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Query: UMLS:C0034186 (pyelonephritis)
 6,144 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Uropathogenic strains of Escherichia coli are characterized by the expression of distinctive bacterial properties, products, or structures referred to as virulence factors because they help the organism overcome host defenses and colonize or invade the urinary tract. Virulence factors of recognized importance in the pathogenesis of urinary tract infection (UTI) include adhesins (P fimbriae, certain other mannose-resistant adhesins, and type 1 fimbriae), the aerobactin system, hemolysin, K capsule, and resistance to serum killing. This review summarizes the virtual explosion of information regarding the epidemiology, biochemistry, mechanisms of action, and genetic basis of these urovirulence factors that has occurred in the past decade and identifies areas in need of further study. Virulence factor expression is more common among certain genetically related groups of E. coli which constitute virulent clones within the larger E. coli population. In general, the more virulence factors a strain expresses, the more severe an infection it is able to cause. Certain virulence factors specifically favor the development of pyelonephritis, others favor cystitis, and others favor asymptomatic bacteriuria. The currently defined virulence factors clearly contribute to the virulence of wild-type strains but are usually insufficient in themselves to transform an avirulent organism into a pathogen, demonstrating that other as-yet-undefined virulence properties await discovery. Virulence factor testing is a useful epidemiological and research tool but as yet has no defined clinical role. Immunological and biochemical anti-virulence factor interventions are effective in animal models of UTI and hold promise for the prevention of UTI in humans.
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PMID:Virulence factors in Escherichia coli urinary tract infection. 167 63

Urinary tract infection with Proteus mirabilis may lead to serious complications, including cystitis, acute pyelonephritis, fever, bacteremia, and death. In addition to the production of hemolysin and the enzyme urease, fimbriae and flagellum-mediated motility have been postulated as virulence factors for this species. We purified mannose-resistant/proteuslike (MR/P) fimbriae and flagella from strains CFT322 and HU2450, respectively. Electron microscopy revealed highly concentrated preparations of fimbriae and flagella. Fimbrial and flagellar structural subunits were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 18.5 and 41 kDa, respectively. N-terminal sequencing revealed that 10 of the first 20 amino acids of the major MR/P subunit matched the sequence of the P. mirabilis uroepithelial cell adhesin N terminus and 11 of 20 amino acids matched the predicted amino acid sequence of the Escherichia coli P fimbriae structural subunit, PapA. In addition, 90 and 80% homologies were found between the first 20 amino acids of P. mirabilis flagellin and those of Salmonella typhimurium phase-1 flagellin and the E. coli hag gene product, respectively. An enzyme-linked immunosorbent assay using purified antigens showed a strong reaction between the MR/P fimbriae or flagella and sera of CBA mice challenged transurethrally with P. mirabilis. A possible role for MR/P fimbriae in the pathogenesis of urinary tract infection is supported by (i) a strong immune response to the antigen in experimentally infected animals, (ii) amino acid sequence similarity to other enteric surface structure, and (iii) our previously reported observation that MR/P fimbriae are expressed preferentially as the sole fimbrial type in human pyelonephritis isolates.
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PMID:Proteus mirabilis flagella and MR/P fimbriae: isolation, purification, N-terminal analysis, and serum antibody response following experimental urinary tract infection. 168 Jan 6

In order to determine the pathogenic responsibility of Escherichia coli adhesins (ADHs) in urinary infections (UI), 2,000 different patients suffering different clinical urinary and male sexual gland infections were monitored. The ADHs were determined by agglutination techniques with human and guinea-pig red blood cells, Candida albicans and Saccharomyces cerevisiae cells and latex sensitized with GAL-GAL. In uncomplicated UIs, the possession of ADH is the main invasion mechanism for E. coli. The rate of E. coli ADH strains is very high (89%) in acute cases (727 of 818 cases: 310 of 362 cystitis; 104 of 113 recidivant cystitis; 120 of 126 pyelonephritis; 158 of 173 prostatitis, and 34 of 43 orchiepididymitis) and rare (10%) in asymptomatic or chronic cases (24 of 235 cases: 14 of 148 bacteriurias; 8 of 74 prostatitis, and 2 of 13 orchiepididymitis). A close relation is established between the presence of ADH and clinical symptoms. 90% (218 of 242) of acute cases with systemic symptoms are due to MR-type ADH strains, especially the P subtype. 71% (409 of 576) of acute cases with local symptoms are due to MS-type ADH strains. In complicated UIs the expression of ADH is not an essential condition for the invasion of the urinary apparatus. It has been strongly suggested that males are significantly more resistant to UI, both in the tract and parenchyma, than women. It can be deduced that the underlying disease is more liable to UI the lower the adherence level shown by isolated strains. Thus catheters, reflux and neurogenic bladder are, by far, more aggressive alterations than the prostatic adenoma, vesical tumor or lithiasis.
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PMID:Frequency and distribution of uropathogenic Escherichia coli adhesins: a clinical correlation over 2,000 cases. 168 Jun 92

