Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag...Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.展开更多
BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly apparent.The gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin...BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly apparent.The gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin-producing Escherichia coli(CoPEC).AIM To evaluate the association between CoPEC prevalence and anxiety-and depressive-like behaviors with both preclinical and clinical approaches.METHODS Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric interview.Results were compared according to the CoPEC colonization.In parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC strain.Their behavior was assessed using the Elevated Plus Maze test,the Forced Swimming Test and the Behavior recognition system PhenoTyper®.RESULTS In a limited cohort,all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis,whereas only one patient(17%)without CoPEC did.This result was confirmed in C57BL6/J wildtype mice and in a CRC susceptibility mouse model(adenomatous polyposis colimultiple intestinal neoplasia/+).Mice exhibited a significant increase in anxiety-and depressive-like behaviors after chronic infection with a CoPEC strain.CONCLUSION This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.展开更多
Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin producti...Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin production regulation,locus A,herein renamed AbsR,a blood survival regulator),a member of the MarR(multiple antibiotic resistance regulator)transcriptional regulator family,governs the expression of capsule biosynthetic genes in human ExPEC and represents a promising druggable target for antimicrobials.However,a deep understanding of the AbsR regulatory mechanism as well as its regulon is lacking.In this study,we present a systems-level analysis of the APEC AbsR regulon using ChIP-Seq(chromatin immunoprecipitation sequencing)and RNA-Seq(RNA sequencing)methods.We found that AbsR directly regulates 99 genes and indirectly regulates 667 genes.Furthermore,we showed that:1)AbsR contributes to antiphagocytotic effects by macrophages and virulence in a mouse model for systemic infection by directly activating the capsular gene cluster;2)AbsR positively impacts biofilm formation via direct regulation of the T2SS(type II secretion system)but plays a marginal role in virulence;and 3)AbsR directly upregulates the acid tolerance signaling system EvgAS to withstand acid stress but is dispensable in ExPEC virulence.Finally,our data indicate that the role of AbsR in virulence gene regulation is relatively conserved in ExPEC strains.Altogether,this study provides a comprehensive analysis of the AbsR regulon and regulatory mechanism,and our data suggest that AbsR likely influences virulence primarily through the control of capsule production.Interestingly,we found that AbsR severely represses the expression of the type I-F CRISPR(clustered regularly interspaced short palindromic repeats)-Cas(CRISPR associated)systems,which could have implications in CRISPR biology and application.展开更多
Escherichia coli is the commonest bacterial uropathogen of UTIs, the commonest infections in immunocompromised diabetic patients. Better understanding of their main resistance mechanisms to commonly used antibacterial...Escherichia coli is the commonest bacterial uropathogen of UTIs, the commonest infections in immunocompromised diabetic patients. Better understanding of their main resistance mechanisms to commonly used antibacterial agents will help to reduce the burden of this infection. The prevalence of drug resistant uropathogenic Escherichia coli isolates from immunocompromised diabetic patients attending selected health facilities in Benue State was investigated. Two hundred and ninety-six midstream urine samples were collected for both study and control diabetic patients. Bacterial isolation was done using semi-quantitative method. Drug resistant Escherichia coli were identified as multidrug resistant (MDR), extensive drug resistant (XDR) and pan-drug resistant organisms (PDR). Statistical significance was considered at p E. coli isolates from the study and control subjects with overall prevalence of 20.9% and 8.4% respectively. The isolates were highly resistant to penicillin (ampicillin), monobactam (aztreonam), older quinolone (nalidixic acid) whereas the majority of them showed high susceptibility to aminoglycoside (streptomycin), cephalosporin (cefotaxime) and carbapenem (imipenem). None showed complete susceptibility to all the tested antibiotics. Twenty-five E. coli were identified in this MDR, eight, XDR while 5 were PDR. High numbers of drug resistant E. coli isolates were identified in the study group of which 25 were MDR, 8 XDR while 5 were PDR isolates. High prevalence of UTI and drug resistant isolates occur in diabetic patients with hyperglycemic condition.展开更多
Urinary tract infections (UTIs) are common infections caused by normal skin or rectum bacteria that get into the urethra and infect the urinary tract. Although the infection can affect various parts of the tract, blad...Urinary tract infections (UTIs) are common infections caused by normal skin or rectum bacteria that get into the urethra and infect the urinary tract. Although the infection can affect various parts of the tract, bladder infections are the most prevalent kind. Uropathogenic Escherichia Coli (UPEC) is the most common pathogen associated with UTI development. Therefore, inhibiting the UPEC protein target (PDB ID: 8BVD) appears to be a promising therapeutic strategy. Therefore, in this study, molecular docking and dynamics were conducted to examine the antibacterial activity of Aloe barbadensis miller against UPEC bacteria. The Aloe barbadensis miller natural compounds licochalcone A, palmidin B and palmidin C were downloaded from PubChem with amoxicillin, which was used as a control drug and studied against the target molecule. The potential parameters examined were the docking scores, absorption, distribution, metabolism, excretion, toxicity (ADMET), bioavailability, root mean square deviation (RMSD), root mean square fluctuation (RMSF), hydrogen bonding, radius of gyration, and potential energy of the system. Docking scores showed that all ligands demonstrated an admirable candidature as an inhibitor to 8BVD molecule, and the score hierarchy is licochalcone A (-6.4 kcal/mol), palmidin C (-6.1 kcal/mol), palmidin B (-6.0 kcal/mol), and amoxicillin (-5.9 kcal/mol). All ligands appeared to have good drug-like properties and oral bioavailability. Molecular dynamic studies showed that all ligands exhibited an excellent nominee as inhibitors in their vicinity at 20 ns. However, there is a relatively high fluctuation of palmidin B compared with other compounds, which seems to be more stable. This work suggests that the selected phytoconstituents could be used as inhibitors of the 8BVD protein in the fight against UTIs. However, further investigation on the clinical and experimental validation of UTI treatment’s specific mechanisms and effects is still welcomed.展开更多
Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales site...Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.展开更多
Fecal coliform bacteria such as Escherichia coli (E. coli) are one of the main sources of groundwater pollution. An assessment of the transport and Persistence of E. coli in poultry litter amended Decatur silty Clay s...Fecal coliform bacteria such as Escherichia coli (E. coli) are one of the main sources of groundwater pollution. An assessment of the transport and Persistence of E. coli in poultry litter amended Decatur silty Clay soil and Hartsells Sandy soil was conducted using soil columns and simulated groundwater leaching. Enumeration of initial E. coli was determined to range from 2.851 × 10<sup>3</sup> to 3.044 × 10<sup>3</sup> CFU per gram of soil. These results have been used in a batch study to determine the persistence rate of E. coli in Decatur silty Clay soil and Hartsells Sandy soil. Results prove that E. coli survival growth rate increases for clay soil later than and at a higher rate than sandy soil. The column study has determined that E. coli was transported at a rate of 3.7 × 10<sup>6</sup><sup> </sup>CFU for Decatur silty loam and 6.3 × 10<sup>6</sup><sup> </sup>CFU for Hartsells sandy per gram of soil. Further, linear regression analysis predictions show higher porosity and soil moisture content affect transport, and Hartsells sandy soil has higher transport of E. coli due to its higher porosity and lower volumetric water content.展开更多
Background Post-weaned piglets suffer from F18+Escherichia coli(E.coli)infections resulting in post-weaning diar-rhoea or oedema disease.Frequently used management strategies,including colistin and zinc oxide,have con...Background Post-weaned piglets suffer from F18+Escherichia coli(E.coli)infections resulting in post-weaning diar-rhoea or oedema disease.Frequently used management strategies,including colistin and zinc oxide,have contrib-uted to the emergence and spread of antimicrobial resistance.Novel antimicrobials capable of directly interacting with pathogens and modulating the host immune responses are being investigated.Lactoferrin has shown promising results against porcine enterotoxigenic E.coli strains,both in vitro and in vivo.Results We investigated the influence of bovine lactoferrin(bLF)on the microbiome of healthy and infected weaned piglets.Additionally,we assessed whether bLF influenced the immune responses upon Shiga toxin-producing E.coli(STEC)infection.Therefore,2 in vivo trials were conducted:a microbiome trial and a challenge infection trial,using an F18+STEC strain.BLF did not affect theα-andβ-diversity.However,bLF groups showed a higher relative abundance(RA)for the Actinobacteria phylum and the Bifidobacterium genus in the ileal mucosa.When analysing the immune response upon infection,the STEC group exhibited a significant increase in F18-specific IgG serum levels,whereas this response was absent in the bLF group.Conclusion Taken together,the oral administration of bLF did not have a notable impact on theα-andβ-diversity of the gut microbiome in weaned piglets.Nevertheless,it did increase the RA of the Actinobacteria phylum and Bifi-dobacterium genus,which have previously been shown to play an important role in maintaining gut homeostasis.Furthermore,bLF administration during STEC infection resulted in the absence of F18-specific serum IgG responses.展开更多
Background Our previous study has reported that supplementation of oligosaccharide-based polymer enhances gut health and disease resistance of pigs infected with enterotoxigenic E.coli(ETEC)F18 in a manner similar to ...Background Our previous study has reported that supplementation of oligosaccharide-based polymer enhances gut health and disease resistance of pigs infected with enterotoxigenic E.coli(ETEC)F18 in a manner similar to carbadox.The objective of this study was to investigate the impacts of oligosaccharide-based polymer or antibiotic on the host metabolic profiles and colon microbiota of weaned pigs experimentally infected with ETEC F18.Results Multivariate analysis highlighted the differences in the metabolic profiles of serum and colon digesta which were predominantly found between pigs supplemented with oligosaccharide-based polymer and antibiotic.The relative abundance of metabolic markers of immune responses and nutrient metabolisms,such as amino acids and carbohydrates,were significantly differentiated between the oligosaccharide-based polymer and antibiotic groups(q<0.2 and fold change>2.0).In addition,pigs in antibiotic had a reduced(P<0.05)relative abundance of Lachnospiraceae and Lactobacillaceae,whereas had greater(P<0.05)Clostridiaceae and Streptococcaceae in the colon digesta on d 11 post-inoculation(PI)compared with d 5 PI.Conclusions The impact of oligosaccharide-based polymer on the metabolic and microbial profiles of pigs is not fully understood,and further exploration is needed.However,current research suggest that various mechanisms are involved in the enhanced disease resistance and performance in ETEC-challenged pigs by supplementing this polymer.展开更多
Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomi...Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomial urinary tract infections, surgical site infections and pneumonia in surgical clinic were studied. ESBL synthesis were observed 38.9% of E. coli strains obtained from urine, 92.3% of strains obtained from surgical site infections, and 50% of strains obtained from sputum. ESBL synthesis were observed 37.5% of K. pneumoniae strains obtained from urine, 85.7% of strains obtained from surgical site infections, and 60% of strains obtained from sputum. Different levels of ESBL synthesize of E. coli and K. pneumoniae strains isolated from different pattern is discussed. Conclusion. ESBL synthesis is common in E. coli and K. pneumoniae strains, which cause nosocomial infections. The frequency of occurrence of ESBL s synthesis among of these strains depends on clinical forms of nosocomial infections.展开更多
This study was designed to find the susceptibility of Nitrofurantoin and Fosfomycin among urinary isolates of Escherichia.coli.Four hundred(400)urine samples were collected for susceptibility of nitrofurantoin and fos...This study was designed to find the susceptibility of Nitrofurantoin and Fosfomycin among urinary isolates of Escherichia.coli.Four hundred(400)urine samples were collected for susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E.coli.All indoor and outdoor patients'urinary samples yielded growth of E.coli.Mid-stream urine specimens were inoculated on blood agar and CLED agar and incubated at 35±2°C.Growth was observed,and Escherichia coli was identified by Gram staining,Catalase,Motility test and API 20E(Bio murex)as per standard procedure.Antimicrobial susceptibility testing of isolates for nitrofurantoin and fosfomycin was carried out by the modified Kirby-Bauer disc diffusion method according to CLSI guidelines ATCC 25922.E.coli was used as a quality control strain.A total of 400 samples were tested susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E.coli during this period.A total of 400 samples yielded the growth of E.coli,out of which 178(44.5%)were male and 222(55.5%)were female samples.Among males,18(10%)were tolerant to nitrofurantoin,and 2(1.1%)were tolerant to fosfomycin.Among females,9(4.09%)were susceptible to nitrofurantoin while 6(2.72%)were susceptible to fosfomycin.Among age groups below 45 years old,6(4.76%)were tolerant to nitrofurantoin,and 2(1.58%)were sensitive to fosfomycin.Between 46-66 years old,4(2.81%)were sensitive to nitrofurantoin,and 3(2.11%)were sensitive to fosfomycin.Between 67-90 years old,17(12.87%)were sensitive to nitrofurantoin,and 4(3.03%)were tolerant to fosfomycin.Fosfomycin and nitrofurantoin showed good susceptibility in urinary isolates of E.coli and can be used empirically in our setup.展开更多
