EII

EII
  • 文章类型: Journal Article
    单核细胞增生李斯特菌,一种广泛的食源性病原体,通过PEP-磷酸转移酶(PTS)系统利用包括单糖和二糖在内的多种生长底物。我们评估了一系列不同来源的单核细胞增生李斯特菌分离株利用乳糖的能力,由半乳糖和葡萄糖组成的二糖,是牛奶和乳制品中的主要碳源。值得注意的是,乳制品相关爆发菌株F2365不能有效利用乳糖,可以想象是由于移码突变(lacR887del)导致截短的LacR。转录激活因子LacR参与两个PTS系统的表达,由lmo1718-1720与lmo2708和lmo2683-2685操纵子组合的lpo操纵子编码,并与单核细胞增生李斯特菌的乳糖和/或纤维二糖代谢有关。通过祖先菌株F2365的实验进化,获得了进化的分离株F2365EV,其显示出乳糖的生长和代谢增强。使用乳糖阳性模型菌株单核细胞增生李斯特菌EGDe作为对照,HPLC实验表明,EGDe和F2365EV可以消耗乳糖并利用葡萄糖部分,而半乳糖部分从细胞中输出。F2365EV的基因组测序发现原始lacR887del突变仍然存在,但发生了额外的点突变lmo2766C415T,导致推定的调节因子Lmo2766中的氨基酸取代。lmo2766基因位于操纵子lmo2761-2765旁边,在基因组中具有推定的PTS基因。值得注意的是,比较RNAseq分析证实,在存在乳糖的情况下,lmo2761-2765操纵子在F2365EV中强烈上调,但在EGDe和F2365中没有上调。相反,LacR调节的lpo操纵子,lmo2708和lmo2683-2685操纵子仅在EGDe中上调。额外的生长和HPLC实验,使用在乳糖阳性单核细胞增生李斯特菌EGDe中构建的突变体,显示EGDelacR887del突变体的生长减少,没有利用乳糖,而双突变体EGDelacR887dellmo2766C415T显示出增强的生长和乳糖利用率。因此,这些结果表明,Lmo2766调节因子中的氨基酸取代激活了PTS操纵子lmo2761-2765编码的先前沉默的乳糖利用途径,促进了以乳糖为底物的单核细胞增生李斯特菌的生长和代谢.这一发现增强了我们对单核细胞增生李斯特菌代谢能力和适应性的理解,为这种病原体的乳糖利用能力提供了更广泛的视角。
    Listeria monocytogenes, a widespread food-borne pathogen, utilizes diverse growth substrates including mono- and di-saccharides via PEP-phosphotransferase (PTS) systems. We evaluated a collection of L. monocytogenes isolates of different origins for their ability to utilize lactose, a disaccharide composed of galactose and glucose and the main carbon source in milk and dairy products. Notably, the dairy-associated outbreak strain F2365 could not utilize lactose efficiently, conceivably due to a frameshift mutation (lacR887del) resulting in a truncated LacR. Transcriptional activator LacR is involved in the expression of two PTS systems, encoded by the lpo operon lmo1718-1720 in combination with lmo2708 and the lmo2683-2685 operon, and linked to lactose and/or cellobiose metabolism in L. monocytogenes. Via experimental evolution of the ancestral strain F2365, an evolved isolate F2365 EV was obtained which showed enhanced growth and metabolism of lactose. Using the lactose-positive model strain L. monocytogenes EGDe as a control, HPLC experiments showed that EGDe and F2365 EV could consume lactose and utilize the glucose moiety, while the galactose moiety was exported from the cells. Genome sequencing of F2365 EV found the original lacR887del mutation was still present but an additional point mutation lmo2766C415T had occurred, resulting in an amino acid substitution in the putative regulator Lmo2766. The lmo2766 gene is located next to operon lmo2761-2765 with putative PTS genes in the genome. Notably, comparative RNAseq analysis confirmed that the lmo2761-2765 operon was strongly upregulated in F2365 EV in the presence of lactose but not in EGDe and F2365. Conversely, the LacR-regulated lpo operon, lmo2708, and lmo2683-2685 operon were only upregulated in EGDe. Additional growth and HPLC experiments, using mutants constructed in lactose-positive L. monocytogenes EGDe, showed reduced growth of the EGDe lacR887del mutant with no utilization of lactose, while the double mutant EGDe lacR887dellmo2766C415T showed enhanced growth and lactose utilization. Hence, these results demonstrate that an amino acid substitution in the Lmo2766 regulator activates a previously silent lactose utilization pathway encoded by PTS operon lmo2761-2765, facilitating the growth and metabolism of L. monocytogenes with lactose as a substrate. This finding enhances our understanding of the metabolic capabilities and adaptability of L. monocytogenes, offering a broader view of the lactose utilization capacity of this pathogen.
