Quorum Sensing and Multidrug Resistance Mechanism in Helicobacter pylori

2019 ◽  
pp. 101-119 ◽  
Author(s):  
Surekha Challa ◽  
Titash Dutta ◽  
Pallaval Veera Bramhachari ◽  
Neelapu Nageswara Rao Reddy
Keyword(s):  
Helicobacter Pylori ◽  
Multidrug Resistance ◽  
Quorum Sensing ◽  
Resistance Mechanism

scholarly journals Multidrug resistance: The clinical dilemma of refractory Helicobacter pylori infection

2021 ◽  
Author(s):  
Chia-Jung Kuo ◽  
Cheng-Han Lee ◽  
Ming-Ling Chang ◽  
Cheng-Yu Lin ◽  
Wey-Ran Lin ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Multidrug Resistance ◽  
Helicobacter Pylori Infection ◽  
Clinical Dilemma

scholarly journals The Quorum-Sensing Molecule Autoinducer 2 Regulates Motility and Flagellar Morphogenesis in Helicobacter pylori

2007 ◽  
Vol 189 (17) ◽  
pp. 6109-6117 ◽  
Author(s):  
Bethany A. Rader ◽  
Shawn R. Campagna ◽  
Martin F. Semmelhack ◽  
Bonnie L. Bassler ◽  
Karen Guillemin
Keyword(s):  
Helicobacter Pylori ◽  
Quorum Sensing ◽  
Sigma Factor ◽  
Critical Role ◽  
Soft Agar ◽  
Dependent Manner ◽  
Flagellar Gene ◽  
Wild Type ◽  
Autoinducer 2 ◽  
Mutant Phenotypes

ABSTRACT The genome of the gastric pathogen Helicobacter pylori contains a homologue of the gene luxS, which has been shown to be responsible for production of the quorum-sensing signal autoinducer 2 (AI-2). We report here that deletion of the luxS gene in strain G27 resulted in decreased motility on soft agar plates, a defect that was complemented by a wild-type copy of the luxS gene and by the addition of cell-free supernatant containing AI-2. The flagella of the luxS mutant appeared normal; however, in genetic backgrounds lacking any of three flagellar regulators—the two-component sensor kinase flgS, the sigma factor σ28 (also called fliA), and the anti-sigma factor flgM—loss of luxS altered flagellar morphology. In all cases, the double mutant phenotypes were restored to the luxS + phenotype by the addition of synthetic 4,5-dihydroxy-2,3-pentanedione (DPD), which cyclizes to form AI-2. Furthermore, in all mutant backgrounds loss of luxS caused a decrease in transcript levels of the flagellar regulator flhA. Addition of DPD to luxS cells induced flhA transcription in a dose-dependent manner. Deletion of flhA in a wild-type or luxS mutant background resulted in identical loss of motility, flagella, and flagellar gene expression. These data demonstrate that AI-2 functions as a secreted signaling molecule upstream of FlhA and plays a critical role in global regulation of flagellar gene transcription in H. pylori.

Influence of N ‐acylhomoserine lactonase silver nanoparticles on the quorum sensing system of Helicobacter pylori : A potential strategy to combat biofilm formation

2020 ◽  
Vol 60 (3) ◽  
pp. 207-215 ◽  
Author(s):  
Vinoj Gopalakrishnan ◽  
Esakkirajan Masanam ◽  
Vijayan S. Ramkumar ◽  
Vaseeharan Baskaraligam ◽  
Gopinath Selvaraj
Keyword(s):  
Silver Nanoparticles ◽  
Helicobacter Pylori ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Sensing System ◽  
Quorum Sensing System ◽  
Potential Strategy

scholarly journals Alterations in Penicillin-Binding Protein 1A Confer Resistance to β-Lactam Antibiotics in Helicobacter pylori

