Phytochemicals of Aloe barbadensis miller as Potential Inhibitors of Uropathogenic Escherichia coli for Urinary Tract Infection Therapy: An in Silico Approach

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.

Prevalence of Uropathogenic Escherichia coli among Adult Male Patients 40 Years and above with Haematuria and Impaired Kidney Attending General Hospitals in Benue State

Haematuria is the presence of red blood cells in urine. It is most often caused by urinary tract infections of which Escherichia coli is frequently implicated. Impairment of kidney functions could occur as a result of infection or other complications of the kidney. The aim of the study was to determine the prevalence of uropathogenic Escherichia coli among adult male patients with haematuria and impaired kidneys attending a general hospital in Benue state. Three hundred and sixty-eight (368) samples of urine were collected from 368 male patients (≥ 40 years) attending the 23 general hospitals in Benue state. Each of the urine samples was divided into two parts for haematuria and isolation and identification of Escherichia coli. Blood samples (368) were also collected from the patients and used for quantitative determination of creatinine and estimation of glomerular filtration rate. The presence of haematuria was 45.1% and ranges from 12.5% to 100%. Prevalence of haematuria with respect to age shows that patients within the age group of 90 - 99 years had the highest rate (100%) and the least were those within the ages of 40 - 49 years (20.0%). Isolation rate of uropathogenic Escherichia coli was 16.3% and ranged from 6.3 to 37.5%. Patients within the age group of 90 - 99 years had the highest elevated impaired renal function of 4 (80%), followed by patients within the ages of 80 - 89 years [17 (77.3%)] and the lowest were those within the ages of 40 - 49 [6 (10.0%)]. The overall presence of haematuria in the patients was high (45.1%) with similar high Escherichia coli isolation rate and impaired renal function which could mean that acute or chronic kidney disease may set in.

Correlation of biofilm formation of uropathogenic Escherichia coli(UPEC) and fimbriae genotypes

Objective:In the present study we try to correlate between pathogenic intrinsic factor of Escherichia coli(E.coli) presented with different fimbria genotyes and biofilm formation with host immune factor entitled interleukin-6(IL-6) secretion as defense mechanism.Methods:A total of 91 pediatrics complaining of pyuria were included in the present study.In addition,20 healthy control children were included.Full microbiological study was performed for isolated E.coli.PapC alleles were studied by multiple alleles PCR and biofilm formation was studied.IL-6 was measured in urine.Results:IL-6 had statistically significant elevation in patients’urine compared to control.From biofilm study, it was found that 19 isolated E.coli had formed biofilm in vitro.Moreover,urine samples with positive biofilm formation of E.coli had statistically significant lower IL-6 secretion than those with negative E.coli for biofilms.The distribution of fimbria genotypes showed that the frequent genotype was for alleleⅠ(34.3%) followed by mixed allelesⅠandⅡ(24.1%).There was significant correlation between mixed alleles(Ⅰ&Ⅱ)and biofilm formation.Conclusion: The present study highlights the presence of significant strains of E.coli causing urinary tract infections capable of biofilm formation.Biofilm formation is associated with less innate immunity manifested by lower urinary IL- 6.The majority of isolates had fimbria genes.It appears that mixed allelesⅠandⅡhave prominent virulence effect with tendency for biofilm formation.

Regulation of fim genes in uropathogenic Escherichia coli

Uropathogenic Escherichia coli(UPEC)is the leading cause of urinary tract infections in women,causing significant morbidity and mortality in this population.Adherence to host epithelial cells is a pivotal step in the pathogenesis of UPEC.One of the most important virulence factors involved in mediating this attachment is the type 1 pilus(type 1 fimbria)encoded by a set of fim genes arranged in an operon.The expression of type 1 pili is controlled by a phenomenon known as phase variation,which reversibly switches between the expression of type 1 pili(Phase-ON)and loss of expression(Phase-OFF).Phase-ON cells have the promoter for the fimA structural gene on an invertible DNA element called fimS,which lines up to allow transcription,whereas transcription of the structural gene is silenced in Phase-OFF cells.The orientation of the fimS invertible element is controlled by two site-specific recombinases,FimB and FimE.Environmental conditions cause transcriptional and post-transcriptional changes in UPEC cells that affect the level of regulatory proteins,which in turn play vital roles in modulating this phase switching ability.The role of fim gene regulation in UPEC pathogenesis will be discussed.

