佳木斯地区女性泌尿系统感染大肠埃希菌耐药性分析

目的分析女性患者泌尿系统感染大肠埃希菌的耐药性,为临床合理使用抗生素提供依据。方法采用全自动微生物鉴定系统对女性泌尿系统感染患者分离出的病原菌进行鉴定和药敏分析。结果大肠埃希菌非产ESBLs株对氨苄西林、第一、二代头孢菌素类药品高度耐药。大肠埃希菌非产ESBLs株对碳青霉烯类药物美罗培南无耐药,对第三代头孢菌素敏感率高,耐药率低。产ESBLs大肠埃希菌,仅碳青霉烯类抗生素美罗培南敏感。结论女性泌尿系统感染大肠埃希菌的多重耐药性日趋严重,需加强对抗生素使用的规范化管理,合理使用抗菌药物,控制耐药菌的传播和流行。     

Mutator phenotype confers advantage in Escherichia coli chronic urinary tract infection pathogenesis

It has been suggested that mutator phenotype could be associated with an increase in virulence, but to date experimental evidences are lacking. Epidemiological studies have revealed that urinary tract infection isolates encompass the highest proportion of mutator strains within the Escherichia coli species. Using the uropathogenic strain CFT073 and its mutS- mutator mutant, we show that the mutator strain is selected in vitro in urine and in the late stages of infection in a mouse model having urinary tract infection. Thus, we report that, under specific conditions, i.e., urinary tract infection, the mutator phenotype may confer an advantage in pathogenesis.     

156例尿路感染大肠埃希菌耐药性分析

目的探讨大肠埃希菌尿路感染的临床发病特点及对抗生素的耐药情况。方法对2001年1月至2005年12月尿路感染患者尿培养分离出的156株大肠埃希菌进行耐药性分析,用纸片扩散法表型确证试验检测ESBLs。结果大肠埃希菌耐药率最低的抗菌药物是亚胺培南、美罗培南、头孢哌酮/舒巴坦、氧哌嗪青霉素/他唑巴坦,分别为1.28%、1.92%、3.21%、5.13%;对氨苄西林、氟喹诺酮类、庆大霉素、复方新诺明耐药率均>70%。产ESBLs的大肠埃希菌对亚胺培南、美罗培南、头孢哌酮/舒巴坦、氧哌嗪青霉素/他唑巴坦的耐药性均<10%,对氨苄西林、头孢菌素类、氟喹诺酮类均表现出很强的耐药性。结论治疗大肠埃希菌感染时,需根据药敏结果选用碳青霉烯类、β-内酰胺类/β-内酰胺酶抑制剂等。     

女性糖尿病患者合并尿路感染大肠埃希菌耐药性分析

目的 回顾性分析女性糖尿病(DM)合并尿路感染( UTI)大肠埃希菌的耐药情况及产超广谱β-内酰胺酶(ESBLs)的发生率,以指导临床合理选择抗菌药物.方法 对近4年在浙江大学医学院附属第二医院确诊DM合并UTI女性患者的中段尿标本中分离出的95株大肠埃希菌进行耐药性分析,用纸片扩散法表型确证试验检测ESBLs,以女性非糖尿病患者为对照组,并以年份进行分组分析.结果 95株大肠埃希菌ESBLs阳性率为40.0％,明显高于对照组,糖尿病组对氨苄西林、环丙沙星、左氧氟沙星耐药率较高,均＞60.0％,对环丙沙星、左氧氟沙星、头孢曲松、头孢唑林、头孢吡肟、头孢呋辛耐药率明显高于对照组,早期组与近期组的产ESBLs率及耐药率差异无统计学意义.结论 女性糖尿病伴尿路感染大肠埃希菌对多种抗菌药物的耐药率较高,临床应根据药敏试验结果合理使用抗菌药物.     

Effect of the adhesive antibiotic TA on adhesion and initial growth of E. coli on silicone rubber

Catheter-associated urinary tract infection is the most common nosocomial infection, and contributes to patient morbidity and mortality. We investigated the effect that the TA adhesive antibiotic had on adhesion and initial growth in urine of Escherichia coli on silicone rubber. The TA antibiotic had reduced adhesion, and inhibited initial growth of the bacteria on the surface. Since adhesion and initial growth on the surface are an essential part of biofilm formation and subsequent infection, we speculate that the TA antibiotic coating might decrease the infection rate associated with indwelling urinary catheter.     

