Biofilm generation by Piscirickettsia salmonis under growth stress conditions: a putative in vivo survival/persistence strategy in marine environments

Marshall, Sergio H.; Gómez, Fernando; Ramírez, Ramón; Nilo, Luis; Henríquez, Vitalia

doi:10.1016/j.resmic.2012.08.002

Cited by 52 publications

(70 citation statements)

References 64 publications

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“…Notably, even in the nutrient-rich medium (BM3), all of the flagellar genes were transcribed, and, independent of the growth conditions, all flagellar genes followed the same induction profile (data not shown). Also worth highlighting, P. salmonis grown on the MB medium did evidence biofilm formation by the bacteria (Marshall et al 2012). Future studies should determine the role of flagellar genes, if any, in P. salmonis biofilm formation.…”

Section: Discussionmentioning

confidence: 86%

“…Relative gene expression were estimated using threshold cycle (Ct) values and the Livak 2 −ΔΔCt method without modification (Livak & Schmittgen 2001). For growth kinetics in MB, the Ct value obtained for each sample at each time point for ITS was used as a normalization factor (Marshall et al 2012). The growth kinetics in BM3 were used as a calibrator: static for static and mixing for mixing, at each time point for all genes to measure relative fold differences in expression under the other media conditions.…”

Section: Quantitative Reverse Transcription Polymerase Chain Reactionmentioning

confidence: 99%

“…Biofilm formation is a known persistence and survival strategy used by pathogenic bacteria under harsh metabolic conditions, such as in the marine environment where P. salmonis must live, survive, and evolve (Marshall et al 2012). Two genetic features have been described in P. salmonis that could play key roles in pathogen survival.…”

Section: Introductionmentioning

confidence: 99%

“…Firstly, at least 2 different insertion sequences are constituent parts of the bacterial genome, acting as functional structures that regulate gene expression (GenBank: AF184152; Marshall et al 2011). Secondly, 2 different functional chromosomal toxinantitoxin modules are particularly upregulated under stress, with distinctive features contributing to the bacterium's adaptation to environmental cues (Gó -mez et al 2011, Marshall et al 2012. The search for new pathogenic features has been facilitated by the recent genome sequencing of P. salmonis isolates (Eppinger et al 2013).…”

Section: Introductionmentioning

confidence: 99%

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Expression of flagellin and key regulatory flagellar genes in the non-motile bacterium Piscirickettsia salmonis

Carril

Gómez²,

Marshall³

2017

Dis. Aquat. Org.

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The Piscirickettsia salmonis genome was screened to evaluate potential flagellarelated open reading frames, as well as their genomic organization and eventual expression. A complete and organized set of flagellar genes was found for P. salmonis, although no structural flagellum has ever been reported for this bacterium. To gain further understanding, the hierarchical flagellar cascade described for Legionella pneumophila was used as a reference model for putative analysis in P. salmonis. Specifically, 5 of the most relevant genes from this cascade were chosen, including 3 regulatory genes (fleQ, triggers the cascade; fliA, regulates the σ28-coding gene; and rpoN, an RNA polymerase-dependent gene) and 2 terminal structural genes (flaA and flaB, flagellin and a flagellin-like protein, respectively). Kinetic experiments evaluated gene expressions over time, with P. salmonis assessed in 2 liquid, cell-free media and during infection of the SHK-1 fish cell line. Under all conditions, the 5 target genes were primarily expressed during early growth/infection and were differentially expressed when bacteria encountered environmental stress (i.e. a high-salt concentration). Intriguingly, the flagellin monomer was fully expressed under all growth conditions and was located near the bacterial membrane. While no structural flagellum was detected under any condition, the recombinant flagellin monomer induced a proinflammatory response in SHK-1 cells, suggesting a possible immunomodulatory function. The potential implications of these observations are discussed in the context of P. salmonis biology and pathogenic potential.

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Section: Discussionmentioning

confidence: 86%

Section: Quantitative Reverse Transcription Polymerase Chain Reactionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Expression of flagellin and key regulatory flagellar genes in the non-motile bacterium Piscirickettsia salmonis

Carril

Gómez²,

Marshall³

2017

Dis. Aquat. Org.

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“…Once permanently attached, bacteria start to synthesize insoluble exopolysaccharide (EPS) fibrils that encase the adherent bacteria in a three-dimensional matrix [17]. Freely floating bacteria that entrapped by cellulosic fibrils [19,20] into the 3 dimensional network (Fig. 1) will develop biofilm.…”

Section: Chemotaxis Assaymentioning

confidence: 99%

Mapping of the Interaction Between Agrobacterium tumefaciens and Vanda Kasem’s Delight Orchid Protocorm-Like Bodies

Gnasekaran

Subramaniam

2015

Indian J Microbiol

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Physical contact between A. tumefaciens and the target plant cell walls is essential to transfer and integrate the transgene to introduce a novel trait. Chemotaxis response and attachment of Agrobacterium towards Vanda Kasem's Delight (VKD) protocorm-like bodies (PLBs) were studied to analyse the interaction between Agrobacterium and PLB during the transformation event. The study shows that initially A. tumefaciens reversibly attached to PLB surface via polar and lateral mode of adherence followed by the irreversible attachment which involved the production of cellulosic fibril by A. tumefaciens. Cellulosic fibril allows formation of biofilm at the tip of trichome. Contrarily, attachment mutant Escherichia coli strain DH5a was significantly deficient in the attachment process. Spectrophotometric GUS assay showed the mean value of attachment by A. tumefaciens was 8.72 % compared to the negative control E. coli strain DH5a that produced 0.16 %. A. tumefaciens swarmed with sharper and brighter edge when severe wounding was applied to the PLBs producing the highest swarming ratio of 1.46 demonstrating the positive effect of the plant exudates on bacterial movement. The study shows that VKD's PLBs are the suitable explants for Agrobacterium-mediated transformation since the bacteria expressed higher competency rate.

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Vaccination against Piscirickettsiosis

Marshall

Tobar²

2014

Fish Vaccination

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Biofilm generation by Piscirickettsia salmonis under growth stress conditions: a putative in vivo survival/persistence strategy in marine environments

Cited by 52 publications

References 64 publications

Expression of flagellin and key regulatory flagellar genes in the non-motile bacterium Piscirickettsia salmonis

Expression of flagellin and key regulatory flagellar genes in the non-motile bacterium Piscirickettsia salmonis

Mapping of the Interaction Between Agrobacterium tumefaciens and Vanda Kasem’s Delight Orchid Protocorm-Like Bodies

Vaccination against Piscirickettsiosis

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