Genetic Diversity of Uropathogenic Escherichia coli Isolated from Human T Lymphotropic Virus Type I (HTLV-I) Infected Individuals

Urinary tract infection (UTI) is a frequent pathology among HTLV-I+ individuals being capable of severely compromising the kidneys and bladder. Molecular characteristics of uropathogenic Escherichia coli (UPEC) from HTLV-I+ infected individuals are unknown. UPEC isolates from HTVL-I+ individuals, with and without clinical symptoms of myelopathy, were submitted to genetic typing seeking to infer bacterial diversity and potential virulence. 71 bacterial isolates were characterized according to random amplified polymorphic DNA and phylotypes. Phylotyping classified E. coli into four phylogenetic groups: A (18.3%), B1 (16.9%), B2 (39.4%), and D (25.3%) and 8 phylotypes according to the presence of the genetic sequences chuA, yjaA and the DNA fragment TSPE4.C2: ﹣﹣﹣ (5.6%) and ﹣+﹣ (12.6%) in phylogroup A, ﹣﹣+ (7.0%) and ﹣++ (9.8%) in B1, +++ (32.3%) and ++﹣ (7.0%) in B2, +﹣﹣ (15.4%) and +﹣+ (9.8%) in D. The B2 phylogroup was the most prevalent among HTLV﹣ associated myelopathy and asymptomatic individuals. RAPD-PCR typing revealed a high degree of bacterial polymorphism indicating a non-clonal origin. Genotypes were not found to be distributed according to clinical status or epidemiological features. Our results lead us to suggest that the neurological impairment in HTLV-I+ individuals can be a risk factor for urinary infections due E. coli which are caused by distinct bacterial lineages.

尿路感染细胞实验中庆大霉素对尿路致病大肠杆菌的杀伤作用及细胞毒性研究

目的在尿路感染体外细胞实验中,比较不同浓度庆大霉素(0、10、20、50、100、200μg/mL)对尿路致病大肠杆菌(UPEC)的杀伤作用,对尿路上皮细胞及炎性细胞如巨噬细胞的毒性作用。方法比较不同浓度庆大霉素对不同量UPEC J96菌株(10^(8)、10^(7)、10^(6))的杀伤情况;CCK-8实验检测不同浓度庆大霉素在不同时间内(2 h或24 h)对原代培养的C57BL/6雄鼠肾小管上皮细胞、腹腔巨噬细胞、人膀胱上皮细胞系J82的毒性作用;根据实验选择合适的庆大霉素浓度和作用时间,检测J96对小鼠肾小管上皮细胞的黏附、入侵以及小鼠巨噬细胞对J96的吞噬、清除作用。结果庆大霉素(≥10μg/mL)对J96的杀伤作用均强于1%的青霉素/链霉素双抗(P<0.0001),高浓度庆大霉素(≥100μg/mL)可在30 min内完全杀伤高达10^(8)的J96。50μg/mL庆大霉素作用2 h可对人膀胱上皮细胞系J82产生毒性作用(P<0.05)。结论本文明确了不同细胞体外实验时适宜的庆大霉素处理浓度及时间,人膀胱上皮细胞系J82对庆大霉素更为敏感。

UPEC双组分信号系统KguS/KguR调控基因缺失株的构建及其生长特性研究

[目的]构建尿道致病性大肠杆菌(uropathogenic Escherichia coli,UPEC) CFT073株的双组分信号系统Kgu S/KguR调控的c5032—c5037基因的缺失株,并研究基因缺失株在有氧和厌氧条件下的生长特性。[方法]运用Red重组系统将带有c5032—c5037基因同源臂的氯霉素抗性基因取代c5032—c5037基因,在温度敏感型质粒p CP20作用下消除氯霉素抗性基因,构建基因缺失株CFT073Δc5032—c5037,用PCR和基因测序验证基因敲除是否成功,测定有氧和厌氧条件下CFT073Δc5032—c5037在以α-酮戊二酸为唯一碳源的M9培养基中培养不同时间的菌液D600值。[结果]构建了CFT073Δc5032—c5037,PCR验证及基因测序结果均表明已成功敲除c5032—c5037基因;厌氧条件下CFT073Δc5032—c5037在以α-酮戊二酸为唯一碳源的M9培养基中生长比野生型菌株CFT073缓慢,且差异极显著(P<0.01),但在有氧条件下二者的生长无显著差异。[结论]成功构建了基因缺失株CFT073Δc5032—c5037,并试验证实Kgu S/KguR调控的c5032—c5037基因在厌氧条件下参与α-酮戊二酸的利用,为进一步研究Kgu S/KguR在UPEC中的代谢适应机制奠定了基础。

