• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.135-139
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• 2014

Pathogenic E. coli associated post-weaning diarrhea (PWD) and edema disease are common diseases in commercially-housed weanling pigs. An enterotoxigenic E. coli (ETEC) oral challenge model has been used to mimic the physiological responses observed in commercial conditions. However, an oral challenge procedure has two major limitations: (1) the ETEC cell density is unknown at the point of oral inoculation, and (2) blending ETEC with traditional TSB (trypticase soy broth) is not palatable and hence decreases acceptability by piglets. Therefore, the purposes of this study were to (1) establish a regression equation that can be used for estimation of ETEC concentration in dilution media using the spectrophotometric measurement of cell density; and (2) examine survival of ETEC after blending either with TSB, sweetener or dextrose. A strain of ETEC (serogroup beta-hemolytic E. coli O149; K91; F4; toxins LT, STa, STb) was grown in TSB for 3.5 hours, centrifuged, the supernatant was discarded, and the ETEC pellet was then blended either with TSB (100 mL), sweetener (60 mL TSB + 40 mL fruit flavored concentrate), or dextrose (50 mL TSB + 50 mL dextrose; 0.5g/mL dextrose). Cell density was measured using the colorimetric method and also plated on a 5% sheep blood agar for counting of ETEC colony forming units at 0, 5, 35, 65 and 125 min after blending. The optical density at 600 nm explained 83% of ETEC colony forming units, indicating that the established linear equation (y= 6E+08x - 4E+07, P<0.004) can be used for robust quantification of ETEC cell density in TSB, sweetener and dextrose media. When ETEC was blended with sweetener and dextrose, survival of ETEC was decreased by 45% and 72% within 5 min post-blending. Therefore, further research is required to find out the suitable medium that has potential to improve palatability without compromising survival of ETEC.

• 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.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.293-295
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• 2003

Total 70 isolates of Escherichia coli obtained from pigs were studied. Forty four isolates had $\textregistered$-hemolytic activity which was heat labile. Minimum inhibitory concentration test indicated that 40 isolates (57.1%), 15 isolates (21.4%), 23 isolates (32.9%), and 5 isolates (7.1%) were resistant to ampicillin, cephalothin, gentamicin, and norfloxacin, respectively. None of them were extended spectrum $\textregistered$-lactamases (ESBLs) producer when the double disk synergy test (DDST) was performed.

• Childhood Kidney Diseases
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• v.8 no.1
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• pp.86-90
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• 2004

Hemolytic uremic syndrome(HUS) is characterized by acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia and the most common pathogen is Escherichia coli (E. coli) O157 : H7. Ischemic colitis, which rarely occurs in children, is due to the reduced local blood flow to the intestine, tissue necrosis and secondary bacterial infection. We describe a patient who was admitted with abdominal pain, vomiting and hematochezia, and diagnosed as ischemic colitis by barium enema. This patient showed hemolytic anemia, thrombocytopenia and progressive renal failure and was subsequently diagnosed as hemolytic uremic syndrome. After hemodialysis, the patient showed improvement of symptoms and resolution of renal failure and ischemic colitis.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.93-94
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• 2000

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.931-937
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• 2007

The hemolytic uremic syndrome (HUS) is a rare disease of microangiopathic hemolytic anemia, low platelet count and renal impairment. HUS usually occurs in young children after hemorrhagic colitis by shigatoxin-producing enterohemorrhagic E. coli (D+HUS). HUS is the most common cause of acute renal failure in infants and young children, and is a substantial cause of acute mortality and morbidity; however, renal function recovers in most of them. About 10% of children with HUS do not reveal preceding diarrheal illness, and is referred to as D- HUS or atypical HUS. Atypical HUS comprises a heterogeneous group of thrombomicroangiopathy (TMA) triggered by non-enteric infection, virus, drug, malignancies, transplantation, and other underlying medical condition. Emerging data indicate dysregulation of alternative complement pathway in atypical HUS, and genetic analyses have identified mutations of several regulatory genes; i.e. the fluid phase complement regulator Factor H (CFH), the integral membrane regulator membrane cofactor protein (MCP; CD46) and the serine protease Factor I (IF). The uncontrolled activation of the complement alternative pathway results in the excessive consumption of C3. Plasma exchange or plasma infusion is recommended for treatment of, and has dropped the mortality rate. However, overall prognosis is poor, and many patients succumb to end-stage renal disease. Clinical presentations, response to plasma therapy, and outcome after renal transplantation are influenced by the genotype of the complement regulators. Thrombotic thrombocytopenic purpura (TTP), another type of TMA, occurs mainly in adults as an acquired disease accompanied by fever, neurologic deficits and renal abnormalities. However, less frequent cases of congenital or hereditary TTP associated with ADAMTS-13 (a disintegrin and metalloprotease, with thrombospondin 1-like domains 13) gene mutations have been reported, also. Recent advances in molecular genetics better allow various HUS to be distinguished on the basis of their pathogenesis. The genetic analysis of HUS is important in defining the underlying etiology, predicting the genotype-related outcome and optimizing the management of the patients.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.82-85
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• 2003

