Transcriptional analysis of the groE and dnaK heat-shock operons of Enterococcus faecalis

Laport, Marinella Silva; Lemos, José A.; Bastos, Maria do Carmo F.; Burne, Robert A.; Marval, Marcia Giambiagi-de

doi:10.1016/j.resmic.2004.02.002

Cited by 28 publications

(15 citation statements)

References 21 publications

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“…The protein groL was also present in the spot 10 of the vanA E. faecium SG 41 isolate. This protein prevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions [32,33]. …”

Section: Discussionmentioning

confidence: 99%

Proteomic characterization of van A-containing Enterococcu s recovered from Seagulls at the Berlengas Natural Reserve, W Portugal

et al. 2010

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BackgroundEnterococci have emerged as the third most common cause of nosocomial infections, requiring bactericidal antimicrobial therapy. Although vancomycin resistance is a major problem in clinics and has emerged in an important extend in farm animals, few studies have examined it in wild animals. To determine the prevalence of vanA-containing Enterococcus strains among faecal samples of Seagulls (Larus cachinnans) of Berlengas Natural Reserve of Portugal, we developed a proteomic approach integrated with genomic data. The purpose was to detect the maximum number of proteins that vary in different enterococci species which are thought to be connected in some, as yet unknown, way to antibiotic resistance.ResultsFrom the 57 seagull samples, 54 faecal samples showed the presence of Enterococcus isolates (94.7%). For the enterococci, E. faecium was the most prevalent species in seagulls (50%), followed by E. faecalis and E. durans (10.4%), and E. hirae (6.3%). VanA-containing enterococcal strains were detected in 10.5% of the 57 seagull faecal samples studied. Four of the vanA-containing enterococci were identified as E. faecium and two as E. durans. The tet(M) gene was found in all five tetracycline-resistant vanA strains. The erm(B) gene was demonstrated in all six erythromycin-resistant vanA strains. The hyl virulence gene was detected in all four vanA-containing E. faecium isolates in this study, and two of them harboured the purK1 allele. In addition these strains also showed ampicillin and ciprofoxacin resistance. The whole-cell proteomic profile of vanA-containing Enterococcus strains was applied to evaluate the discriminatory power of this technique for their identification. The major differences among species-specific profiles were found in the positions corresponding to 97-45 kDa. Sixty individualized protein spots for each vanA isolate was identified and suitable for peptide mass fingerprinting measures by spectrometry measuring (MALDI/TOF MS) and their identification through bioinformatic databases query. The proteins were classified in different groups according to their biological function: protein biosynthesis, ATP synthesis, glycolysis, conjugation and antibiotic resistance. Taking into account the origin of these strains and its relation to infectious processes in humans and animals, it is important to explore the proteome of new strains which might serve as protein biomarkers for biological activity.ConclusionsThe comprehensive description of proteins isolated from vancomycin-resistant Enterococcus faecium and E. durans may provide new targets for development of antimicrobial agents. This knowledge may help to identify new biomarkers of antibiotic resistance and virulence factors.

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Section: Discussionmentioning

confidence: 99%

Proteomic characterization of van A-containing Enterococcu s recovered from Seagulls at the Berlengas Natural Reserve, W Portugal

et al. 2010

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“…The system consists of DnaK, its cochaperone (DnaJ), and a nucleotide exchange factor (GrpE) (286). Expression analyses conducted at the transcript and/or protein level revealed that production of DnaK is induced in different LAB under diverse stress conditions (287)(288)(289)(290). A deletion in dnaK resulted in a thermosensitive phenotype for Lc.…”

Section: Treating Damaged Macromoleculesmentioning

confidence: 99%

“…GroES is the most abundant protein in B. subtilis, with some 500,000 molecules per cell after 30 min of exposure to heat stress (295). The production of the highly conserved GroEL and GroES proteins is activated under various stress conditions in LAB (287)(288)(289)(290)296).…”

Section: Treating Damaged Macromoleculesmentioning

confidence: 99%

Stress Physiology of Lactic Acid Bacteria

Papadimitriou

Alegría

Bron

et al. 2016

Microbiol Mol Biol Rev

541

404

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SUMMARYLactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g.,Lactococcus lactis), probiotic (e.g., severalLactobacillusspp.), and pathogenic (e.g.,EnterococcusandStreptococcusspp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the “stressome” of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.

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“…It has been demonstrated that preexposure to sublethal stresses, oligotrophic conditions or glucose starvation leads to an overall increase in stress resistance (Flahaut et al, 1996a(Flahaut et al, , b, 1997Giard et al, 1997;Hartke et al, 1998). A correlation has been made between the capacity to adapt to stress and the cross-protection phenomenon with the increased synthesis of many proteins, but, with a few exceptions such as the general stress protein Gls24 and the molecular chaperones GroEL and DnaK, the identity of the majority of these proteins remains unknown (Flahaut et al, 1996a(Flahaut et al, , b, 1997Hartke et al, 1998;Giard et al, 2000;Laport et al, 2004Laport et al, , 2006. In many bacteria, Clp ATPases and ClpP proteolytic complexes are protein machines that play crucial roles in promoting folding, assembly or degradation of proteins during normal growth and, in particular, under stressinducing conditions (Houry, 2001;Frees et al, 2004 classes of Clp ATPases have been identified based on the presence of one or two ATP-binding domains and the occurrence of specific signature sequences (Wawrzynow et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

clpB, a class III heat-shock gene regulated by CtsR, is involved in thermotolerance and virulence of Enterococcus faecalis

et al. 2011

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Here, we transcriptionally and phenotypically characterized the clpB gene from Enterococcus faecalis. Northern blot analysis identified a monocistronic mRNA strongly induced at 48 and 50 6C. In silico analysis identified that the clpB gene encodes a protein of 868 aa with a predicted molecular mass of approximately 98 kDa, presenting two conserved ATP-binding domains. Sequence analysis also identified a CtsR-binding box upstream of the putative "10 sequence, and inactivation of the ctsR gene resulted in an approximately 2-log increase in clpB mRNA expression, confirming ClpB as a member of the CtsR regulon. While expression of clpB was induced by heat stress, a DclpB strain grew relatively well under many different stressful conditions, including elevated temperatures. However, expression of ClpB appears to play a major role in induced thermotolerance and in pathogenesis, as assessed by using the Galleria mellonella virulence model.

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Transcriptional analysis of the groE and dnaK heat-shock operons of Enterococcus faecalis

Cited by 28 publications

References 21 publications

Proteomic characterization of van A-containing Enterococcu s recovered from Seagulls at the Berlengas Natural Reserve, W Portugal

Proteomic characterization of van A-containing Enterococcu s recovered from Seagulls at the Berlengas Natural Reserve, W Portugal

Stress Physiology of Lactic Acid Bacteria

clpB, a class III heat-shock gene regulated by CtsR, is involved in thermotolerance and virulence of Enterococcus faecalis

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