Background:This study was conducted to investigate the effects of each phytogenic feed additive(PFA;PFA1,bitter citrus extract;PFA2,a microencapsulated blend of thymol and carvacrol;PFA3,a mixture of bitter citrus ext...Background:This study was conducted to investigate the effects of each phytogenic feed additive(PFA;PFA1,bitter citrus extract;PFA2,a microencapsulated blend of thymol and carvacrol;PFA3,a mixture of bitter citrus extract,thymol,and carvacrol;PFA4,a premixture of grape seed,grape marc extract,green tea,and hops;PFA5,fenugreek seed powder)on the growth performance,nutrient digestibility,intestinal morphology,and immune response in weaned pigs infected with Escherichia coli(E.coli).Results:A total of 634-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups.The seven treatments were as follows:1)NC;basal diet without E.coli challenge,2)PC;basal diet with E.coli challenge,3)T1;PC+0.04%PFA1,4)T2;PC+0.01%PFA2,5)T3;PC+0.10%PFA3,6)T4;PC+0.04%PFA4,7)T5;PC+0.10%PFA5.The experiments lasted in 21 d,including 7 d before and 14 d after the first E.coli challenge.In the E.coli challenge treatments,all pigs were orally inoculated by dividing a total of 10 mL of E.coli F18 for 3 consecutive days.The PFA-added groups significantly increased(P<0.05)average daily gain and feed efficiency and decreased(P<0.05)the fecal score at d 0 to 14 post-inoculation(PI).Tumor necrosis factorαwas significantly lower(P<0.05)in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment.The T3 had a higher(P<0.05)immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI.Also,T3 showed significantly higher(P<0.05)villus height:crypt depth and claudin 1 expression in ileal mucosa,and significantly downregulated(P<0.05)the expression of calprotectin compared to the PC treatment.Conclusions:Supplementation of PFA in weaned pigs challenged with E.coli alleviated the negative effects of E.coli and improved growth performance.Among them,the mixed additive of bitter citrus extract,thymol,and carvacrol showed the most effective results,improving immune response,intestinal morphology,and expression of tight junctions.展开更多
An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibil...An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.展开更多
Objective To explore the genotyping characteristics of human fecal Escherichia coli(E. coli) and the relationships between antibiotic resistance genes(ARGs) and multidrug resistance(MDR) of E. coli in Miyun District, ...Objective To explore the genotyping characteristics of human fecal Escherichia coli(E. coli) and the relationships between antibiotic resistance genes(ARGs) and multidrug resistance(MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.Methods Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs,multilocus sequence typing(MLST), and polymorphism trees were analyzed using whole-genome sequencing data(WGS).Results This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal(49/70) and healthy groups(15/24).Conclusion We developed a random forest(RF) prediction model of TEM.1 + baeR + mphA + mphB +QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.展开更多
BACKGROUND Pyogenic spondylitis is often manifested as atypical low back pain and fever,which makes it easy to be confused with other diseases.Here we report a case of pyogenic spondylitis and describe the diagnosis a...BACKGROUND Pyogenic spondylitis is often manifested as atypical low back pain and fever,which makes it easy to be confused with other diseases.Here we report a case of pyogenic spondylitis and describe the diagnosis and treatment based on the related literature.CASE SUMMARY The reported case suffered from pyogenic spondylitis caused by Escherichia coli and complicated with bacteremia and psoas abscess.Acute pyelonephritis was initially diagnosed due to atypical symptoms.Symptoms were improved from antibiotic treatment while developing progressive lower limb dysfunction.One month post the admission,the patient underwent anterior lumbar debridement+autogenous iliac bone graft fusion+posterior percutaneous screw-rod internal fixation,and received 6 wk of antibiotic treatment after the operation.Reexamination 4 mo post the operation showed that the patient had no evident pain in the waist,and walked well with no evident dysfunction of lower limbs.CONCLUSION Here we describe the application value of several imaging examinations,such as X-ray,computed tomography and magnetic resonance imaging,and certain tests like erythrocyte sedimentation rate and C-reactive protein in the clinical treatment of pyogenic spondylitis.This disease requires early diagnosis and treatment.Sensitive antibiotics should be used in early stages and surgical intervention should be taken if necessary,which may help for a speedy recovery and prevent the occurrence of severe complications.展开更多
Context: Gastroenteritis remains an infectious disease with high morbidity and mortality particularly in low incomes countries, where the capacity to search all etiological agents, especially pathogenic Escherichia co...Context: Gastroenteritis remains an infectious disease with high morbidity and mortality particularly in low incomes countries, where the capacity to search all etiological agents, especially pathogenic Escherichia coli, is very limited. We investigated the contribution of pathogenic Escherichia coli and their antibiotic resistance profiles in cases of gastroenteritis. Methods: A cross-sectional study was carried out on human stool samples from October 2021 to June 2022 at Laquintinie Hospital. Samples were received from patients of all age groups and screened for bacteriological and parasitological identification by microscopy, bacterial culture, biochemical identification, and antimicrobial susceptibility tests. Results: A total of 296 patients with gastroenteritis complaints, were enrolled in the study with ages ranging from 5 months to 90 years old (Median = 35.5;SD = 20.8). Among the samples analyzed, 1.7% (n = 5/296) were positive for parasites and 27% (n = 80/296) were positive for bacterial pathogens. Parasites were found in mono parasitism, mainly Entamoeba histolytica (60%;n = 3/5), followed by Trichomonas intestinalis (20%;n = 1/5), and Giardia intestinalis (20%;n = 1/5). Three species of bacterial pathogens were identified with no co-infection: diarrheic Escherichia coli (DEC), Salmonella sp, and Shigella sp with respective proportions of 90% (n = 72/80), 6.3% (n = 5/80), and 3.7% (n = 3/80). For antibiotic resistance profiles (ARPs) of the 72 isolates of DEC, high levels of resistance were observed globally with amoxicillin (93.1%;n = 67/72), followed by ciprofloxacin (75%;n = 54/72), and to trimethoprim + sulfamethazole (73.6%;n = 53/72). In contrast, DEC showed low resistance rates with nitrofurans (6.9%;n = 5/72) and imipenem (2.8%;n = 2/72). The strains had 56 distinct ARPs, of which 88.9% (n = 64/72) were MDR. Salmonella sp and Shigella sp showed high levels of resistance to amoxicillin and trimethoprim + sulfamethazole. Conclusion: These results emphasize the need to consider DEC as the main cause of consultation in cases of gastroenteritis and reiterate the urgent need to rationalize antibiotic use in Cameroon.展开更多
