Influence of P blood group phenotype on susceptibility to urinary tract infection

Abstract Bacterial attachment is an important event in the pathogenesis of urinary tract infection (UTI). Increased receptivity on the host cells has been suggested influence proneness to infection. The dual function of the globoseries of glycolipids both as receptors for attaching E. coli and as P blood group antigens lead us to examine the P blood group phenotype distribution in UTI prone patient populations. A correlation between the P₁ blood group phenotype and susceptibility to UTI was found. Patients with recurrent pyelonephritis had 74/79 (94%), P₁ compared to 75% in healthy controls. In contrast patients with asymptomatic bacteriuria (ABU) had a reduced frequency of P₁, 43/74 (58%). P₁ and P₂ individuals differ in amount and composition of the globoseries of glycolipids on their erythrocytes. A similar difference in other tissues, e.g. uroepithelial cells might explain the association of P₁ with UTI. There was, however, no significant difference in bacterial adherence to uroepithelial cells from P₁ and P₂ individuals. Other mechanisms explaining the increase in P₁ individuals in recurrent pyelonephritis are discussed.     

Contribution of macrophage secretory products to urovirulence of Pseudomonas aeruginosa

Macrophages form one of the first lines of defense on mucosal surfaces like urinary tract, providing protection against pathogens. These cells pour their secretory products, which include a cocktail of biomolecules, at the site of infection. In the present investigation, the effect of macrophage secretory products (MSPs) obtained after interaction of macrophages with Pseudomonas aeruginosa on the virulence of this organism in planktonic and biofilm cell mode was assessed employing a mouse model of ascending pyelonephritis. When urinary tract infection (UTI) was established with P. aeruginosa grown in the presence of 30% MSPs, the extent of pyelonephritis was enhanced. Of the two cell forms, biofilm cells had an edge over the planktonic cells with respect to in vivo virulence. The enhanced virulence of MSP-grown P. aeruginosa may be attributed to increased production of quorum-sensing systems as well as increased adherence to uroepithelial cells and evasion of phagocytosis. The results of the present study reveal that macrophages can play a key role during the course of UTI, not only through their phagocytic activity, but also through effects mediated by their secretory products. Utilization of MSPs by P. aeruginosa can have far-reaching consequences, including chronicity and recurrence of infections caused by this pathogen.     

Serum and urine levels of interleukin-6 and interleukin-8 in children with acute pyelonephritis

Urinary tract infection (UTI) is a common clinical disorder in younger infants and children and may result in permanent renal damage. The inflammatory cytokines interleukin (IL)-6 and IL-8 play an important role in response to bacterial infection. This prospective study investigated the association between serum and urine IL-6 and IL-8 levels and acute pyelonephritis confirmed by (99m)Tc-dimercaptosuccinic acid (DMSA) scan. A total of 78 children aged 1-121 months with a diagnosis of first-time febrile UTI were included. The following inflammatory markers were assessed: fever; white blood cells count (WBC); C-reactive protein (CRP); and serum and urine IL-6 and IL-8. The patients were divided into the acute pyelonephritis group (n=42) and the lower UTI group (n=36) according to the results of DMSA scan. Fever, WBC and CRP levels were significantly higher in children with acute pyelonephritis than in those with lower UTI (all p <0.001). Significantly, higher initial serum and urine IL-6 and IL-8 levels were found in children with acute pyelonephritis than in those with lower UTI (all p <0.001). Serum and urine IL-6 in children with acute pyelonephritis were positively correlated with fever, CRP and leucocyturia. These results indicate that both serum and urine IL-6 and IL-8 levels, particularly IL-6, are useful diagnostic tools for early recognition of acute pyelonephritis in febrile children.     

Quantitative studies of the binding of the class II PapG adhesin from uropathogenic Escherichia coli to oligosaccharides

Binding of the class II PapG adhesin, found at the tip of filamentous pili on Escherichia coli, to the carbohydrate moiety of globoseries glycolipids in the human kidney is a key step in development of pyelonephritis, a severe form of urinary tract infection. An assay based on surface plasmon resonance for quantification of the binding of the class II PapG adhesin to oligosaccharides has been developed. Using this assay dissociation constants ranging from 80 to 540 microM were determined for binding of the PapG adhesin to di-pentasaccharide fragments from the globoseries of glycolipids. A series of galabiose derivatives, modified at the anomeric position, O-2' or O-3', was also investigated. The anomeric position appeared to be the most promising for development of improved inhibitors of PapG-mediated adhesion of E. coli. p-Methoxyphenyl galabioside was found to be most potent (K(d)=140 microM), and binds to PapG almost as well as the Forssman pentasaccharide.     

