Tellurite-dependent blackening of bacteria emerges from the dark ages

2019 ◽  
Vol 16 (4) ◽  
pp. 266 ◽  
Author(s):  
Alessandro Presentato ◽  
Raymond J. Turner ◽  
Claudio C. Vásquez ◽  
Vladimir Yurkov ◽  
Davide Zannoni
Keyword(s):  
Chemical Elements ◽  
Research Work ◽  
Resistance Mechanisms ◽  
Rare Element ◽  
Tellurite Resistance ◽  
Resistance Determinants ◽  
Dark Ages ◽  
Technological Developments ◽  
Pathogen Screening ◽  
Biochemical Mechanisms

Environmental contextAlthough tellurium is a relatively rare element in the earth’s crust, its concentration in some niches can be naturally high owing to unique geology. Tellurium, as the oxyanion, is toxic to prokaryotes, and although prokaryotes have evolved resistance to tellurium, no universal mechanism exists. We review the interaction of tellurite with prokaryotes with a focus on those unique strains that thrive in environments naturally rich in tellurium. AbstractThe timeline of tellurite prokaryotic biology and biochemistry is now over 50 years long. Its start was in the clinical microbiology arena up to the 1970s. The 1980s saw the cloning of tellurite resistance determinants while from the 1990s through to the present, new strains were isolated and research into resistance mechanisms and biochemistry took place. The past 10 years have seen rising interest in more technological developments and considerable advancement in the understanding of the biochemical mechanisms of tellurite metabolism and biochemistry in several different prokaryotes. This research work has provided a list of genes and proteins and ideas about the fundamental metabolism of Te oxyanions. Yet the biomolecular mechanisms of the tellurite resistance determinants are far from established. Regardless, we have begun to see a new direction of Te biology beyond the clinical pathogen screening approaches, evolving into the biotechnology fields of bioremediation, bioconversion and bionanotechnologies and subsequent technovations. Knowledge on Te biology may still be lagging behind that of other chemical elements, but has moved beyond its dark ages and is now well into its renaissance.

scholarly journals Resistance Mechanisms of Multiresistant Pseudomonas aeruginosa Strains from Germany and Correlation with Hypermutation

2007 ◽  
Vol 51 (11) ◽  
pp. 4062-4070 ◽  
Author(s):  
B. Henrichfreise ◽  
I. Wiegand ◽  
W. Pfister ◽  
B. Wiedemann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Type Ii ◽  
Mechanisms Of Resistance ◽  
Resistance Determinants ◽  
Class 1 ◽  
Mutator Strains ◽  
Multiresistant Strains

ABSTRACT In this study, we analyzed the mechanisms of multiresistance for 22 clinical multiresistant and clonally different Pseudomonas aeruginosa strains from Germany. Twelve and 10 strains originated from cystic fibrosis (CF) and non-CF patients, respectively. Overproduction of the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM was studied. Furthermore, loss of OprD, alterations in type II topoisomerases, AmpC overproduction, and the presence of 25 acquired resistance determinants were investigated. The presence of a hypermutation phenotype was also taken into account. Besides modifications in GyrA (91%), the most frequent mechanisms of resistance were MexXY-OprM overproduction (82%), OprD loss (82%), and AmpC overproduction (73%). Clear differences between strains from CF and non-CF patients were found: numerous genes coding for aminoglycoside-modifying enzymes and located, partially in combination with β-lactamase genes, in class 1 integrons were found only in strains from non-CF patients. Furthermore, multiple modifications in type II topoisomerases conferring high quinolone resistance levels and overexpression of MexAB-OprM were exclusively detected in multiresistant strains from non-CF patients. Correlations of the detected phenotypes and resistance mechanisms revealed a great impact of efflux pump overproduction on multiresistance in P. aeruginosa. Confirming previous studies, we found that additional, unknown chromosomally mediated resistance mechanisms remain to be determined. In our study, 11 out of 12 strains and 3 out of 10 strains from CF patients and non-CF patients, respectively, were hypermutable. This extremely high proportion of mutator strains should be taken into consideration for the treatment of multiresistant P. aeruginosa.