2002 ◽  
Vol 46 (7) ◽  
pp. 2229-2233 ◽  
Author(s):  
M. M. Gerrits ◽  
D. Schuijffel ◽  
A. A. van Zwet ◽  
E. J. Kuipers ◽  
C. M. J. E. Vandenbroucke-Grauls ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Binding Protein ◽  
Resistance Mechanism ◽  
Fold Increase ◽  
Single Amino Acid ◽  
Penicillin Binding Protein ◽  
H Pylori ◽  
High Level

ABSTRACT Most Helicobacter pylori strains are susceptible to amoxicillin, an important component of combination therapies for H. pylori eradication. The isolation and initial characterization of the first reported stable amoxicillin-resistant clinical H. pylori isolate (the Hardenberg strain) have been published previously, but the underlying resistance mechanism was not described. Here we present evidence that the β-lactam resistance of the Hardenberg strain results from a single amino acid substitution in HP0597, a penicillin-binding protein 1A (PBP1A) homolog of Escherichia coli. Replacement of the wild-type HP0597 (pbp1A) gene of the amoxicillin-sensitive (Amxs) H. pylori strain 1061 by the Hardenberg pbp1A gene resulted in a 100-fold increase in the MIC of amoxicillin. Sequence analysis of pbp1A of the Hardenberg strain, the Amxs H. pylori strain 1061, and four amoxicillin-resistant (Amxr) 1061 transformants revealed a few amino acid substitutions, of which only a single Ser414→Arg substitution was involved in amoxicillin resistance. Although we cannot exclude that mutations in other genes are required for high-level amoxicillin resistance of the Hardenberg strain, this amino acid substitution in PBP1A resulted in an increased MIC of amoxicillin that was almost identical to that for the original Hardenberg strain.

scholarly journals A Computational Approach towards the Understanding of Plasmodium falciparum Multidrug Resistance Protein 1

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Saumya K. Patel ◽  
Linz-Buoy George ◽  
Sivakumar Prasanth Kumar ◽  
Hyacinth N. Highland ◽  
Yogesh T. Jasrai ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Multidrug Resistance ◽  
Resistance Mechanism ◽  
Structural Motif ◽  
Multidrug Resistance Protein ◽  
Mutant Type ◽  
Multidrug Resistance Protein 1 ◽  
Antimalarial Resistance ◽  
Resistant Strains ◽  
Resistance Protein

The emergence of drug resistance in Plasmodium falciparum tremendously affected the chemotherapy worldwide while the intense distribution of chloroquine-resistant strains in most of the endemic areas added more complications in the treatment of malaria. The situation has even worsened by the lack of molecular mechanism to understand the resistance conferred by Plasmodia species. Recent studies have suggested the association of antimalarial resistance with P. falciparum multidrug resistance protein 1 (PfMDR1), an ATP-binding cassette (ABC) transporter and a homologue of human P-glycoprotein 1 (P-gp1). The present study deals about the development of PfMDR1 computational model and the model of substrate transport across PfMDR1 with insights derived from conformations relative to inward- and outward-facing topologies that switch on/off the transportation system. Comparison of ATP docked positions and its structural motif binding properties were found to be similar among other ATPases, and thereby contributes to NBD domains dimerization, a unique structural agreement noticed in Mus musculus Pgp and Escherichia coli MDR transporter homolog (MsbA). The interaction of leading antimalarials and phytochemicals within the active pocket of both wild-type and mutant-type PfMDR1 demonstrated the mode of binding and provided insights of less binding affinity thereby contributing to parasite’s resistance mechanism.

scholarly journals Rifampin and Rifabutin Resistance Mechanism inHelicobacter pylori

1999 ◽  
Vol 43 (6) ◽  
pp. 1497-1499 ◽  
Author(s):  
Markus Heep ◽  
Daniela Beck ◽  
Ekkehard Bayerdörffer ◽  
Norbert Lehn
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Resistance Mechanism ◽  
Clinical Isolates ◽  
Gene Sequences ◽  
H Pylori

