Background The emergence of antibiotic resistant microorganisms associated with conventional swine production practices has increased interest in acid-based compounds having antimicrobial properties and other biologic...Background The emergence of antibiotic resistant microorganisms associated with conventional swine production practices has increased interest in acid-based compounds having antimicrobial properties and other biological functions as nutritional interventions.Despite the interest in organic acids and monoglycerides,few studies have examined the effects of the combination of these acid-based additives in weaned pigs under disease challenge conditions.Therefore,this study aimed to investigate the effects of dietary supplementation with blend of organic acids and/or medium-chain fatty acid monoglycerides on intestinal health and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC)F18 at 4-week of age.Results Dietary supplementation of organic acids,monoglycerides,or both organic acids and monoglycerides(combination)reduced(P<0.05)the diarrhea frequency of ETEC F18-infected pigs throughout the experimental period(d−7 to 21 post-inoculation).This is consistent with the reduced(P<0.05)proportion ofβ-hemolytic coliforms in feces observed for the organic acid and combination treatments on d 10 post-inoculation.Supplementation of organic acids,monoglycerides,or combination also reduced(P<0.05)bacterial translocation in mesenteric lymph nodes on d 21 post-inoculation.Pigs fed with monoglycerides or combination had lower(P<0.05)white blood cells on d 5 post-inoculation,and pigs fed the combination also had lower(P<0.05)lymphocytes than pigs in control group.Monoglyceride supplementation increased(P<0.05)white blood cells and neutrophils compared with control group on d 14 post-inoculation.However,supplementation with organic acid blend,monoglyceride blend,or combination did not affect growth performance in this experiment.Conclusions Supplementation with monoglycerides or organic acids alone or in combination improves the detrimental effects of ETEC F18 infection in weaned pigs,as indicated by reduced diarrhea,fecal shedding ofβ-hemolytic coliforms,and bacterial translocation,and thus enhancing disease resistance.Monoglycerides reduced the inflammatory response during peak infection,but their immunomodulatory and possible synergistic effects with organic acids need to be further investigated.展开更多
In clinical practice,antibiotics have historically been utilized for the treatment of pathogenic bacteria.However,the gradual emergence of antibiotic resistance among bacterial strains has posed a significant challeng...In clinical practice,antibiotics have historically been utilized for the treatment of pathogenic bacteria.However,the gradual emergence of antibiotic resistance among bacterial strains has posed a significant challenge to this approach.In 2022,Escherichia coli,a Gram-negative bacterium renowned for its widespread pathogenicity and high virulence,emerged as the predominant pathogenic bacterium in China.The rapid emergence of antibiotic-resistant E.coli strains has rendered antibiotics insufficient to fight E.coli infections.Traditional Chinese medicine(TCM)has made remarkable contributions to the health of Chinese people for thousands of years,and its significant therapeutic effects have been proven in clinical practice.In this paper,we provide a comprehensive review of the advances and mechanisms of TCM and its active ingredients against antibiotic-resistant E.coli infections.First of all,this review introduces the classification,antibiotic resistance characteristics and mechanisms of E.coli.Then,the TCM formulas and extracts are listed along with their active ingredients against E.coli,including extraction solution,minimum inhibitory concentration(MIC),and the antibacterial mechanisms.In addition,there is growing evidence supporting the synergistic therapeutic strategy of combining TCM with antibiotics for the treatment of antibiotic-resistant E.coli infections,and we provide a summary of this evidence and its underlying mechanisms.In conclusion,we present a comprehensive review of TCM and highlight its potential and advantages in the prevention and treatment of E.coli infections.We hold the opinion that TCM will play an important role in global health,pharmaceutical development,and livestock farming in the future.展开更多
[Objective]To construct an Escherichia coli mutant strain that accumulates pyruvate by genetic modification guided by the genome-scale metabolic network model.[Methods]Using a genome-scale metabolic network model as a...[Objective]To construct an Escherichia coli mutant strain that accumulates pyruvate by genetic modification guided by the genome-scale metabolic network model.[Methods]Using a genome-scale metabolic network model as a guide,we simulated pyruvate production of E.coli,screened key genes in metabolic pathways,and developed gene editing procedures accordingly.We knocked out the acetate kinase gene ackA,phosphate acetyltransferase gene pta,alcohol dehydrogenase adhE,glycogen synthase gene glgA,glycogen phosphorylase gene glgP,phosphoribosyl pyrophosphate(PRPP)synthase gene prs,ribose 1,5-bisphosphate phosphokinase gene phnN,and transporter encoding gene proP.Furthermore,we knocked in the transporter encoding gene ompC,flavonoid toxin gene fldA,and D-serine ammonia lyase gene dsdA.[Results]A shake flask process with the genetically edited mutant strain MG1655-6-2 under anaerobic conditions produced pyruvate at a titer of 10.46 g/L and a yield of 0.69 g/g.Metabolomic analysis revealed a significant increase in the pyruvate level in the fermentation broth,accompanied by notable decreases in the levels of certain related metabolic byproducts.Through 5 L fed-batch fermentation and an adaptive laboratory evolution,the strain finally achieved a pyruvate titer of 45.86 g/L.[Conclusion]This study illustrated the efficacy of a gene editing strategy predicted by a genome-scale metabolic network model in enhancing pyruvate accumulation in E.coli under anaerobic conditions and provided novel insights for microbial metabolic engineering.展开更多
