scholarly journals The Response of Cupriavidus Metallidurans CH34 to Cadmium Involves a Decrease in Intracellular Levels of C-Di-GMP Probably Mediated by a Novel Metal Regulated Phosphodiesterase That Inhibits the Biofilm Lifestyle

2018 ◽  
Author(s):  
Pablo Alviz ◽  
Sebastian Fuentes ◽  
Luis Rojas ◽  
Raymond Turner ◽  
Michael Seeger ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Biofilm Formation ◽  
Bioinformatic Analysis ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Cadmium Resistance ◽  
Toxic Heavy Metal ◽  
Transcription Analysis ◽  
Cupriavidus Metallidurans Ch34 ◽  
Cupriavidus Metallidurans

Cadmium is a highly toxic heavy metal for biological systems. Cupriavidus metallidurans CH34 is a model strain for heavy metal resistance and bioremediation. The aim of this study was to determine the role of the c-di-GMP pathway in the C. metallidurans CH34 response to cadmium in both planktonic and biofilm cells. Increasing cadmium concentrations correlates with an inhibition of biofilm formation and EPS production in C. metallidurans cells. Planktonic and biofilm cells showed similar tolerance to cadmium. During exposure to cadmium an acute decrease of c-di-GMP levels in planktonic and biofilm cells was observed. Transcription analysis by RT-qPCR showed that cadmium induced in planktonic cells and strongly induced in biofilm cells the expression of the urf2 gene and the mercuric reductase encoding merA gene, which belong to the Tn501/Tn21 mer operon. After exposure to cadmium the cadA gene involved in cadmium resistance was equally upregulated in both lifestyles. Bioinformatic analysis and null mutant complementation assays indicated that the protein encoded by the urf2 gene is a functional phosphodiesterase involved in the c-di-GMP metabolism. We propose to rename the urf2 gene as mrp gene for metal regulated phosphodiesterase. An increase of the second messenger c-di-GMP content by the heterologous expression of the constitutively active diguanylate cyclase PleD* correlated with an increase in biofilm formation and cadmium susceptibility. These results indicate that the response to cadmium in C. metallidurans CH34 involves a decrease in c-di-GMP content that inhibits the biofilm lifestyle.

Heavy metal resistance in Cupriavidus metallidurans CH34 is governed by an intricate transcriptional network

BioMetals ◽  
2011 ◽  
Vol 24 (6) ◽  
pp. 1133-1151 ◽  
Author(s):  
Pieter Monsieurs ◽  
Hugo Moors ◽  
Rob Van Houdt ◽  
Paul J. Janssen ◽  
Ann Janssen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Transcriptional Network ◽  
Cupriavidus Metallidurans Ch34 ◽  
Cupriavidus Metallidurans

scholarly journals Genetic Determinants for Cadmium and Arsenic Resistance among Listeria monocytogenes Serotype 4b Isolates from Sporadic Human Listeriosis Patients

2013 ◽  
Vol 79 (7) ◽  
pp. 2471-2476 ◽  
Author(s):  
Sangmi Lee ◽  
M. Rakic-Martinez ◽  
L. M. Graves ◽  
T. J. Ward ◽  
R. M. Siletzky ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Listeria Monocytogenes ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Genetic Determinants ◽  
Chromosomal Locus ◽  
Cadmium Resistance ◽  
Arsenic Resistance ◽  
Content Type ◽  
Serotype 4B

ABSTRACTInListeria monocytogenesserotype 4b isolates from sporadic listeriosis, heavy metal resistance was primarily encountered in certain clonal groups (ECI, ECII, and ECIa). All arsenic-resistant isolates harbored the arsenic resistance cassette previously identified in pLI100; ECIa harbored additional arsenic resistance genes and a novel cadmium resistance determinant in a conserved chromosomal locus.

scholarly journals A Klebsiella pneumoniae ST307 outbreak clone from Germany demonstrates features of extensive drug resistance, hypermucoviscosity, and enhanced iron acquisition

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Stefan E. Heiden ◽  
Nils-Olaf Hübner ◽  
Jürgen A. Bohnert ◽  
Claus-Dieter Heidecke ◽  
Axel Kramer ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Drug Resistance ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Iron Acquisition ◽  
Bacterial Species ◽  
Growth Curves ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Extensive Drug Resistance