ABSTRACT Eighty-one clinical isolates of Helicobacter pylorishowed no resistance to rifampin (MIC range, 0.032 to 2 μg/ml; MIC at which 50% of isolates are inhibited [MIC50], 0.25 μg/ml). The MIC50 of rifabutin was 0.008 μg/ml (n = 16). All resistant laboratory mutants of H. pylori ATCC 43504 showed amino acid exchanges in codons 524 to 545 or codon 585 of the rpoB gene, corresponding to the gene sequences from Mycobacterium tuberculosis andEscherichia coli.

scholarly journals High-Level β-Lactam Resistance Associated with Acquired Multidrug Resistance in Helicobacter pylori

2003 ◽  
Vol 47 (7) ◽  
pp. 2169-2178 ◽  
Author(s):  
Dong H. Kwon ◽  
M. P. Dore ◽  
J. J. Kim ◽  
M. Kato ◽  
M. Lee ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Multidrug Resistance ◽  
Natural Transformation ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Terminal Portion ◽  
Nucleotide Substitutions ◽  
H Pylori ◽  
High Level ◽  
Level Resistance

ABSTRACT Four clinical Helicobacter pylori isolates with high-level resistance to β-lactams exhibited low- to moderate-level resistance to the structurally and functionally unrelated antibiotics ciprofloxacin, chloramphenicol, metronidazole, rifampin, and tetracycline. This pattern of multidrug resistance was transferable to susceptible H. pylori by natural transformation using naked genomic DNA from a clinical multidrug-resistant isolate. Acquisition of the multidrug resistance was also associated with a change in the genotype of the transformed multidrug-resistant H. pylori. DNA sequence analyses of the gene encoding penicillin binding protein 1A (PBP 1A) showed 36 nucleotide substitutions resulting in 10 amino acid changes in the C-terminal portion (the putative penicillin binding domain). Acquisition of β-lactam resistance was consistently associated with transfer of a mosaic block containing the C-terminal portion of PBP 1A. No changes of genes gyrA, rpoB, rrn16S, rdxA, and frxA, and nine other genes (ftsI, hcpA, llm, lytB, mreB, mreC, pbp2, pbp4, and rodA1) encoding putative PBPs or involved in cell wall synthesis were found among the transformed resistant H. pylori. Antibiotic accumulations of chloramphenicol, penicillin, and tetracycline were all significantly decreased in the natural and transformed resistant H. pylori compared to what was seen with susceptible H. pylori. Natural transformation also resulted in the outer membrane protein profiles of the transformed resistant H. pylori becoming similar to that of the clinical resistant H. pylori isolates. Overall, these results demonstrate that high-level β-lactam resistance associated with acquired multidrug resistance in clinical H. pylori is mediated by combination strategies including alterations of PBP 1A and decreased membrane permeability.

scholarly journals Plasticity of the MFS1 Promoter Leads to Multidrug Resistance in the Wheat Pathogen Zymoseptoria tritici

mSphere ◽  
2017 ◽  
Vol 2 (5) ◽  
Author(s):  
Selim Omrane ◽  
Colette Audéon ◽  
Amandine Ignace ◽  
Clémentine Duplaix ◽  
Lamia Aouini ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Disease Control ◽  
Fungicide Resistance ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
Type I ◽  
Drug Efflux ◽  
Zymoseptoria Tritici ◽  
Active Efflux ◽  
Multiple Drugs

