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

E. coli strain 536 (O6:K15:H31) isolated from a case of acute pyelonephritis, expresses S-fimbrial adhesins, P-related fimbriae, common type I fimbriae, and hemolysins. The respective chromosomally encoded determinants were cloned by constructing a genomic library of this strain. Furthermore, the strain produces the iron uptake substance, enterocheline, damages HeLa cells, and behaves in a serum-resistant mode. Genetic analysis of spontaneously arising non-hemolytic variants revealed that some of the virulence genes were physically linked to large unstable DNA regions, termed "pathogenicity islands", which were mapped in the respective positions on the E. coli K-12 linkage map. By comparing the wild type strain and mutants in in vitro and in vivo assays, virulence features have been evaluated. In addition, a regulatory cross talk between adhesin determinants was found for the wild-type isolate. This particular mode of virulence regulation is missing in the mutant strain.
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PMID:Genetics of Escherichia coli uropathogenicity: analysis of the O6:K15:H31 isolate 536. 155 5

Escherichia coli 536 (O6:K15:H31), which was isolated from a case of urinary tract infection, determines high nephropathogenicity in a rat pyelonephritis system as measured by renal bacterial counts 7 days after infection. The loss of S fimbrial adhesin formation (Sfa-) (mannose-resistant hemagglutination [Mrh-] and fimbria production [Fim-]), serum resistance (Sre-), and hemolysin production (Hly-) in the mutant 536-21 led to a dramatic reduction of bacterial counts from almost 10(5) to only 40 cells per g of kidney. The reintroduction of the cloned S fimbrial adhesin determinant (sfa) increases the virulence of the avirulent mutant strain by a factor of 20; almost the same effect was observed after restoration of serum resistance by integration of an sfa+ recombinant cosmid into the chromosome. Additional reintroduction of the Hly+ phenotype by transformation of two hly determinants increased the virulence of the strains. Hemolysin production determined increased renal elimination of leukocytes and erythrocytes. Thus all three determinants investigated, S fimbriae, serum resistance, and hemolysin, contribute to the multifactorial phenomenon of E. coli nephropathogenicity.
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PMID:Contribution of cloned virulence factors from uropathogenic Escherichia coli strains to nephropathogenicity in an experimental rat pyelonephritis model. 287 50

Molecular typing methods were used to characterize 38 Escherichia coli strains that originally were isolated from extraintestinal infections and represented 5 multilocus enzyme electrophoretic types (ETs) recovered from both humans and animals. Within each ET, the human and animal isolates did not consistently segregate by host group, according to individual virulence factors (VFs), composite VF-serotype profiles, or pulsed-field gel electrophoresis profiles. Several close matches with respect to VF-serotype profiles were identified between human and canine isolates from different locales. One canine and 2 human isolates of serogroup O6 closely resembled archetypal human pyelonephritis isolate 536 (O6:K15:H31), according to papA sequence and VF-serotype profile. These findings support the hypothesis that certain pathogenic lineages of E. coli cause disease in both humans and animals and that humans may acquire pathogenic E. coli from domestic pets.
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PMID:Molecular comparison of extraintestinal Escherichia coli isolates of the same electrophoretic lineages from humans and domestic animals. 1110 42

Molecular evidence is limited for the hypothesis that humans, dogs, and cats can become colonized and infected with similar virulent Escherichia coli strains. To further assess this possibility, archived E. coli O6 isolates (n = 130) from humans (n = 55), dogs (n = 59), and cats (n = 16), representing the three main H (flagellar) types within serogroup O6 (H1, H7, and H31), were analyzed, along with selected reference strains. Isolates underwent PCR-based phylotyping, multilocus sequence typing, PCR-based detection of 55 virulence-associated genes, and XbaI pulsed-field gel electrophoresis (PFGE) profiling. Three major sequence types (STs), which corresponded closely with H types, accounted for 99% of the 130 O6 isolates. Each ST included human, dog, and cat isolates; two included reference pyelonephritis isolates CFT073 (O6:K2:H1) and 536 (O6:K15:H31). Virulence genotypes overlapped considerably among host species, despite statistically significant differences between human and pet isolates. Several human and dog isolates from ST127 (O6:H31) exhibited identical virulence genotypes and highly similar PFGE profiles, consistent with cross-species exchange of specific E. coli clones. In conclusion, the close similarity in the genomic backbone and virulence genotype between certain human- and animal-source E. coli isolates within serogroup O6 supports the hypothesis of zoonotic potential.
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PMID:Virulence genotypes and phylogenetic background of Escherichia coli serogroup O6 isolates from humans, dogs, and cats. 1800 5