One thousand five hundred strains obtained from patients suffering from different clinical forms of urinary infections (UI) and dependent glands have been studied with the aim of establishing the pathogenic responsibility of E. coli adhesion protein (ADH) in urinary infections (UI). ADH were determined using agglutination techniques with guinea pig and human red cells, C. albicans and S. cerevisiae spores and GAL-GAL sensitized latex. In non complicated UI, the presence of ADH is the main invasion mechanism for E. coli. The frequency of adherent strains is very high (569/648) in acute cases (207/247 cystitis + 69/98 recurrent cystitis + 108/114 pyelonephritis + 140/154 prostatitis + 28/35 orchyepidimitis and scarce (14/184) in asymptomatic or chronic cases (6/107 bacteriurias + 7/67 prostatitis + 1/10 orchyepidimitis). A close relationship is established between the presence of ADH and clinical symptoms. The acute cases with general symptoms are caused in 85% of cases (188/216) by strains with ADH type MR specially subtype P. The acute cases with local symptoms (only urinary syndrome) are caused in 77% of cases (297/387) by strains with ADH type Ms. In complicated UI the expression of adhesion proteins does not constitute and essential requisite in order to invade the urinary tract. It is suggested that males are significantly more resistant the females to UI both parenchymal and urinary tract. It is deduced that underlying factors are more predisposing to UI the smaller the adherence rate of isolated strains is. Thus, reflux and neurogenic bladder probes are by far more aggressive alterations than prostatic adenoma, bladder tumor and lithiasis.
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PMID:[The role of E. coli adhesins in the pathogenesis of urinary infection]. 168 74

One hundred and twenty three strains of Escherichia coli isolated from the urine of patients with urogenital infections and 55 strains isolated from the fecal samples of healthy individuals were assayed for 0 antigen and hemolysin production as virulence factors, and for pilus type and in vitro tests of adhesion to human exfoliated uroepithelial cells as colonization factors. The incidence of MS pili in Escherichia coli isolated from patients with acute uncomplicated cystitis, chronic complicated cystitis, acute uncomplicated pyelonephritis and acute prostatitis was 60.9%, 22.7%, 87.5%, 68.2% and 30.9%, respectively. The incidence of P pili was 69.7%, 51.2%, 62.5%, 54.5% and 25.5%, respectively. The strains showing haemolysin production had MS pili and P pili, which show strong virulence. MS pili strains and P pili strains isolated from the patients with acute uncomplicated cystitis and acute uncomplicated pyelonephritis adhered to human exfoliated uroepithelial cells well. Consequently, the pilus type might be the most significant colonization factor in uncomplicated urogenital infection which is shown by the normal defense mechanism in host side.
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PMID:[Studies on the virulent factor of Escherichia coli isolated from urogenital infection--pilus type and adherence to human exfoliated uroepithelial cells etc]. 168 66

The incidence of P-fimbriated E. coli from patients with pyelonephritis, cystitis and asymptomatic bacteriuria was 78.6%, 31.9% and 22.2%, respectively. Almost all of the P-fimbriated E. coli have also type-1 fimbriae. In the in vitro test, P-fimbriated E. coli attached to the uroepithelial cells in higher number than the type 1 fimbriated E. coli. The results of the adhesion inhibition test suggested that simultaneous presence of P-and type 1 fimbriae is the most significant virulence factor in urinary tract infections.
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PMID:[The role of fimbriae of Escherichia coli in urinary tract infections]. 168 48

