• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.20 no.1
• /
• pp.47-54
• /
• 2017

Purpose: Clinical symptoms associated with Clostridium difficile infection (CDI) can vary widely. Carrier state without apparent symptoms is relatively common during infancy. The objective of this study was to determine the association of C. difficile colonization with bowel habit change and the effect of C. difficile colonization treatment on restoration of normal bowel habit. Methods: Between 2006 and 2014, infants at 1 to 12 months of age with diarrhea for more than 2 weeks who did not improve with conservative care were recruited from Gachon University Gil Medical Center. Infants who were followed up for at least 7 days were included. The presence or absence of C. difficile colonization, effect of metronidazole, and other medical records were reviewed. To determine the association between CDI and bowel habit change, logistic regression analysis was used. Results: Of a total of 126 infants, 74 (58.7%) were male patients. Of the 126 patients, 27 (21.4%) had C. difficile colonization. Significant (p<0.05) risk factors for C. difficile colonization included artificial milk feeding (odds ratio [OR], 4.310; 95% confidence interval [CI], 1.564-11.878), prior rotavirus vaccination (OR, 4.322; 95% CI, 1.018-18.349), and antibiotic use (OR, 4.798; 95% CI, 1.430-16.101). There was improvement in bowel habit after metronidazole therapy (OR, 0.34; 95% CI, 0.15-0.79; p<0.05), regardless of the presence or absence of C. difficile colonization, Conclusion: There was no significant correlation between bowel habit change and C. difficile colonization during infancy. However, metronidazole can be used as an optional method to manage functional gastrointestinal disorders.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.1
• /
• pp.46-55
• /
• 2022

Clostridioides difficile infection (CDI) is a significant cause of hospital-acquired and antibiotic-mediated intestinal diseases and is a growing global public health concern. Overuse of antibiotics and their effect on normal intestinal flora has increased the incidence and severity of infections. Thus, the development of new, effective, and safe treatment options is a high priority. Here, we report a new probiotic strain, Bacillus amyloliquefaciens (BA PMC-80), and its in vitro/in vivo anti-C. difficile effect as a prospective novel candidate for replacing conventional antibiotics. BA PMC-80 showed a significant anti-C. difficile effect in coculture assay, and its cell-free supernatant (CFS) also exhibited a considerable anti-C. difficile effect with an 89.06 ㎍/ml 50% minimal inhibitory concentration (MIC) in broth microdilution assay. The CFS was stable and equally functional under different pHs, heat, and proteinase treatments. It also exhibited a high sensitivity against current antibiotics and no toxicity in subchronic toxicity testing in hamsters. Finally, BA PMC-80 showed a moderate effect in a hamster CDI model with reduced infection severity and delayed death. However, further studies are required to optimize the treatment condition of the hamster CDI model for better efficacy and identify the antimicrobial compound produced by BA PMC-80.

• Journal of Korean Medicine Rehabilitation
• /
• v.31 no.1
• /
• pp.47-57
• /
• 2021

Objectives This study was conducted to confirm the possibility of Clostridium difficile infection (CDI) treatment through natural herbal medicines. Methods After screening a total of 77 herbal medicines through the paper disc agar diffusion method, we selected the herbal medicines that showed a effectiveness compared to the positive control vancomycin. Afterwards, drugs that showed inhibitory effects compared to C. difficile without inhibition of Bifidobacterium bifidum and Lactobacillus plantarum, known as beneficial bacteria, were selected and minimal inhibitory concentration (MIC) was confirmed by applying the Broth microdilution method. Results The Coptidis Rhizoma, well known for its antimicrobial effect, was found to have antimicrobial effects on C. difficile, but also had inhibitory effects on the beneficial bacterium B. bifidum. 30% ethanol extraction Crataegi fructus, Corni fructus and Mume fructus had antimicrobial effects on C. difficile without inhibiting the beneficial bacteria B. bifidum and L. plantarum. The MIC values of 30% ethanol extraction Crataegi fructus, Corni fructus and Mume fructus were found to be 10 mg/mL, 20 mg/mL and 5 mg/mL, respectively. Conclusions Crataegi fructus, Corni fructus and Mume fructus were identified as candidate medicines for C. difficile. Further researchs will need to be done in vivo, and to find an optimal extraction method accompanied by economic evaluation.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.5
• /
• pp.696-703
• /
• 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
• /
• v.25 no.5
• /
• pp.387-395
• /
• 2022