Diarrhea is among the leading causes of morbidity and mortality in children aged Escherichia coli (DEC) accounts for 30% - 40% of childhood diarrhea cases. To identify the pathotypes involved in diarrheal outbreaks in...Diarrhea is among the leading causes of morbidity and mortality in children aged Escherichia coli (DEC) accounts for 30% - 40% of childhood diarrhea cases. To identify the pathotypes involved in diarrheal outbreaks in Kenya, we analyzed archived E. coli isolates from children E. coli confirmation and antimicrobial susceptibility testing were done using the VITEK<sup>®</sup>2 instrument. Pathotype identification was performed via conventional polymerase chain reaction. Of 175 E. coli isolates, 48 (27%) were DEC pathotypes, with enteroaggregative E. coli (EAEC) predominating (71%, 34/48). Enterohemorrhagic (EHEC) and enteropathogenic E. coli (EPEC) represented 19% and 10% of isolates, respectively. Enteroinvasive and enterotoxigenic pathotypes were not identified. All DEC isolates were susceptible to amikacin, ertapenem, imipenem, meropenem and tigecycline. Conversely, most (>80%) isolates were resistant to ampicillin, ampicillin-sulbactam and sulfamethoxazole-trimethoprim. Half of all EAEC and EPEC strains were resistant to cefazolin while half of EHEC isolates were resistant to ciprofloxacin and moxifloxacin. In total, 18 resistance phenotypes were identified with “ampicillin-cefazolin-ampicillin/ sulbactam-sulfamethoxazole/trimethoprim” predominating (33%, 16/48). The majority (81%) of DEC isolates were multidrug-resistant, with extended-spectrum beta-lactamase production identified in 8% of these isolates. This study highlights the predominance of Enteroaggregative E. coli and multidrug resistance of DEC pathotypes. Studying the epidemiology of diarrheal disease and antimicrobial resistance surveillance, will aid in identifying dominant etiological agents of diarrhea and newly emerging resistant strains in informal settlements.展开更多
Mesaconic acid has a special chemical structure and can undergo a series of reactions such as polymerization and addition. It is an important chemical intermediate and widely used in material, chemical and other indus...Mesaconic acid has a special chemical structure and can undergo a series of reactions such as polymerization and addition. It is an important chemical intermediate and widely used in material, chemical and other industries. The chemical synthesis of mesaconic acid requires nitric acid, which is dangerous and harmful to the environment. The production of mesaconic acid by microbial fermentation has the characteristics of low raw material price, high efficiency and strong specificity, and thus a strong industrial application prospect. Mesaconic acid is an intermediate product of glutamic acid degradation pathway of microorganisms such as Clostridium tetani. However, at present, few reports have been conducted on the production of mesaconic acid by metabolic engineering microorganisms. In this study, glutamate mutase(GLM) and 3-methylaspartate ammonialyase(MAL) from C. tetani were recombined and expressed in Escherichia coli, and the obtained strain, BL21(DE3)/pETDuet-1-MAL-mutS-mutE, achieved the yield of mesaconic acid of 1.06 g/L. Compared with the wild type, the yields of mesaconic acid from mutants G133A and G133S increased by 21% and 16%, respectively. After 24 h of flask fermentation, the yields of mesaconic acid reached 1.28 and 1.23 g/L, respectively. This study can provide reference for microbial synthesis of mesaconic acid.展开更多
Background: The emergence and spread of multidrug-resistant bacteria have become a major public health problem worldwide, particularly in developing countries such as Burkina Faso. This study aims to determine phenoty...Background: The emergence and spread of multidrug-resistant bacteria have become a major public health problem worldwide, particularly in developing countries such as Burkina Faso. This study aims to determine phenotypic and genotypic antibiotic resistant diarrheagenic Escherichia coli (DEC) from patients with diarrhea in Ouagadougou, Burkina Faso. Methodology: Microbiological and biochemical analysis were done to detect two hundred and ninety-two (292) strains. The susceptibility of the strains to antibiotics was determined by the agar disc diffusion method. 16-plex-PCR assays were carried out to detect both virulence and resistance genes encoding betalactams, quinolones, phenicols, tetracyclines and virulence gene of DEC. Results: Diarrheagenic Escherichia coli was detected in 8% (23/292) of patients with diarrhea using the 16-plex-PCR and 39.1% (9/23) of the DEC detected carry at least one resistance gene. Resistance rate in disc diffusion test was 86.96% to tetracycline, 65.23% to cotrimoxazole, 17.4% to nalidixic acid, 17.4% to norfloxacin, 17.4% to ciprofloxacin, 13.04% to ceftriaxone, 13.04% to cefotaxime, 8.7% to gentamicin, 8.7% to Chloramphenicol, 0% to netilmicin. The prevalence of different resistance genes in the studied strains varied from 44.4% to 5.5%. The gene Tet coding for resistance to tetracycline was found in 8 strains (44.4%). The CatA gene coding for resistance to Chloramphenicol was detected in 38.9% of isolates. The qnrS, bla<sub>SHV</sub> and bla<sub>OXA</sub> genes were each detected in 5.5% of isolates. No strain hosts the qnrA, qnrB and bla<sub>TEM</sub> genes. Conclusion: This study identified β-lactams, quinolones, phenicols and tetracyclines resistance genes in DEC isolates from patients with diarrhea in Ouagadougou, Burkina Faso. These results indicate the need for a surveillance program to reduce the prevalence of resistance to Enterobacteriaceae strains in hospitals.展开更多
基金supported by National Natural Science Foundation of China(31972021)R&D Projects in Key Areas of Guangdong Province(2019B020212003)+4 种基金the Science and Technology Program of Guangzhou,China(202206010177)Guangdong key research and development program(2021B0202060001)Foshan and agricultural academy cooperation projectGuangdong Modern Agriculture project(2022KJ117)Aquatic Products Center Project of GAAS。
文摘Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.
基金Supported by the French patient’s association against cancer(ligue contre le cancer),No.00001005238the French government IDEXISITE initiative,No.16-IDEX-0001-CAP 20-25+2 种基金CPER(Nex-N-Mob)the Auvergne-Rhône-Alpes region(“Thématiquesémergentes”),No.AV0004111the Ministère de l'Enseignement supérieur,de la Recherche et de l'Innovation,INSERM,University of Clermont Auvergne[UMR1071,UMR1107],INRAE[USC-1382].
