• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권5호
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• pp.387-395
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• 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.

• Food Science and Biotechnology
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• 제14권5호
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• pp.685-688
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• 2005

Antibacterial and antiplatelet activities of Acorus gramineus rhizome-derived asaronaldehyde and asaron were analyzed using platelet aggregometer and six human intestinal bacteria. Active constituent of A. gramineus rhizome was isolated and characterized as asaronaldehyde by spectral analyses. At 2 and 1 mg/disk, asaronaldehyde exhibited strong inhibition of Clostridium perfringens and C. difficile without adverse effects on growth of beneficial bacteria such as Bifidobacterium bifidum, Lactobacillus acidophilus, and L. casei. Asaron also revealed moderate growth inhibition against C. perfringens and C. difficile at 2 mg/disk, no growth-inhibiting activity was observed on B. bifidum, L. acidophilus, L. casei, and E. coli. At 50% inhibitory concentration ($IC_{50}$) value, asaronaldehyde was effective in inhibiting platelet aggregation induced by collagen ($IC_{50}$, $27.6\;{\mu}M$) and arachidonic acid ($IC_{50}$, $53.7\;{\mu}M$). These results suggest asaronaldehyde may be useful as lead compound for inhibiting platelet aggregation induced by collagen and arachidonic acid.

• Food Science and Biotechnology
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• 제18권3호
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• pp.755-760
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• 2009

The growth-inhibiting activities of persimmon roots-derived materials against intestinal bacteria were evaluated and compared with that of 1,4-naphthoquinone as a positive control. The active constituent isolated from persimmon roots was characterized as 5-hydroxy-2-methyl-1,4-naphthoquinone using various spectroscopic analyses. Treatment with 1,4-naphthoquinone at a dose of 1.0 mg/disc strongly inhibited the growth of 6 intestinal bacteria. Furthermore, when the structure-activity relationships of 1,4-naphthoquinone's derivatives were evaluated, 5-hydroxy-2-methyl-1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone were found to strongly inhibit the growth of Clostridium difficile, Clostridium perfringens, and Escherichia coli without adversely affecting the growth of Bifidobacterium adolescentis, Bifidobacterium longum, and Lactobacillus acidophilus. Additionally, 2-hydroxy-1,4-naphthoquinone and 5-hydroxy-1,4-naphthoquinone strongly inhibited the growth of C. difficile and C. perfringens, but did not inhibit the growth of E. coli. Taken together, these results indicate that persimmon roots-derived materials and some of 1,4-naphthoquinone's derivatives could be useful preventive agents against diseases caused by harmful intestinal bacteria.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.659-665
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• 2016

The oligosaccharides in human milk constitute a major innate immunological mechanism by which breastfed infants gain protection against infectious diarrhea. Clostridium difficile is the most important cause of nosocomial diarrhea, and the C-terminus of toxin A with its carbohydrate binding site, TcdA-f2, demonstrates specific abolishment of cytotoxicity and receptor binding activity upon diethylpyrocarbonate modification of the histidine residues in TcdA. TcdA-f2 was cloned and expressed in E. coli BL21 (DE3). A human milk oligosaccharide (HMO) mixture displayed binding with TcdA-f2 at 38.2 respond units (RU) at the concentration of 20 μg/ml, whereas the eight purified HMOs showed binding with the carbohydrate binding site of TcdA-f2 at 3.3 to 14 RU depending on their structures via a surface plasma resonance biosensor. Among them, Lacto-N-fucopentaose V (LNFPV) and Lacto-N-neohexaose (LNnH) demonstrated tight binding to TcdA-f2 with docking energy of −9.48 kcal/mol and −12.81 kcal/mol, respectively. It displayed numerous hydrogen bonding and hydrophobic interactions with amino acid residues of TcdA-f2.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.30-36
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• 2019

Numerous studies have reported that enteric neurons involved in controlling neurotransmitter secretion and motility in the gut critically contribute to the progression of gut inflammation. Clostridium difficile toxins, which cause severe colonic inflammation, are also known to affect enteric neurons. Our previous study showed that C. difficile toxin A directly induces neural cell toxicities, such as viability loss and apoptosis. In the current study, we attempted to identify a potent inhibitor of toxin A-induced neural cell toxicity that may aid in managing toxin A-induced gut inflammation. In our recent study, we found that the Korea dung beetle-derived antimicrobial peptide CopA3 completely blocked neural cell apoptosis caused by okadaic acid or 6-OHDA. Here, we examined whether the antimicrobial peptide CopA3 inhibited toxin A-induced neural cell damage. In neuroblastoma SH-SY5Y cells, CopA3 treatment protected against both apoptosis and viability loss caused by toxin A. CopA3 also completely inhibited activation of the pro-apoptotic factor, caspase-3. Additionally, CopA3 rescued toxin A-induced downregulation of neural cell proliferation. However, CopA3 had no effect on signaling through ROS/p38 $MAPK/p27^{kip1}$, suggesting that CopA3 inhibits toxin A-induced neural cell toxicity independent of this well-characterized toxin A pathway. Our data further suggest that ability of CopA3 to rescue toxin A-induced neural cell damage may also ameliorate the gut inflammation caused by toxin A.

• Journal of Microbiology and Biotechnology
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• 제34권8호
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• pp.1718-1726
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• 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.