Multi-drug Resistant Uropathogenic Escherichia coli and Its Treatment by Chinese Medicine

Objectives： To investigate the resistance and virulence profiles of uropathogenic Escherichia coli（UPEC） and its treatment by Chinese medicine（CM） Fuzheng Qingre Lishi Formula（扶正清热利湿方, FQLF）. Methods： UPEC strains were isolated from recurrent urinary tract infections（UTIs） patients. Patient sensitivities to 17 antibiotics were tested by the disk diffusion method. Virulence genes were screened by plolymerase chain reaction. A mouse model was constructed using a multi-drug resistant and virulent UPEC strain and treated with FQLF or the antibiotic imipenem. The treatment efficacy was evaluated by bacterial clearance from urine and the urinary organs. Results： A total of 90 UPEC strains were collected, and 94.4% of the isolates were resistant to at least 1 antibiotic. Approximately 66.7% of the UPEC strains were multi-drug resistant. More than one virulence gene was found in 85.6% of the isolates. The extended-spectrum β-lactamases（ESBL）-positive strains were more resistant than the negative ones. The virulence gene number was positively correlated with the resistance number（P〈0.05）. A mouse model was successful y constructed using UPEC10. Treatment with either FQLF or antibiotics significantly cleared bacteria from the mouse urine after 14 days. In the untreated control, the bacteria lasted for 28 days. FQLF treatment of the UTI mouse model greatly reduced the bacterial number in the kidney and bladder, but could not completely clear the bacteria. Conclusions： Multi-drug resistance is common among UPEC isolates, and the resistance is positively related with virulence. FQLF could treat UPEC UTIs, but could not completely clear the bacteria from the host.

Comparison of infection of different cell lines by uropathogenic Escherichia coli

Studying the interaction between uropathogenic Escherichia coli (UPEC) and uroepithelial cells is important in elucidating the pathogenesis of urinary tract infection. In this study, the African green monkey kidney cells (Vero), human kidney carcinoma cells (Ketr-3) and bladder carcinoma cells (EJ) were infected by UPEC132, a clinical strain isolated from Tianjin, China, and were compared for their capacities to allow the adherence and invasion by this strain. The results revealed that all these cell lines could be attached and invaded by UPEC132. The adherence rates for Vero, Ketr-3 and EJ cells were (49.20 ± 7.55)%, (55.22 ± 4.09)% and (73.20 ± 5.26)%, respectively, and invasion frequencies were (2.61 ± 0.32)×10-3, (3.00 ± 0.34)×10-3 and (3.25 ± 0.20)×10-3, respectively. The statistical analysis showed that the adherence rate for EJ cells was significantly higher than those for the other two cell lines (P<0.05), and the invasion frequencies for EJ and Ketr-3 cells had no statistical differences (P>0.05) but were higher than that for Vero cells (P<0.05). Three cell lines were detected for the receptors for P pili of UPEC by using indirect immunofluorescence. The results showed that receptors existed on the surfaces of all cell lines, and the highest distribution was found on the surface of EJ cells. Additionally, the invasion of EJ cells by recombinant UPEC132/pSELECT-GFP could be directly visualized using confocal microscopy. These data strongly implicated that EJ cells could be more easily infected by UPEC132 than the other cells, and thus could serve as a good experimental target for further investigation of UPEC infection.

Prevalence of ESBL phenotype,bla_(CTX-M-1),bla_(SHV)and bla_(TEM)genes among uropathogenic Escherichia coli isolates from 3 military hospitals of Tehran,Iran

Objective:To determine the extended-spectrum beta-lactamase(ESBL)production and prevalence of bla_(CTX-M-1),bla_(SHV)and bla_(TEM)genes among uropathogenic Escherichia coli(UPEC)isolates from 3 military hospitals of Tehran during 2015-2016.Methods:One-hundred and eleven isolates were adopted.The antibiotic susceptibility testing was conducted according to Clinical and Laboratory Standards Institute guidelines.The combine disk was used for phenotypic ESBL production.The ceftazidime MIC was conducted with the micro-broth dilution test.The PCR assay was used to detect the bla_(CTX-M-1),bla_(SHV)and bla_(TEM)genes.Results:In the broth microdilution method,103(92.7%)isolates showed minimal inhibitory concentration(MIC)≥1μg/mL,and also in the combined disk method,89(80.1%of all)were ESBL positive.On the other hand,among 91 ceftazidime resistant isolates,86(77.4%of all)were ESBL positive.The difference between the two methods for ESBL confirmation was not significant.The result of MIC was similar to the disk diffusion method in the detection of phenotypic ESBL production.Among ESBL producer isolates,the prevalence of bla_(CTX-M-1),bla_(SHV)and bla_(TEM)was 77.4%(n=86),47.4%(n=53)and 2.4%(n=2),respectively.These genes were amplified in a wide range MIC of ceftazidime.Conclusions:The prevalence of multi-drug resistant UPEC and ESBL positive isolates was high in military hospitals.The majority of UPEC isolates amplified bla_(CTX-M-I)and bla_(SHV)typeβ-lactamase genes.One-third of isolates were positive in presence of both these genes.There was no relation between ceftazidime MIC and presence of beta-lactamase genes.

