Physiological characterization of Streptococcus bovis mutants that can resist 2-deoxyglucose-induced lysis

Bond, Daniel R.; Tsai, B. M.; Russell, James B.

doi:10.1099/00221287-145-10-2977

Cited by 12 publications

(15 citation statements)

References 40 publications

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“…The resulting colonies, corresponding to the growth of 2DG-resistant mutants, were isolated twice on the same medium. 2-DG is a toxic molecule that enters bacteria via a PTS permease of the mannose family (Bond et al, 1999). Consequently, this permease is not usually expressed in 2DG-resistant mutants.…”

Section: Methodsmentioning

confidence: 99%

Analysis of σ54-dependent genes in Enterococcus faecalis: a mannose PTS permease (EIIMan) is involved in sensitivity to a bacteriocin, mesentericin Y105

et al. 2001

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, strikingly led to resistance to mesentericin Y105. Moreover, MptD appears to be a peculiar membrane subunit, bearing an additional domain compared to most known IID subunits. According to these results, EII Man t is clearly involved in susceptibility to mesentericin Y105 and could even be its receptor at the E. faecalis surface. Finally, it is hypothesized that MptD could be responsible for the targeting specificity, via an interaction between its additional domain and mesentericin Y105.

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Section: Methodsmentioning

confidence: 99%

Analysis of σ54-dependent genes in Enterococcus faecalis: a mannose PTS permease (EIIMan) is involved in sensitivity to a bacteriocin, mesentericin Y105

et al. 2001

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“…E. faecalis V583, VI01, and VI40 were grown on LB agar containing 0.2% fructose and 10 mM 2-deoxy-D-glucose (2DG) (24). 2DG is a toxic homologue of glucose and enters cells via the mannose PTS permease (5). In E. faecalis, mannose PTS expression is controlled by 54 .…”

Section: Methodsmentioning

confidence: 99%

Deletion of σ ⁵⁴ ( rpoN ) Alters the Rate of Autolysis and Biofilm Formation in Enterococcus faecalis

Iyer

Hancock

2012

J Bacteriol

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Transcription initiation is a critical step in bacterial gene regulation and is often controlled by transcription regulators. The alternate sigma factor ( 54 ) is one such regulator that facilitates activator-dependent transcription initiation and thus modulates the expression of a variety of genes involved in metabolism and pathogenesis in bacteria. This study describes the role of 54 in the nosocomial pathogen Enterococcus faecalis. Biofilm formation is one of the important pathogenic mechanisms of E. faecalis, as it elevates the organism's potential to cause surgical site and urinary tract infections. Lysis of bacterial cells within the population contributes to biofilm formation by providing extracellular DNA (eDNA) as a key component of the biofilm matrix. Deletion of rpoN rendered E. faecalis resistant to autolysis, which in turn impaired eDNA release. Despite the significant reduction in eDNA levels compared to the parental strain, the rpoN mutant formed more robust biofilms as observed using laser scanning confocal microscopy and Comstat analysis, indicating and emphasizing the presence of other matrix components. Initial adherence to a polystyrene surface was also enhanced in the mutant. Proteinase K treatment at early stages of biofilm development significantly reduced the accumulation of biofilm by the rpoN mutant. In conclusion, our data indicate that other factors in addition to eDNA might contribute to the overall composition of the enterococcal biofilm and that the regulatory role of 54 governs the nature and composition of the biofilm matrix.A s opportunistic pathogens, enterococci are the third leading cause of hospital-acquired or associated infections, as they are responsible for 11.2% of surgical site infections (SSI), 14.9% of urinary tract infections (UTI), and 16% of reported bloodstream infections (25). The ability to form a biofilm is an important aspect of the lifestyle of the organism, as biofilm formation is thought to be a property associated with the establishment of SSI and UTI (34), both of which can serve as foci to establish bloodstream infections. Biofilms are aggregates of bacteria that are covered in exoploymer matrix and are more resistant to antibiotics than their planktonic counterparts (15,26). In several bacterial species, nucleic acids, polysaccharides, proteins, and lipids constitute the exopolymer matrix (19). The components of the biofilm matrix form a physical barrier that enhances the inaccessibility of the biofilm cells to antibiotics and the immune system, thereby making the infection difficult to eradicate (33). Extracellular DNA (eDNA) serves as an important biofilm matrix component in several microbial model systems, including but not limited to Neisseria meningitidis, Listeria monocytogenes, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus epidermidis (2,23,29,32,36,47,48,54). The expression of the two secreted E. faecalis proteases, gelatinase and serine protease, is regulated in a quorum-dependent manner by the Fsr re...

