cnf1 and usp) and phylogenetic groups were identified. The most prevalent O-serogroups were O6 (11.1%) in 1989 UPEC strains and O25 (21.0%) in 2010-2014 UPEC strains. The identified VFs, phylogenetic groups in 1989 UPEC strains and 2010-2014 UPEC strains were fimG/H and B2 group. In this study, O6 serotype was revealed the close relationships with VFs. Also, the distribution of prevalence O-serogroups of UPEC has been changed from O6 to O25 and virulence of UPEC strains was increased during past twenty-one years.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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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.

• Biomedical Science Letters
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• v.26 no.2
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• pp.120-126
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• 2020

Fluoroquinolone (FQ) resistant uropathogenic Escherichia coli (UPEC) have become a major problem in urinary tract infections (UTIs). The purpose of this study was to compare the quinolone resistance-determining region (QRDR) and plasmid mediated quinolone resistance (PMQR) determinants of FQ resistant UPEC between 1989 and 2010-2014. A total of 681 strains of UPEC clinical isolates was collected from Korean healthcare facility in 1989 (123 strains) and in 2010-2014 (558 strains). The minimum inhibitory concentrations (MICs) of FQs were determined by agar dilution method. QRDRs (gyrA, gyrB, parC and parE) and PMQR determinants (qnrA, qnrB, qnrS, aac(6')-Ib-cr and qepA) were analyzed polymerase chain reaction and sequencing method. Among 681 isolates, FQ resistant UPEC were 3 strains (2.4%) in 1989 isolates and 220 strains (39.4%) in 2010-2014 isolates. The rate of the FQ resistant UPEC strains in 2010-2014 isolates was increased than that of in 1989 isolates. UPEC isolates from 1989 and 2010-2014 were shown to carry mutations in gyrA (Ser83 and Asp87), gyrB (Ser464 and Thr469), parC (Ser80 and Glu84) and parE (Glu460, Ser458, Ile464 and Leu445). The most common mutations of QRDRs in 1989 isolates were Ser83Leu and Asp87Gly in gyrA and Ser80Ile in parC (2 strains: 66.7%) while those in 2010-2014 isolates were Ser83Leu and Asp87Asn in gyrA and Ser80Il2 and Glu84Val in parC (88 strains: 40.0%). PMQR determinants were detected only in 2010-2014 UPEC strains (47 strains: 21.4%).

• Journal of Microbiology and Biotechnology
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• v.23 no.3
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• pp.422-429
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• 2013

The aim of this study was to investigate the characteristics of canine uropathogenic Escherichia coli (UPEC) and the interaction between canine UPEC and human bladder epithelial cells. Ten E. coli isolates collected from dogs with cystitis were analyzed for antimicrobial resistance patterns, the presence of virulence factors, and biofilm formation. The ability of these isolates to induce cytotoxicity, invade human bladder epithelial cells, and stimulate an immune response was also determined. We observed a high rate of antimicrobial resistance among canine UPEC isolates. All virulence genes tested (including adhesins, iron acquisition, and protectin), except toxin genes, were detected among the canine UPEC isolates. We found that all isolates showed varying degrees of biofilm formation (mean, 0.26; range, 0.07 to 0.82), using a microtiter plate assay to evaluate biofilm formation by the isolates. Cytotoxicity to human bladder epithelial cells by the canine UPEC isolates increased in a time-dependent manner, with a 56.9% and 36.1% reduction in cell viability compared with the control at 6 and 9 h of incubation, respectively. We found that most canine UPEC isolates were able to invade human bladder epithelial cells. The interaction between these isolates and human bladder epithelial cells strongly induced the production of proinflammatory cytokines such as IL-6 and IL-8. We demonstrated that canine UPEC isolates can interact with human bladder epithelial cells, although the detailed mechanisms remain unknown. The results suggest that canine UPEC isolates, rather than dogspecific pathogens, have zoonotic potential.