尿路致病性大肠杆菌与宿主相互作用的研究进展

泌尿系感染(UTI)是泌尿外科常见的感染性疾病,通常由尿路致病性大肠杆菌(UPEC)引起。UPEC入侵及定殖于尿路上皮细胞,造成泌尿系感染以及复杂的宿主免疫清除和病原体免疫逃逸,包括物理屏障的防御、中性粒细胞迁移、募集和吞噬以及细胞因子的分泌等。病原体与宿主之间复杂的免疫反应与免疫逃避是疾病发生发展的关键,也是UTI治疗的基础。本文针对最新的UTI中宿主-尿路致病大肠杆菌相互作用作一综述。

尿路感染患者常见病原菌分布及耐药性分析

目的分析徐州医科大学附属医院尿路感染患者尿液标本的病原菌分布及大肠埃希菌对常用抗菌药物的耐药情况,为合理选用抗菌药物提供指导依据。方法收集2021年8月—2022年7月徐州医科大学附属医院送检的3882份自行收集或无菌导出的尿液标本,并进行中段尿培养,分析尿培养阳性标本病原菌分布结果、大肠埃希菌检出科室分布情况及其抗菌药物敏感性。结果3882份送检尿培养标本中尿培养阳性标本共881份(22.69%),其中由单一菌株引起的有846份,由2种混合菌株引起的有35份;共分离出916株病原菌,其中检出512株革兰阴性菌(55.90%),以大肠埃希菌(306株,33.41%)和肺炎克雷伯菌(75株,8.19%)为主;检出革兰阳性菌188株(20.52%),以屎肠球菌(80株,8.73%)和粪肠球菌(27株,2.95%)为主;检出216株真菌(23.58%),以白假丝酵母菌(77株,8.41%)和热带假丝酵母菌(58株,6.33%)为主。尿路致病性大肠埃希菌(UPEC)分离株中8.50%(26/306)分离自门诊患者,91.50%(280/306)分离自住院患者,其中泌尿外科、肾脏内科、风湿免疫科、神经内科和重症监护室(ICU)的检出率依次为32.68%、20.92%、8.50%、6.86%、6.21%。UPEC对替卡西林(88.24%)、头孢呋辛(61.49%)、头孢呋辛酯(62.94%)、左氧氟沙星(72.46%)和复方新诺明(58.03%)的耐药性较高,耐药率均高于50%;对其他抗菌药物较为敏感。结论该院尿路感染标本中病原菌构成复杂、种类多样,其中革兰阴性菌是尿路感染的主要致病菌,以大肠埃希菌占比最多,部分病原菌呈现高水平耐药。患者应积极配合医生开展病原菌鉴定及药物敏感试验,以便合理选用抗菌药物,避免多重耐药菌和新型耐药菌的出现。

尿路致病性大肠杆菌Ⅰ型菌毛fimH和fimC基因原核表达质粒的构建及表达

目的构建以尿路致病性大肠杆菌(UPEC)Ⅰ型菌毛编码基因fimH和fimC为目的基因的原核重组表达质粒,诱导其在E.coliBL-21中表达,并对其免疫原性进行分析。方法PCR法自UPEC标准菌株J96获取fimH和fimC基因,分别插入原核表达载体pGEX-4T-2;将重组表达质粒转染感受态E.coliBL-21,经IPTG诱导表达、SDS-PAGE和Westernblot鉴定并纯化目的蛋白fimH和fimC蛋白,定量后免疫BALB/c小鼠,动态检测抗体产生水平。结果PCR法克隆出全长为903bp的fimH和720bp的fimC基因,构建的原核表达质粒pGEX-4T-2-fimH及pGEX-4T-2-fimC经诱导可分别表达出60KD和48KD左右的GST融合蛋白;蛋白经纯化后免疫动物能诱导产生高效价的IgG抗体。结论成功获取了UP-ECⅠ型菌毛基因fimH和fimC,所构建的原核表达质粒在BL-21中成功表达;fimH有免疫原性。