New aspects of the role of MR/P fimbriae in Proteus mirabilis urinary tract infection

Proteus mirabilis, a common cause of urinary tract infection (UTI), produces a number of different fimbriae including mannose-resistant Proteus-like fimbriae (MR/P). The precise role of different P. mirabilis fimbriae in ascending UTI has not yet been elucidated. In this study, a clinical isolate of P. mirabilis and an isogenic mutant unable to express MR/P were tested using different experimental approaches. They were tested for their ability to cause infection in an ascending co-infection model of UTI and in a haematogenous model in the mouse. In both models, the mutant was less able than the wild-type strain to colonise the lower and upper urinary tracts although infectivity was not abolished. In vitro adherence to uroepithelial cells was also assessed. Significant differences in adherence between both strains were observed at 1 h but not at 15 min post infection. We have also shown that a wild-type strain carries two copies of the mrpA gene. These data reinforce the importance of MR/P fimbriae in P. mirabilis UTI although other virulence factors may be necessary for efficient colonisation and development of infection.     

Structures of blood group glycosphingolipids of human small intestine. A relation between the expression of fucolipids of epithelial cells and the ABO, Le and Se phenotype of the donor

Small intestinal epithelial cells (enterocytes) were isolated from specimens obtained at operation from four human individuals with different blood group ABO, Lewis, and secretor phenotypes. The non-acid glycolipids were isolated and characterized by thin-layer chromatography, mass spectrometry, and proton NMR spectroscopy and for reactivity with monoclonal antibodies on thin-layer chromatograms. Monohexosylceramides and blood group ABH (type 1 chain) and Lewis glycolipids with 5-7 sugar residues were the major compounds present in all cases, and the expression of the major blood group glycolipids was in agreement with the ABO, Lewis, and secretor phenotype of the individual donors. Small amounts of more complex glycolipids with up to 10 sugar residues were identified by mass spectrometry in all cases. In addition, small amounts of lactotetraosylceramide, a blood group H-active triglycosylceramide with the structure of Fuc alpha 1-2Gal-Hex-Cer (where Fuc is fucose, Hex is hexose, and Cer is ceramide), and dihexosylceramides were identified in some cases. Globotriaosyl- and globotetraosylceramides were absent from the epithelial cells. Small amounts of Leb-active glycolipids in blood group OLe(a+b-), non-secretor and OLe(a-b-), secretor individuals as well as trace amounts of type 2 carbohydrate chain compounds in all individuals were detected by specific monoclonal antibodies.     

Pathogenesis of urinary tract infection in the elderly: the role of bacterial adherence to uroepithelial cells

The in vitro adherence of nine strains of Gram-negative bacteria to uroepithelial cells from 24 women patients (>65 years) was significantly higher than to cells from 24 premenopausal women (18–40 years). Uroepithelial cells from patients with a history of previous urinary tract infection (UTI) were marginally more receptive to attachment of uropathogens than cells from women without a history of UTI, but this was not statistically significant. Serum from four elderly women with asymptomatic bacteriuria was used to stabilize samples for electron-microscopic examination, which showed the presence of fibrous glycocalyx material surrounding the bacteria and attached to the uroepithelial cells. Eighty uropathogenic isolates from elderly and premenopausal women were found to express adhesins, to produce urease and hemolysins, and to ferment sucrose, salicin, and dulcitol. These results suggest that the increased receptivity of uroepithelial cells to bacterial attachment may be a predisposing factor in the onset of UTI in the hospitalized and domiciliary elderly population.     

Blood group glycosphingolipid expression in kidney of an individual with the rare blood group A1 Le(a−b+) p phenotype: absence of blood group structures based on the globoseries

