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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
14:05

Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes

Published on: September 19, 2013

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Listeria monocytogenes PdeE, a phosphodiesterase that contributes to virulence and has hydrolytic activity against

Swetha Reddy1, Gokul Turaga1, Hossam Abdelhamed1

  • 1College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.

Microbial Pathogenesis
|July 17, 2017
PubMed

Insights

Researchers identified a novel enzyme, phosphodiesterase E (PdeE), crucial for Listeria monocytogenes replication and infection. This enzyme plays a key role in nucleotide metabolism, impacting bacterial adhesion, invasion, and colonization.

Area of Science:

  • Microbiology
  • Enzymology
  • Bacterial Pathogenesis

Background:

  • Listeria monocytogenes is an intracellular pathogen that causes severe foodborne illness.
  • Understanding bacterial virulence factors is crucial for developing effective treatments.
  • A putative hydrolase, LMOf2365_2464, was identified with unknown function during intracellular replication.

Purpose of the Study:

  • To characterize the function of the putative hydrolase LMOf2365_2464 in Listeria monocytogenes.
  • To determine the enzymatic activity and role of LMOf2365_2464 in bacterial pathogenesis.
  • To investigate the impact of LMOf2365_2464 on bacterial adherence, invasion, replication, and host colonization.

Main Methods:

  • Genetic manipulation to create an isogenic mutant strain (F2365Δ2464).
  • In vitro assays using Caco-2 intestinal epithelial cells to assess adherence, invasion, and replication.
  • In vivo colonization studies in mouse liver and spleen.
  • Biochemical assays to determine the enzymatic activity of the recombinant protein.

Main Results:

  • The F2365Δ2464 mutant showed significantly reduced adherence, invasion, and replication in Caco-2 cells compared to the parent strain.
  • The mutant strain exhibited significantly lower colonization of mouse liver and spleen.
  • The recombinant LMOf2365_2464 protein demonstrated phosphodiesterase activity, particularly against cyclic di-AMP and cyclic AMP, in the presence of divalent metal ions.
  • The enzyme was designated phosphodiesterase E (PdeE).

Conclusions:

  • LMOf2365_2464, now designated PdeE, is a crucial enzyme for Listeria monocytogenes virulence.
  • PdeE plays a significant role in nucleotide metabolism, impacting bacterial pathogenesis.
  • PdeE is essential for L. monocytogenes adherence, invasion, intracellular replication, and host colonization.
Keywords:
Cyclic dinucleotidesCyclic nucleotidesHD domainIntracellular replicationListeria monocytogenesPhosphodiesteraseVirulence

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