Purpose: Toxins produced by Clostridioides difficile infection (CDI) can cause enteritis and diarrhea. Although the number of pediatric CDI cases is increasing, the clinical management of pediatric CDI, including patient characteristics and prognosis, remains unclear. This study aimed to elucidate the background and clinical course of patients with CDI and evaluate the reliability of diagnostic tests in a tertiary pediatric hospital in Japan. Methods: We retrospectively analyzed the clinical data of children diagnosed with CDI between 2011 and 2021 at the Saitama Children's Medical Center in Saitama, Japan. Results: During the study period, 1,252 C. difficile antigen/toxin tests were performed, and 37 patients were diagnosed with CDI. The main underlying diseases among the patients were hematological and malignant disorders and gastrointestinal diseases, including inflammatory bowel disease (IBD) (59.4%). Two patients (5.4%) had an unremarkable medical history. Among the 37 patients, 27 (73.0%) were immunocompromised, 25 (67.6%) had a history of antibiotic use within the past two months, and 6 (16.2%) were negative on the initial test but were positive on the second test. Finally, 28 patients (75.7%) required primary antibiotic therapy only, and two patients with IBD required additional antibiotic therapy as secondary treatment. Conclusion: The number of pediatric patients with CDI is increasing. Both a comprehensive interview, including underlying diseases and history of antibiotic use, and an understanding of the features of clinical examinations should be emphasized to appropriately diagnose and treat CDI.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.25 no.1
• /
• pp.41-51
• /
• 2022

Purpose: Community-acquired bacterial enteritis (CABE) is a common problem in developed countries. It is important to understand the epidemiologic changes in bacterial pathogens for prevention and treatment. Therefore, we studied the epidemiologic changes in CABE in Korean children. Methods: A total of 197 hospitalized pediatric patients aged <19 years that presented with dysentery symptoms and showed positive polymerase chain reaction results for bacterial species in stool samples, were enrolled in this study for 10 years (June 2010 to June 2020). We classified patients in phase I (06, 2010-06, 2015) and phase II (07, 2015-06, 2020) and analyzed their epidemiologic and clinical characteristics. Results: The most common pathogens were Campylobacter species (42.6%) and Salmonella species were the second most common pathogens (23.9%). The abundance of pathogens decreased in the following order: Clostridium difficile (9.6%), Shigella (5.6%), and Clostridium perfringens (5.6%). Escherichia coli O157:H7 was found to be the rarest pathogen (2.0%). Campylobacter species showed an increase in the infection rate from 32.1% in phase I to 49.6% in phase II (p=0.0011). Shigella species showed a decline in the infection rate in phase I from 14.1% to 0.0% in phase II (p<0.001). C. difficile and C. perfringens showed an increase in infection rate in phase II compared to phase I, but the difference was not statistically significant. Conclusion: The infection rate of Campylobacter species in CABE has been rising more recently, reaching almost 50%. This study may help establish policies for prevention and treatment of CABE in Korean children.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.8
• /
• pp.1718-1726
• /
• 2024

Development of novel antibacterial agents is imperative due to the increasing threat of antibiotic-resistant pathogens. This study aimed to develop the enhanced antibacterial activity and in-vivo efficacy of a novel truncated endolysin, CHAP^SAP26-161, derived from the endolysin Lys^SAP26, against multidrug-resistant bacteria. CHAP^SAP26-161 exhibited higher protein purification efficiency in E. coli and antibacterial activity than Lys^SAP26. Moreover, CHAP^SAP26-161 showed the higher lytic activity against A. baumannii with minimal bactericidal concentrations (MBCs) of 5-10 ㎍/ml, followed by Staphylococcus aureus with MBCs of 10-25 ㎍/ml. Interestingly, CHAP^SAP26-161 could lyse anaerobic bacteria, such as Clostridioides difficile, with MBCs of 25-50 ㎍/ml. At pH 4-8 and temperatures of 4℃-45℃, CHAP^SAP26-161 maintained antibacterial activity without remarkable difference. The lytic activity of CHAP^SAP26-161 was increased with Zn²⁺. In vivo tests demonstrated the therapeutic effects of CHAP^SAP26-161 in murine systemic A. baumannii infection model. In conclusion, CHAP^SAP26-161, a truncated endolysin that retains only the CHAP domain from Lys^SAP26, demonstrated enhanced protein purification efficiency and antibacterial activity compared to Lys^SAP26. It further displayed broad-spectrum antibacterial effects against S. aureus, A. baumannii, and C. difficile. Our in vitro and in-vivo results of CHAP^SAP26-161 highlights its promise as an innovative therapeutic option against those bacteria with multiple antibiotic resistance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.134-143
• /
• 2020