Total neutral glycolipid fractions were isolated from kidney and ureter tissue obtained at autopsy of an individual of the rare blood group A₁ Le(a–b+) p. The amount of glycolipids isolated were 3.7 and 2.5 mg g^–1 dry tissue weight for the kidney and ureter tissue, which is in the range of reference blood group P kidneys. Part of the kidney glycolipid fraction was subfractionated by HPLC. Glycolipid compounds were structurally characterized by thin-layer chromatography (chemical detection and immunostaining with monoclonal antibodies), proton NMR spectroscopy and mass spectrometry. Globotriaosyl- and globotetraosyl-ceramides, which are the major compounds in kidneys of P individuals, were absent in the p kidney, and a comparatively increased amount of monoglycosyland lactosylceramides was found. A shift to longer fatty acyl chains in the ceramide part of lactosylceramides was noted. Elongated globoseries compounds with five to seven sugar residues, including the blood group A type 4 chain structure, were lacking. A slight increase in neolactotetraosyl- and blood group X pentaglycosyl-ceramides was noticed. The study confirms an enzymatic block in the conversion of lactosylceramide to elongated globoseries compounds in the kidney tissue similar to that of erythrocytes of p individuals.Abbreviations: for blood group glycolipid antigens the short hand designation stands for: blood group — number of sugar residues — type of carbohydrate chain. Thus A-7-4 means a blood group A heptaglycoconjugate on a type 4 chain. The sugar types are abbreviated for mass spectrometry to Hex for hexose, HexNAc forN-acetylhexosamine and dHex for deoxyhexose. HPLC, high-performance liquid chromatography; HPTLC, high performance thin layer chromatography; EI, electron impact ionisation; LSI, liquid secondary ion; MS, mass spectrometry; NMR, nuclear magnetic resonance.     

P blood group regulation of glycosphingolipid levels in human erythrocytes.

The neutral glycosphingolipid content of normal human erythrocytes was analyzed by a new method which utilizes high performance liquid chromatography. This rapid and accurate technique permits the quantitation of each of the major neutral glycolipids from individual blood samples. A correlation between the P blood group and the relative quantities of neutral glycosphingolipids is demonstrated. Erythrocytes from P1 individuals are shown to contain more globotriaosylceramide and less lactosylceramide than do erythrocytes from P2 individuals. The results of these experiments suggest the existence of a new phenotype in the P blood group system, and have further implications regarding the biosynthesis of the P blood group glycosphingolipids.     

Glycosphingolipids of porcine blood: human blood group A and H antigens with type 1 chain in erythrocytes and plasma

Glycosphingolipids were purified from porcine erythrocytes and plasma. Two minor glycolipids with human blood group A and H antigenicities were found in both sources as components. The two antigenic glycolipids were identified as a hexaglycosylceramide (IV3 alpha GalNAc,IV2 alpha Fuc-Lc4Cer) for the A antigen and pentaglycosylceramide (IV2 alpha Fuc-Lc4Cer) for the H antigen and belonged to lactoseries (type 1 sugar chain) in contrast to those with neolacto core (type 2 sugar chain) in human erythrocytes, thereby endorsing biochemically the previous serological observations that the A antigen on porcine erythrocytes is uptake from plasma, probably the H antigen being the case. In addition to major glycolipids of globoseries in red cells and plasma, a variety of acidic glycolipids including two classes of sulphatides (sulphated galactosylceramide and sulphated lactosylceramide) and five classes of gangliosides (GM3, GD3, GM1, fucosyl GM1 and GD1a) containing N-acetylneuraminic acid and N-glycolylneuraminic acid were obtained from plasma.     

乌司他丁对急性肺损伤/急性呼吸窘迫综合征的治疗研究

目的研究大剂量乌司他丁在急性肺损伤/急性呼吸窘迫综合征中的治疗效果。方法回顾性分析2006年1月至2010年1月广西医科大学第一附属医院ICU收治的154例ALI/ARDS患者的临床资料,根据治疗方案分为乌司他丁组(UTI组)(n=80),对照组(n=74)。记录两组患者开始治疗、治疗第3天、治疗第7天的生命体征、动脉血气分析、血生化检查结果;记录患者在ICU治疗的转归。应用SPSS 13.0软件对结果进行统计学分析。结果经治疗3天UTI组呼吸频率低于对照组;动脉血气分析提示两组患者PaO2、PaO2/Fi O2、SaO2均有上升,UTI组PaO2/Fi O2略低于对照组(P0.01),而两组患者PaO2、SaO2比较无统计学差异。UTI组与对照组的死亡率比较(UTI组52.5%,对照组52.7%,P=0.980)无统计学差异,机械通气时间UTI组低于对照组[UTI组(14.8±3.9)天,对照组(16.7±4.2)天,P=0.020]。根据ALI/ARDS发生的病因分为肺内源性及肺外源性进行亚组分析(A组:肺内源性ALI/ARDS,使用UTI治疗;B组:肺内源性ALI/ARDS,不使用UTI治疗;C组:肺外源性ALI/ARDS,使用UTI治疗;D组:肺外源性ALI/ARDS,不使用UTI治疗),发现乌司他丁对肺外源性ALI/ARDS患者(C组)的ICU时间、ICU内死亡率及机械通气时间均低于不使用UTI的患者(D组)。结论大剂量乌司他丁用于ALI/ARDS的临床治疗可有效改善患者氧合指数,减少机械通气时间,且高血糖的发生率低,尤其是乌司他丁治疗肺外源性ALI/ARDS患者的预后优于肺内源性的ALI/ARDS。     