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“…TLC conditions were performed with modified methods of Bond et al [13] as follows: after spotting the samples on the TLC plate (Silica gel 60; EMD Chemicals Inc. Gibbstown, NJ, USA), chromatography was developed in a solvent containing n-butanol, glacial acetic acid and water (at ratio of 2:1:1) for 90 min. The plate, after drying with a stream of warm air, was stained by spraying with p-anisaldehyde reagent (ethanol:glacial acetic acid:sulfuric acid:p-anisaldehyde = 9.0:0.1:0.75:0.75) and heated in an oven at 115˚C for about 5 min.…”

Section: Thin Layer Chromatography (Tlc) and Liquid Chromatography-mamentioning

confidence: 99%

Degradation of Chitin and Chitosan by a Recombinant Chitinase Derived from a Virulent <i>Aeromonas hydrophila</i> Isolated from Diseased Channel Catfish

Zhang¹,

Bland²,

Xu³

et al. 2015

AiM

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A chitinase was identified in extracellular products of a virulent Aeromonas hydrophila isolated from diseased channel catfish (Ictalurus punctatus). Recombinant chitinase (rChi-Ah) was produced in Escherichia coli. Purified rChi-Ah had optimal activity at temperature of 42˚C and pH 6.5. The affinity (Km) for chitosan was 4.18 mg•ml −1 with Vmax of 202.5 mg•min −1 •mg −1 . With colloidal chitin as substrate, rChi-Ah generated N,N'-diacetyl-glucosamine predominantly. Conversion of chitosan (≥75% deacetylated) by rChi-Ah revealed five major products: 2 to 4 units of glucosamine, all of which had at least one acetyl group. It was determined that N-acetylated glucosamine was the recognition and cleavage site of rChi-Ah; the minimal and maximal cleavages were two and four glucosamine units, respectively. Functional analysis of rChi-Ah suggests that A. hydrophilachitinase is a bioactive chitinolytic enzyme, which may benefit the pathogen for survival and/or infection.

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Physiological characterization of Streptococcus bovis mutants that can resist 2-deoxyglucose-induced lysis

Cited by 12 publications

References 40 publications

Analysis of σ54-dependent genes in Enterococcus faecalis: a mannose PTS permease (EIIMan) is involved in sensitivity to a bacteriocin, mesentericin Y105

Analysis of σ54-dependent genes in Enterococcus faecalis: a mannose PTS permease (EIIMan) is involved in sensitivity to a bacteriocin, mesentericin Y105

Deletion of σ ⁵⁴ ( rpoN ) Alters the Rate of Autolysis and Biofilm Formation in Enterococcus faecalis

Degradation of Chitin and Chitosan by a Recombinant Chitinase Derived from a Virulent <i>Aeromonas hydrophila</i> Isolated from Diseased Channel Catfish

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Physiological characterization of Streptococcus bovis mutants that can resist 2-deoxyglucose-induced lysis

Cited by 12 publications

References 40 publications

Analysis of σ54-dependent genes in Enterococcus faecalis: a mannose PTS permease (EIIMan) is involved in sensitivity to a bacteriocin, mesentericin Y105

Analysis of σ54-dependent genes in Enterococcus faecalis: a mannose PTS permease (EIIMan) is involved in sensitivity to a bacteriocin, mesentericin Y105

Deletion of σ 54 ( rpoN ) Alters the Rate of Autolysis and Biofilm Formation in Enterococcus faecalis

Degradation of Chitin and Chitosan by a Recombinant Chitinase Derived from a Virulent &lt;i&gt;Aeromonas hydrophila&lt;/i&gt; Isolated from Diseased Channel Catfish

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Deletion of σ ⁵⁴ ( rpoN ) Alters the Rate of Autolysis and Biofilm Formation in Enterococcus faecalis

Degradation of Chitin and Chitosan by a Recombinant Chitinase Derived from a Virulent <i>Aeromonas hydrophila</i> Isolated from Diseased Channel Catfish