文摘BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly apparent.The gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin-producing Escherichia coli(CoPEC).AIM To evaluate the association between CoPEC prevalence and anxiety-and depressive-like behaviors with both preclinical and clinical approaches.METHODS Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric interview.Results were compared according to the CoPEC colonization.In parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC strain.Their behavior was assessed using the Elevated Plus Maze test,the Forced Swimming Test and the Behavior recognition system PhenoTyper®.RESULTS In a limited cohort,all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis,whereas only one patient(17%)without CoPEC did.This result was confirmed in C57BL6/J wildtype mice and in a CRC susceptibility mouse model(adenomatous polyposis colimultiple intestinal neoplasia/+).Mice exhibited a significant increase in anxiety-and depressive-like behaviors after chronic infection with a CoPEC strain.CONCLUSION This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.
基金supported by the National Natural Science Foundation of China Young Scholars Project(31902242)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences(2017–2020)。
文摘Avian pathogenic Escherichia coli(APEC)belonging to extraintestinal pathogenic E.coli(ExPEC)can cause severe infections in extraintestinal tissues in birds and humans,such as the lungs and blood.MprA(microcin production regulation,locus A,herein renamed AbsR,a blood survival regulator),a member of the MarR(multiple antibiotic resistance regulator)transcriptional regulator family,governs the expression of capsule biosynthetic genes in human ExPEC and represents a promising druggable target for antimicrobials.However,a deep understanding of the AbsR regulatory mechanism as well as its regulon is lacking.In this study,we present a systems-level analysis of the APEC AbsR regulon using ChIP-Seq(chromatin immunoprecipitation sequencing)and RNA-Seq(RNA sequencing)methods.We found that AbsR directly regulates 99 genes and indirectly regulates 667 genes.Furthermore,we showed that:1)AbsR contributes to antiphagocytotic effects by macrophages and virulence in a mouse model for systemic infection by directly activating the capsular gene cluster;2)AbsR positively impacts biofilm formation via direct regulation of the T2SS(type II secretion system)but plays a marginal role in virulence;and 3)AbsR directly upregulates the acid tolerance signaling system EvgAS to withstand acid stress but is dispensable in ExPEC virulence.Finally,our data indicate that the role of AbsR in virulence gene regulation is relatively conserved in ExPEC strains.Altogether,this study provides a comprehensive analysis of the AbsR regulon and regulatory mechanism,and our data suggest that AbsR likely influences virulence primarily through the control of capsule production.Interestingly,we found that AbsR severely represses the expression of the type I-F CRISPR(clustered regularly interspaced short palindromic repeats)-Cas(CRISPR associated)systems,which could have implications in CRISPR biology and application.
文摘Escherichia coli is the commonest bacterial uropathogen of UTIs, the commonest infections in immunocompromised diabetic patients. Better understanding of their main resistance mechanisms to commonly used antibacterial agents will help to reduce the burden of this infection. The prevalence of drug resistant uropathogenic Escherichia coli isolates from immunocompromised diabetic patients attending selected health facilities in Benue State was investigated. Two hundred and ninety-six midstream urine samples were collected for both study and control diabetic patients. Bacterial isolation was done using semi-quantitative method. Drug resistant Escherichia coli were identified as multidrug resistant (MDR), extensive drug resistant (XDR) and pan-drug resistant organisms (PDR). Statistical significance was considered at p E. coli isolates from the study and control subjects with overall prevalence of 20.9% and 8.4% respectively. The isolates were highly resistant to penicillin (ampicillin), monobactam (aztreonam), older quinolone (nalidixic acid) whereas the majority of them showed high susceptibility to aminoglycoside (streptomycin), cephalosporin (cefotaxime) and carbapenem (imipenem). None showed complete susceptibility to all the tested antibiotics. Twenty-five E. coli were identified in this MDR, eight, XDR while 5 were PDR. High numbers of drug resistant E. coli isolates were identified in the study group of which 25 were MDR, 8 XDR while 5 were PDR isolates. High prevalence of UTI and drug resistant isolates occur in diabetic patients with hyperglycemic condition.
文摘Urinary tract infections (UTIs) are common infections caused by normal skin or rectum bacteria that get into the urethra and infect the urinary tract. Although the infection can affect various parts of the tract, bladder infections are the most prevalent kind. Uropathogenic Escherichia Coli (UPEC) is the most common pathogen associated with UTI development. Therefore, inhibiting the UPEC protein target (PDB ID: 8BVD) appears to be a promising therapeutic strategy. Therefore, in this study, molecular docking and dynamics were conducted to examine the antibacterial activity of Aloe barbadensis miller against UPEC bacteria. The Aloe barbadensis miller natural compounds licochalcone A, palmidin B and palmidin C were downloaded from PubChem with amoxicillin, which was used as a control drug and studied against the target molecule. The potential parameters examined were the docking scores, absorption, distribution, metabolism, excretion, toxicity (ADMET), bioavailability, root mean square deviation (RMSD), root mean square fluctuation (RMSF), hydrogen bonding, radius of gyration, and potential energy of the system. Docking scores showed that all ligands demonstrated an admirable candidature as an inhibitor to 8BVD molecule, and the score hierarchy is licochalcone A (-6.4 kcal/mol), palmidin C (-6.1 kcal/mol), palmidin B (-6.0 kcal/mol), and amoxicillin (-5.9 kcal/mol). All ligands appeared to have good drug-like properties and oral bioavailability. Molecular dynamic studies showed that all ligands exhibited an excellent nominee as inhibitors in their vicinity at 20 ns. However, there is a relatively high fluctuation of palmidin B compared with other compounds, which seems to be more stable. This work suggests that the selected phytoconstituents could be used as inhibitors of the 8BVD protein in the fight against UTIs. However, further investigation on the clinical and experimental validation of UTI treatment’s specific mechanisms and effects is still welcomed.
文摘Resistant bacteria can be transmitted to humans through feces or contaminated meat from local chickens. Bacterial strains were isolated from the intestinal contents of 400 local chicken samples from various sales sites. These strains were then characterized using bacteriological and biochemical methods to identify resistant strains. In a study conducted in Ouagadougou, we systematically collected chicken fecal samples from 20 locations across the city, followed by isolation and identification of Salmonella spp. using specific enrichment and culture methods, as well as Escherichia coli. Bacterial strains were characterized using antibiotic resistance profiles were determined through agar diffusion tests, revealing sensitivity or resistance to a range of antibiotics based on established scientific criteria. The results showed that out of the 400 samples collected, 81.25% and 63.5% were contaminated by Escherichia coli and Salmonella spp., respectively. Among these, 86.15% of identified Escherichia coli and 50.78% of Salmonella spp. displayed resistance to at least one tested antibiotic. Among 280 Escherichia coli isolates identified resistant to at least one antibiotic, 31.07% were resistant to cefotaxime (CTX), 20.35% to ceftazidime (CAZ), 21.07% to ceftriaxone (CTR), 75% to amoxicillin clavulanic acid (AMC), 23.57% aztreoname (ATM) and 27.14% were resistant to imipenem (IMP). In the case of the 129 Salmonella spp. isolates resistant to at least one tested antibiotic, 34.88% were resistant to CTX;41.08% to CAZ;35.65% to CTR, 92% to AMC, 39.53% to ATM and finally 47.28% were resistant to IMP. Our study revealed high prevalence of resistance in bacterial strains isolated from local chickens sold outdoors in Ouagadougou. These findings raise significant public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.