Background L-Glutamate and L-aspartate are functional amino acids that play pivotal roles in the cellular metabolic pathways of swine enterocytes.Therefore,this study aimed to investigate the effects of dietary L-glut...Background L-Glutamate and L-aspartate are functional amino acids that play pivotal roles in the cellular metabolic pathways of swine enterocytes.Therefore,this study aimed to investigate the effects of dietary L-glutamate and L-aspartate on growth performance,diarrhea severity,intestinal barrier integrity,and fecal microbiota of weaned piglets challenged with F18 enterotoxigenic Escherichia coli(ETEC).Weaned piglets were randomly assigned to seven dietary treatments,including unchallenged and ETEC-challenged controls,amino acid-supplemented groups,and an antibiotic control,to assess their responses to ETEC challenge.Results Supplementation with 1%L-glutamate or 2%L-aspartate enhanced growth performance,with significantly greater(P<0.05)average daily weight gain and gain-to-feed ratio compared with the positive control group from d 0 to d 5 post-inoculation.Pigs fed with 1%or 2%L-aspartate had reduced(P<0.05)diarrhea severity in ETEC-challenged pigs compared with the positive control group.The 1%L-aspartate supplementation also supported intestinal structure by increasing(P<0.05)duodenal villi height and ileal villi width compared with carbadox supplementation.Additionally,1%L-glutamate supplementation significantly improved(P<0.05)resilience in ETEC-challenged pigs by reducing fecal shedding ofβ-hemolysin-producing bacteria compared with the positive control group on d 14 post-inoculation.Moreover,1%L-aspartate supplementation promoted intestinal barrier integrity by significantly up-regulated(P<0.05)the expression of ileal OCDN and ileal ZO-1 compared with the positive control group on d 14 post-inoculation.Interestingly,2%L-aspartate supplementation altered the intestinal mucosa by down-regulating(P<0.05)the expression of jejunal CLDN-1,while up-regulating(P<0.05)the expression of ileal CLDN-1 compared with the negative control group on d 14 post-inoculation.Furthermore,L-glutamate supplementation significantly changed proportions of Firmicutes and Bacteroidota and showed the trend for enrichment in beneficial bacterial genera such as Bifidobacterium and Megasphaera in ETEC-infected pigs by d 14 post-inoculation.Conclusion Supplementation with L-glutamate or L-aspartate promoted growth performance,supported gut health,and enhanced disease resistance in weaned pigs challenged with F18 ETEC.During the weaning period,L-glutamate or L-aspartate could potentially be considered conditionally essential amino acids,helping to alleviate weaning complications and reduce the need for antibiotic use in swine farming.展开更多
Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging,yet there is limited understanding of gut microbiome variation in advanced age.Here,we performed a metagenom...Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging,yet there is limited understanding of gut microbiome variation in advanced age.Here,we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years,with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations.In addition to two adult-like enterotypes dominated by Bacteroides(ET-Bacteroides)and Prevotella(ET-Prevotella),we identified a novel enterotype dominated by Escherichia(ET-Escherichia),whose prevalence increased in advanced age.Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus(T2DM)or diet.We characterized the distinct taxonomic and functional profiles of ET-Escherichia,and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype,as well as the lowest species diversity.In addition,we carried out a series of correlation analyses and co-abundance network analyses,which showed that several factors were likely linked to the overabundance of Escherichia members,including advanced age,vegetable intake,and fruit intake.Overall,our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population.Considering the different age distribution of each enterotype,these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.展开更多
Background Monoglycerides have emerged as a promising alternative to conventional practices due to their biolog-ical activities,including antimicrobial properties.However,few studies have assessed the efficacy of mono...Background Monoglycerides have emerged as a promising alternative to conventional practices due to their biolog-ical activities,including antimicrobial properties.However,few studies have assessed the efficacy of monoglyceride blend on weaned pigs and their impacts on performance,immune response,and gut health using a disease chal-lenge model.Therefore,this study aimed to investigate the effects of dietary monoglycerides of short-and medium-chain fatty acids on the immunity and gut health of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli F18.Results Pigs supplemented with high-dose zinc oxide(ZNO)had greater(P<0.05)growth performance than other treatments,but no difference was observed in average daily feed intake between ZNO and monoglycerides groups during the post-challenge period.Pigs in ZNO and antibiotic groups had lower(P<0.05)severity of diarrhea than control,but the severity of diarrhea was not different between antibiotic and monoglycerides groups.Pigs fed with monoglycerides or ZNO had lower(P<0.05)serum haptoglobin on d 2 or 5 post-inoculation than control.Pigs in ZNO had greater(P<0.05)goblet cell numbers per villus,villus area and height,and villus height:crypt depth ratio(VH:CD)in duodenum on d 5 post-inoculation than pigs in other treatments.Pigs supplemented with monoglyc-erides,ZNO,or antibiotics had reduced(P<0.05)ileal crypt depth compared with control on d 5 post-inoculation,contributing to the increase(P=0.06)in VH:CD.Consistently,pigs in ZNO expressed the lowest(P<0.05)TNFa,IL6,IL10,IL12,IL1A,IL1B,and PTGS2 in ileal mucosa on d 5 post-inoculation,and no difference was observed in the expres-sion of those genes between ZNO and monoglycerides.Supplementation of ZNO and antibiotic had significant impacts on metabolic pathways in the serum compared with control,particularly on carbohydrate and amino acid metabolism,while limited impacts on serum metabolites were observed in monoglycerides group when compared with control.Conclusions The results suggest that supplementation of monoglyceride blend may enhance disease resist-ance of weaned pigs by alleviating the severity of diarrhea and mitigating intestinal and systemic inflammation,although the effectiveness may not be comparable to high-dose zinc oxide.展开更多