Glutathione is a target in tellurite toxicity and is protected by tellurite resistance determinants inEscherichia coli

2001 ◽  
Vol 47 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Raymond J Turner ◽  
Yair Aharonowitz ◽  
Joel H Weiner ◽  
Diane E Taylor
Keyword(s):  
Reduced Glutathione ◽  
Resistance Mechanism ◽  
Thiol Oxidation ◽  
Wild Type ◽  
Response Curves ◽  
Tellurite Resistance ◽  
Thiol Compounds ◽  
Mechanisms Of Toxicity ◽  
Resistance Determinants ◽  
Glutathione Oxidation

Tellurite (TeO32-) is highly toxic to most microorganisms. The mechanisms of toxicity or resistance are poorly understood. It has been shown that tellurite rapidly depletes the reduced thiol content within wild-type Escherichia coli. We have shown that the presence of plasmid-borne tellurite-resistance determinants protects against general thiol oxidation by tellurite. In the present study we observe that the tellurite-dependent depletion of cellular thiols in mutants of the glutathione and thioredoxin thiol:redox system was less than in wild-type cells. To identify the type of low-molecular-weight thiol compounds affected by tellurite exposure, the thiol-containing molecules were analyzed by reverse phase HPLC as their monobromobimane derivatives. Results indicated that reduced glutathione is a major initial target of tellurite reactivity within the cell. Other thiol species are also targeted by tellurite, including reduced coenzyme A. The presence of the tellurite resistance determinants kilA and ter protect against the loss of reduced glutathione by as much as 60% over a 2 h exposure. This protection of glutathione oxidation is likely key to the resistance mechanism of these determinants. Additionally, the thiol oxidation response curves were compared between selenite and tellurite. The loss of thiol compounds within the cell recovered from selenite but not to tellurite.Key words: tellurite, resistance, thiol oxidation, heavy metal toxicity, selenite, glutathione.

scholarly journals Clonal Diversity and Resistance Mechanisms in Tetracycline-Nonsusceptible Streptococcus pneumoniae Isolates in Poland

2007 ◽  
Vol 51 (4) ◽  
pp. 1155-1163 ◽  
Author(s):  
Radosław Izdebski ◽  
Ewa Sadowy ◽  
Janusz Fiett ◽  
Paweł Grzesiowski ◽  
Marek Gniadkowski ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Tetracycline Resistance ◽  
Clonal Diversity ◽  
Resistance Mechanisms ◽  
Pfge Type ◽  
Cross Resistance ◽  
M Gene ◽  
Conjugative Transposons ◽  
Tetracycline Resistance Genes ◽  
Resistance Determinants

ABSTRACT The frequency of tetracycline resistance in Streptococcus pneumoniae isolates in Poland is one of the highest in Europe. The aim of this study was to analyze the clonal diversity and resistance determinants of tetracycline-nonsusceptible S. pneumoniae isolates identified in Poland and to investigate the effect of tetracycline resistance on their susceptibilities to tigecycline, doxycycline, and minocycline. We have analyzed 866 pneumococcal isolates collected from 1998 to 2003 from patients with respiratory tract diseases, and 242 of these (27.9%) were found to be resistant to tetracycline. All of the resistant isolates were characterized by testing of their susceptibilities to other antimicrobials, serotyping, pulsed-field gel electrophoresis (PFGE), and identification of tetracycline resistance genes and transposons. Selected isolates representing the main PFGE types were analyzed by multilocus sequence typing. Among the isolates investigated, 27 serotypes and 146 various PFGE patterns, grouped into 90 types, were discerned. The most common PFGE type, corresponding to serotype 19F and sequence type 423, was represented by 22.3% of all of the tetracycline-resistant isolates. The tet(M) gene was the sole resistance gene in the group of isolates studied, and in over 96% of the isolates, the Tn916 family of tet(M)-containing conjugative transposons was detected. Several isolates contained specific variants of the transposons, the Tn1545-like, Tn3872-like, or Tn2009-like element. The correlation between the MICs of tetracycline, doxycycline, and minocycline was revealed, whereas no cross-resistance to tetracycline and tigecycline was observed.

scholarly journals Nosocomial Spread of Colistin-Only-Sensitive Sequence Type 235 Pseudomonas aeruginosa Isolates Producing the Extended-Spectrum β-Lactamases GES-1 and GES-5 in Spain

2009 ◽  
Vol 53 (11) ◽  
pp. 4930-4933 ◽  
Author(s):  
Esther Viedma ◽  
Carlos Juan ◽  
Joshi Acosta ◽  
Laura Zamorano ◽  
Joaquín R. Otero ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Resistance Mechanisms ◽  
Pulsed Field Gel Electrophoresis ◽  
Sequence Type ◽  
Pulsed Field ◽  
Resistance Determinants ◽  
Extended Spectrum ◽  
Spanish Hospital

ABSTRACT The mechanisms responsible for the increasing prevalence of colistin-only-sensitive (COS) Pseudomonas aeruginosa isolates in a Spanish hospital were investigated. Pulsed-field gel electrophoresis revealed that 24 (50%) of the studied isolates belonged to the same clone, identified as the internationally spread sequence type 235 (ST235) through multilocus sequence typing. In addition to several mutational resistance mechanisms, an integron containing seven resistance determinants was detected. Remarkably, the extended-spectrum β-lactamase GES-1 and its Gly170Ser carbapenem-hydrolyzing derivative GES-5 were first documented to be encoded in a single integron. This work is the first to describe GES enzymes in Spain and adds them to the growing list of β-lactamases of concern (PER, VIM, and OXA) detected in ST235 clone isolates.