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  • 文章类型: Journal Article
    背景:粒细胞和单核细胞吸附分离术(GMA)从外周血中去除中性粒细胞和单核细胞,防止它们掺入发炎组织也影响细胞因子平衡。在溃疡性结肠炎(UC)中发表的治疗效果比在克罗恩氏病(CD)中更为一致。我们在最后一次诱导后4周评估了GMA在UC和CD中的临床疗效,在3个月和12个月时,持续缓解和无皮质类固醇缓解。
    方法:对接受GMA治疗的UC和CD患者进行回顾性观察研究。UC中的部分疾病活动指数-DAIp和CD中的Harvey-Bradshaw指数-HBI评估了Adacolumn®的诱导和可选的维持疗程的功效。
    结果:我们治疗了87例患者(CD-25,UC-62),87.3%皮质类固醇依赖性(CSD),42.5%对免疫调节剂难治/不耐受。在UC,诱导后缓解和反应分别为32.2%和19.3%,12周时为35.5%和6.5%,52周时为29%和6.5%。在CD中,缓解率为60%,分别为52%和40%。在对INM患者(UC-41,CD-14)的皮质类固醇依赖性和难治性或不耐受中,68.3%的UC在诱导后达到缓解或反应,12周时51.2%,52周时46.3%,和62.3%,CD中的64.3%和42.9%。CD和UC的缓解率分别为66.6%和53.1%。高达74.5%的患者在某个时间点需要皮质类固醇。无皮质类固醇反应/缓解在UC中为17.7%,在CD中为24%。
    结论:GMA是UC和CD患者的良好治疗工具。在皮质类固醇依赖性和难治性或不耐受的INM患者中,一年内高达40%的患者避免了生物治疗或手术。
    BACKGROUND: Granulocyte and monocyte adsorptive apheresis (GMA) removes neutrophils and monocytes from peripheral blood, preventing their incorporation into the inflamed tissue also influencing cytokine balance. Published therapeutic efficacy in ulcerative colitis (UC) is more consistent than in Crohn\'s disease (CD). We assessed clinical efficacy of GMA in UC and CD 4 weeks after last induction session, at 3 and 12 months, sustained remission and corticosteroid-free remission.
    METHODS: Retrospective observational study of UC and CD patients treated with GMA. Partial Disease Activity Index-DAIp in UC and Harvey-Bradshaw Index-HBI in CD assessed efficacy of Adacolumn® with induction and optional maintenance sessions.
    RESULTS: We treated 87 patients (CD-25, UC-62), 87.3% corticosteroid-dependent (CSD), 42.5% refractory/intolerant to immunomodulators. In UC, remission and response were 32.2% and 19.3% after induction, 35.5% and 6.5% at 12 weeks and 29% and 6.5% at 52 weeks. In CD, remission rates were 60%, 52% and 40% respectively. In corticosteroid-dependent and refractory or intolerant to INM patients (UC-41, CD-14), 68.3% of UC achieved remission or response after induction, 51.2% at 12 weeks and 46.3% at 52 weeks, and 62.3%, 64.3% and 42.9% in CD. Maintained remission was achieved by 66.6% in CD and 53.1% in UC. Up to 74.5% of patients required corticosteroids at some timepoint. Corticosteroid-free response/remission was 17.7% in UC and 24% in CD.
    CONCLUSIONS: GMA is a good therapeutic tool for both in UC and CD patients. In corticosteroid-dependent and refractory or intolerant to INM patients it avoids biological therapy or surgery in up to 40% of them in one year.