文摘Fecal coliform bacteria such as Escherichia coli (E. coli) are one of the main sources of groundwater pollution. An assessment of the transport and Persistence of E. coli in poultry litter amended Decatur silty Clay soil and Hartsells Sandy soil was conducted using soil columns and simulated groundwater leaching. Enumeration of initial E. coli was determined to range from 2.851 × 10<sup>3</sup> to 3.044 × 10<sup>3</sup> CFU per gram of soil. These results have been used in a batch study to determine the persistence rate of E. coli in Decatur silty Clay soil and Hartsells Sandy soil. Results prove that E. coli survival growth rate increases for clay soil later than and at a higher rate than sandy soil. The column study has determined that E. coli was transported at a rate of 3.7 × 10<sup>6</sup><sup> </sup>CFU for Decatur silty loam and 6.3 × 10<sup>6</sup><sup> </sup>CFU for Hartsells sandy per gram of soil. Further, linear regression analysis predictions show higher porosity and soil moisture content affect transport, and Hartsells sandy soil has higher transport of E. coli due to its higher porosity and lower volumetric water content.
基金The research that yielded these results,was funded by the Belgian Federal Public Service of Health,Food Chain Safety and Environment through the contract RF 17/6314 LactoPigHealthMatthias Dierick is supported by the Flemish fund for scientific research(FWO3S036319).
文摘Background Post-weaned piglets suffer from F18+Escherichia coli(E.coli)infections resulting in post-weaning diar-rhoea or oedema disease.Frequently used management strategies,including colistin and zinc oxide,have contrib-uted to the emergence and spread of antimicrobial resistance.Novel antimicrobials capable of directly interacting with pathogens and modulating the host immune responses are being investigated.Lactoferrin has shown promising results against porcine enterotoxigenic E.coli strains,both in vitro and in vivo.Results We investigated the influence of bovine lactoferrin(bLF)on the microbiome of healthy and infected weaned piglets.Additionally,we assessed whether bLF influenced the immune responses upon Shiga toxin-producing E.coli(STEC)infection.Therefore,2 in vivo trials were conducted:a microbiome trial and a challenge infection trial,using an F18+STEC strain.BLF did not affect theα-andβ-diversity.However,bLF groups showed a higher relative abundance(RA)for the Actinobacteria phylum and the Bifidobacterium genus in the ileal mucosa.When analysing the immune response upon infection,the STEC group exhibited a significant increase in F18-specific IgG serum levels,whereas this response was absent in the bLF group.Conclusion Taken together,the oral administration of bLF did not have a notable impact on theα-andβ-diversity of the gut microbiome in weaned piglets.Nevertheless,it did increase the RA of the Actinobacteria phylum and Bifi-dobacterium genus,which have previously been shown to play an important role in maintaining gut homeostasis.Furthermore,bLF administration during STEC infection resulted in the absence of F18-specific serum IgG responses.
基金supported by Pancosma SA,Geneva,Switzerland,Jastro & Shields Graduate Research Awardthe United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA),multistate projects W4002 and NC1202
文摘Background Our previous study has reported that supplementation of oligosaccharide-based polymer enhances gut health and disease resistance of pigs infected with enterotoxigenic E.coli(ETEC)F18 in a manner similar to carbadox.The objective of this study was to investigate the impacts of oligosaccharide-based polymer or antibiotic on the host metabolic profiles and colon microbiota of weaned pigs experimentally infected with ETEC F18.Results Multivariate analysis highlighted the differences in the metabolic profiles of serum and colon digesta which were predominantly found between pigs supplemented with oligosaccharide-based polymer and antibiotic.The relative abundance of metabolic markers of immune responses and nutrient metabolisms,such as amino acids and carbohydrates,were significantly differentiated between the oligosaccharide-based polymer and antibiotic groups(q<0.2 and fold change>2.0).In addition,pigs in antibiotic had a reduced(P<0.05)relative abundance of Lachnospiraceae and Lactobacillaceae,whereas had greater(P<0.05)Clostridiaceae and Streptococcaceae in the colon digesta on d 11 post-inoculation(PI)compared with d 5 PI.Conclusions The impact of oligosaccharide-based polymer on the metabolic and microbial profiles of pigs is not fully understood,and further exploration is needed.However,current research suggest that various mechanisms are involved in the enhanced disease resistance and performance in ETEC-challenged pigs by supplementing this polymer.
文摘Background: Recently micro-organisms that synthesize extended-spectrum β-lactamase (ESBLs) were increased. The peculiarities of ESBL synthesis of Escherichia coli and Klebsiella pneumoniae strains that cause nosocomial urinary tract infections, surgical site infections and pneumonia in surgical clinic were studied. ESBL synthesis were observed 38.9% of E. coli strains obtained from urine, 92.3% of strains obtained from surgical site infections, and 50% of strains obtained from sputum. ESBL synthesis were observed 37.5% of K. pneumoniae strains obtained from urine, 85.7% of strains obtained from surgical site infections, and 60% of strains obtained from sputum. Different levels of ESBL synthesize of E. coli and K. pneumoniae strains isolated from different pattern is discussed. Conclusion. ESBL synthesis is common in E. coli and K. pneumoniae strains, which cause nosocomial infections. The frequency of occurrence of ESBL s synthesis among of these strains depends on clinical forms of nosocomial infections.