Background:Urinary tract infections(UTIs),primarily caused by uropathogenic Escherichia coli(UPEC),are a significant global health concern.The complications arise from antibiotic resistance and biofilm formation,which...Background:Urinary tract infections(UTIs),primarily caused by uropathogenic Escherichia coli(UPEC),are a significant global health concern.The complications arise from antibiotic resistance and biofilm formation,which reduce the effectiveness of conventional treatments.This study aims to evaluate the antibiofilm activity of the homeopathic medicine Terebinthinae oleum in potencies 30C,200C,and 1M against UTI-causing E.coli,and to compare its effectiveness with the standard antibiotic Gentamycin.Methods:An in-vitro biofilm model was employed.E.coli biofilms were cultivated in microtiter plates and treated with Terebinthinae oleum(30C,200C,1M)and Gentamycin.Biofilm biomass was assessed through crystal violet staining,and optical density(OD)was measured using an ELISA microplate reader.Results:Among the tested potencies,Terebinthinae oleum 30C showed the most prominent inhibitory activity on E.coli biofilms.The inhibition percentage was compared with Gentamycin as a control.Terebinthinae oleum 30C demonstrated 41.88%inhibition of biofilm biomass,while Gentamycin exhibited up to 78.98%inhibition.Higher potencies of Terebinthinae oleum(200C and 1M)showed reduced activity(30.15%and 24.81%,respectively).Conclusion:Terebinthinae oleum,especially at 30C potency,exhibits measurable antibiofilm activity against E.coli,although less effective than Gentamycin.These findings support its use as a complementary therapy in managing biofilm-associated UTIs,justifying further clinical and immunological research.展开更多
Quorum sensing(QS)represents a mechanism through which bacteria engage in communication via chemical signals,a phenomenon prevalent across diverse bacterial species.Recent investigations have elucidated that QS signal...Quorum sensing(QS)represents a mechanism through which bacteria engage in communication via chemical signals,a phenomenon prevalent across diverse bacterial species.Recent investigations have elucidated that QS signaling pathways are pivotal in governing bacterial physiological processes,collective behaviors,and the emergence of drug resistance.Escherichia coli(E.coli),a prominent pathogenic bacterium,is increasingly exhibiting severe drug resistance issues,posing substantial hurdles for clinical interventions.Presently,a burgeoning body of research is exploring the connection between QS signaling pathways and the drug resistance mechanisms in E.coli,unveiling the coordinating function of QS within bacterial communities and its influence on antibiotic resistance.Despite some research advancements,the precise mechanisms underlying the QS signaling pathway remain ambiguous,and its potential applications are somewhat constrained.This article endeavors to systematically review the research progress concerning the QS signaling pathway in the context of clinical drug resistance mechanisms in E.coli,delving into its potential clinical applications and future research avenues,with the aim of offering novel insights and strategies to counteract drug resistance.展开更多
Background Enterotoxigenic Escherichia coli(E.coli)is a threat to humans and animals that causes intestinal dis-orders.Antimicrobial resistance has urged alternatives,including Lactobacillus postbiotics,to mitigate th...Background Enterotoxigenic Escherichia coli(E.coli)is a threat to humans and animals that causes intestinal dis-orders.Antimicrobial resistance has urged alternatives,including Lactobacillus postbiotics,to mitigate the effects of enterotoxigenic E.coli.Methods Forty-eight newly weaned pigs were allotted to NC:no challenge/no supplement;PC:F18^(+)E.coli chal-lenge/no supplement;ATB:F18^(+)E.coli challenge/bacitracin;and LPB:F18^(+)E.coli challenge/postbiotics and fed diets for 28 d.On d 7,pigs were orally inoculated withF18^(+)E.coli.At d 28,the mucosa-associated microbiota,immune and oxidative stress status,intestinal morphology,the gene expression of pattern recognition receptors(PRR),and intestinal barrier function were measured.Data were analyzed using the MIXED procedure in SAS 9.4.Results PC increased(P<0.05)Helicobacter mastomyrinus whereas reduced(P<0.05)Prevotella copri and P.ster-corea compared to NC.The LPB increased(P<0.05)P.stercorea and Dialister succinatiphilus compared with PC.The ATB increased(P<0.05)Propionibacterium acnes,Corynebacterium glutamicum,and Sphingomonas pseudosanguinis compared to PC.The PC tended to reduce(P=0.054)PGLYRP4 and increased(P<0.05)TLR4,CD14,MDA,and crypt cell proliferation compared with NC.The ATB reduced(P<0.05)NOD1 compared with PC.The LPB increased(P<0.05)PGLYRP4,and interferon-γand reduced(P<0.05)NOD1 compared with PC.The ATB and LPB reduced(P<0.05)TNF-αand MDA compared with PC.Conclusions TheF18^(+)E.coli challenge compromised intestinal health.Bacitracin increased beneficial bacteria show-ing a trend towards increasing the intestinal barrier function,possibly by reducing the expression of PRR genes.Lac-tobacillus postbiotics enhanced the immunocompetence of nursery pigs by increasing the expression of interferon-γand PGLYRP4,and by reducing TLR4,NOD1,and CD14.展开更多
