Hydrogen Peroxide Linked to Lysine Oxidase Activity Facilitates Biofilm Differentiation and Dispersal in Several Gram-Negative Bacteria

School of Biotechnology and Biomolecular Sciences and Centre for Marine Bio-Innovation, Biological Sciences Building, University of New South Wales, Kensington, Sydney, NSW 2052, Australia.
Journal of bacteriology (Impact Factor: 2.81). 09/2008; 190(15):5493-501. DOI: 10.1128/JB.00549-08
Source: PubMed


The marine bacterium Pseudoalteromonas tunicata produces an antibacterial and autolytic protein, AlpP, which causes death of a subpopulation of cells during biofilm formation
and mediates differentiation, dispersal, and phenotypic variation among dispersal cells. The AlpP homologue (LodA) in the
marine bacterium Marinomonas mediterranea was recently identified as a lysine oxidase which mediates cell death through the production of hydrogen peroxide. Here we
show that AlpP in P. tunicata also acts as a lysine oxidase and that the hydrogen peroxide generated is responsible for cell death within microcolonies
during biofilm development in both M. mediterranea and P. tunicata. LodA-mediated biofilm cell death is shown to be linked to the generation of phenotypic variation in growth and biofilm formation
among M. mediterranea biofilm dispersal cells. Moreover, AlpP homologues also occur in several other gram-negative bacteria from diverse environments.
Our results show that subpopulations of cells in microcolonies also die during biofilm formation in two of these organisms,
Chromobacterium violaceum and Caulobacter crescentus. In all organisms, hydrogen peroxide was implicated in biofilm cell death, because it could be detected at the same time
as the killing occurred, and the addition of catalase significantly reduced biofilm killing. In C. violaceum the AlpP-homologue was clearly linked to biofilm cell death events since an isogenic mutant (CVMUR1) does not undergo biofilm
cell death. We propose that biofilm killing through hydrogen peroxide can be linked to AlpP homologue activity and plays an
important role in dispersal and colonization across a range of gram-negative bacteria.

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Available from: Anne Mai-Prochnow
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    • "Mai-Prochnow et al. [26] have suggested that H2O2 allows to (directly or indirectly) kill a subpopulation of cells and increase in DNA damage and mutation frequency of the remaining live cells and shown that high CAT activity can prevent penetration of hydrogen peroxide into biofilms of Pseudomonas aeruginosa at a concentration of 50 mM. In our work, it was observed that biofilm development is influenced by the production of oxidants metabolites and the levels of antioxidant defenses, which can be variable in different environmental conditions. "
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    ABSTRACT: The present study was designed to determine the relationships among biofilm formation, cellular stress and release of Shiga toxin (Stx) by three different clinical Shiga toxin-producing Escherichia coli (STEC) strains. The biofilm formation was determined using crystal violet stain in tryptic soy broth or thioglycollate medium with the addition of sugars (glucose or mannose) or hydrogen peroxide. The reactive oxygen species (ROSs) were detected by the reduction of nitro blue tetrazolium and reactive nitrogen intermediates (RNI) determined by the Griess assay. In addition, the activities of two antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), were studied. For the cytotoxicity studies, Vero cells were cultured with Stx released of STEC biofilms. The addition of sugars in both culture mediums resulted in an increase in biofilm biomass, with a decrease in ROS and RNI production, low levels of SOD and CAT activity, and minimal cytotoxic effects. However, under stressful conditions, an important increase in the antioxidant enzyme activity and high level of Stx production were observed. The disturbance in the prooxidant-antioxidant balance and its effect on the production and release of Stx evaluated under different conditions of biofilm formation may contribute to a better understanding of the relevance of biofilms in the pathogenesis of STEC infection.
    Full-text · Article · Nov 2013 · The Scientific World Journal
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    • "and it is not possible to make predictions about their actual enzymatic activities. For instance, two proteins from Chromobacterium violaceum NP_902938 and Caulobacter crescentus NP_419374 belonging to the same group but with lower sequence identity to LodA (29.5% and 23.1%, respectively) also play a role in biofilm development and differentiation which is mediated by hydrogen peroxide production, although their actual enzymatic activity was not described (Mai-Prochnow et al. 2008). Preliminary studies in our lab have failed to detect either GO or lysine oxidase in C. crescentus or C. violaceum (J. "
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    ABSTRACT: A novel enzyme with lysine-epsilon oxidase activity was previously described in the marine bacterium Marinomonas mediterranea. This enzyme differs from other l-amino acid oxidases in not being a flavoprotein but containing a quinone cofactor. It is encoded by an operon with two genes lodA and lodB. The first one codes for the oxidase, while the second one encodes a protein required for the expression of the former. Genome sequencing of M. mediterranea has revealed that it contains two additional operons encoding proteins with sequence similarity to LodA. In this study, it is shown that the product of one of such genes, Marme_1655, encodes a protein with glycine oxidase activity. This activity shows important differences in terms of substrate range and sensitivity to inhibitors to other glycine oxidases previously described which are flavoproteins synthesized by Bacillus. The results presented in this study indicate that the products of the genes with different degrees of similarity to lodA detected in bacterial genomes could constitute a reservoir of different oxidases.
    Full-text · Article · Aug 2013 · MicrobiologyOpen
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    • "Enzymes secreted by the bacteria modify EPS composition in response to changes in nutrient availability (Sauer et al. 2004; Gjermansen et al. 2005), thereby tailoring biofilm architecture to the specific environment (Sauer et al. 2004; Ma et al. 2009). Thus, the structural components of the matrix give rise to a highly hydrated, robust structure with high tensile strength that keeps bacteria in close proximity, enabling intimate cell-to-cell interactions and DNA exchange (Flemming and Wingender 2010; Koo et al. 2010), while protecting the biomass from desiccation , predation, oxidizing molecules, radiation , and other damaging agents (Walters et al. 2003; Jefferson et al. 2005; Mai-Prochnow et al. 2008; Flemming and Wingender 2010). The resilient nature of biofilms is also partly attributed to the presence of environmental gradients within the biomass, which give rise to community " division of labor " with subpopulations of bacteria showing differential gene expression in response to local nutrient and oxygen availability (Lewis 2005; Domka et al. 2007). "
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    ABSTRACT: Biofilm formation constitutes an alternative lifestyle in which microorganisms adopt a multicellular behavior that facilitates and/or prolongs survival in diverse environmental niches. Biofilms form on biotic and abiotic surfaces both in the environment and in the healthcare setting. In hospital wards, the formation of biofilms on vents and medical equipment enables pathogens to persist as reservoirs that can readily spread to patients. Inside the host, biofilms allow pathogens to subvert innate immune defenses and are thus associated with long-term persistence. Here we provide a general review of the steps leading to biofilm formation on surfaces and within eukaryotic cells, highlighting several medically important pathogens, and discuss recent advances on novel strategies aimed at biofilm prevention and/or dissolution.
    Full-text · Article · Apr 2013 · Cold Spring Harbor Perspectives in Medicine
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