Abstract Background Antibiotic-resistant Klebsiella pneumoniae are a major cause of hospital- and community-acquired infections, including sepsis, liver abscess, and pneumonia, driven mainly by the emergence of successful high-risk clonal lineages. The K. pneumoniae sequence type (ST) 307 lineage has appeared in several different parts of the world after first being described in Europe in 2008. From June to October 2019, we recorded an outbreak of an extensively drug-resistant ST307 lineage in four medical facilities in north-eastern Germany. Methods Here, we investigated these isolates and those from subsequent cases in the same facilities. We performed whole-genome sequencing to study phylogenetics, microevolution, and plasmid transmission, as well as phenotypic experiments including growth curves, hypermucoviscosity, siderophore secretion, biofilm formation, desiccation resilience, serum survival, and heavy metal resistance for an in-depth characterization of this outbreak clone. Results Phylogenetics suggest a homogenous phylogram with several sub-clades containing either isolates from only one patient or isolates originating from different patients, suggesting inter-patient transmission. We identified three large resistance plasmids, carrying either NDM-1, CTX-M-15, or OXA-48, which K. pneumoniae ST307 likely donated to other K. pneumoniae isolates of different STs and even other bacterial species (e.g., Enterobacter cloacae) within the clinical settings. Several chromosomally and plasmid-encoded, hypervirulence-associated virulence factors (e.g., yersiniabactin, metabolite transporter, aerobactin, and heavy metal resistance genes) were identified in addition. While growth, biofilm formation, desiccation resilience, serum survival, and heavy metal resistance were comparable to several control strains, results from siderophore secretion and hypermucoviscosity experiments revealed superiority of the ST307 clone, similar to an archetypical, hypervirulent K. pneumoniae strain (hvKP1). Conclusions The combination of extensive drug resistance and virulence, partly conferred through a “mosaic” plasmid carrying both antibiotic resistance and hypervirulence-associated features, demonstrates serious public health implications.

scholarly journals Plasmids pMOL28 and pMOL30 of Cupriavidus metallidurans Are Specialized in the Maximal Viable Response to Heavy Metals

2007 ◽  
Vol 189 (20) ◽  
pp. 7417-7425 ◽  
Author(s):  
Sébastien Monchy ◽  
Mohammed A. Benotmane ◽  
Paul Janssen ◽  
Tatiana Vallaeys ◽  
Safiyh Taghavi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Stress ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Genomic Islands ◽  
Specific Response ◽  
Resistance Proteins ◽  
Cupriavidus Metallidurans ◽  
General Response

ABSTRACT We fully annotated two large plasmids, pMOL28 (164 open reading frames [ORFs]; 171,459 bp) and pMOL30 (247 ORFs; 233,720 bp), in the genome of Cupriavidus metallidurans CH34. pMOL28 contains a backbone of maintenance and transfer genes resembling those found in plasmid pSym of C. taiwanensis and plasmid pHG1 of C. eutrophus, suggesting that they belong to a new class of plasmids. Genes involved in resistance to the heavy metals Co(II), Cr(VI), Hg(II), and Ni(II) are concentrated in a 34-kb region on pMOL28, and genes involved in resistance to Ag(I), Cd(II), Co(II), Cu(II), Hg(II), Pb(II), and Zn(II) occur in a 132-kb region on pMOL30. We identified three putative genomic islands containing metal resistance operons flanked by mobile genetic elements, one on pMOL28 and two on pMOL30. Transcriptomic analysis using quantitative PCR and microarrays revealed metal-mediated up-regulation of 83 genes on pMOL28 and 143 genes on pMOL30 that coded for all known heavy metal resistance proteins, some new heavy metal resistance proteins (czcJ, mmrQ, and pbrU), membrane proteins, truncated transposases, conjugative transfer proteins, and many unknown proteins. Five genes on each plasmid were down-regulated; for one of them, chrI localized on pMOL28, the down-regulation occurred in the presence of five cations. We observed multiple cross-responses (induction of specific metal resistance by other metals), suggesting that the cellular defense of C. metallidurans against heavy metal stress involves various regulons and probably has multiple stages, including a more general response and a more metal-specific response.