Bacterial infections of avian embryos can lead to an increase in embryo mortality,and the proliferation of antimicrobial-resistant bacteria aggravates the situation.A low hatching rate also poses a challenge to the po...Bacterial infections of avian embryos can lead to an increase in embryo mortality,and the proliferation of antimicrobial-resistant bacteria aggravates the situation.A low hatching rate also poses a challenge to the population of artificially bred Crested Ibises(Nipponia nippon).This study aims to determine the potential association between bacterial infection and the death of Crested Ibis embryos,and whether there is convergence between antimicrobial resistance and virulence in strain.In this study,13 Escherichia coli and 12 Proteus mirabilis isolates were recovered from dead Crested Ibis embryos.The pathogenicity examination confirmed the pathogenicity of all isolates,and multiple virulence genes detected by PCR-sequencing demonstrated the presence of irp2 and iuc D(100%),fim C and iss(92.31%)in E.coli,and uca A(58.33%)in P.mirabilis.Antimicrobial susceptibility test demonstrated that isolates were mainly resistant to amoxicillin(E.coli:76.92%,P.mirabilis:91.67%),cefazolin(E.coli:76.92%,P.mirabilis:91.67%),oxytetracycline(E.coli:92.31%,P.mirabilis:75.00%)and sulfamethoxazole-trimethoprim(E.coli:53.85%,P.mirabilis:33.33%),and more than 30%of isolates showed multidrug-resistance(MDR).Further analyses detected extended-spectrumβ-lactamase(ESBL)genes,of which blaTEM-1(E.coli:100%,P.mirabilis:100%)had the highest frequency,followed by the blaCTX-M-55(E.coli:92.31%,P.mirabilis:50%),blaCTX-M-14(E.coli:76.92%,P.mirabilis:33.33%),blaCTX-M-65(E.coli:15.38%,P.mirabilis:16.67%),and all isolates were negative for blaSHV and blaOXA.Pearson's correlation analysis showed a positive correlation between the presence ofβ-lactam resistance and ESBL genes,while mainly negative correlations were observed between the presence of ESBL genes and virulence genes.Furthermore,the conjugation experiment and PFGE revealed that the isolates were primarily polyclonal,and there was horizontal transfer of resistance or virulence genes by plasmids.Based on the results,E.coli and P.mirabilis were responsible for embryonic mortality of the ibises in this study.The co-presence and co-transfer of ESBL genes and virulence genes can pose a potential threat to the health of the Crested Ibis,and measures such as prudent use of antimicrobials,and constant surveillance of resistance and pathogenicity,must be implemented at the Crested Ibis breeding base.展开更多
Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate asse...Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate assembly technique,utilizing Escherichia coli as the model organism.Through polymerase chain reaction(PCR)amplification,restriction enzyme digestion,ligation,transformation,and Sanger sequencing,we assessed the operational efficiency and cloning fidelity of both strategies.Our results demonstrated that Golden Gate assembly,leveraging type IIS restriction enzymes and simultaneous ligation,significantly enhanced cloning efficiency and precision,particularly for seamless multi-fragment assembly.In contrast,the classical cloning approach maintained certain advantages in simplicity and robustness for specific experimental conditions.Challenges encountered during transformation and sequencing highlighted the critical impact of technical accuracy on experimental outcomes.This study underscores the importance of selecting appropriate cloning methodologies tailored to experimental objectives and laboratory capabilities,providing a foundation for optimized molecular cloning workflows in future synthetic biology and biotechnology applications.展开更多
Enterotoxigenic E.coli is one of the bacterial pathogens contributing to the global resistance crisis in public health and animal husbandry.The problem of antibiotic resistance is becoming more and more serious,and ph...Enterotoxigenic E.coli is one of the bacterial pathogens contributing to the global resistance crisis in public health and animal husbandry.The problem of antibiotic resistance is becoming more and more serious,and phage is con-sidered one of the potential alternatives to antibiotics that could be utilized to treat bacterial infections.Our study isolated and identified a lytic phage PGX1 against multidrug-resistant enterotoxigenic E.coli EC6 strain from sew-age.The phage lysis profile revealed that PGX1 exhibited a lytic effect on multidrug-resistant enterotoxigenic E.coli strains of serotype O60.Through phage whole genome sequencing and bioinformatics analysis,PGX1 was found to be the class Caudoviricetes,family Autographiviridae,genus Teseptimavirus.The length of the PGX1 genome is about 37,009 bp,containing 54 open reading frames(ORFs).Notably,phage PGX1 lacks any lysogenic-related genes or virulence genes.Furthermore,phage PGX1 demonstrates strong adaptability,tolerance,and stability in various pH(pH4-10)and temperatures(4–40°C).The in vivo and in vitro tests demonstrated that phage PGX1 significantly removes and inhibits the formation of multidrug-resistant EC6 biofilm and effectively controls the Galleria mel-lonella larvae and enterotoxigenic E.coli EC6 during mice infection.In conclusion,the above findings demonstrated that phage PGX1 may be a novel antimicrobial agent to control multidrug-resistant E.coli infections.展开更多
[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis fo...[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis for cattle manure harmless treatment.[Method] Both experimental groups supplemented with 2.0% bacterial inhibitor and control groups without bacterial inhibitor were cultured under different temperatures(20,30,37,50,60 ℃)to determine the optimal composing temperature.Under 30 ℃,different bacterial inhibitor doses(0,2.0%,2.5%,3.0%)were added into the compost to obtain the optimal bacterial inhibitor addition dose.[Result] 30,50 and 60 ℃ were ideal temperatures for sterilization of E.coli.Under 30 ℃,E.coli couldn't be detected in 2.5% dose group and 3.0% dose group after culture for 48 h,demonstrating no less than 2.5% bacterial inhibitor should be added.[Conclusion] It has an important significance to enhance the sterilization effects on E.coli by adding CaCN2 into cattle manure compost especially in winter.展开更多
Several technical parameters were studied during the fermentation of recombinant E.coli for the production of collagen-like biopolymer.The effects of dissolved oxygen as well as glucose concentration on fermentation w...Several technical parameters were studied during the fermentation of recombinant E.coli for the production of collagen-like biopolymer.The effects of dissolved oxygen as well as glucose concentration on fermentation were observed.The OD 600 value could reach 98 when dissolved oxygen was controlled at 50% and glucose around 1%.The production of human-like collagen with a yield of 29.4% was obtained.展开更多
基金supported by Animal Nutrition,Eastman Chemical Company,Kingsport,TN,USA.