文摘This study was designed to find the susceptibility of Nitrofurantoin and Fosfomycin among urinary isolates of Escherichia.coli.Four hundred(400)urine samples were collected for susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E.coli.All indoor and outdoor patients'urinary samples yielded growth of E.coli.Mid-stream urine specimens were inoculated on blood agar and CLED agar and incubated at 35±2°C.Growth was observed,and Escherichia coli was identified by Gram staining,Catalase,Motility test and API 20E(Bio murex)as per standard procedure.Antimicrobial susceptibility testing of isolates for nitrofurantoin and fosfomycin was carried out by the modified Kirby-Bauer disc diffusion method according to CLSI guidelines ATCC 25922.E.coli was used as a quality control strain.A total of 400 samples were tested susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E.coli during this period.A total of 400 samples yielded the growth of E.coli,out of which 178(44.5%)were male and 222(55.5%)were female samples.Among males,18(10%)were tolerant to nitrofurantoin,and 2(1.1%)were tolerant to fosfomycin.Among females,9(4.09%)were susceptible to nitrofurantoin while 6(2.72%)were susceptible to fosfomycin.Among age groups below 45 years old,6(4.76%)were tolerant to nitrofurantoin,and 2(1.58%)were sensitive to fosfomycin.Between 46-66 years old,4(2.81%)were sensitive to nitrofurantoin,and 3(2.11%)were sensitive to fosfomycin.Between 67-90 years old,17(12.87%)were sensitive to nitrofurantoin,and 4(3.03%)were tolerant to fosfomycin.Fosfomycin and nitrofurantoin showed good susceptibility in urinary isolates of E.coli and can be used empirically in our setup.
基金carried out with the support of“Cooperative Research Program for Agriculture Science&Technology Development(Project No.PJ01622001)”Rural Development Administration,Korea。
文摘Background:This study was conducted to investigate the effects of each phytogenic feed additive(PFA;PFA1,bitter citrus extract;PFA2,a microencapsulated blend of thymol and carvacrol;PFA3,a mixture of bitter citrus extract,thymol,and carvacrol;PFA4,a premixture of grape seed,grape marc extract,green tea,and hops;PFA5,fenugreek seed powder)on the growth performance,nutrient digestibility,intestinal morphology,and immune response in weaned pigs infected with Escherichia coli(E.coli).Results:A total of 634-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups.The seven treatments were as follows:1)NC;basal diet without E.coli challenge,2)PC;basal diet with E.coli challenge,3)T1;PC+0.04%PFA1,4)T2;PC+0.01%PFA2,5)T3;PC+0.10%PFA3,6)T4;PC+0.04%PFA4,7)T5;PC+0.10%PFA5.The experiments lasted in 21 d,including 7 d before and 14 d after the first E.coli challenge.In the E.coli challenge treatments,all pigs were orally inoculated by dividing a total of 10 mL of E.coli F18 for 3 consecutive days.The PFA-added groups significantly increased(P<0.05)average daily gain and feed efficiency and decreased(P<0.05)the fecal score at d 0 to 14 post-inoculation(PI).Tumor necrosis factorαwas significantly lower(P<0.05)in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment.The T3 had a higher(P<0.05)immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI.Also,T3 showed significantly higher(P<0.05)villus height:crypt depth and claudin 1 expression in ileal mucosa,and significantly downregulated(P<0.05)the expression of calprotectin compared to the PC treatment.Conclusions:Supplementation of PFA in weaned pigs challenged with E.coli alleviated the negative effects of E.coli and improved growth performance.Among them,the mixed additive of bitter citrus extract,thymol,and carvacrol showed the most effective results,improving immune response,intestinal morphology,and expression of tight junctions.
基金the National Key Research and Development Program of China(2018YFE0192600)the Shanghai Agriculture Applied Technology Development Program,China(T20200104)+1 种基金the Fundamental Research Funds for the Central Universities,China(2020JB05)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ZDRW202203).
文摘An extensively drug-resistant(XDR)Escherichia coli strain 258E was isolated from an anal swab sample of a chicken farm of Anhui province in China.Genomic analyses indicated that the strain 258E harbors an incompatibility group N(IncN)plasmid pEC258-3,which co-produces bla_(CTX-M-3),bla_(KPC-2),bla_(TEM-1B),qnrS1,aac(6')-Ib-cr,dfrA14,arr-3,and aac(6')-Ib3.Multiple genome arrangement analyses indicated that pEC258-3 is highly homologous with pCRKP-1-KPC discovered in Klebsiella pneumoniae from a patient.Furthermore,conjugation experiments proved that plasmid pEC258-3 can be transferred horizontally and may pose a significant potential threat in animals,community and hospital settings.
基金funded by the National Pathogen Identification Network project and Research on Key Technologies of Intelligent Monitoring,Early Warning and Tracing of Infectious Diseases in Miyun。
文摘Objective To explore the genotyping characteristics of human fecal Escherichia coli(E. coli) and the relationships between antibiotic resistance genes(ARGs) and multidrug resistance(MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.Methods Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs,multilocus sequence typing(MLST), and polymorphism trees were analyzed using whole-genome sequencing data(WGS).Results This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal(49/70) and healthy groups(15/24).Conclusion We developed a random forest(RF) prediction model of TEM.1 + baeR + mphA + mphB +QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.
基金Supported by Medicine and Health Foundation of Zhejiang Province,No.2021KY864.
文摘BACKGROUND Pyogenic spondylitis is often manifested as atypical low back pain and fever,which makes it easy to be confused with other diseases.Here we report a case of pyogenic spondylitis and describe the diagnosis and treatment based on the related literature.CASE SUMMARY The reported case suffered from pyogenic spondylitis caused by Escherichia coli and complicated with bacteremia and psoas abscess.Acute pyelonephritis was initially diagnosed due to atypical symptoms.Symptoms were improved from antibiotic treatment while developing progressive lower limb dysfunction.One month post the admission,the patient underwent anterior lumbar debridement+autogenous iliac bone graft fusion+posterior percutaneous screw-rod internal fixation,and received 6 wk of antibiotic treatment after the operation.Reexamination 4 mo post the operation showed that the patient had no evident pain in the waist,and walked well with no evident dysfunction of lower limbs.CONCLUSION Here we describe the application value of several imaging examinations,such as X-ray,computed tomography and magnetic resonance imaging,and certain tests like erythrocyte sedimentation rate and C-reactive protein in the clinical treatment of pyogenic spondylitis.This disease requires early diagnosis and treatment.Sensitive antibiotics should be used in early stages and surgical intervention should be taken if necessary,which may help for a speedy recovery and prevent the occurrence of severe complications.