BarA-UvrY two-component system regulates virulence of uropathogenic E. coli CFT073

Uropathogenic Escherichia coli (UPEC), a member of extraintestinal pathogenic E. coli, cause ～80% of community-acquired urinary tract infections (UTI) in humans. UPEC initiates its colonization in epithelial cells lining the urinary tract with a complicated life cycle, replicating and persisting in intracellular and extracellular niches. Consequently, UPEC causes cystitis and more severe form of pyelonephritis. To further understand the virulence characteristics of UPEC, we investigated the roles of BarA-UvrY two-component system (TCS) in regulating UPEC virulence. Our results showed that mutation of BarA-UvrY TCS significantly decreased the virulence of UPEC CFT073, as assessed by mouse urinary tract infection, chicken embryo killing assay, and cytotoxicity assay on human kidney and uroepithelial cell lines. Furthermore, mutation of either barA or uvrY gene reduced the production of hemolysin, lipopolysaccharide (LPS), proinflammatory cytokines (TNF-α and IL-6) and chemokine (IL-8). The virulence phenotype was restored similar to that of wild-type by complementation of either barA or uvrY gene in trans. In addition, we discussed a possible link between the BarA-UvrY TCS and CsrA in positively and negatively controlling virulence in UPEC. Overall, this study provides the evidences for BarA-UvrY TCS regulates the virulence of UPEC CFT073 and may point to mechanisms by which virulence regulations are observed in different ways may control the long-term survival of UPEC in the urinary tract.     

Mannose-resistant Proteus-like and P. mirabilis fimbriae have specific and additive roles in P. mirabilis urinary tract infections

Proteus mirabilis is an important uropathogen that can cause complicated urinary tract infections (UTI). It produces several types of fimbriae, including mannose-resistant Proteus-like (MR/P) fimbriae and P. mirabilis fimbriae (PMF). Previously, we determined that these fimbriae affect the ability of P. mirabilis to colonize the urinary tract. The objective of this study was to analyse the effect of the simultaneous lack of P. mirabilis MR/P and PMF fimbriae in UTI pathogenesis. A double mutant lacking both fimbriae was generated by allelic replacement mutagenesis. This mutant was characterized genetically and phenotypically, and tested using an in vitro uroepithelial cell adhesion assay and the ascending UTI murine model. In vitro adhesion to uroepithelial cells by the P. mirabilis pmfA/mrpA-D mutant was reduced when compared with the wild-type, although no significant differences were observed when it was compared with the single mrpA-D and pmfA mutants. However, in vivo assays showed that colonization of kidneys and bladders by the P. mirabilis pmfA/mrpA-D mutant was significantly reduced when compared with the wild-type and both single mutants. These results indicate that, although redundancy can occur, MR/P and PMF fimbriae have specific and additive roles in P. mirabilis UTI.     

Contribution of Tamm-Horsfall protein to virulence of Pseudomonas aeruginosa in urinary tract infection

Tamm-Horsfall glycoprotein (THP) is the most abundant protein which is synthesized by renal tubular cells and excreted in urine. Its role in urinary tract infection has yet not been identified. In the present study, the contribution of THP towards adherence of Pseudomonas aeruginosa to uroepithelial cells and murine peritoneal macrophages was studied. Decreased adherence of THP-coated P. aeruginosa to UECs and phagocytes was observed in vitro. In vivo, P. aeruginosa showed increased renal bacterial load and tissue pathology in a mouse model of acute ascending pyelonephritis, when THP-coated P. aeruginosa was used to cause infection. This study shows that THP may not necessarily act as a host defense component; rather, it may help in renal colonization of P. aeruginosa in vivo.     