Copper Resistance Mechanisms of Biomining Bacteria and Archaea Living under Extremely High Concentrations of Metals

2009 ◽  
Vol 71-73 ◽  
pp. 279-282 ◽  
Author(s):  
A. Orell ◽  
C.A. Navarro ◽  
Carlos A. Jerez
Keyword(s):  
Resistance Mechanisms ◽  
Metal Resistance ◽  
Copper Resistance ◽  
Inorganic Polyphosphate ◽  
Resistance Determinants ◽  
High Metal ◽  
Pi Complex ◽  
Cu Resistance ◽  
High Concentrations ◽  
Cu Tolerance

Extremophiles such as the acidophilic Sulfolobus metallicus (Archaea) and Acidithiobacillus ferrooxidans (Bacteria) can resist Cu (CuSO4) concentrations of 200 mM and 800 mM respectively. These microorganisms are important in biomining processes to extract copper and other metals. A. ferrooxidans grown at low Cu concentrations (5 mM) expressed genes coding for ATPases most likely involved in pumping the metal from the cytoplasm to the periplasm of the bacterium. At 100 mM Cu the previous systems were repressed and there was a great induction in the expression of efflux systems known to use the proton motive force energy to export the metal outside the cell. These Cu-resistance determinants from A. ferrooxidans were found to be functional since when expressed in Escherichia coli they conferred higher Cu tolerance to it. Novel Cu-resistance determinants for A. ferrooxidans were found and characterized. S. metallicus possessed at least 2 CopM metallochaperones and 2 CopA ATPases whose expressions were induced by Cu (5 to 50 mM). Furthermore, we previously reported that both microorganisms accumulate high levels of inorganic polyphosphate (PolyP) and that intracellular Cu concentration stimulates polyP hydrolysis. The resulting Pi would then be transported out of the cell as a metal-Pi complex to detoxify the cells. In addition, our results suggest that at high Cu concentrations polyP could also provide energy for the metal efflux. All the data suggest that both biomining microorganisms use different systems to respond to Cu depending on the extracellular concentrations of the metal and suggest that the presence of different additional systems to respond to Cu may explain the extremely high metal resistance of these extremophiles.

scholarly journals ANTIBIOTIC RESISTANCE MECHANISMS OF UROGENITAL MYCOPLASMAS

2019 ◽  
pp. 45-49
Author(s):  
E.A. Kolesnikova ◽  
N.F. Brusnigina ◽  
G.I. Grigor’eva
Keyword(s):  
Antibiotic Resistance ◽  
Mycoplasma Hominis ◽  
Mycoplasma Genitalium ◽  
Resistance Mechanisms ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Resistance Determinants ◽  
New Knowledge ◽  
High Level ◽  
Ureaplasma Spp

Urogenital mycoplasmas (Mycoplasma genitalium, Mycoplasma hominis and Ureaplasma spp.) currently prevail in the etiology of infections of the urogenital tract and are characterized by a high level of genetic polymorphism responsible for the occurrence of their antibiotic resistance. The review presents the data of domestic and foreign researchers on the resistance mechanisms of mycoplasmas and ureaplasmas to antibiotics and considers the acquisition by mycoplasmas of antibiotic resistance determinants. New knowledge of resistance mechanisms is important theoretical basis for improving measures to limit and prevent the spread of antibiotic resistant bacteria.

scholarly journals Genomic Insights into Drug Resistance Determinants in Cedecea neteri, A Rare Opportunistic Pathogen

2021 ◽  
Vol 9 (8) ◽  
pp. 1741
Author(s):  
Dorothea K. Thompson ◽  
Stephen M. Sharkady
Keyword(s):  
Drug Resistance ◽  
Sequence Data ◽  
Opportunistic Pathogen ◽  
Resistance Mechanisms ◽  
Whole Genome Sequence ◽  
Multidrug Efflux ◽  
Resistance Determinants ◽  
Multidrug Efflux Pumps ◽  
Novel Variant ◽  
Immunocompromised Hosts