This study investigated the status of infectious disease inpatients at long-term care hospitals in Korea. A descriptive study was conducted on patients with 14 infectious diseases at 798 long-term care hospitals during 2016-2017. The number of infected patients, total admission days, and total medical expenses were higher in 2017 than in 2016. The most common infectious diseases were enterocolitis due to Clostridium difficile, influenza, and scabies. The number of hospitals with patients who had enterocolitis due to C. difficile and resistance to carbapenem was higher in 2017 than in 2016. Hospitals with 150-299 beds had higher numbers of infectious disease patients than those with under 150 or over 300 beds. Therefore, intensive efforts are needed to control the most common diseases at long-term care hospitals, such as enterocolitis due to C. difficile, influenza, and scabies. It is recommended to apply relevant guidelines related to infection control management as well as implement educational programs. It will also be necessary to develop applicable infection monitoring standards and support the facilities and health workforce of long-term care hospitals under 300 beds through an effective infection surveillance system.

• The Korean journal of internal medicine
• /
• v.39 no.3
• /
• pp.513-523
• /
• 2024

Background/Aims: Since the coronavirus disease 2019 (COVID-19) outbreak, hospitals have implemented infection control measures to minimize the spread of the virus within facilities. This study aimed to investigate the impact of COVID-19 on the incidence of healthcare-associated infections (HCAIs) and common respiratory virus (cRV) infections in hematology units. Methods: This retrospective study included all patients hospitalized in Catholic Hematology Hospital between 2019 and 2020. Patients infected with vancomycin-resistant Enterococci (VRE), carbapenemase-producing Enterobacterales (CPE), Clostridium difficile infection (CDI), and cRV were analyzed. The incidence rate ratio (IRR) methods and interrupted time series analyses were performed to compare the incidence rates before and after the pandemic. Results: The incidence rates of CPE and VRE did not differ between the two periods. However, the incidence of CDI increased significantly (IRR: 1.41 [p = 0.002]) after the COVID-19 pandemic. The incidence of cRV infection decreased by 76% after the COVID-19 outbreak (IRR: 0.240 [p < 0.001]). The incidence of adenovirus, parainfluenza virus, and rhinovirus infection significantly decreased in the COVID-19 period (IRRs: 0.087 [p = 0.003], 0.031 [p < 0.001], and 0.149 [p < 0.001], respectively). Conclusions: The implementation of COVID-19 infection control measures reduced the incidence of cRV infection. However, CDI increased significantly and incidence rates of CPE and VRE remained unchanged in hematological patients after the pandemic. Infection control measures suitable for each type of HCAI, such as stringent hand washing for CDI and enough isolation capacities, should be implemented and maintained in future pandemics, especially in immunocompromised patients.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.20 no.2
• /
• pp.107-113
• /
• 2017

Purpose: This study clarified the bacterial pathogens currently causing acute infectious enterocolitis (AIE) in children and evaluated the clinical characteristics and ultrasonographic findings according to the different pathogens. Methods: Medical records regarding age, sex, clinical symptoms, laboratory data, identified enteropathogens, ultrasonographic findings, treatment, and outcome of 34 patients who were diagnosed with AIE via stool examination using multiplex polymerase chain reaction (PCR) or culture, were retrospectively reviewed. Results: Twenty-four patients (70.6%) were male. The mean age of the patients was $8.5{\pm}6.2$ (range, 1.1-17.1) years. Six bacterial pathogens were isolated: Salmonella species (spp.) (32.4%), Campylobacter spp. (20.6%), verotoxin-producing Escherichia coli (14.7%), Staphylococcus aureus (11.8%), Clostridium difficile (8.8%), and Shigella spp. (2.9%). Abdominal pain occurred in all patients regardless of pathogen. The patients infected with Salmonella were older than those infected with verotoxin-producing E. coli (p<0.05). C-reactive protein levels were higher in patients with Salmonella and Campylobacter infections than in those with verotoxin-producing E. coli infection (p< 0.05), the other clinical and laboratory data were indistinguishable between pathogens. Ultrasonography demonstrated diverse involvement of bowel segments according to pathogen. Wall thickening of both the ileum and the entire colon was the most common lesion site regardless of pathogen. Conclusion: Various bacterial agents cause AIE and the symptoms are diverse symptoms, however, all most children recovered spontaneously. Use of multiplex PCR on stool samples warrants improvement of its sensitivity for diagnosis of enteropathogenic bacteria. Ultrasonographic examination is useful for diagnosis of AIE; it can also detect the disease extent and severity.