乌司他丁在急性呼吸窘迫综合征的临床应用研究

目的:观察乌司他丁(UTI)对急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的临床应用。方法:选择我院ICU自2008年1月至2011年1月收治的160例ARDS患者作为研究对象,采用随机对照的方法,并且经患者或患者家属知情并签字同意分组。分为UTI组(A组)和对照组(B组)。两组均给予相同综合治疗措施,A组除综合治疗外还给予注射用乌司他丁,每次30万U,每日2次。分别记录两组患者开始治疗、治疗后第3天、治疗第7天的生命体征,动脉血气分析、血生化检查结果、并且记录患者在ICU治疗的转归,应用SPSS13.0软件对结果进行统计学分析。结果:经治疗3天A组呼吸频率低于B组,动脉血气分析提示两组PO2、PO2/FiO2、SaO2均有上升。比较后发现A组PO2、PO2/FiO2、SaO2高于B组(P<0.05),两组PO2、SaO2比较有统计学差异。经治疗3天A组与B组生化指标比较、白细胞计数、肾功及血乳酸均有下降,有统计学差异,P<0.05。全部治疗结束后A组与B组死亡率比较(UTI组34.29%,对照组38.26%,P=0.0097)及机械通气时间比较(UTI组7.54±3.27天,对照组11.78±2.69天,P=0.0086),均有统计学差异。结论:大剂量UTI用于ARDS的临床治疗可有效改善患者氧合指数,减少机械通气时间,降低患者的病死率。     

Human teratocarcinoma stem cells: glycolipid antigen expression and modulation during differentiation

Teratocarcinomas are germ cell tumors in which pluripotent stem cells, embryonal carcinoma (EC) cells, undergo differentiation along the pathways resembling those occurring during early embryogenesis. Human EC cell lines established in vitro provide a model for studying embryonic cellular differentiation in a way that is pertinent to early human development. The predominant glycolipid antigens expressed by EC cells of both humans and mice have globoseries core structures; in humans they are terminally modified to yield the monoclonal antibody-defined stage-specific embryonic antigens SSEA-3 and SSEA-4, and also globo-ABH antigens; in the mouse terminal modification yields the Forssman antigen rather than SSEA-3 and -4. These observations focus attention on the possible role of the P-blood group system, which regulates synthesis of globoseries oligosaccharides, in the behavior of cells in the early embryo and in teratocarcinomas. Marked changes in the core structures of the cell surface glycolipids occur as the EC cells differentiate; thus globoseries structures rapidly diminish and are replaced by lactoseries and then by ganglioseries glycolipids. During differentiation of the NTERA-2 line of pluripotent human EC cells into neurons and other cell types, the various subsets of differentiated cells that arise are distinguished by their differential expression of new glycolipid antigens, particularly ganglioside GT3 (recognized by antibody A2B5), and ganglioside 9-0-acetyl GD3 (recognized by antibody ME311). Neurons are found among the A2B5+/ME311- cells.     

The structural basis of blood group A-related glycolipids in an A3 red cell phenotype and a potential explanation to a serological phenomenon

Glycolipids from the red cells of a rare blood group A subgroup individual, expressing the blood group A(3) phenotype with the classical mixed-field agglutination phenomenon, A(2(539G>A))/O(1) genotype, and an unusual blood group A glycolipid profile, were submitted to a comprehensive biochemical and structural analysis. To determine the nature of blood group A glycolipids in this A(3) phenotype, structural determination was carried out with complementary techniques including proton nuclear magnetic resonance (1D and 2D), mass spectrometry (MS) (nano-electrospray ionization/quadrupole time-of-flight and tandem mass spectrometry) and thin layer chromatography with immunostaining detection. As expected, total blood group A structures were of low abundance, but contrary to expectations extended-A type 2 and A type 3 glycolipids were more dominant than A hexaglycosylceramides based on type 2 chain (A-6-2 glycolipids), which normally is the major A glycolipid. Several para-Forssman (GalNAcβ3GbO(4)) structures, including extended forms, were identified but surmised not to contribute to the classic mixed-field agglutination of the A(3) phenotype. It is proposed that the low level of A antigen combined with an absence of extended branched glycolipids may be the factor determining the mixed-field agglutination phenomenon in this individual.     

泌尿道感染动物模型制作研究现状

建立与人类泌尿道感染相似的可靠动物模型,对探讨泌尿道感染发病机制和研究治疗方法十分必要。本文介绍了急性肾盂肾炎,慢性肾盂肾炎,腺性膀胱炎等泌尿道感染模型制作研究现状,并从菌种,品系等角度进行探讨。     

Urovirulence of<Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>: Planktonic cells<Emphasis Type="Italic">vs.</Emphasis> biofilm cells

Planktonic and biofilm cells of a clinical urinary isolate of P. aeruginosa were compared in vitro for their ability to adhere to uroepithelial cells, interaction with macrophages, and for production of virulence factors like extracellular proteinase, elastase, hemolysin, phospholipase C and pyochelin. Biofilm cells showed increased adherence to UECs, which was coupled with reduced uptake and intracellular killing by macrophages. Overall there was a decrease in production of extracellular products by biofilm cells. Comparing the two cell forms for their ability to establish infection in an ascending model of acute pyelonephritis, significant enhancement of renal bacterial load, as well as more pronounced renal pathology developed with biofilm cells.