ABSTRACT Disease control through fungicides remains an important means to protect crops from fungal diseases and to secure the harvest. Plant-pathogenic fungi, especially Zymoseptoria tritici, have developed resistance against most currently used active ingredients, reducing or abolishing their efficacy. While target site modification is the most common resistance mechanism against single modes of action, active efflux of multiple drugs is an emerging phenomenon in fungal populations reducing additionally fungicides’ efficacy in multidrug-resistant strains. We have investigated the mutations responsible for increased drug efflux in Z. tritici field strains. Our study reveals that three different insertions of repeated elements in the same promoter lead to multidrug resistance in Z. tritici. The target gene encodes the membrane transporter MFS1 responsible for drug efflux, with the promoter inserts inducing its overexpression. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici. The ascomycete Zymoseptoria tritici is the causal agent of Septoria leaf blotch on wheat. Disease control relies mainly on resistant wheat cultivars and on fungicide applications. The fungus displays a high potential to circumvent both methods. Resistance against all unisite fungicides has been observed over decades. A different type of resistance has emerged among wild populations with multidrug-resistant (MDR) strains. Active fungicide efflux through overexpression of the major facilitator gene MFS1 explains this emerging resistance mechanism. Applying a bulk-progeny sequencing approach, we identified in this study a 519-bp long terminal repeat (LTR) insert in the MFS1 promoter, a relic of a retrotransposon cosegregating with the MDR phenotype. Through gene replacement, we show the insert as a mutation responsible for MFS1 overexpression and the MDR phenotype. Besides this type I insert, we found two different types of promoter inserts in more recent MDR strains. Type I and type II inserts harbor potential transcription factor binding sites, but not the type III insert. Interestingly, all three inserts correspond to repeated elements present at different genomic locations in either IPO323 or other Z. tritici strains. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici and which contribute to its adaptive potential. IMPORTANCE Disease control through fungicides remains an important means to protect crops from fungal diseases and to secure the harvest. Plant-pathogenic fungi, especially Zymoseptoria tritici, have developed resistance against most currently used active ingredients, reducing or abolishing their efficacy. While target site modification is the most common resistance mechanism against single modes of action, active efflux of multiple drugs is an emerging phenomenon in fungal populations reducing additionally fungicides’ efficacy in multidrug-resistant strains. We have investigated the mutations responsible for increased drug efflux in Z. tritici field strains. Our study reveals that three different insertions of repeated elements in the same promoter lead to multidrug resistance in Z. tritici. The target gene encodes the membrane transporter MFS1 responsible for drug efflux, with the promoter inserts inducing its overexpression. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici.

scholarly journals Comparative Genomics of the IncA/C Multidrug Resistance Plasmid Family

2009 ◽  
Vol 191 (15) ◽  
pp. 4750-4757 ◽  
Author(s):  
W. Florian Fricke ◽  
Timothy J. Welch ◽  
Patrick F. McDermott ◽  
Mark K. Mammel ◽  
J. Eugene LeClerc ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistance ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
Comparative Sequence Analysis ◽  
Conjugative Transfer ◽  
Host Chromosome ◽  
Type Iv ◽  
Reference Plasmid ◽  
Cell Subpopulations

ABSTRACT Multidrug resistance (MDR) plasmids belonging to the IncA/C plasmid family are widely distributed among Salmonella and other enterobacterial isolates from agricultural sources and have, at least once, also been identified in a drug-resistant Yersinia pestis isolate (IP275) from Madagascar. Here, we present the complete plasmid sequences of the IncA/C reference plasmid pRA1 (143,963 bp), isolated in 1971 from the fish pathogen Aeromonas hydrophila, and of the cryptic IncA/C plasmid pRAx (49,763 bp), isolated from Escherichia coli transconjugant D7-3, which was obtained through pRA1 transfer in 1980. Using comparative sequence analysis of pRA1 and pRAx with recent members of the IncA/C plasmid family, we show that both plasmids provide novel insights into the evolution of the IncA/C MDR plasmid family and the minimal machinery necessary for stable IncA/C plasmid maintenance. Our results indicate that recent members of the IncA/C plasmid family evolved from a common ancestor, similar in composition to pRA1, through stepwise integration of horizontally acquired resistance gene arrays into a conserved plasmid backbone. Phylogenetic comparisons predict type IV secretion-like conjugative transfer operons encoded on the shared plasmid backbones to be closely related to a group of integrating conjugative elements, which use conjugative transfer for horizontal propagation but stably integrate into the host chromosome during vegetative growth. A hipAB toxin-antitoxin gene cluster found on pRA1, which in Escherichia coli is involved in the formation of persister cell subpopulations, suggests persistence as an early broad-spectrum antimicrobial resistance mechanism in the evolution of IncA/C resistance plasmids.

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