A Toxic Environment : a Growing Understanding of How Microbial Communities Affect Escherichia coli O157:H7 Shiga Toxin Expression

Copyright © 2020 American Society for Microbiology..

Enterohemorrhagic Escherichia coli (EHEC) strains, including E. coli O157:H7, cause severe illness in humans due to the production of Shiga toxin (Stx) and other virulence factors. Because Stx is coregulated with lambdoid prophage induction, its expression is especially susceptible to environmental cues. Infections with Stx-producing E. coli can be difficult to model due to the wide range of disease outcomes: some infections are relatively mild, while others have serious complications. Probiotic organisms, members of the gut microbiome, and organic acids can depress Stx production, in many cases by inhibiting the growth of EHEC strains. On the other hand, the factors currently known to amplify Stx act via their effect on the stx-converting phage. Here, we characterize two interactive mechanisms that increase Stx production by O157:H7 strains: first, direct interactions with phage-susceptible E. coli, and second, indirect amplification by secreted factors. Infection of susceptible strains by the stx-converting phage can expand the Stx-producing population in a human or animal host, and phage infection has been shown to modulate virulence in vitro and in vivo Acellular factors, particularly colicins and microcins, can kill O157:H7 cells but may also trigger Stx expression in the process. Colicins, microcins, and other bacteriocins have diverse cellular targets, and many such molecules remain uncharacterized. The identification of additional Stx-amplifying microbial interactions will improve our understanding of E. coli O157:H7 infections and help elucidate the intricate regulation of pathogenicity in EHEC strains.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:86

Enthalten in:

Applied and environmental microbiology - 86(2020), 24 vom: 24. Nov.

Sprache:

Englisch

Beteiligte Personen:

Nawrocki, Erin M [VerfasserIn]
Mosso, Hillary M [VerfasserIn]
Dudley, Edward G [VerfasserIn]

Links:

Volltext

Themen:

1403-96-9
75757-64-1
Bacteriocins
Colicins
EHEC
Escherichia coli
Journal Article
Microcin
Microcins
O157:H7
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.
Review
Shiga Toxin
Shiga toxins

Anmerkungen:

Date Completed 21.12.2020

Date Revised 25.05.2021

published: Electronic-Print

Citation Status MEDLINE

doi:

10.1128/AEM.00509-20

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM309416663