两种营养条件对尿路致病性大肠埃希菌生物膜形成的影响

目的研究2种培养基对尿路致病性大肠埃希菌(UPEC)生物膜形成能力的影响。方法将5株UPEC分别接种LB培养基或M63基础培养基,用结晶紫染色半定量法检测各菌株生物膜形成能力,分别用荧光显微镜和共聚焦显微镜观察绿色荧光蛋白标记的UPEC在2种培养基中的生物膜形成过程与厚度的差异。结果 5株UPEC在2种培养基中均为生物膜阳性菌株,早期生物膜的形成趋势基本一致,但同时期LB培养基中的生物膜菌量少于M63基础培养基中的生物膜菌量。共聚焦显微镜观察发现在M63基础培养基中各菌株生物膜最大平均厚度均大于LB培养基的相应数值(P<0.05)。结论培养基成分对UPEC生物膜的形成具有重要影响,M63基础培养基相对于LB培养基更适于培养UPEC生物膜。

尿路致病性大肠埃希菌生物膜形成与耐药性的关系

目的研究50株临床分离的尿路致病性大肠埃希菌(UPEC)形成生物膜情况及其对抗菌药物敏感性的影响。方法采用结晶紫染色法检测生物膜阳性菌株,K-B纸片扩散法分析UPEC对8种抗菌药物的敏感性,再通过统计学方法分析细菌耐药性与生物膜形成之间的关系。结果 50株UPEC中,生物膜阳性34株,占68.00%。UPEC对8种抗菌药物均有不同程度耐药性;经统计学分析,生物膜阳性菌株对氨苄西林和庆大霉素耐药率(76.47%和55.88%)明显高于生物膜阴性菌株(43.75%和18.75%),差异有统计学意义(P<0.05)。结论 UPEC产生物膜现象较普遍,生物膜形成与其对氨苄两林和庆大霉素的耐药性具有相关性。

尿道致病性大肠杆菌HEC4株和禽源致病性大肠杆菌E058株毒力相关特性的比较(英文)

对人尿道致病性大肠杆菌(uropathogenic Escherichia coli,UPEC)HEC4株和禽致病性大肠杆菌(avian pathogen-ic Escherichia coli,APEC)E058株进行毒力基因和其他相关特性的比较,结果显示,它们具有一些共同的毒力基因,包括一些存在于APEC中一个大的可传递质粒上的基因;同时,它们也具有一些相似的生化特性。对SPF鸡的致病性试验显示,这两株分离株具有相似的致病力。因此,对于APEC和UPEC的相关性,以及APEC是否有可能导致人尿道感染或者成为UPEC的毒力基因贮主,有待进一步研究。

尿路致病性大肠杆菌外膜蛋白T的致病机制

目的探讨大肠杆菌外膜蛋白T(OmpT)参与尿路致病性大肠杆菌致病的机制。方法通过建立人膀胱癌移行上皮细胞模型,检测野生株CFT073、ompT基因敲除株COTD、回补株COTD(pST)的体外黏附情况;比较野生株、敲除株和回补株对细胞外基质的体外黏附能力;通过荧光定量PCR方法,比较ompT基因敲除以后,iha和iroN基因的mRNA表达水平;建立小鼠动物模型,比较有无OmpT菌株所致小鼠膀胱和肾脏的细菌载量、血液菌浓度及炎症因子IL-6和IL-8的蛋白表达水平,验证OmpT的致炎作用。结果野生株细胞黏附率为(8.81±1.13)%,敲除株为(4.62±0.39)%,敲除株的黏附率明显低于野生株(P<0.05);野生株的细胞外基质黏附率为(8.85±0.79)%,敲除株为(4.95±0.59)%,敲除株的黏附率明显低于野生株(P<0.05);与敲除株比较,iha和iroN基因在野生株中的表达水平分别是敲除株的2.1和3.8倍;野生株感染的小鼠膀胱组织中细菌载量均数为6.36±0.06,敲除株为6.01±0.07,回补株为6.29±0.06,野生株感染的小鼠肾脏组织中细菌载量为6.25±0.05,敲除株为5.87±0.06,差异均有统计学意义(P<0.05);野生株和回补株所致小鼠膀胱和肾脏组织炎症中IL-6检出的阳性率分别为60%和50%,而ompT基因敲除株则为12.5%。IL-8的表达情况同IL-6。结论初步证实OmpT通过发挥毒力因子的作用,从而影响尿路致病性大肠杆菌对宿主细胞的黏附,其可能机制是影响细菌对细胞外基质的黏附和参与iha和iroN基因的表达并在致炎过程中发挥重要作用。