To clarify the usefulness of histopathology in evaluating invasiveness during acute cystitis and pyelonephritis in a mouse model of urinary tract infection, findings from bladder and kidney sections of mice inoculated transurethrally with Escherichia coli were compared with results of bladder, kidney, spleen, and blood cultures and with changes in peripheral blood leukocyte counts. All of the 14 bladder histopathologic abnormalities evaluated were significantly associated with a positive bladder culture, and 7 were associated with splenic infection. Histopathologic features of cystitis were present in some culture-negative bladders. Eleven of 12 renal histopathologic abnormalities evaluated were significantly associated both with a positive kidney culture and with splenic infection, and two correlated with the development of peripheral leukocytosis. Histopathologic features of pyelitis and nephritis permitted culture-positive kidneys to be categorized as exhibiting colonization only, pyelitis only, or pyelitis plus frank nephritis and demonstrated that some culture-negative kidneys exhibit signs of pyelitis and nephritis. These findings suggest that detailed, semiquantitative histopathologic evaluation can add to quantitative cultures in the assessment of bacterial urovirulence in the mouse model of ascending urinary tract infection.
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PMID:Histopathologic-microbiologic correlates of invasiveness in a mouse model of ascending unobstructed urinary tract infection. 173 Aug 96

Urinary tract infection (UTI) is common in pediatric age groups and may cause permanent renal damage. Because UTI may occur as the first manifestation of urinary tract malformation, evaluation, of urinary tract morphology should be routine. Variables influencing selection of the most appropriate therapy include the causative organism, location of the infection to the distal and/or proximal urinary tract, severity of constitutional symptoms, age, and history for prior urologic disease. Treatment of pyelonephritis requires bactericidal antimicrobial agents capable of achieving rapid sterilization of the renal parenchyma. Animal experiments have shown that the most effective agents are third-generation cephalosporins and aminoglycosides. Antibiotics are selected on the basis of age and severity of infectious symptoms. In infants under 18 months of age and in patients with severe constitutional symptoms, parenteral administration of both a third-generation cephalosporin and an aminoglycoside is recommended. Patients above 18 months of age who are not severely ill can be given a single oral drug, e.g., a cephalosporin, amoxicillin with clavulanic acid, or cotrimoxazole. Therapy should be continued for ten days in patients with infection of the proximal urinary tract, whereas 5 to 7 days are adequate in patients with cystitis and normal urinary tract morphology.
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PMID:[Treatment of urinary tract infections]. 174 54

Different strains of E. coli, that were isolated during years 1986-1990 from 217 urine samples in patients with asymptomatic bacteriuria, cystitis, cysto-pyelitis and pyelonephritis, appeared to be more frequently haemolytic (34.5%) than strains of E. coli isolated from faecal samples in patients with acute enteropathy. It was confirmed that the haemolysin production occurs during log -phase of bacterial growth. The degree of haemolysis can vary widely according to the strain involved. Agglutination tests, using 53 O-antiserum, showed a great variety of serogroups. Some of them (04, 018, 022) are prevalent among the haemolytic strains isolated from urine; some others (055, 0111, 075) are prevalent among the anhaemolytic strains isolated from urine and faeces.
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PMID:[Hemolytic properties of Escherichia coli strains isolated from cases of urinary tract infection and enteropathy]. 184 19

This investigation was conducted to study the incidence and the causes of sow mortality in breeding herds. Data were obtained from 24 swine breeding herds with an average inventory of 3755 sows and served gilts for the total sample. Producers were involved for 12 consecutive months and agreed to submit to the diagnostic laboratory every dead or moribund sow and served gilt. The average herd death rate was 3.3% +/- 0.5 (SEM), but varied considerably among herds, ranging from 0% to 9.2%. A total of 137 sows and mated gilts died during the year, and these females had produced an average of 4.2 litters +/- 0.2 (SEM). The number of deaths was significantly higher during the months of July, August and October. The peripartum period appeared to be when sows were most at risk, with 42% of all deaths occurring during this short period of the reproductive cycle. The three major causes of death were heart failure (31.4%), torsions and accidents of abdominal organs (15.3%) and cystitis-pyelonephritis (8.0%). Other causes included endometritis (6.6%), uterine prolapses (6.6%), pneumonia (3.6%), gastric ulcers (3.6%), downer sow syndrome (2.2%), miscellaneous (8.0%) and unknown (14.6%).
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PMID:A prospective study of sow mortality in breeding herds. 188 99


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