The hemolytic uremic syndrome(HUS), a heterogenous group of disorders characterized by micorangiopathic hemolytic anemia, thrombocytopenia, and azotemia, is the most frequent cause of acute renal failure in children. The association of the HUS with E. coli O157 : H7 has been well-described, but the other intestinal infection have been relatively less reported to date. We report a 18-month-old boy presenting with typical clinical characteristics of HUS associated with amoebic dysentery with a brief review of literatures.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1320-1325
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• 2005

A 2${\times}$3 factorial arrangement of treatments was used to determine the effects of olaquindox and cyadox on immune response of Landrace${\times}$Large-White geld piglets that had been orally given 10$^{10}$ CFU of Escherichia coli (E. coli, O$_{139}$:K$_{88}$). Factors included (1) E. coli inoculation or control, and (2) no antimicrobials, 100 mg/kg olaquindox and 100 mg/kg cyadox in the basal diet respectively. E. coli inoculums were orally administered 7 days after the diets were supplemented with olaquindox and cyadox. The effects of the two antimicrobials were assessed in terms of: (1) average daily gain (ADG), (2) systemic immune response (the number of white blood cells and lymphocytes, leukocyte bactericidal capacity, lymphocyte proliferation response to PHA, immunoglobulin concentrations, and total serous hemolytic complement activity), and (3) intestinal mucosal immunity including the number of intraepithelial lymphocytes (IELs) and immunoglobulin A secreting cells (ASCs) in the intestinal lamina propria. E. coli inoculation reduced ADG (p<0.05) during the period of d 0 to d 14 after the challenge while the antimicrobial supplementations improved ADG (p<0.01) during the experiment. ADG in cyadox-supplemented pigs was higher (p<0.05) than that in olaquindox-supplemented pigs. The antimicrobials decreased IEL and ASC counts in the jejunum and ileum (p<0.01) while E. coli inoculation caused them to increase (p<0.01). Jejunal ASCs in the cyadox-supplemented pigs were lower (p<0.05) than those in the olaquindox-supplemented. E. coli elicited increase (p<0.05) in white blood cell counts, leukocyte bactericidal capacity, lymphocyte proliferation rate, serous IgA concentrations, and serous hemolytic complement activity. The antimicrobials decreased the measured systemic immune parameters, but not significantly (p>0.05). The data suggest that olaquindox and cyadox suppress E. coli-induced immune activation, especially intestinal mucosal immune activation, which may be involved in the observed growth promotion.

• Korean Journal of Veterinary Research
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• v.30 no.3
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• pp.287-295
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• 1990

The purpose of this study was the examination for presence of pilus antigen, O serogroups, colicin production, antibiotic susceptibility and plasmid profiles among E coli isolated from diarrheal piglets and fattening pigs in Taegu province. Of 145 E coli isolated, 98 strains (67.4%) possesed pilus antigens which belonged to either K88 (47.6%), K99 (11.7%) or 987P (8.3%) types. Fifty-nine strains (40.7%) were classified into tenO serogroups and their types were O8 (22.0%), O20(16.9%), O141(15.3%), O9(10.2%), O45(10.2%), O139(8.5%), O064(6.8%), O149(5.0%), O157(3.4%), and O115(1.7%). Thirty-three strains (22.8%) were colicinogenic and 6 strains (4.1%) were hemolytic. One hundred and thirty-nine strains (95.9%) of 145 E coli isolates were resistant to ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, tetracycline, rifampicin and nalidixic acid, alone or in combination thereof. Ninety strains (64.7%) of 139 drug resistant strains carried R factor (R) which were transferable to the recipient by conjugation. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmid DNA band varied from 2 to 11 in 16 E coli with pilus antigen. It's molecular weight ranged from 1.0 to 60.0 megadalton.

• Childhood Kidney Diseases
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• v.6 no.1
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• pp.102-108
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• 2002

We report two cases of hemolytic uremic syndrome (HUS) associated with Escherichia coli O114. Two cases were similar and showed the same clinical courses. After prodrome of diarrhea and vomiting lasting 1-2 days, azotemia persisted for about 10 days, and during that period, the patients were on peritoneal dialysis. They recovered without any sequelae after about 15 days. Direct multiplex PCR of stool culture revealed eae and stx2 gene and the result of ELISA done on the colony positive of one gene confirmed Escherichia coli O114. This is the first report of HUS associated with Escherichia coli O114. We recommend, Shiga toxin producing bacterial Infection must be considered and efforts should be made to scrutinize the organism in all diarrhea-prodrome HUS patients.(J Korean Soc Pediatr Nephrol 2002 ;6 : 102-8)