3 research outputs found
<i>Pseudomonas aeruginosa</i> cells attached to a surface display a typical proteome early as 20 minutes of incubation
<div><p>Biofilms are present in all environments and often result in negative effects due to properties of the biofilm lifestyle and especially antibiotics resistance. Biofilms are associated with chronic infections. Controlling bacterial attachment, the first step of biofilm formation, is crucial for fighting against biofilm and subsequently preventing the persistence of infection. Thus deciphering the underlying molecular mechanisms involved in attachment could allow discovering molecular targets from it would be possible to develop inhibitors against bacterial colonization and potentiate antibiotherapy. To identify the key components and pathways that aid the opportunistic pathogen <i>Pseudomonas aeruginosa</i> in attachment we performed for the first time a proteomic analysis as early as after 20 minutes of incubation using glass wool fibers as a surface. We compared the protein contents of the attached and unattached bacteria. Using mass spectrometry, 3043 proteins were identified. Our results showed that, as of 20 minutes of incubation, using stringent quantification criteria 616 proteins presented a modification of their abundance in the attached cells compared to their unattached counterparts. The attached cells presented an overall reduced gene expression and characteristics of slow-growing cells. The over-accumulation of outer membrane proteins, periplasmic folding proteins and O-antigen chain length regulators was also observed, indicating a profound modification of the cell envelope. Consistently the sigma factor AlgU required for cell envelope homeostasis was highly over-accumulated in attached cells. In addition our data suggested a role of alarmone (p)ppGpp and polyphosphate during the early attachment phase. Furthermore, almost 150 proteins of unknown function were differentially accumulated in the attached cells. Our proteomic analysis revealed the existence of distinctive biological features in attached cells as early as 20 minutes of incubation. Analysis of some mutants demonstrated the interest of this proteomic approach in identifying genes involved in the early phase of adhesion to a surface.</p></div
Attachment capacity of <i>P</i>. <i>aeruginosa</i> PAO1 reference strains and isogenic mutants.
<p>The attachment capacity of reference strains, mutants and complemented mutants (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180341#pone.0180341.s011" target="_blank">S9A Table</a>) was assayed after 20 min at 37°C in our glass wool system (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180341#sec021" target="_blank">materials and methods</a>). Only the attachment capacity of <i>P</i>. <i>aeruginosa</i> PAO1 was presented for reason of clarity, the other reference strains (PAO1-L and MPAO1) showed results similar to those obtained for PAO1. In the same manner, the attachment capacities of the different mutants were not altered by introducing the empty plasmid pUCP20 or pUCP22. For each of the mutants presented herein, the complemented strain displayed an attachment capacity ranging from 80% to 140% of the reference strain (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0180341#pone.0180341.s010" target="_blank">S8 Table</a>). The results corresponded to the average of 3 independent experiments (bar = SD).</p
New evidence of a mitochondrial genetic background paradox: Impact of the J haplogroup on the A3243G mutation-0
Impacts on the OXPHOS level, their implications on an individual level, and their impact on the distribution of populations studied within the phylogeny.<p><b>Copyright information:</b></p><p>Taken from "New evidence of a mitochondrial genetic background paradox: Impact of the J haplogroup on the A3243G mutation"</p><p>http://www.biomedcentral.com/1471-2350/9/41</p><p>BMC Medical Genetics 2008;9():41-41.</p><p>Published online 7 May 2008</p><p>PMCID:PMC2409300.</p><p></p