• Food Science and Biotechnology
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• v.17 no.2
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• pp.402-407
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• 2008

The synergistic antimicrobial effect of Achyranthes japonica Nakai (AJN) and Bifidobacterium extracellular factors against Clostridium difficile were measured using a turbidity method. Each broth supernatant of Bifidobacterium infantis ($68.8{\pm}0.02%$) and Bifidobacterium adolescentis ($33.2{\pm}0.2%$) obtained by adding ethyl acetate soluble fractionate from A. japonica Nakai ethanolic extracts (AJNEA, 100 ppm, no inhibition) showed high synergistic antimicrobial activity against C. difficile. In addition, the antimicrobial activity in a laboratory medium and yogurt products against C. difficile were evaluated. In yogurt prepared with a starter 5 (Lactobacillus acidophilus: Streptococcus thermophilus: B. adolescentis =1 : 1 : 1) and a starter 4 (L. acidophilus: S. thermophilus: B. infantis=1 : 1 : 1) and 0.5% AJNEA powder, high antimicrobial effects were recorded that measured 79.0 and 65.2%, respectively. The results indicated the potential of AJN extract for use as an antimicrobial agent. In addition, the efficiency of the antimicrobial activity of the extracts was further improved in combination with lactic acid bacteria, which suggests that they have the potential to be used as a highly effective antibiotic-tolerant microorganism prevention system. Such a strategy can be used for alternative drugs or functional food additives for treatment of antibiotic-associated diarrhea.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.696-703
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• 2014

Clostridium difficile causes mucosal damage and diarrhea by releasing two exotoxins: toxin A and toxin B. C. difficile colitis is associated with alterations in bowel flora and the failure to mount an effective antibody response. The aim of the current study was to investigate whether antitoxin sera prevent toxin-A-induced apoptosis, cytoskeletal disaggregation, cell detachment, and tight junction loss in cultured colonic epithelial cells. Serum samples were isolated from mice that survived a C. difficile infection following antibiotic treatment, and the antitoxin effects of these samples were investigated in toxin-A-exposed HT29 colonic epithelial cells and a toxin-A-induced animal model of gut inflammation. Unchallenged mice did not produce IgG against toxin A, whereas serum (antiserum) from C. difficile-challenged mice showed significant IgG responses against toxin A. Treatment with the antiserum markedly inhibited mucosal damage and inflammation in the toxin-A-treated mouse model. In contrast to control mouse serum, the antiserum also markedly inhibited toxin-A-induced DNA fragmentation, dephosphorylation of paxillin and Epo receptor (EpoR), deacetylation of tubulin, and upregulation of p21(WAF1/CIP1) and p53. Taken together, these results reveal that the generated antitoxin serum has biotherapeutic effects in preventing various C. difficile toxin-A-induced cellular toxicities.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.13 no.2
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• pp.146-153
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• 2010

Purpose: Recent studies have reported an increase in the incidence of community-acquired Clostridium difficile-associated disease (CA-CDAD) among children. There is an overall lack of information on CA-CDAD in the pediatric population. The aim of our study was to compare the epidemiologic and clinical features between CA-CDAD and hospital-acquired C. difficile-associated disease (HA-CDAD) in children. Methods: We retrospectively reviewed the medical records of all patients who were diagnosed with C. difficile-associated disease (CDAD) at Gil Hospital between April 2008 and March 2009. The diagnosis of CDAD was made when patients with gastrointestinal symptoms had positive results for C. difficile toxins A and B assay or stool culture. Results: Sixty-one (male, 32 and female, 29) patients were included. The mean age was 3.79${\pm}$4.54 years. Of the 61 patients, 22 (36.1%) were <1 year of age. Twenty-three patients (37.7%) had a history of antibiotic exposure in the previous 3 months. Forty-one patients (67.2%) were diagnosed with CA-CDAD. There were no significant differences in age, gender, symptoms, laboratory findings, recovery period, complications, and recurrence between the CA-CDAD and HA-CDAD groups. On the other hand, exposure to antibiotics was significantly more frequent among patients in the HA-CDAD group (p=0.005). Conclusion: This study suggests that the occurrence of CA-CDAD is increasing in the pediatric population, especially in younger children with no history of exposure to antibiotics and in outpatients. Awareness of the increasing incidence of CA-CDAD and prompt investigation of C. difficile in susceptible patients is needed to avoid misdiagnosis and for appropriate therapy.