Hemolytic escherichia coli strains in the human fecal flora as potential urinary pathogens

Hacker, Jörg; Schröter, G; Schrettenbrunner, A.; Goebel, Werner

doi:10.1016/s0174-3031(83)80118-8

Cited by 29 publications

(32 citation statements)

References 36 publications

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“…The production and activity of E. coli a-hemolysin which belongs to the family of pore-forming cytotoxins (RTX toxins) was intensively studied [14,[17][18][19][20]. In human E. coli the production of a-hemolysin is frequent in strains causing extraintestinal infections and often associated with P-fimbriae, capsular antigens, serum resistance and high toxicity for mice [19]. Human enterotoxigenic (ETEC) and enteroinvasive (EIEC) strains do not produce a-hemolysin, whereas EPEC are rarely a-hemolysin positive.…”

Section: Discussionmentioning

confidence: 99%

The large-sized plasmids of enterohemorrhagic Escherichia coli O157 strains encode hemolysins which are presumably members of the E. coli α-hemolysin family

Schmidt¹

1994

FEMS Microbiology Letters

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Most enterohemorrhagic Escherichia coli O157:H7 strains harbor a large-sized (90 kb) plasmid designated pO157 and show an enterohemolytic phenotype. In this study the hemolytic activity of E. coli O157:H7 strain EDL933 was investigated. Curing of strain EDL933 from pO157 resulted in loss of its hemolytic activity. By transformation with Tn801-tagged pO157 (pSK3), the hemolysin-negative E. coli K-12 strains C600 and DH5 alpha became positive for hemolysin production. By transformation of recombinant plasmids carrying a 11.9 kb BamHI fragment and a 5.3 kb SalI fragment of pSK3 hemolytic activity is revealed when transformed in E. coli C600 or DH5 alpha DNA-hybridization of pO157 and subclones with the alpha-hemolysin specific DNA probe was only found under conditions of low stringency. No hybridization was found with enterohemolysin I (EHly1) and enterohemolysin II (EHly2) probes. Our results indicate that a hitherto not described hemolysin belonging to the alpha-hemolysin family is encoded by the 90 kb plasmid of E. coli O157 strains.

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Section: Discussionmentioning

confidence: 99%

The large-sized plasmids of enterohemorrhagic Escherichia coli O157 strains encode hemolysins which are presumably members of the E. coli α-hemolysin family

Schmidt¹

1994

FEMS Microbiology Letters

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“…However, its potential pathogenicity in respect to intestinal cells is unclear (Elliott et al, 1998;Johnson and Russo, 2002). From studies on healthy subjects, it is assumed that as much as 10% of the E. coli population of the intestinal microflora are haemolytic strains (Hacker et al, 1983;Siitonen, 1992).…”

Section: Introductionmentioning

confidence: 99%

Escherichia�coli ?-haemolysin induces focal leaks in colonic epithelium: a novel mechanism of bacterial translocation

et al. 2007

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SummaryExtraintestinal pathogenic Escherichia coli (ExPEC) are usually harmless colonizer of the intestinal microflora. However, they are capable to translocate and cause life-threatening disease. Translocation of ExPEC isolates was quantified in colonic monolayers. Transepithelial resistance (R t ) was monitored and local changes in conductivity analysed with conductance scanning. Confocal microscopy visualized the translocation route. Corroboratory experiments were performed on native rat colon. One translocating strain E. coli O4 was identified. This translocation process was associated with an R t decrease (36 Ϯ 1% of initial resistance) beginning only 2 h after inoculation. The sites of translocation were small defects in epithelial integrity (focal leaks) exhibiting highly increased local ion permeability. Translocation was enhanced by preincubation of monolayers with tumour necrosis factor-a or interleukin-13. Mutant strains lacking alpha-haemolysin lost the ability to induce focal leaks, while this effect could be restored by re-introducing the haemolysin determinant. Filtrate of a laboratory strain carrying the alphahaemolysin operon was sufficient for focal leak induction. In native rat colon, E. coli O4 decreased R t and immunohistology demonstrated focal leaks resembling those in cell monolayers. E. coli a-haemolysin is able to induce focal leaks in colonic cell cultures as well as in native colon. This process represents a novel route of bacterial translocation facilitated by pro-inflammatory cytokines.