Immunization with killed Escherichia coli increases resistance of lipopolysaccharide-hyporesponsive C3H/HeJ mice to experimental urinary tract infection

Abstract C3H/HeJ mice are highly susceptible to experimental ascending urinary tract infection. After a 4-week intraperitoneal immunization regimen with killed Escherichia coli , these mice became more resistant to urinary tract infection. The level of resistance induced by this regimen in this strain was similar to that of the normally more resistant C3HeB/FeJ strain of mouse and was evident from 3 to 14 days after transurethral challenge with E. coli . Increased resistance also developed after a 2- or 3-week immunization regimen, but this resistance was not apparent until 14 days after challenge.     

大肠埃希菌泌尿系统感染患者临床分布及药物敏感性分析

摘要 目的：探讨大肠埃希菌引起泌尿系统感染患者的临床分布情况及其药物敏感性分析,为临床诊断及合理使用抗菌药物提供理论性依据。方法：选取2015年1月至2020年12月期间诊治的2052例大肠埃希菌泌尿系统感染患者为研究对象,使用MALDI-TOF MS全自动微生物鉴定质谱仪对细菌进行鉴定,应用VITEK 2 Compact全自动微生物鉴定及药敏分析仪进行药物敏感性分析。结果：2052例大肠埃希菌泌尿系统感染患者中泌尿外科患者占比最高,为17.50%,其次为肾病科患者,占12.87%。其中检出803株产ESBLs的大肠埃希菌,泌尿外科占比最高,为18.56%,其次是肾病科占13.95%,内分泌科占11.71%,重症医学科10.09%。2052株大肠埃希菌整体药敏分析结果显示,大肠埃希菌对美罗培南、亚胺培南、阿米卡星、哌拉西林/他唑巴坦、呋喃妥因、米诺环素、头孢西丁等药物敏感率高,均>90%,头孢唑啉、环丙沙星、左氧氟沙星、氨苄西林/舒巴坦、复方新诺明、氨苄西林敏感率低,均<50%,其中氨苄西林敏感率最低,只有28.17%。结论：大肠埃希菌泌尿系统感染主要发生在泌尿外科,产ESBLs大肠埃希菌整体检出率较高,临床应重视泌尿系统感染患者的尿细菌培养及药物敏感性分析,尽量避免仅凭经验性用药,根据药物敏感性结果合理选择抗菌药物。     

Molecular evidence supporting the existence of two major groups in uropathogenic Escherichia coli

Abstract Molecular methods allow an extremely fine strain typing that can be used to establish the population structure of bacterial species. This methodology has been used to characterize a collection of 74 uropathogenic Escherichia coli obtained from three hospitals located in geographically distant towns in Spain, some representatives of the ECOR collection and other reference strains. Genomic DNA was analyzed by RAPD (Random Amplified Polymorphic DNA) that can characterize a bacterial strain to the level of defining individual clones. The 16S rDNA-23S rDNA spacers were amplified by PCR and submitted to restriction analysis. Finally, the presence or absence of G adhesins in Escherichia coli as well as the type of adhesin (three types are known) have been shown by PCR amplification followed by digestion with restriction enzymes. As expected a wide diversity was shown by RAPD and identical patterns were only found in the case of strains isolated from the same individual, an obvious case of relapse. Analysis of the spacers' restriction patterns showed the presence of two markedly differentiated clusters that we have named α and ß. Both RAPD and spacer restriction patterns originated similar clusters of strains showing a consistency in the evolution of the global genome with the sequence variation of the ribosomal spacers. Furthermore, most of the strains having G-adhesin, with only a few exceptions, corresponded to the α rRNA spacer group. The two spacer types detected were also consistent with some phenotypic markers such as sucrose and raffinose utilization. The α and β clusters could be intraspecific groups produced by partial sexual isolation or other barriers that are originating a divergent evolution.     