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  • 文章类型: Journal Article
    背景:回盲肠切除克罗恩病(CD)后并发症很常见。这项研究的目的是分析这些手术后术后并发症的危险因素。
    方法:我们对拉丁美洲10个专门治疗炎症性肠病(IBD)的医疗中心进行了为期8年的局限在回盲部接受手术治疗的克罗恩病患者进行了回顾性分析。将患者分为两组:出现严重术后并发症的患者(Clavien-Dindo>II),“术后并发症”(POC)组;那些没有,“无术后并发症”(NPOC)组。分析术前特征和术中变量,以确定POC的可能因素。
    结果:总计,包括337名患者,POC队列中有51人(15.13%)。吸烟在POC患者中更为普遍(31.37vs17.83;P=0.026),术前贫血较多(33.33vs17.48%;P=0.009),需要更多的紧急护理(37.25vs22.38;P=.023),白蛋白水平较低。复杂疾病与较高的术后发病率相关。POC患者的手术时间较长(188.77vs143.86分钟;P=0.005),术中并发症较多(17.65vs4.55%;P<.001),和较低的原发性吻合率。在多变量分析中,吸烟和术中并发症与术后主要并发症的发生独立相关.
    结论:这项研究表明,拉丁美洲克罗恩病原发性回盲部切除术后并发症的危险因素与其他地方报道的相似。该区域今后的努力应旨在通过控制一些已确定的因素来改善这些成果。
    BACKGROUND: Complications after ileocecal resection for Crohn\'s disease (CD) are frequent. The aim of this study was to analyze risk factors for postoperative complications after these procedures.
    METHODS: We conducted a retrospective analysis of patients treated surgically for Crohn\'s disease limited to the ileocecal region during an 8-year period at 10 medical centers specialized in inflammatory bowel disease (IBD) in Latin America. Patients were allocated into 2 groups: those who presented major postoperative complications (Clavien-Dindo > II), the \"postoperative complication\" (POC) group; and those who did not, the \"no postoperative complication\" (NPOC) group. Preoperative characteristics and intraoperative variables were analyzed to identify possible factors for POC.
    RESULTS: In total, 337 patients were included, with 51 (15.13%) in the POC cohort. Smoking was more prevalent among the POC patients (31.37 vs. 17.83; P = .026), who presented more preoperative anemia (33.33 vs. 17.48%; P = .009), required more urgent care (37.25 vs. 22.38; P = .023), and had lower albumin levels. Complicated disease was associated with higher postoperative morbidity. POC patients had a longer operative time (188.77 vs. 143.86 min; P = .005), more intraoperative complications (17.65 vs. 4.55%; P < .001), and lower rates of primary anastomosis. In the multivariate analysis, both smoking and intraoperative complications were independently associated with the occurrence of major postoperative complications.
    CONCLUSIONS: This study shows that risk factors for complications after primary ileocecal resections for Crohn\'s disease in Latin America are similar to those reported elsewhere. Future efforts in the region should be aimed at improving these outcomes by controlling some of the identified factors.
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  • 文章类型: Journal Article
    针对SARS-CoV-2的有效疫苗已经可用,并为控制COVID-19大流行提供了有希望的行动。服用生物制剂的IBD患者接受疫苗以及额外的剂量(如果推荐的话)。
    背景:接种COVID-19疫苗可以预防其严重形式和相关的死亡率,并为控制这种大流行提供了有希望的行动。2021年9月,在免疫抑制患者中批准了额外剂量的疫苗,包括使用生物制剂的IBD患者。我们评估了这组高危患者的疫苗接种率和额外剂量意愿。
    方法:单中心,横断面研究是在接受生物制剂治疗并符合额外剂量COVID-19疫苗条件的IBD患者中进行的.在医疗记录中检查IBD临床特征和疫苗类型以及给药日期。在IBD患者的电话或面对面调查后评估接受度。
    结果:在总共344名患者中,纳入269例患者(46.1%为男性;平均年龄47±16岁;克罗恩病73.6%)。只有15名(5.6%)患者拒绝COVID-19疫苗,主要是(40%)被定罪(COVID-19大流行否认)。33.3%的人会在与医生讨论和/或收到有关疫苗不良反应的信息后重新考虑。在额外剂量之前,94.4%的患者(n=254)存在COVID-19疫苗接种。不良反应发生在53.9%的病例中,主要是手臂疼痛(40%)。高达94.1%的患者同意额外剂量,79.4%的患者在评估的最后时间已经接受了额外剂量。
    结论:服用生物制剂的IBD患者接受疫苗以及额外的剂量(如果推荐)。负责IBD单位的医师应提供信息和信心,以在这些IBD患者中使用疫苗。
    Effective vaccines against the SARS-CoV-2 are already available and offer a promising action to control the COVID-19 pandemic. IBD patients on biological agents accept the vaccine as well as an additional dose if recommended.