文摘Background The emergence of antibiotic resistant microorganisms associated with conventional swine production practices has increased interest in acid-based compounds having antimicrobial properties and other biological functions as nutritional interventions.Despite the interest in organic acids and monoglycerides,few studies have examined the effects of the combination of these acid-based additives in weaned pigs under disease challenge conditions.Therefore,this study aimed to investigate the effects of dietary supplementation with blend of organic acids and/or medium-chain fatty acid monoglycerides on intestinal health and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC)F18 at 4-week of age.Results Dietary supplementation of organic acids,monoglycerides,or both organic acids and monoglycerides(combination)reduced(P<0.05)the diarrhea frequency of ETEC F18-infected pigs throughout the experimental period(d−7 to 21 post-inoculation).This is consistent with the reduced(P<0.05)proportion ofβ-hemolytic coliforms in feces observed for the organic acid and combination treatments on d 10 post-inoculation.Supplementation of organic acids,monoglycerides,or combination also reduced(P<0.05)bacterial translocation in mesenteric lymph nodes on d 21 post-inoculation.Pigs fed with monoglycerides or combination had lower(P<0.05)white blood cells on d 5 post-inoculation,and pigs fed the combination also had lower(P<0.05)lymphocytes than pigs in control group.Monoglyceride supplementation increased(P<0.05)white blood cells and neutrophils compared with control group on d 14 post-inoculation.However,supplementation with organic acid blend,monoglyceride blend,or combination did not affect growth performance in this experiment.Conclusions Supplementation with monoglycerides or organic acids alone or in combination improves the detrimental effects of ETEC F18 infection in weaned pigs,as indicated by reduced diarrhea,fecal shedding ofβ-hemolytic coliforms,and bacterial translocation,and thus enhancing disease resistance.Monoglycerides reduced the inflammatory response during peak infection,but their immunomodulatory and possible synergistic effects with organic acids need to be further investigated.
基金supported by the Fundamental Research Funds for the Central Public Welfare Research Institutes,China(Grant Nos.:ZZ16-YQ-037,JIPY2023003,and JJPY2022022)China Academy of Chinese Medical Sciences(CACMS)Innovation Fund(Grant No.:CI2021A00601).
文摘In clinical practice,antibiotics have historically been utilized for the treatment of pathogenic bacteria.However,the gradual emergence of antibiotic resistance among bacterial strains has posed a significant challenge to this approach.In 2022,Escherichia coli,a Gram-negative bacterium renowned for its widespread pathogenicity and high virulence,emerged as the predominant pathogenic bacterium in China.The rapid emergence of antibiotic-resistant E.coli strains has rendered antibiotics insufficient to fight E.coli infections.Traditional Chinese medicine(TCM)has made remarkable contributions to the health of Chinese people for thousands of years,and its significant therapeutic effects have been proven in clinical practice.In this paper,we provide a comprehensive review of the advances and mechanisms of TCM and its active ingredients against antibiotic-resistant E.coli infections.First of all,this review introduces the classification,antibiotic resistance characteristics and mechanisms of E.coli.Then,the TCM formulas and extracts are listed along with their active ingredients against E.coli,including extraction solution,minimum inhibitory concentration(MIC),and the antibacterial mechanisms.In addition,there is growing evidence supporting the synergistic therapeutic strategy of combining TCM with antibiotics for the treatment of antibiotic-resistant E.coli infections,and we provide a summary of this evidence and its underlying mechanisms.In conclusion,we present a comprehensive review of TCM and highlight its potential and advantages in the prevention and treatment of E.coli infections.We hold the opinion that TCM will play an important role in global health,pharmaceutical development,and livestock farming in the future.
基金supported by the Hebei Provincial Key Research and Development Project(21372803D)。
文摘[Objective]To construct an Escherichia coli mutant strain that accumulates pyruvate by genetic modification guided by the genome-scale metabolic network model.[Methods]Using a genome-scale metabolic network model as a guide,we simulated pyruvate production of E.coli,screened key genes in metabolic pathways,and developed gene editing procedures accordingly.We knocked out the acetate kinase gene ackA,phosphate acetyltransferase gene pta,alcohol dehydrogenase adhE,glycogen synthase gene glgA,glycogen phosphorylase gene glgP,phosphoribosyl pyrophosphate(PRPP)synthase gene prs,ribose 1,5-bisphosphate phosphokinase gene phnN,and transporter encoding gene proP.Furthermore,we knocked in the transporter encoding gene ompC,flavonoid toxin gene fldA,and D-serine ammonia lyase gene dsdA.[Results]A shake flask process with the genetically edited mutant strain MG1655-6-2 under anaerobic conditions produced pyruvate at a titer of 10.46 g/L and a yield of 0.69 g/g.Metabolomic analysis revealed a significant increase in the pyruvate level in the fermentation broth,accompanied by notable decreases in the levels of certain related metabolic byproducts.Through 5 L fed-batch fermentation and an adaptive laboratory evolution,the strain finally achieved a pyruvate titer of 45.86 g/L.[Conclusion]This study illustrated the efficacy of a gene editing strategy predicted by a genome-scale metabolic network model in enhancing pyruvate accumulation in E.coli under anaerobic conditions and provided novel insights for microbial metabolic engineering.
基金Funding support was from the Novo Nordisk Foundation with the project's grant number NNFSA210073688.
