Prevention and Cure of Systemic
 Escherichia coli
 K1 Infection by Modification of the Bacterial Phenotype

Mushtaq, Naseem; Redpath, Maria B.; Luzio, J. Paul; Taylor, Peter W.

doi:10.1128/aac.48.5.1503-1508.2004

Cited by 98 publications

(129 citation statements)

References 30 publications

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“…With a litter of 12 pups as a single test cohort, power calculations using G* Power Software determined that this sample size equates to a 98.6% probability of finding an effect based on survival using six animals from the cohort and >99% probability if all twelve are taken into consideration. The model is therefore suitable for evaluation of novel agents specifically tailored for the treatment of neonatal bacterial infections and has been used in the procedure to evaluate the therapeutic potential of the capsule depolymerase EndoE that selectively removes the K1 capsule from the bacterial surface [24][25][26] . It may also be used to investigate hostbacteria interactions that impact on the pathogenesis of E. coli neuropathogens; within this context it has been employed for studies of E. coli A192PP colonization and dissemination.…”

Section: Representative Resultsmentioning

confidence: 99%

Non-Invasive Model of Neuropathogenic Escherichia coli Infection in the Neonatal Rat

Dalgakiran

Witcomb

McCarthy

et al. 2014

JoVE

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Investigation of the interactions between animal host and bacterial pathogen is only meaningful if the infection model employed replicates the principal features of the natural infection. This protocol describes procedures for the establishment and evaluation of systemic infection due to neuropathogenic Escherichia coli K1 in the neonatal rat. Colonization of the gastrointestinal tract leads to dissemination of the pathogen along the gut-lymph-blood-brain course of infection and the model displays strong age dependency. A strain of E. coli O18:K1 with enhanced virulence for the neonatal rat produces exceptionally high rates of colonization, translocation to the blood compartment and invasion of the meninges following transit through the choroid plexus. As in the human host, penetration of the central nervous system is accompanied by local inflammation and an invariably lethal outcome. The model is of proven utility for studies of the mechanism of pathogenesis, for evaluation of therapeutic interventions and for assessment of bacterial virulence.

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Section: Representative Resultsmentioning

confidence: 99%

Non-Invasive Model of Neuropathogenic Escherichia coli Infection in the Neonatal Rat

Dalgakiran

Witcomb

McCarthy

et al. 2014

JoVE

Self Cite

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“…We postulate that tumors co-opt the immune system's strategy of using polySia to modulate responses to chemokines and growth factors, thus gaining a competitive advantage. Regarding bacteria, polySia expression is correlated with the virulence of pathogenic strains of Escherichia coli K1 and group B Neisseria meningitidis (38,39). It is possible that bacterial polySia binds and neutralizes AMPs, sequestering them at a safe distance from the cell wall.…”

Section: Discussionmentioning

confidence: 99%

Polysialic Acid, a Glycan with Highly Restricted Expression, Is Found on Human and Murine Leukocytes and Modulates Immune Responses

Drake¹,

Nathan²,

Stock³

et al. 2008

The Journal of Immunology

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Polysialic acid (polySia) is a large glycan with restricted expression, typically found attached to the protein scaffold neural cell adhesion molecule (NCAM). PolySia is best known for its proposed role in modulating neuronal development. Its presence and potential functions outside the nervous systems are essentially unexplored. Herein we show the expression of polySia on hematopoietic progenitor cells, and demonstrate a role for this glycan in immune response using both acute inflammatory and tumor models. Specifically, we found that human NK cells modulate expression of NCAM and the degree of polymerization of its polySia glycans according to activation state. This contrasts with the mouse, where polySia and NCAM expression are restricted to multipotent hematopoietic progenitors and cells developing along a myeloid lineage. Sialyltransferase 8Sia IV−/− mice, which lacked polySia expression in the immune compartment, demonstrated an increased contact hypersensitivity response and decreased control of tumor growth as compared with wild-type animals. This is the first demonstration of polySia expression and regulation on myeloid cells, and the results in animal models suggest a role for polySia in immune regulation.

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“…Avery and Dubos extended these ideas to demonstrate that microbial enzymes could be used to remove the capsule from the pneumococcus and successfully treat experimental infections (2). Similar approaches have been used in experimental Escherichia coli infections (37,38).…”

mentioning

confidence: 98%

Poly-γ-Glutamate Capsule-Degrading Enzyme Treatment Enhances Phagocytosis and Killing of EncapsulatedBacillus anthracis

Scorpio

Chabot

Day

et al. 2007

Antimicrob Agents Chemother

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The poly-␥-D-glutamic acid capsule confers antiphagocytic properties on Bacillus anthracis and is essential for virulence. In this study, we showed that CapD, a ␥-polyglutamic acid depolymerase encoded on the B. anthracis capsule plasmid, degraded purified capsule and removed the capsule from the surface of anthrax bacilli. Treatment with CapD induced macrophage phagocytosis of encapsulated B. anthracis and enabled human neutrophils to kill encapsulated organisms. A second glutamylase, PghP, a ␥-polyglutamic acid hydrolase encoded by Bacillus subtilis bacteriophage ⌽NIT1, had minimal activity in degrading B. anthracis capsule, no effect on macrophage phagocytosis, and only minimal enhancement of neutrophil killing. Thus, the levels of both phagocytosis and killing corresponded to the degree of enzyme-mediated capsule degradation. The use of enzymes to degrade the capsule and enable phagocytic killing of B. anthracis offers a new approach to the therapy of anthrax.

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Prevention and Cure of Systemic Escherichia coli K1 Infection by Modification of the Bacterial Phenotype

Cited by 98 publications

References 30 publications

Non-Invasive Model of Neuropathogenic <em>Escherichia coli</em> Infection in the Neonatal Rat

Non-Invasive Model of Neuropathogenic <em>Escherichia coli</em> Infection in the Neonatal Rat

Polysialic Acid, a Glycan with Highly Restricted Expression, Is Found on Human and Murine Leukocytes and Modulates Immune Responses

Poly-γ-Glutamate Capsule-Degrading Enzyme Treatment Enhances Phagocytosis and Killing of EncapsulatedBacillus anthracis

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