    BACKGROUND: Vaccination against COVID-19 prevents its severe forms and associated mortality and offers a promising action to control this pandemic. In September 2021, an additional dose of vaccine was approved in patients with immunosuppression including IBD patients on biologic agents. We evaluated the vaccination rate and additional dose willingness in this group of at risk patients.
    METHODS: A single-center, cross-sectional study was performed among IBD patients on biologic agents and eligible for an additional dose of the COVID-19 vaccine. IBD clinical characteristics and type of vaccine and date of administration were checked in medical records. Acceptance was evaluated after telephone or face-to-face surveys in IBD patients.
    RESULTS: Out of a total of 344 patients, 269 patients (46.1% male; mean age 47±16 years; Crohn\'s disease 73.6%) were included. Only 15 (5.6%) patients refused the COVID-19 vaccine mainly (40%) for conviction (COVID-19 pandemic denial). 33.3% would re-consider after discussing with their doctor and/or receiving information on the adverse effects of the vaccine. Previous to the additional dose, the COVID-19 vaccination was present in 94.4% of patients (n=254). Adverse effects occurred in 53.9% of the cases, mainly pain in the arm (40%). Up to 94.1% of the patients agreed to an additional dose and 79.4% had already received the additional dose at the final time of the assessment.
    CONCLUSIONS: IBD patients on biological agents accept the vaccine as well as an additional dose if recommended. Physicians in charge of IBD units should provide information and confidence in the use of the vaccine in these IBD patients.
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  • 文章类型: Multicenter Study
    目的:这项多中心横断面研究旨在评估COVID-19在封锁和第一波大流行期间对西班牙炎症性肠病(IBD)患者的社会心理影响。
    方法:一份自我报告问卷,整合了西班牙语版的抑郁症,焦虑和压力量表-21项目(DASS-21)和感知压力问卷(PSS)旨在收集与封锁对IBD患者生活影响相关的社会人口统计学数据和信息。12个IBD单位邀请他们的患者在2020年7月1日至8月25日之间回答匿名在线调查。
    结果:在693名IBD调查参与者中,67%为女性,平均年龄为43(SD12)。61%的人患有溃疡性结肠炎,36%的克罗恩病和3%的不确定结肠炎。DASS-21得分表明,在封锁期间,抑郁症的估计患病率为11%[95%CI8.2-13%],焦虑20%[95%CI17至23%]和压力18%[95%CI8.2-13%]。多变量分析显示,由于患有IBD和对政府减少疾病传播的措施不适应,认为COVID-19感染的高风险使封锁期间焦虑和压力的风险增加了一倍。
    结论:在短期内,COVID-19大流行期间的封锁似乎对西班牙IBD患者已经受到影响的心理健康产生了影响。
    OBJECTIVE: This multicenter cross-sectional study was conducted to assess the psychosocial impact of COVID-19 on patients with inflammatory bowel disease (IBD) in Spain during lockdown and the first wave of the pandemic.
    METHODS: A self-report questionnaire that integrated the Spanish version of the Depression, Anxiety and Stress Scale-21 items (DASS-21) and the Perceived Stress Questionnaire (PSS) was designed to gather sociodemographic data and information related to the effects of lockdown on the lives of IBD patients. Twelve IBD units invited their patients to answer the anonymous online survey between the 1st July and the 25th August 2020.
    RESULTS: Of the 693 survey participants with IBD, 67% were women and the mean age was 43 (SD 12). Sixty-one percent had ulcerative colitis, 36% Crohn\'s disease and 3% indeterminate colitis. DASS-21 scores indicate that during lockdown the estimated prevalence of depression was 11% [95% CI 8.2-13%], anxiety 20% [95% CI 17 to 23%] and stress 18% [95% CI 8.2-13%]. Multivariate analysis showed that the perceived high risk of COVID-19 infection because of having IBD and maladaptation to government measures to reduce the spread of disease doubled the risk of anxiety and stress during lockdown.
    CONCLUSIONS: In the short-term, lockdown during the COVID-19 pandemic seemed to have an impact on the already affected mental health of our IBD patients in Spain.