文摘Background L-Glutamate and L-aspartate are functional amino acids that play pivotal roles in the cellular metabolic pathways of swine enterocytes.Therefore,this study aimed to investigate the effects of dietary L-glutamate and L-aspartate on growth performance,diarrhea severity,intestinal barrier integrity,and fecal microbiota of weaned piglets challenged with F18 enterotoxigenic Escherichia coli(ETEC).Weaned piglets were randomly assigned to seven dietary treatments,including unchallenged and ETEC-challenged controls,amino acid-supplemented groups,and an antibiotic control,to assess their responses to ETEC challenge.Results Supplementation with 1%L-glutamate or 2%L-aspartate enhanced growth performance,with significantly greater(P<0.05)average daily weight gain and gain-to-feed ratio compared with the positive control group from d 0 to d 5 post-inoculation.Pigs fed with 1%or 2%L-aspartate had reduced(P<0.05)diarrhea severity in ETEC-challenged pigs compared with the positive control group.The 1%L-aspartate supplementation also supported intestinal structure by increasing(P<0.05)duodenal villi height and ileal villi width compared with carbadox supplementation.Additionally,1%L-glutamate supplementation significantly improved(P<0.05)resilience in ETEC-challenged pigs by reducing fecal shedding ofβ-hemolysin-producing bacteria compared with the positive control group on d 14 post-inoculation.Moreover,1%L-aspartate supplementation promoted intestinal barrier integrity by significantly up-regulated(P<0.05)the expression of ileal OCDN and ileal ZO-1 compared with the positive control group on d 14 post-inoculation.Interestingly,2%L-aspartate supplementation altered the intestinal mucosa by down-regulating(P<0.05)the expression of jejunal CLDN-1,while up-regulating(P<0.05)the expression of ileal CLDN-1 compared with the negative control group on d 14 post-inoculation.Furthermore,L-glutamate supplementation significantly changed proportions of Firmicutes and Bacteroidota and showed the trend for enrichment in beneficial bacterial genera such as Bifidobacterium and Megasphaera in ETEC-infected pigs by d 14 post-inoculation.Conclusion Supplementation with L-glutamate or L-aspartate promoted growth performance,supported gut health,and enhanced disease resistance in weaned pigs challenged with F18 ETEC.During the weaning period,L-glutamate or L-aspartate could potentially be considered conditionally essential amino acids,helping to alleviate weaning complications and reduce the need for antibiotic use in swine farming.
基金supported by the National Natural Science Foundation of China(Nos.82101665,82271588,82200665,and 82100795)the Zhejiang Provincial Natural Science Foundation of China(No.LY22H030009)+1 种基金the Zhejiang Provincial Science and Technology Program of Traditional Chinese Medicine(No.2023ZL480)the Medical and Health Research Project of Zhejiang Province(No.2023RC153),China.
文摘Gut microbial communities are likely remodeled in tandem with accumulated physiological decline during aging,yet there is limited understanding of gut microbiome variation in advanced age.Here,we performed a metagenomics-based enterotype analysis in a geographically homogeneous cohort of 367 enrolled Chinese individuals between the ages of 60 and 94 years,with the goal of characterizing the gut microbiome of elderly individuals and identifying factors linked to enterotype variations.In addition to two adult-like enterotypes dominated by Bacteroides(ET-Bacteroides)and Prevotella(ET-Prevotella),we identified a novel enterotype dominated by Escherichia(ET-Escherichia),whose prevalence increased in advanced age.Our data demonstrated that age explained more of the variance in the gut microbiome than previously identified factors such as type 2 diabetes mellitus(T2DM)or diet.We characterized the distinct taxonomic and functional profiles of ET-Escherichia,and found the strongest cohesion and highest robustness of the microbial co-occurrence network in this enterotype,as well as the lowest species diversity.In addition,we carried out a series of correlation analyses and co-abundance network analyses,which showed that several factors were likely linked to the overabundance of Escherichia members,including advanced age,vegetable intake,and fruit intake.Overall,our data revealed an enterotype variation characterized by Escherichia enrichment in the elderly population.Considering the different age distribution of each enterotype,these findings provide new insights into the changes that occur in the gut microbiome with age and highlight the importance of microbiome-based stratification of elderly individuals.
文摘Background Monoglycerides have emerged as a promising alternative to conventional practices due to their biolog-ical activities,including antimicrobial properties.However,few studies have assessed the efficacy of monoglyceride blend on weaned pigs and their impacts on performance,immune response,and gut health using a disease chal-lenge model.Therefore,this study aimed to investigate the effects of dietary monoglycerides of short-and medium-chain fatty acids on the immunity and gut health of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli F18.Results Pigs supplemented with high-dose zinc oxide(ZNO)had greater(P<0.05)growth performance than other treatments,but no difference was observed in average daily feed intake between ZNO and monoglycerides groups during the post-challenge period.Pigs in ZNO and antibiotic groups had lower(P<0.05)severity of diarrhea than control,but the severity of diarrhea was not different between antibiotic and monoglycerides groups.Pigs fed with monoglycerides or ZNO had lower(P<0.05)serum haptoglobin on d 2 or 5 post-inoculation than control.Pigs in ZNO had greater(P<0.05)goblet cell numbers per villus,villus area and height,and villus height:crypt depth ratio(VH:CD)in duodenum on d 5 post-inoculation than pigs in other treatments.Pigs supplemented with monoglyc-erides,ZNO,or antibiotics had reduced(P<0.05)ileal crypt depth compared with control on d 5 post-inoculation,contributing to the increase(P=0.06)in VH:CD.Consistently,pigs in ZNO expressed the lowest(P<0.05)TNFa,IL6,IL10,IL12,IL1A,IL1B,and PTGS2 in ileal mucosa on d 5 post-inoculation,and no difference was observed in the expres-sion of those genes between ZNO and monoglycerides.Supplementation of ZNO and antibiotic had significant impacts on metabolic pathways in the serum compared with control,particularly on carbohydrate and amino acid metabolism,while limited impacts on serum metabolites were observed in monoglycerides group when compared with control.Conclusions The results suggest that supplementation of monoglyceride blend may enhance disease resist-ance of weaned pigs by alleviating the severity of diarrhea and mitigating intestinal and systemic inflammation,although the effectiveness may not be comparable to high-dose zinc oxide.