文摘Context: Gastroenteritis remains an infectious disease with high morbidity and mortality particularly in low incomes countries, where the capacity to search all etiological agents, especially pathogenic Escherichia coli, is very limited. We investigated the contribution of pathogenic Escherichia coli and their antibiotic resistance profiles in cases of gastroenteritis. Methods: A cross-sectional study was carried out on human stool samples from October 2021 to June 2022 at Laquintinie Hospital. Samples were received from patients of all age groups and screened for bacteriological and parasitological identification by microscopy, bacterial culture, biochemical identification, and antimicrobial susceptibility tests. Results: A total of 296 patients with gastroenteritis complaints, were enrolled in the study with ages ranging from 5 months to 90 years old (Median = 35.5;SD = 20.8). Among the samples analyzed, 1.7% (n = 5/296) were positive for parasites and 27% (n = 80/296) were positive for bacterial pathogens. Parasites were found in mono parasitism, mainly Entamoeba histolytica (60%;n = 3/5), followed by Trichomonas intestinalis (20%;n = 1/5), and Giardia intestinalis (20%;n = 1/5). Three species of bacterial pathogens were identified with no co-infection: diarrheic Escherichia coli (DEC), Salmonella sp, and Shigella sp with respective proportions of 90% (n = 72/80), 6.3% (n = 5/80), and 3.7% (n = 3/80). For antibiotic resistance profiles (ARPs) of the 72 isolates of DEC, high levels of resistance were observed globally with amoxicillin (93.1%;n = 67/72), followed by ciprofloxacin (75%;n = 54/72), and to trimethoprim + sulfamethazole (73.6%;n = 53/72). In contrast, DEC showed low resistance rates with nitrofurans (6.9%;n = 5/72) and imipenem (2.8%;n = 2/72). The strains had 56 distinct ARPs, of which 88.9% (n = 64/72) were MDR. Salmonella sp and Shigella sp showed high levels of resistance to amoxicillin and trimethoprim + sulfamethazole. Conclusion: These results emphasize the need to consider DEC as the main cause of consultation in cases of gastroenteritis and reiterate the urgent need to rationalize antibiotic use in Cameroon.
文摘Diarrhea is among the leading causes of morbidity and mortality in children aged Escherichia coli (DEC) accounts for 30% - 40% of childhood diarrhea cases. To identify the pathotypes involved in diarrheal outbreaks in Kenya, we analyzed archived E. coli isolates from children E. coli confirmation and antimicrobial susceptibility testing were done using the VITEK<sup>®</sup>2 instrument. Pathotype identification was performed via conventional polymerase chain reaction. Of 175 E. coli isolates, 48 (27%) were DEC pathotypes, with enteroaggregative E. coli (EAEC) predominating (71%, 34/48). Enterohemorrhagic (EHEC) and enteropathogenic E. coli (EPEC) represented 19% and 10% of isolates, respectively. Enteroinvasive and enterotoxigenic pathotypes were not identified. All DEC isolates were susceptible to amikacin, ertapenem, imipenem, meropenem and tigecycline. Conversely, most (>80%) isolates were resistant to ampicillin, ampicillin-sulbactam and sulfamethoxazole-trimethoprim. Half of all EAEC and EPEC strains were resistant to cefazolin while half of EHEC isolates were resistant to ciprofloxacin and moxifloxacin. In total, 18 resistance phenotypes were identified with “ampicillin-cefazolin-ampicillin/ sulbactam-sulfamethoxazole/trimethoprim” predominating (33%, 16/48). The majority (81%) of DEC isolates were multidrug-resistant, with extended-spectrum beta-lactamase production identified in 8% of these isolates. This study highlights the predominance of Enteroaggregative E. coli and multidrug resistance of DEC pathotypes. Studying the epidemiology of diarrheal disease and antimicrobial resistance surveillance, will aid in identifying dominant etiological agents of diarrhea and newly emerging resistant strains in informal settlements.
文摘Mesaconic acid has a special chemical structure and can undergo a series of reactions such as polymerization and addition. It is an important chemical intermediate and widely used in material, chemical and other industries. The chemical synthesis of mesaconic acid requires nitric acid, which is dangerous and harmful to the environment. The production of mesaconic acid by microbial fermentation has the characteristics of low raw material price, high efficiency and strong specificity, and thus a strong industrial application prospect. Mesaconic acid is an intermediate product of glutamic acid degradation pathway of microorganisms such as Clostridium tetani. However, at present, few reports have been conducted on the production of mesaconic acid by metabolic engineering microorganisms. In this study, glutamate mutase(GLM) and 3-methylaspartate ammonialyase(MAL) from C. tetani were recombined and expressed in Escherichia coli, and the obtained strain, BL21(DE3)/pETDuet-1-MAL-mutS-mutE, achieved the yield of mesaconic acid of 1.06 g/L. Compared with the wild type, the yields of mesaconic acid from mutants G133A and G133S increased by 21% and 16%, respectively. After 24 h of flask fermentation, the yields of mesaconic acid reached 1.28 and 1.23 g/L, respectively. This study can provide reference for microbial synthesis of mesaconic acid.
文摘Background: The emergence and spread of multidrug-resistant bacteria have become a major public health problem worldwide, particularly in developing countries such as Burkina Faso. This study aims to determine phenotypic and genotypic antibiotic resistant diarrheagenic Escherichia coli (DEC) from patients with diarrhea in Ouagadougou, Burkina Faso. Methodology: Microbiological and biochemical analysis were done to detect two hundred and ninety-two (292) strains. The susceptibility of the strains to antibiotics was determined by the agar disc diffusion method. 16-plex-PCR assays were carried out to detect both virulence and resistance genes encoding betalactams, quinolones, phenicols, tetracyclines and virulence gene of DEC. Results: Diarrheagenic Escherichia coli was detected in 8% (23/292) of patients with diarrhea using the 16-plex-PCR and 39.1% (9/23) of the DEC detected carry at least one resistance gene. Resistance rate in disc diffusion test was 86.96% to tetracycline, 65.23% to cotrimoxazole, 17.4% to nalidixic acid, 17.4% to norfloxacin, 17.4% to ciprofloxacin, 13.04% to ceftriaxone, 13.04% to cefotaxime, 8.7% to gentamicin, 8.7% to Chloramphenicol, 0% to netilmicin. The prevalence of different resistance genes in the studied strains varied from 44.4% to 5.5%. The gene Tet coding for resistance to tetracycline was found in 8 strains (44.4%). The CatA gene coding for resistance to Chloramphenicol was detected in 38.9% of isolates. The qnrS, bla<sub>SHV</sub> and bla<sub>OXA</sub> genes were each detected in 5.5% of isolates. No strain hosts the qnrA, qnrB and bla<sub>TEM</sub> genes. Conclusion: This study identified β-lactams, quinolones, phenicols and tetracyclines resistance genes in DEC isolates from patients with diarrhea in Ouagadougou, Burkina Faso. These results indicate the need for a surveillance program to reduce the prevalence of resistance to Enterobacteriaceae strains in hospitals.