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  • 文章类型: Observational Study
    背景:除了中断炎症性肠病(IBD)等其他疾病的日常临床实践外,COVID-19大流行增加了医疗服务需求。在这里,我们提供了一项调查结果,以在日常实践中使用远程医疗来获得IBD专家对患者管理的看法。
    方法:这是一项针对IBD(胃肠病学家,外科医生,和儿科医生)西班牙克罗恩病和溃疡性结肠炎工作组(GETECCU)的成员,西班牙胃肠病学协会(AEG),和西班牙结肠直肠学协会(AECP),关于IBD患者管理的变化。
    结果:我们总共收到了269份调查回复(从2020年5月到6月)。在大流行之前,几乎所有的受访者都报告说他们的面对面访问非常频繁(n=251,93.3%),在大流行期间,电话访问是最频繁的访问(n=138,51.3%)。关于沟通困难,157(58.4%)受访者表示,最相关的问题是无法进行适当的检查。此外,114名(42.4%)受访者认为远程访问比面对面访问更耗时。大多数胃肠病学家(n=188,83.2%)认为患有活动性肛周疾病的患者特别需要面对面咨询,超过一半的外科医生(n=35,50.7%)报告说已立即进行了术后远程随访。
    结论:大多数IBD单位在大流行期间实施了远程访问,但是大多数专业人士发现它们更耗时,不适合某些疾病的概况。因此,需要开发更好的远程医疗系统,以满足专业人员和患者的要求。
    BACKGROUND: COVID-19 pandemic increased medical services demand aside from interrupting daily clinical practice for other diseases such as inflammatory bowel disease (IBD). Here we present the results of a survey to gain the perception of IBD specialists in their patient-management using telemedicine in their daily practice.
    METHODS: This was an observational survey study among physicians focused on IBD (gastroenterologist, surgeons, and pediatricians) members of the Spanish Working Group on Crohn\'s Disease and Ulcerative Colitis (GETECCU), the Spanish Association of Gastroenterology (AEG), and the Spanish Association of Coloproctology (AECP), regarding changes of management of IBD patients.
    RESULTS: We received a total of 269 responses to the survey (from May to June 2020). Before the pandemic, nearly all the respondents reported performing very frequently their visits face-to-face (n=251, 93.3%) while, during the pandemic, the telephone visits were the most frequent visits performed (n=138, 51.3%). Regarding communication difficulties, 157 (58.4%) respondents reported the impossibility of performing a proper examination as the most relevant issue. Also, 114 (42.4%) respondents considered remote visits more time-consuming than face-to-face visits. Most gastroenterologists (n=188, 83.2%) considered patients with active perianal disease in special need of face-to-face consultation and more than half of the surgeons (n=35, 50.7%) reported having performed an immediate postoperative follow-up remotely.
    CONCLUSIONS: Most IBD units have implemented remote visits during the pandemic, but most professionals found them more time-consuming and unsuitable for some disease profiles. Therefore, there is a need for the development of better telemedicine systems that can meet professionals\' and patients\' requirements.
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  • 文章类型: Journal Article
    背景:炎症性肠病(IBD)患者容易受到某些心理障碍的影响。在这里,我们描述了COVID-19大流行封锁对IBD患者的心理影响。
    方法:这项多中心前瞻性队列研究包括145名最近诊断为IBD的患者。关于临床和人口统计学特征的数据,焦虑和抑郁量表,和IBD活动是在两次电话调查中收集的,在西班牙首次COVID-19封锁期间和之后。计算赔率(OR)和95%置信区间(CI)。
    结果:在封锁期间,33.1%和24.1%在焦虑和抑郁量表上得分较高,分别。锁定期间与焦虑相关的独立因素(所有OR值;95%CIs)是女性(2;1.2-5.4)和IBD活动(4.3;1.8-10.4)。与抑郁症相关的因素是合并症(3.3;1.1-9.8),IBD活动(6;1.9-18.1),生物制剂的使用(2.9;1.1-7.6),单独或与一个人一起生活(3.1;1.2-8.2)。封锁后,焦虑和抑郁症状明显改善,其中24.8%和15.2%的人在焦虑和抑郁方面得分很高,分别。与锁定后焦虑相关的因素是女性(2.5;1.01-6.3),克罗恩病(3.3;1.3-8.5),和活动性IBD(4.1;1.2-13.7)。与抑郁症相关的因素是既往有情绪和/或焦虑症(6.3;1.6-24.9),活动性IBD(7.5;2.1-26.8),和类固醇的使用(6.4;1.4-29)。
    结论:COVID-19大流行期间的封锁对IBD患者的心理影响显著。疾病活动与封锁期间和之后焦虑和抑郁症状的存在有关。
    BACKGROUND: Patients with inflammatory bowel disease (IBD) are vulnerable to some psychological disorders. Here we describe the psychological impact of a COVID-19 pandemic lockdown in patients with IBD.