文摘Background:Urinary tract infections(UTIs),primarily caused by uropathogenic Escherichia coli(UPEC),are a significant global health concern.The complications arise from antibiotic resistance and biofilm formation,which reduce the effectiveness of conventional treatments.This study aims to evaluate the antibiofilm activity of the homeopathic medicine Terebinthinae oleum in potencies 30C,200C,and 1M against UTI-causing E.coli,and to compare its effectiveness with the standard antibiotic Gentamycin.Methods:An in-vitro biofilm model was employed.E.coli biofilms were cultivated in microtiter plates and treated with Terebinthinae oleum(30C,200C,1M)and Gentamycin.Biofilm biomass was assessed through crystal violet staining,and optical density(OD)was measured using an ELISA microplate reader.Results:Among the tested potencies,Terebinthinae oleum 30C showed the most prominent inhibitory activity on E.coli biofilms.The inhibition percentage was compared with Gentamycin as a control.Terebinthinae oleum 30C demonstrated 41.88%inhibition of biofilm biomass,while Gentamycin exhibited up to 78.98%inhibition.Higher potencies of Terebinthinae oleum(200C and 1M)showed reduced activity(30.15%and 24.81%,respectively).Conclusion:Terebinthinae oleum,especially at 30C potency,exhibits measurable antibiofilm activity against E.coli,although less effective than Gentamycin.These findings support its use as a complementary therapy in managing biofilm-associated UTIs,justifying further clinical and immunological research.
基金Research on the Resistance Mechanism of Carbapenem-Resistant Escherichia coli in Patients with Urosepsis Based on Bacterial Droplet Single-Cell RNA Sequencing(Project No.:MTyk2024-34,2024.01-2026-12)。
文摘Quorum sensing(QS)represents a mechanism through which bacteria engage in communication via chemical signals,a phenomenon prevalent across diverse bacterial species.Recent investigations have elucidated that QS signaling pathways are pivotal in governing bacterial physiological processes,collective behaviors,and the emergence of drug resistance.Escherichia coli(E.coli),a prominent pathogenic bacterium,is increasingly exhibiting severe drug resistance issues,posing substantial hurdles for clinical interventions.Presently,a burgeoning body of research is exploring the connection between QS signaling pathways and the drug resistance mechanisms in E.coli,unveiling the coordinating function of QS within bacterial communities and its influence on antibiotic resistance.Despite some research advancements,the precise mechanisms underlying the QS signaling pathway remain ambiguous,and its potential applications are somewhat constrained.This article endeavors to systematically review the research progress concerning the QS signaling pathway in the context of clinical drug resistance mechanisms in E.coli,delving into its potential clinical applications and future research avenues,with the aim of offering novel insights and strategies to counteract drug resistance.
文摘Background Enterotoxigenic Escherichia coli(E.coli)is a threat to humans and animals that causes intestinal dis-orders.Antimicrobial resistance has urged alternatives,including Lactobacillus postbiotics,to mitigate the effects of enterotoxigenic E.coli.Methods Forty-eight newly weaned pigs were allotted to NC:no challenge/no supplement;PC:F18^(+)E.coli chal-lenge/no supplement;ATB:F18^(+)E.coli challenge/bacitracin;and LPB:F18^(+)E.coli challenge/postbiotics and fed diets for 28 d.On d 7,pigs were orally inoculated withF18^(+)E.coli.At d 28,the mucosa-associated microbiota,immune and oxidative stress status,intestinal morphology,the gene expression of pattern recognition receptors(PRR),and intestinal barrier function were measured.Data were analyzed using the MIXED procedure in SAS 9.4.Results PC increased(P<0.05)Helicobacter mastomyrinus whereas reduced(P<0.05)Prevotella copri and P.ster-corea compared to NC.The LPB increased(P<0.05)P.stercorea and Dialister succinatiphilus compared with PC.The ATB increased(P<0.05)Propionibacterium acnes,Corynebacterium glutamicum,and Sphingomonas pseudosanguinis compared to PC.The PC tended to reduce(P=0.054)PGLYRP4 and increased(P<0.05)TLR4,CD14,MDA,and crypt cell proliferation compared with NC.The ATB reduced(P<0.05)NOD1 compared with PC.The LPB increased(P<0.05)PGLYRP4,and interferon-γand reduced(P<0.05)NOD1 compared with PC.The ATB and LPB reduced(P<0.05)TNF-αand MDA compared with PC.Conclusions TheF18^(+)E.coli challenge compromised intestinal health.Bacitracin increased beneficial bacteria show-ing a trend towards increasing the intestinal barrier function,possibly by reducing the expression of PRR genes.Lac-tobacillus postbiotics enhanced the immunocompetence of nursery pigs by increasing the expression of interferon-γand PGLYRP4,and by reducing TLR4,NOD1,and CD14.
基金supported by Research on Breeding and Healthy Breeding Technology of Xueyu White Chicken(mating line)in Tibet Science and Technology Program(XZ202101ZY0002N)the National Key R&D Program Project(2022YFD1600902-4)Sichuan Province Regional Innovation Cooperation Project(2023YFQ0050)。
文摘Bacterial infections of avian embryos can lead to an increase in embryo mortality,and the proliferation of antimicrobial-resistant bacteria aggravates the situation.A low hatching rate also poses a challenge to the population of artificially bred Crested Ibises(Nipponia nippon).This study aims to determine the potential association between bacterial infection and the death of Crested Ibis embryos,and whether there is convergence between antimicrobial resistance and virulence in strain.In this study,13 Escherichia coli and 12 Proteus mirabilis isolates were recovered from dead Crested Ibis embryos.The pathogenicity examination confirmed the pathogenicity of all isolates,and multiple virulence genes detected by PCR-sequencing demonstrated the presence of irp2 and iuc D(100%),fim C and iss(92.31%)in E.coli,and uca A(58.33%)in P.mirabilis.Antimicrobial susceptibility test demonstrated that isolates were mainly resistant to amoxicillin(E.coli:76.92%,P.mirabilis:91.67%),cefazolin(E.coli:76.92%,P.mirabilis:91.67%),oxytetracycline(E.coli:92.31%,P.mirabilis:75.00%)and sulfamethoxazole-trimethoprim(E.coli:53.85%,P.mirabilis:33.33%),and more than 30%of isolates showed multidrug-resistance(MDR).Further analyses detected extended-spectrumβ-lactamase(ESBL)genes,of which blaTEM-1(E.coli:100%,P.mirabilis:100%)had the highest frequency,followed by the blaCTX-M-55(E.coli:92.31%,P.mirabilis:50%),blaCTX-M-14(E.coli:76.92%,P.mirabilis:33.33%),blaCTX-M-65(E.coli:15.38%,P.mirabilis:16.67%),and all isolates were negative for blaSHV and blaOXA.Pearson's correlation analysis showed a positive correlation between the presence ofβ-lactam resistance and ESBL genes,while mainly negative correlations were observed between the presence of ESBL genes and virulence genes.Furthermore,the conjugation experiment and PFGE revealed that the isolates were primarily polyclonal,and there was horizontal transfer of resistance or virulence genes by plasmids.Based on the results,E.coli and P.mirabilis were responsible for embryonic mortality of the ibises in this study.The co-presence and co-transfer of ESBL genes and virulence genes can pose a potential threat to the health of the Crested Ibis,and measures such as prudent use of antimicrobials,and constant surveillance of resistance and pathogenicity,must be implemented at the Crested Ibis breeding base.