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“…Long-range DNA mapping is therefore useful for the evaluation of genetic relatedness among individual isolates and facilitates the performance of precise molecular epidemiology.Escherichia coli strains of the Ki capsular serotype represent 80% of all E. coli strains isolated from cases of newborn meningitis and sepsis in humans (24,57,63). Moreover, Kl strains and isolates of other serotypes, including 018:K5 and 075:K100, are able to cause urinary tract infection, and Kl E. coli isolates are also often found to be the causative agent of systemic infections in animals (3,48,64,70,71).It has been clear for several years that the capsular antigens, especially Kl and certain types of 0 antigen, are strongly associated with such extraintestinal infections (4, 33, 60, 61, 64), as are specific fimbrial adhesins (18,42,45,46), hemolysin (Hly) (20,22,23), and aerobactin (Aer) (11,28,37). Extraintestinal E. coli isolates may carry different types of fimbrial adhesins which can be distinguished serologically (47) and can show different binding properties.…”

mentioning

confidence: 99%

“…It has been clear for several years that the capsular antigens, especially Kl and certain types of 0 antigen, are strongly associated with such extraintestinal infections (4,33,60,61,64), as are specific fimbrial adhesins (18,42,45,46), hemolysin (Hly) (20,22,23), and aerobactin (Aer) (11,28,37). Extraintestinal E. coli isolates may carry different types of fimbrial adhesins which can be distinguished serologically (47) and can show different binding properties.…”

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confidence: 99%

Virulence patterns and long-range genetic mapping of extraintestinal Escherichia coli K1, K5, and K100 isolates: use of pulsed-field gel electrophoresis

et al. 1991

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A total of 127 extraintestinal Escherichia coli strains of the capsule serotypes Kl, K5, and K100 from human and animal sources were analyzed for DNA sequences specific for the genes for various adhesins (P fimbriae [pap] and P-related sequences [prs], S fimbriae [sfa]IFIC fimbriae [foc], and type I fimbriae [fim]), aerobactin (aer), and hemolysin (hly). The expression of corresponding virulence factors was also tested. Twenty-four selected strains were analyzed by long-range DNA mapping to evaluate their genetic relationships. DNA sequences for the adhesins were often found in strains not expressing them, while strains with hemolysin and aerobactin genes usually did express them. Different isolates of the same serotype often expressed different virulence patterns. The use of virulence-associated gene probes for Southern hybridization with genomic DNA fragments separated by pulsed-field gel electrophoresis revealed that a highly heterogeneous restriction fragment length and hybridization pattern existed even within strains of the same serotype. Long-range DNA mapping is therefore useful for the evaluation of genetic relatedness among individual isolates and facilitates the performance of precise molecular epidemiology.Escherichia coli strains of the Ki capsular serotype represent 80% of all E. coli strains isolated from cases of newborn meningitis and sepsis in humans (24,57,63). Moreover, Kl strains and isolates of other serotypes, including 018:K5 and 075:K100, are able to cause urinary tract infection, and Kl E. coli isolates are also often found to be the causative agent of systemic infections in animals (3,48,64,70,71).It has been clear for several years that the capsular antigens, especially Kl and certain types of 0 antigen, are strongly associated with such extraintestinal infections (4, 33, 60, 61, 64), as are specific fimbrial adhesins (18,42,45,46), hemolysin (Hly) (20,22,23), and aerobactin (Aer) (11,28,37). Extraintestinal E. coli isolates may carry different types of fimbrial adhesins which can be distinguished serologically (47) and can show different binding properties. P fimbriae (also termed Pap pili [45]) are associated with pyelonephritis and recognize an Ot-D-galactosyl-(1-4)-p-galactose receptor (29, 66). P-related sequences (Prs) mediate binding to galactosyl-N-acetyl-(ox1-3)-galactosyl-N-acetyl residues (40). The S-fimbrial adhesin (Sfa) interacts with a-sialyl(2-3p)-D-galactose receptor molecules (32,54). Another adhesin, the type I fimbrial adhesin, is produced by pathogenic and nonpathogenic strains and is able to bind to a-D-mannose-containing receptors (47). Fimbriae of serotype FIC are unable to agglutinate erythrocytes but do seem to interact with cells of the human urinary tract (56,68,69).E. coli strains may be subdivided into clones by electrophoretic typing of alloenzymes (4) and by outer membrane protein (OMP) profiles (3). In some cases, the clones have a characteristic serotype based on the 0 lipopolysaccharide and K capsular antigens (4). Attempts have been made to * Corres...

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Hemolytic escherichia coli strains in the human fecal flora as potential urinary pathogens

Cited by 29 publications

References 36 publications

The large-sized plasmids of enterohemorrhagic Escherichia coli O157 strains encode hemolysins which are presumably members of the E. coli α-hemolysin family

The large-sized plasmids of enterohemorrhagic Escherichia coli O157 strains encode hemolysins which are presumably members of the E. coli α-hemolysin family

Escherichia�coli ?-haemolysin induces focal leaks in colonic epithelium: a novel mechanism of bacterial translocation

Virulence patterns and long-range genetic mapping of extraintestinal Escherichia coli K1, K5, and K100 isolates: use of pulsed-field gel electrophoresis

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