Gene clusters governing the production of hemolysin and mannose-resistant hemagglutination are closely linked in Escherichia coli serotype O4 and O6 isolates from urinary tract infections

Low, David A.; David, Victor A.; Lark, D; Schoolnik, Gary K.; Falkow, Stanley

doi:10.1128/iai.43.1.353-358.1984

Cited by 113 publications

(48 citation statements)

References 28 publications

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“…The uropathogenic wild-type E. coli strain J96 (O4:K6) (Low et al, 1984;Blum et al, 1995) was used as a model all over this work, and was the source of chromosomal DNA for cloning regions of the cnf1 gene and its upstream part up to the end of the hly operon and hlyD gene. Some tests were also performed with a CNF1-producing E. coli strain (E170) isolated from a 79-year-old man with cystitis.…”

Section: Bacterial Strains and Plasmidsmentioning

confidence: 99%

Expression of cnf1 by Escherichia coli J96 involves a large upstream DNA region including the hlyCABD operon, and is regulated by the RfaH protein

Landraud

Gibert

Popoff

et al. 2003

Molecular Microbiology

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Summary Examination of 55 clinical isolates of uropathogenicEscherichia coli producing the CNF1 toxin demonstrated that the cnf1 gene is systematically associated with a hly operon via a highly conserved hlyDcnf1 intergenic region ( igs , 943 bp) as shown in the J96 UPEC strain. We examined if this association could reflect a co-regulation of the production of these toxins. Translation of cnf1 from an immediately upstream promoter has been shown to be controlled by means of an anti-Shine-Dalgarno sequence present in the cnf1 coding sequence [fold-back inhibition ( cnf1 fbi )]. The cnf1 fbi was not regulated by elements present in the igs . An RNA covering the full hlyD sequence, the igs and extending on the cnf1 gene, was then detected in the J96 strain. This RNA could be part of a HlyCABD mRNA. Transcription of the haemolysin operon requires RfaH antitermination activity. Inactivation of rfaH in J96 resulted in a 100-fold reduction of the CNF1 content of bacteria. The production of CNF1 from a plasmidic igscnf1 DNA was not sensitive to RfaH, indicating that this factor acted on cnf1 transcription via the hly promoter. This way the cnf1 fbi mechanism might be overcome by transcription of cnf1 from the haemolysin promoter and antitermination by RfaH. This constitutes a novel system of bacterial virulence factors co-regulation.

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Section: Bacterial Strains and Plasmidsmentioning

confidence: 99%

Expression of cnf1 by Escherichia coli J96 involves a large upstream DNA region including the hlyCABD operon, and is regulated by the RfaH protein

Landraud

Gibert

Popoff

et al. 2003

Molecular Microbiology

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“…Fiftyone dog, 33 human and 22 cat papEF E. coli strains isolated from human, canine and feline patients with UTI were examined in this study (Table 1). Control strains for the papG multiplex were prototype uropathogenic E. coli strains J96 and IA2 [16,17].…”

Section: Bacterial Strainsmentioning

confidence: 99%

Distribution of papG alleles among uropathogenic Escherichia coli isolated from different species

Féria¹

2001

FEMS Microbiology Letters

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The distribution of alleles I, II and III of the P adhesin gene papG among Escherichia coli isolated from urinary tract infections in humans, dogs and cats was studied by PCR. Allele I was present in 6% and 5% of the human and cat isolates. Allele II as such was present in 30% and 22%, or in association with allele III in 12% and 2% of the human and canine isolates, respectively. Allele III was present in 33% of the human strains and predominated largely over allele II in E. coli isolates from cystitis of animal origin (72% in dog and 95% in cat strains). The three different classes of the PapG adhesin have been suggested to play a role in host specificity, for example human versus canine specificity. Recent studies, however, showed papG III positive human and dog cystitis isolates to be largely indistinguishable. We found the Class II allele in animal isolates and detected for the first time in Europe the Class I allele in a different genetic background than the J96-like clonal group. Our findings show that uropathogenic E. coli isolates from different species can have the same papG alleles and thus may have zoonotic potential. ß

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“…The human uropathogenic E. coli strain J96 (O4:K6) (Low et al, 1984;Blum et al, 1995) was used as the source of chromosomal DNA for cloning the cnf1 gene into E. coli TG1 (Sambrook et al, 1989). Plasmid pCR2.1 was used for cloning cnf1 and the C-terminal and N-terminal regions of cnf1 into E. coli INV␣FЈ (TA Cloning Kit, Amersham).…”

Section: Bacterial Strains Plasmids and Growth Conditionsmentioning

confidence: 99%

Molecular localization of the Escherichia coli cytotoxic necrotizing factor CNF1 cell‐binding and catalytic domains

Lemichez

Flatau

Bruzzone

et al. 1997

Molecular Microbiology

128

105

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Cytotoxic necrotizing factor type 1 (CNF1) induces, in epithelial cells, the development of stress fibres via the GTPase Rho pathway. We showed that CNF1 is able to modify Rho both in vitro and in vivo. Recombinant N-terminal 33kDa (CNF1Nter) and C-terminal 14.8-31.5 kDa (CNF1Cter) regions of the CNF1 protein allowed us to demonstrate that the N-terminal region contains the cell-binding domain of the toxin and that the C-terminal region is responsible for its catalytic activity. CNF1Nter lowered the activity of CNF1 when provided to cells before the toxin whereas CNF1Cter had no effect on CNF1 cell toxicity. CNF1Cter was sufficient to induce a typical CNF1 phenotype when microinjected into African green monkey kidney cells (Vero cells), and was able to modify Rho as previously reported for CNF1. The C-terminal domain lost its catalytic activity when deleted of various subdomains, suggesting a scattered distribution of catalytic-site amino acids. Elucidation of the CNF1 functional organization and analysis of amino acid homologies between CNFs (CNF1, CNF2), Pasteurella multocida toxin (PMT) and dermonecrotic toxin of Bordetella pertussis (DNT) allowed us to postulate that CNFs and DNT act on Rho via the same enzymatic activity located in their C-terminus, and that CNFs and PMT probably bind to analogous cell receptors.

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Gene clusters governing the production of hemolysin and mannose-resistant hemagglutination are closely linked in Escherichia coli serotype O4 and O6 isolates from urinary tract infections

Cited by 113 publications

References 28 publications

Expression of cnf1 by Escherichia coli J96 involves a large upstream DNA region including the hlyCABD operon, and is regulated by the RfaH protein

Expression of cnf1 by Escherichia coli J96 involves a large upstream DNA region including the hlyCABD operon, and is regulated by the RfaH protein

Distribution of papG alleles among uropathogenic Escherichia coli isolated from different species

Molecular localization of the Escherichia coli cytotoxic necrotizing factor CNF1 cell‐binding and catalytic domains

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