文摘Molecular cloning remains a cornerstone technique in genetic engineering and synthetic biology.In this study,we conducted a systematic comparative analysis between the classical cloning method and the Golden Gate assembly technique,utilizing Escherichia coli as the model organism.Through polymerase chain reaction(PCR)amplification,restriction enzyme digestion,ligation,transformation,and Sanger sequencing,we assessed the operational efficiency and cloning fidelity of both strategies.Our results demonstrated that Golden Gate assembly,leveraging type IIS restriction enzymes and simultaneous ligation,significantly enhanced cloning efficiency and precision,particularly for seamless multi-fragment assembly.In contrast,the classical cloning approach maintained certain advantages in simplicity and robustness for specific experimental conditions.Challenges encountered during transformation and sequencing highlighted the critical impact of technical accuracy on experimental outcomes.This study underscores the importance of selecting appropriate cloning methodologies tailored to experimental objectives and laboratory capabilities,providing a foundation for optimized molecular cloning workflows in future synthetic biology and biotechnology applications.
基金supported by grants from the National Program on Key Research Project of China[2022YFD1800800,2021YFD1800300]the Yingzi Tech&Huazhong Agricultural University Intelligent Research Institute of Food Health[No.IRIFH202209,No.IRIFH202301]The National Program on Key Research Project of China,2022YFD1800800,Ping Qian,2021YFD1800300,Ping Qian,The Yingzi Tech&Huazhong Agricultural University Intelligent Research Institute of Food Health,IRIFH202209,Ping Qian,IRIFH202301,Ping Qian.
文摘Enterotoxigenic E.coli is one of the bacterial pathogens contributing to the global resistance crisis in public health and animal husbandry.The problem of antibiotic resistance is becoming more and more serious,and phage is con-sidered one of the potential alternatives to antibiotics that could be utilized to treat bacterial infections.Our study isolated and identified a lytic phage PGX1 against multidrug-resistant enterotoxigenic E.coli EC6 strain from sew-age.The phage lysis profile revealed that PGX1 exhibited a lytic effect on multidrug-resistant enterotoxigenic E.coli strains of serotype O60.Through phage whole genome sequencing and bioinformatics analysis,PGX1 was found to be the class Caudoviricetes,family Autographiviridae,genus Teseptimavirus.The length of the PGX1 genome is about 37,009 bp,containing 54 open reading frames(ORFs).Notably,phage PGX1 lacks any lysogenic-related genes or virulence genes.Furthermore,phage PGX1 demonstrates strong adaptability,tolerance,and stability in various pH(pH4-10)and temperatures(4–40°C).The in vivo and in vitro tests demonstrated that phage PGX1 significantly removes and inhibits the formation of multidrug-resistant EC6 biofilm and effectively controls the Galleria mel-lonella larvae and enterotoxigenic E.coli EC6 during mice infection.In conclusion,the above findings demonstrated that phage PGX1 may be a novel antimicrobial agent to control multidrug-resistant E.coli infections.
基金Supported by Key Project of Natural Science Foundation of Inner Mongolia Autonomous Region(200607010403)National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science&Technology of China(2006BAD04A15)~~
文摘[Objective] The aim of this study was to explore the sterilization effects on Escherichia coli by adding bacterial inhibitor(CaCN2)during the process of cattle manure composting so as to provide a theoretical basis for cattle manure harmless treatment.[Method] Both experimental groups supplemented with 2.0% bacterial inhibitor and control groups without bacterial inhibitor were cultured under different temperatures(20,30,37,50,60 ℃)to determine the optimal composing temperature.Under 30 ℃,different bacterial inhibitor doses(0,2.0%,2.5%,3.0%)were added into the compost to obtain the optimal bacterial inhibitor addition dose.[Result] 30,50 and 60 ℃ were ideal temperatures for sterilization of E.coli.Under 30 ℃,E.coli couldn't be detected in 2.5% dose group and 3.0% dose group after culture for 48 h,demonstrating no less than 2.5% bacterial inhibitor should be added.[Conclusion] It has an important significance to enhance the sterilization effects on E.coli by adding CaCN2 into cattle manure compost especially in winter.
文摘Several technical parameters were studied during the fermentation of recombinant E.coli for the production of collagen-like biopolymer.The effects of dissolved oxygen as well as glucose concentration on fermentation were observed.The OD 600 value could reach 98 when dissolved oxygen was controlled at 50% and glucose around 1%.The production of human-like collagen with a yield of 29.4% was obtained.