Mechanisms of cadmium resistance in anaerobic bacterial enrichments degrading pentachlorophenol

2003 ◽  
Vol 49 (7) ◽  
pp. 418-424 ◽  
Author(s):  
S R Kamashwaran ◽  
Don L Crawford
Keyword(s):  
Heavy Metal ◽  
Cadmium Sulfide ◽  
Electron Micrographs ◽  
Enrichment Culture ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Cadmium Resistance ◽  
Equal Concentration ◽  
X Ray ◽  
Transmission Electron

The mechanisms of heavy-metal resistance used by adapted sulfidogenic and methanogenic enrichments degrading pentachlorophenol in the presence of cadmium (Cd) were studied. The enrichment cultures adapted to and readily tolerated bioavailable Cd concentrations up to 50 ppm while degrading an equal concentration of pentachlorophenol. Both cultures removed >95% of the Cd from solution. Transmission electron micrographs revealed (i) the presence of electron-dense particles surrounding the cells in the sulfidogenic enrichments and (ii) the unusual clumping of cells and the presence of an exopolymer in the methanogenic enrichments. Energy dispersive X-ray analysis showed that the sulfidogenic enrichments removed Cd by extracellular precipitation of cadmium sulfide, while the methanogenic enrichment culture removed Cd by extracellular sequestration of Cd into the exopolymer.Key words: cadmium, pentachlorophenol, sulfidogenic, methanogenic, resistance.

scholarly journals Roles of Extracellular Polysaccharides and Biofilm Formation in Heavy Metal Resistance of Rhizobia

Materials ◽  
2016 ◽  
Vol 9 (6) ◽  
pp. 418 ◽  
Author(s):  
Natalia Nocelli ◽  
Pablo Bogino ◽  
Erika Banchio ◽  
Walter Giordano
Keyword(s):  
Heavy Metal ◽  
Biofilm Formation ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Extracellular Polysaccharides

scholarly journals Adaptation of Cupriavidus metallidurans CH34 to Toxic Zinc Concentrations Involves an Uncharacterized ABC-Type Transporter

2021 ◽  
Vol 9 (2) ◽  
pp. 309
Author(s):  
Rob Van Houdt ◽  
Joachim Vandecraen ◽  
Natalie Leys ◽  
Pieter Monsieurs ◽  
Abram Aertsen
Keyword(s):  
Abc Transporter ◽  
Rhizobium Leguminosarum ◽  
Constitutive Expression ◽  
Metal Resistance ◽  
Cadmium Resistance ◽  
Gene Encoding ◽  
Cupriavidus Metallidurans Ch34 ◽  
Cupriavidus Metallidurans ◽  
High Zinc ◽  
Zinc Concentrations

Cupriavidus metallidurans CH34 is a well-studied metal-resistant β-proteobacterium and contains a battery of genes participating in metal metabolism and resistance. Here, we generated a mutant (CH34ZnR) adapted to high zinc concentrations in order to study how CH34 could adaptively further increase its resistance against this metal. Characterization of CH34ZnR revealed that it was also more resistant to cadmium, and that it incurred seven insertion sequence-mediated mutations. Among these, an IS1088 disruption of the glpR gene (encoding a DeoR-type transcriptional repressor) resulted in the constitutive expression of the neighboring ATP-binding cassette (ABC)-type transporter. GlpR and the adjacent ABC transporter are highly similar to the glycerol operon regulator and ATP-driven glycerol importer of Rhizobium leguminosarum bv. viciae VF39, respectively. Deletion of glpR or the ABC transporter and complementation of CH34ZnR with the parental glpR gene further demonstrated that loss of GlpR function and concomitant derepression of the adjacent ABC transporter is pivotal for the observed resistance phenotype. Importantly, addition of glycerol, presumably by glycerol-mediated attenuation of GlpR activity, also promoted increased zinc and cadmium resistance in the parental CH34 strain. Upregulation of this ABC-type transporter is therefore proposed as a new adaptation route towards metal resistance.

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