    METHODS: This multicenter prospective cohort study included 145 patients recently diagnosed with IBD. Data on clinical and demographic characteristics, anxiety and depression scales, and IBD activity were collected in two telephone surveys, during and after the first COVID-19 lockdown in Spain. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.
    RESULTS: During lockdown, 33.1% and 24.1% scored high on the anxiety and depression scales, respectively. Independent factors related to anxiety (all values ORs; 95% CIs) during lockdown were female sex (2; 1.2-5.4) and IBD activity (4.3; 1.8-10.4). Factors related to depression were comorbidity (3.3; 1.1-9.8), IBD activity (6; 1.9-18.1), use of biologics (2.9; 1.1-7.6), and living alone or with one person (3.1; 1.2-8.2). After lockdown, anxiety and depression symptoms showed significant improvement, with 24.8% and 15.2% having high scores for anxiety and depression, respectively. Factors related to post-lockdown anxiety were female sex (2.5; 1.01-6.3), Crohn\'s disease (3.3; 1.3-8.5), and active IBD (4.1; 1.2-13.7). Factors associated with depression were previous history of mood and/or anxiety disorders (6.3; 1.6-24.9), active IBD (7.5; 2.1-26.8), and steroid use (6.4; 1.4-29).
    CONCLUSIONS: Lockdown during the COVID-19 pandemic had a significant psychological impact in patients with IBD. Disease activity was related to the presence of anxiety and depression symptoms during and after lockdown.
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  • 文章类型: Journal Article
    理解嵌入在主要代谢中的基本原理对于解释发酵数据非常重要。为此,基于系统生物学方法理解调控机制可能是有用的。在本研究中,我们考虑了扰动分析和基于模型的计算机模拟,这些模型包括全局调节因子对大肠杆菌主要代谢途径激活的影响。主要关注的是乙酸盐溢流代谢和多种碳源的共发酵。首先进行了扰动分析,以了解FDP(F1,6BP)激活Pyk所形成的前馈回路的性质,以及糖酵解中PEP对Pfk的抑制作用形成的反馈回路。那些连同转录因子Cra的效应所惹起的FDP程度影响了糖酵解活性。PTS(磷酸转移酶系统)通过抑制葡萄糖摄取速率以增加葡萄糖摄取速率而充当反馈系统。还表明,增加的PTS通量(或葡萄糖消耗率)导致PEP/PYR比率降低,和EIIA-P,Cya,cAMP-Crp下降,其中cAMP-Crp又抑制了TCA循环,并形成了更多的乙酸盐。详细的盘算机仿真进一步验证了这一点。在多种碳源如葡萄糖和木糖的情况下,结果表明,在野生型中观察到碳源的顺序利用,虽然通过计算机模拟观察到ptsG突变体消耗速率缓慢的多种碳源的共同消耗,并通过实验验证了这一点。此外,还基于计算机模拟研究了诸如Δpyk的特定基因敲除对代谢特征的影响。
    It is quite important to understand the basic principle embedded in the main metabolism for the interpretation of the fermentation data. For this, it may be useful to understand the regulation mechanism based on systems biology approach. In the present study, we considered the perturbation analysis together with computer simulation based on the models which include the effects of global regulators on the pathway activation for the main metabolism of Escherichia coli. Main focus is the acetate overflow metabolism and the co-fermentation of multiple carbon sources. The perturbation analysis was first made to understand the nature of the feed-forward loop formed by the activation of Pyk by FDP (F1,6BP), and the feed-back loop formed by the inhibition of Pfk by PEP in the glycolysis. Those together with the effect of transcription factor Cra caused by FDP level affected the glycolysis activity. The PTS (phosphotransferase system) acts as the feed-back system by repressing the glucose uptake rate for the increase in the glucose uptake rate. It was also shown that the increased PTS flux (or glucose consumption rate) causes PEP/PYR ratio to be decreased, and EIIA-P, Cya, cAMP-Crp decreased, where cAMP-Crp in turn repressed TCA cycle and more acetate is formed. This was further verified by the detailed computer simulation. In the case of multiple carbon sources such as glucose and xylose, it was shown that the sequential utilization of carbon sources was observed for wild type, while the co-consumption of multiple carbon sources with slow consumption rates were observed for the ptsG mutant by computer simulation, and this was verified by experiments. Moreover, the effect of a specific gene knockout such as Δpyk on the metabolic characteristics was also investigated based on the computer simulation.
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