绵羊肺源性致病性大肠杆菌的分离与鉴定

【目的】近年来,羊呼吸系统疾病日益频发,由肠外致病性大肠杆菌感染引起的呼吸道疾病也日渐增多,给养羊业带来了一定经济损失。本文旨在确定新疆石河子地区某羊场表现为呼吸道感染症状的病死羔羊的细菌性病原及其特性。【方法】采用细菌常规分离鉴定结合16S rRNA基因序列分析的方法从发病羔羊的肺脏中分离鉴定细菌,并对分离株进行药敏试验、特异基因PCR检测、小鼠致病性试验及肺脏组织的病理学观察。【结果】从病死羔羊肺脏组织分离得到一株致病性大肠杆菌,该分离株呈多重耐药现象,检测到iutA、fyuA和ireA三种毒力基因;病变肺脏肺泡壁毛细血管充血,界限不清,支气管管腔充血,周围淋巴细胞浸润、增生。【结论】从病死羔羊肺中分离的细菌性病原是肠外致病性大肠杆菌(ExPEC)。     

Escherichia coli outer membrane protease OmpT confers resistance to urinary cationic peptides

Escherichia coli OmpT, located in the outer membrane, has been characterized as a plasminogen activator, with the ability to hydrolyze protamine and block its entry. In this investigation, a complex of low molecular weight cationic peptides purified from human urine by a combination of membrane ultrafiltration and weak cation exchange chromatography was characterized. The impact of OmpT on E. coli resistance to urinary cationic peptides was investigated by testing ompT knockout strains. The ompT mutants were more susceptible to urinary cationic peptides than ompT⁺ strains, and this difference was abolished by complementation of the mutants with pUC19 carrying the ompT gene. The urinary protease inhibitor ulinastatin greatly decreased the resistance of the ompT⁺ strains. Overall, the data indicate that OmpT may help E. coli persist longer in the urinary tract by enabling it to resist the antimicrobial activity of urinary cationic peptides.     

Endemic occurrence of infections by multidrug-resistant Escherichia coli of four unique serotypes in the elderly population of Israel

During a period of four years, multidrug-resistant Escherichia coli of particular serotypes have been isolated from 255 elderly (>65 years) patients from four hospitals in central Israel. 83% of the isolates belonged to one of four predominant serotypes (O153:H31, O101:H-, O2:H42, and O102:H6). All isolates were producers of extended spectrum beta-lactamases and resistant to ciprofloxacin. To our knowledge, the involved serotypes have hitherto not been reported as etiological agents of extraintestinal human infections (MEDLINE). Pulsed-field gel electrophoresis of isolates from one of the most frequent serotypes indicated a clonal relationship between them. Further investigation of these strains and analysis of their virulence factors may help to confine their spread.     

Aerobactin production and dulcitol fermentation in clonal groups of Escherichia coli O1: K1 strains from urinary tract infections

Abstract 70 urinary Escherichia coli O1:K1 strains were characterized for O1 antigen factors, mannose-resistant hemagglutination of human erythrocytes, flagellar and fimbrial antigens, dulcitol fermentation and aerobactin production. On the basis of their O1 and H antigens the strains could be assigned to 6 distinct groups. The most prevalent groups were: O1abcd: H⁻ :F9 (33 strains; pattern II), O1abc: H⁻ :F11 (9 strains; pattern IV), and O1abc: H7: F11 (19 strains; pattern V). Strains with patterns IV and V, both expressing fimbrial antigen F11, fermented dulcitol and produced aerobactin, whereas strains with pattern II were negative for both characteristics.     

Role of collectin-11 in innate defence against uropathogenic Escherichia coli infection

Classical collectins (surfactant protein A and D) play a significant role in innate immunity and host defence in uropathogenic Escherichia coli (UPEC)-induced urinary tract infection (UTI). However, the functions of collectin-11 (CL-11) with respect to UPEC and UTI remain largely unexplored. This study aimed to investigate the effect of CL-11 on UPEC and its role in UTI. We further examined its modulatory effect on inflammatory reactions in proximal tubular epithelial cells (PTECs). The present study provides evidence for the effect of CL-11 on the growth, agglutination, binding, epithelial adhesion and invasion of UPEC. We found increased basal levels of phosphorylated p38 MAPK and human cytokine homologue (keratinocyte-derived chemokine) expression in CL-11 knockdown PTECs. Furthermore, signal regulatory protein α blockade reversed the increased basal levels of inflammation associated with CL-11 knockdown in PTECs. Additionally, CL-11 knockdown effectively inhibited UPEC-induced p38 MAPK phosphorylation and cytokine production in PTECs. These were further inhibited by CD91 blockade. We conclude that CL-11 functions as a mediator of innate immunity via direct antibacterial roles as well as dual modulatory roles in UPEC-induced inflammatory responses during UTI. Thus, the study findings suggest a possible function for CL-11 in defence against UTI.     