• 한국산학기술학회논문지
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• 제21권9호
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• pp.134-143
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• 2020

본 연구의 목적은 국내 요양병원에 입원한 감염병 환자의 실태를 파악하기 위함이다. 본 연구는 국내 요양병원에 입원한 감염병 환자의 실태를 조사하기 위한 서술적 조사연구이다. 798개의 요양병원을 대상으로 14개 감염병에 대해 2016년 1월 1일부터 2017년 12월 31일까지 2년 동안 지속적으로 운영된 요양병원에 입원한 감염병 환자수, 내원일수, 총 진료비 현황을 조사하였다. 2016년에 비해 2017년에 감염병 환자수, 내원일수, 총 진료비는 증가하였고, 요양병원에 많은 감염병은 클로스트리듐디피실리에 의한 장결장염, 인플루엔자, 옴이었다. 또한 연도별로 감염병이 발생한 요양병원 수를 확인한 결과, 인플루엔자, 클로스트리듐디피실리에 의한 장결장염, 카바페넴계내성 감염증이 발생한 병원이 2016년에 비해 2017년 증가하였다. 병상수에 따른 환자수는 150병상 이상 300병상 미만인 군이 가장 많았다. 따라서 요양병원에 많이 발생하는 클로스트리듐디피실리에 의한 장결장염, 인플루엔자, 옴에 대한 관리방안이 집중적으로 이루어져야 하며, 해당 질병에 대한 감염관리방법과 교육 등 가이드라인을 제공하는 것이 도움이 될 것이다. 또한 300병상 미만 요양병원에서의 감염관리를 위해 요양병원에 적용 가능한 감염감시기준을 마련하고, 감염관련시설 및 인력 확충을 지원하는 등 감염관리 시스템 구축이 필요하다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권1호
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• pp.41-51
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• 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.

• 농업생명과학연구
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• 제43권3호
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• pp.45-54
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• 2009

본 연구에서는 인체 내 장내 세균 및 병원성 식중독 세균에 선인장 추출물이 미치는 영향과 항산화, 항고혈압 활성에 대하여 분석하였다. 항균활성은 96well-plate법과 paper disc법을 이용하여 실험하였으며 줄기 추출물의 경우 96well-plate 및 paper disc법의 결과, 장내유해균인 Eubacterium limosum 및 Clostridium perfringens, C. butyricum, C. difficile과 Staphylococcus aureus에 대하여 높은 억제율을 보였으나 Bacteroides fragilis, Bifidobacterium bifidum, Lactobacillus acidophilis, Streptococcus thermophilus의 경우 억제율을 나타내지 않았다. 열매 추출물의 경우 장내유해균 및 장내유익균에 Bacteroides fragilis, Bifidobacterium bifidum, Lactobacillus acidophilis, and Streptococcus thermophilis에 대하여 억제율을 나타내지 않았다. 또한 줄기 추출물의 경우 열 및 pH에서도 장내미생물에 대한 항균활성에 안정함을 나타내었다. 선인장 추출물의 폴리페놀과 플라보노이드 함량 및 DPPH 전자공여능을 측정한 결과 열처리하지 않은 열매와 줄기 추출물의 폴리페놀은 3.02 mg/g, 5.85 mg/g, 플라보노이드는 1.04 mg/g, 2.1 mg/g, 전자공여능은 87, 88%로 높은 수율을 나타내었다. 선인장 추출물의 항고혈압활성은 줄기 추출물의 경우 88.8% 열매 추출물의 경우 69.2%의 항고혈압활성을 보였으며 상기 결과를 종합할 때, 선인장 줄기추출물은 장내 유해균의 억제 및 유익균의 증진을 통한 장내 균총 개선을 위한 기능성 식품소재로 활용할 수 있다고 판단된다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제9권2호
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• pp.162-168
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• 2006

목 적: 자궁 내에서 태아의 소화기는 무균상태에 있다가 출생 후 신생아기에 점차 장내세균의 집락화가 이루어진다. 출생 초기에 처음으로 나타나는 세균은 Staphylococcus, Enterobacteriaceae, Streptococcus가 있으며, 이후 Bifidobacterium spp.와 같은 혐기성 세균이 나타난다. 이에 저자들은 정상 신생아의 대변에서 생후 1주일 동안 장내세균총의 분포와 변화를 규명하고자 하였다. 방 법: 한림의대 강동성심병원에서 출생한 정상 신생아 15명(자연분만 3명, 제왕절개 12명)(모유수유 1명, 분유수유 8명, 혼합수유 6명)을 대상으로 하였다. 출생 첫 대변과 1일, 3일, 7일째의 대변을 채취하였다. 대변 배양 배지와 조건를 달리하여 호기성균(blood agar plate), E. coli (trypton bile X-glucuronide 배지), 그람 양성 혐기성균(phenylethyl alcohol agar), lactobacillus (MRS 배지), Bifidobacterium spp. (bifidobacterium selective agar), Clostridium difficile (cefoxitincycloserine-fructose agar)을 검출하여 배양된 균 집락의 수를 측정하여 기록하였다. 결 과: 출생 첫 대변에서는 균이 거의 검출되지 않았다. 호기성균, E. coli, 그람 양성 혐기성균은 출생 시부터 생후 7일까지 유의하게 증가하였다(p<0.05). Lactobacilli는 한명의 신생아에서 생후 7일에 검출되었다. Bifidobacterium spp.은 2명에서 검출되었다. Clostridium difficile은 생후 7일까지 검출되지 않았다. 분만 방법과 수유 방법에 따른 균 집락의 차이는 없었다. 결 론: 정상 신생아에서 생후 1주일 동안 장내세균총의 다양한 변화를 관찰할 수 있었다. 앞으로 생후 1주일 이후의 장내세균총의 변화와 더 많은 환아에서의 연구를 진행한다면 생균제 사용에 도움이 되리라 생각된다.