Cedecea, a genus in the Enterobacteriaceae family, includes several opportunistic pathogens reported to cause an array of sporadic acute infections, most notably of the lung and bloodstream. One species, Cedecea neteri, is associated with cases of bacteremia in immunocompromised hosts and has documented resistance to different antibiotics, including β-lactams and colistin. Despite the potential to inflict serious infections, knowledge about drug resistance determinants in Cedecea is limited. In this study, we utilized whole-genome sequence data available for three environmental strains (SSMD04, M006, ND14a) of C. neteri and various bioinformatics tools to analyze drug resistance genes in this bacterium. All three genomes harbor multiple chromosome-encoded β-lactamase genes. A deeper analysis of β-lactamase genes in SSMD04 revealed four metallo-β-lactamases, a novel variant, and a CMY/ACT-type AmpC putatively regulated by a divergently transcribed AmpR. Homologs of known resistance-nodulation-cell division (RND)-type multidrug efflux pumps such as OqxB, AcrB, AcrD, and MdtBC were also identified. Genomic island prediction for SSMD04 indicated that tolC, involved in drug and toxin export across the outer membrane of Gram-negative bacteria, was acquired by a transposase-mediated genetic transfer mechanism. Our study provides new insights into drug resistance mechanisms of an environmental microorganism capable of behaving as a clinically relevant opportunistic pathogen.

scholarly journals Pivoting Lean Manufacturing through Industry 4.0 in the Indian Context

2019 ◽  
Vol 8 (2) ◽  
pp. 1-7
Author(s):  
Protik Basu ◽  
Pranab K. Dan
Keyword(s):  
Lean Manufacturing ◽  
Industry 4.0 ◽  
Industrial Revolution ◽  
Manufacturing Sector ◽  
Empirical Studies ◽  
Research Work ◽  
Production Model ◽  
Lean Management ◽  
Technological Developments ◽  
Indian Manufacturing Sector

Industry 4.0 and lean management both focus on increasing productivity of industrial systems. Industry 4.0 is foreseen to revolutionize today’s manufacturing environment whereas lean management is an integrated techno-operational system which has gained increasing importance in recent times to bring about a competitive state in an organization. Though in the last three decades there have been rigorous studies on lean manufacturing (LM), its implementation in the Indian manufacturing domain is still in its nascent stage. A lack of research to explore the potential use of Industry 4.0 is also noted. Research work on the compatibility of Industry 4.0 with LM is scarce and any study on the role of Industry 4.0 on LM in the Indian manufacturing sector is practically unavailable. The aim of this research is to explore how the fourth industrial revolution, referred to as Industry 4.0, can strategize LM in the Indian manufacturing context. Empirical studies have disclosed that Indian managers are hesitant to go for automation and technological developments. Results of this work reveal that there needs to be a change in attitude and approach. Lean implementers in India need to embrace Industry 4.0 to pivot LM by automating through Cyber-Physical Systems and creating a flexible design and production model of customized and smart products.

scholarly journals HOMO FABER: COME I METALLI HANNO SEGNATO E SEGNANO ANCHE OGGI LA CIVILTÀ DELL’UOMO

2019 ◽  
Author(s):  
Rinaldo Psaro
Keyword(s):  
Chemical Elements ◽  
Technological Development ◽  
Modern Science ◽  
Chemical Properties ◽  
Art And Technology ◽  
Guggenheim Museum ◽  
Technological Developments ◽  
The 1960S ◽  
Homo Faber ◽  
Frank Gehry

The succession of various ages, from those of copper to that of bronze, then iron and so on, is dictated by the chemical properties of the various metals and, ultimately, by the periodic table of the elements. The capacity expressed by the homo faber to extract and work the different metals, have marked technological developments so radical as to be chosen by historians to designate real civilizations. Gold was the first metal used by man, although it could not be used either as a tool or as a weapon. More than any other ancient element, gold has always been associated with a timeless charm. None of the chemical elements discovered by modern science has been able to overcome its supremacy. Since the time of its discovery, gold has been used for ornamental purposes and only with technological development has it been used also for technical and scientific purposes. For titanium, however, the reverse path was verified, from its essentially technological use it then moved on to the artistic one. Starting in the 1960s, when titanium became available even for non-military uses, its applications have done nothing but grow and diversify. His artistic fame is unquestionably linked to the Guggenheim Museum in Bilbao designed by the architect Frank Gehry in 1997, while in Pedeferri’s titanochromies we have the combination of art and technology.

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