原花青素对尿路致病性大肠杆菌黏附、侵袭膀胱上皮细胞的影响及其机制

目的探讨原花青素对尿路致病性大肠杆菌(UPEC)黏附、侵袭膀胱上皮细胞的影响,并探讨其作用机制。方法体外培养人膀胱上皮细胞T24,随机分为空白对照组、阴性对照组和原花青素组,阴性对照组和原花青素组分别加入等量DMSO和亚抑菌浓度的原花青素溶液。采用平板菌落计数法检测各组UPEC J96对膀胱上皮细胞T24的相对黏附率和相对侵袭率;采用RT-PCR法检测各组细胞表面整合素受体α3和β1 mRNA表达;采用流式细胞术检测各组纤维状肌动蛋白(F-Actin)相对荧光强度。结果与空白对照组和阴性对照组比较,原花青素组UPEC J96的相对黏附率和相对侵袭率均明显降低(P均<0. 01),T24细胞表面整合素受体α3、β1 mRNA相对表达量均明显下降(P均<0. 01)。与空白对照组和阴性对照组比较,原花青素组无论是UPEC J96未感染细胞还是UPEC J96感染细胞,F-Actin相对荧光强度均明显降低(P均<0. 01)。空白对照组与阴性对照组上述指标比较P均> 0. 05。结论原花青素可抑制UPEC黏附、侵袭膀胱上皮细胞,其机制可能通过抑制膀胱上皮细胞表面整合素受体及F-Actin表达实现。

大肠杆菌α-溶血素分泌系统基因表达调控研究进展

引起人泌尿道感染的大肠杆菌(UPEC)的α-溶血素分泌系统属于Ⅰ型分泌系统,能够分泌一种RTX毒素蛋白—α-溶血素。近年来α-溶血素分泌系统的应用日益广泛,特别是在减毒活载体疫苗中呈递外源抗原。本文分析了大肠杆菌α-溶血素分泌系统的遗传特性,详细介绍了其基因的表达调控,为构建更加有效的分泌型载体提供了理论基础。

儿童泌尿系大肠埃希菌感染的耐药性及产ESBLs大肠埃希菌感染危险因素分析

目的探讨儿童泌尿系大肠埃希菌感染的现状及耐药性,分析儿童产超广谱β内酰胺酶(expendedspectrumβ-lactamase,ESBLs)大肠埃希菌感染的危险因素。方法回顾性分析我院2016年7月—2018年9月收治的280例泌尿系感染患儿尿液标本,观察大肠埃希菌检出及耐药情况,并进一步通过回顾产ESBLs大肠埃希菌感染患儿和非产ESBLs大肠埃希菌感染患儿的临床资料,寻找产ESBLs大肠埃希菌感染的危险因素。结果280例尿液标本中共检出大肠埃希菌128株,检出率为45.71%,其中产ESBLs菌株48株,非产ESBLs菌株80株。128株大肠埃希菌对大部分常用抗菌药物耐药,产ESBLs大肠埃希菌对氨苄西林完全耐药,对厄他培南、美罗培南不耐药,非产ESBLs大肠埃希菌对氨苄西林耐药率较高;产ESBLs大肠埃希菌对氨苄西林、氨苄西林钠-舒巴坦钠、氨曲南、环丙沙星、头孢曲松、头孢唑林、头孢吡肟、左氧氟沙星、头孢呋辛、头孢他啶、妥布霉素的耐药率均高于非产ESBLs大肠埃希菌(P<0.05或P<0.01)。多因素logistic回归分析结果显示:尿路梗阻、留置导尿管及近1个月抗菌药物应用史是泌尿系产ESBLs大肠埃希菌感染的独立危险因素。结论儿童泌尿系大肠埃希菌对氨苄西林耐药率最高,对多数头孢菌素类抗菌药物耐药,对碳青霉烯类抗菌药物耐药率较低。儿童泌尿系大肠埃希菌耐药以产ESBLs大肠埃希菌耐药为主,碳青霉烯类抗菌药物治疗产ESBLs大肠埃希菌感染效果最佳。对有尿路梗阻、留置导尿管及近1个月抗菌药物应用史的患儿应警惕泌尿系产ESBLs大肠埃希菌感染。