Inhibitors of lipopolysaccharide biosynthesis impair the virulence potential of Escherichia coli

Inhibition of 3-deoxy-manno-octulosonate cytidylytransferase (CMP-KDO transferase; EC 2.7.7.38) by 8-amino-2,6-anhydro-3,8-dideoxy-D-glycero-D-talo-octonic acid (NH2dKDO) halts the growth of Gram-negative bacteria by depriving the cells of the 3-deoxy-D-manno-2-octulosonate required for the biosynthesis of the core region of the lipopolysaccharide components of the outer membrane. Low levels of this inhibitor increase the vulnerability of Escherichia coli to hydrophobic antibiotics, detergents, the complement-mediated antibacterial activity of serum, phagocytosis, and enhance the rate at which bacteria are cleared from the mouse bloodstream.     

Rapid immunodetection of Escherichia coli

A filtration flow-through design was used to develop the rapid immunodetection of Escherichia coli. Polyclonal anti-E. coli IgG was conjugated to small, 0.8 Blue latex beads. Cells were mixed with conjugated beads in the presence of anti-E. coli monoclonal IgM. The suspension was then filtered through a 5 nitrocellulose membrane. The cell-containing complexes were effectively collected on the filter, forming a blue spot. The method produced reliable detection of E. coli at a concentration of 10⁵ cells ml^–1, which is a current benchmark figure for urinary tract infection (UTI) diagnosis.     

风湿性疾病患者尿路感染大肠埃希菌对左氧氟沙星耐药性及危险因素分析

目的研究风湿性疾病中尿路感染大肠埃希菌对左氧氟沙星耐药性及相关危险因素。方法中国医科大学附属第一医院风湿免疫科2009年1月至2013年12月125株住院患者清洁中段尿培养所分离出大肠埃希菌,依据是否耐药分为两组。分析耐药组相关危险因素。结果 5年来大肠埃希菌对左氧氟沙星耐药率呈逐渐上升趋势。耐药组对氨苄西林、环丙沙星、头孢曲松、哌拉西林、复方新诺明的耐药率高于非耐药组,两组间差异有统计学意义（P〈0.05）。慢性病程、既往喹诺酮类药物应用史、既往尿路感染、菌株产ESBLs为耐药危险因素。各风湿性疾病间耐药率比较差异未见统计学意义。结论风湿性疾病尿路感染危险因素与其他疾病尿路感染危险因素类似。临床工作中应加强对危险因素监视和控制。     

Assessment of the Significance of Virulence Factors of Uropathogenic Escherichia coli in Experimental Urinary Tract Infection in Mice

Four Escherichia coli strains, isolated from cystitis patients, belonging to serotype O2:H^? and possessing different combinations of urovirulence factors were examined in an experimental pyelonephritis mouse model to assess the relative importance of virulence factors in causation of urinary tract infections (UTI). The results suggest not only that the each virulence factor has a role in causation of UTI but also that the presence of P fimbriae and production of hemolysin significantly reduced the LD₅₀ and ID₅₀ of the strains in the mouse model. The results also demonstrate that the presence of additional virulence factors acts in an additive or synergetic fashion enhancing the cumulative impact of the strain.     

The synergistic triad between microcin,colibactin, and salmochelin gene clusters in uropathogenic Escherichia coli

A functional synergy was previously demonstrated between microcin, salmochelin and colibactin islands in Escherichia coli strains from B2 phylogroup. We aimed to determine this association prevalence in uropathogenic E. coli, and whether it was predictive of the infection severity in a collection of 225 E. coli strains from urinary samples. The high prevalence of this triad, even if it wasn’t correlated with infection severity, suggested that it might not be a virulence factor per se within the urinary tract, but would promote its colonization. This triad would enable the strain to dominate the rectal reservoir with a minimal genetic cost.