scholarly journals Macrolide resistance in Helicobacter pylori: mechanism and stability in strains from clarithromycin-treated patients.

1997 ◽  
Vol 41 (11) ◽  
pp. 2550-2553 ◽  
Author(s):  
K Hultén ◽  
A Gibreel ◽  
O Sköld ◽  
L Engstrand
Keyword(s):  
Helicobacter Pylori ◽  
Genetic Relatedness ◽  
Macrolide Resistance ◽  
Biological Assays ◽  
Clarithromycin Resistance ◽  
Stability Of Resistance ◽  
Development Mechanism

Helicobacter pylori strains from seven patients treated with clarithromycin were investigated for development, mechanism, and stability of resistance. Genetic relatedness between pre- and posttreatment isolates was shown by arbitrary primed PCR. Clarithromycin resistance was associated with A-to-G transitions at either position 2143 or 2144 or at both positions 2116 and 2142. In four cases, the mutations were homozygous. The Cla(r) phenotype was stable after 50 subcultivations in vitro. No erythromycin-modifying enzymes or rRNA methylases were found by biological assays, PCR and sequencing, or cloning methods.

scholarly journals In Vitro Activities of Faropenem against Clarithromycin Resistance Helicobacter pylori Isolates

1998 ◽  
Vol 72 (3) ◽  
pp. 207-210 ◽  
Author(s):  
Miyuki HASEGAWA ◽  
Takeshi SAIKA ◽  
Kaoru MATSUZAKI ◽  
Intetsu KOBAYASHI ◽  
Toshio FUJIOKA ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Clarithromycin Resistance

scholarly journals Clarithromycin resistance in Helicobacter pylori: prevalence in untreated dyspeptic patients and stability in vitro

1996 ◽  
Vol 37 (3) ◽  
pp. 473-481 ◽  
Author(s):  
Hua-Xiang Xia ◽  
Martin Buckley ◽  
Conor T. Keane ◽  
Colm A. O'Morain
Keyword(s):  
Helicobacter Pylori ◽  
Clarithromycin Resistance

The rod-to-coccoid body transformation in cultures of Helicobacter pylori

1990 ◽  
Vol 48 (3) ◽  
pp. 626-627
Author(s):  
A. R. Crooker ◽  
W. G. Kraft ◽  
T. L. Beard ◽  
M. C. Myers
Keyword(s):  
Helicobacter Pylori ◽  
Growth Cycle ◽  
Negative Bacterium ◽  
Body Formation ◽  
Coccoid Form ◽  
Spiral Form ◽  
Prolonged Culture ◽  
H Pylori ◽  
Upper Gastrointestinal

Helicobacter pylori is a microaerophilic, gram-negative bacterium found in the upper gastrointestinal tract of humans. There is strong evidence that H. pylori is important in the etiology of gastritis; the bacterium may also be a major predisposing cause of peptic ulceration. On the gastric mucosa, the organism exists as a spiral form with one to seven sheathed flagella at one (usually) or both poles. Short spirals were seen in the first successful culture of the organism in 1983. In 1984, Marshall and Warren reported a coccoid form in older cultures. Since that time, other workers have observed rod and coccal forms in vitro; coccoid forms predominate in cultures 3-7 days old. We sought to examine the growth cycle of H. pylori in prolonged culture and the mode of coccoid body formation.

Effet des bactéries lactiques sur Helicobacter pylori in vitro

2007 ◽  
Vol 43 (3) ◽  
pp. 121-127
Author(s):  
R. Allem ◽  
FZ. Elkebir ◽  
H. Guetarni
Keyword(s):  
Helicobacter Pylori

Helicobacter pylori: clarithromycin resistance and eradication rates in Szeged, Hungary – a pilot study

2005 ◽  
Vol 43 (05) ◽  
Author(s):  
I Kovács ◽  
A Tiszai ◽  
Z Kiss ◽  
F Sükösd ◽  
I Nagy ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Pilot Study ◽  
Clarithromycin Resistance

Synthesis and In Vitro Enzymatic Studies of New 3-Aryldiazenyl Indoles as Promising Helicobacter pylori IMPDH Inhibitors

2019 ◽  
Vol 19 (5) ◽  
pp. 376-382 ◽  
Author(s):  
Sachin Jangra ◽  
Gayathri Purushothaman ◽  
Kapil Juvale ◽  
Srimadhavi Ravi ◽  
Aishwarya Menon ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Bacterial Infections ◽  
Immunosuppressive Drugs ◽  
Multi Drug Resistance ◽  
Metabolic Enzyme ◽  
World Population ◽  
Inhibitor Molecule ◽  
Nucleotide Synthesis ◽  
H Pylori

Background & Objective:Helicobacter pylori infection is one of the primary causes of peptic ulcer followed by gastric cancer in the world population. Due to increased occurrences of multi-drug resistance to the currently available antibiotics, there is an urgent need for a new class of drugs against H. pylori. Inosine 5′-monophosphate dehydrogenase (IMPDH), a metabolic enzyme plays a significant role in cell proliferation and cell growth. It catalyses guanine nucleotide synthesis. IMPDH enzyme has been exploited as a target for antiviral, anticancer and immunosuppressive drugs. Recently, bacterial IMPDH has been studied as a potential target for treating bacterial infections. Differences in the structural and kinetic parameters of the eukaryotic and prokaryotic IMPDH make it possible to target bacterial enzyme selectively.Methods:In the current work, we have synthesised and studied the effect of substituted 3-aryldiazenyl indoles on Helicobacter pylori IMPDH (HpIMPDH) activity. The synthesised molecules were examined for their inhibitory potential against recombinant HpIMPDH.Results:In this study, compounds 1 and 2 were found to be the most potent inhibitors amongst the database with IC50 of 0.8 ± 0.02µM and 1 ± 0.03 µM, respectively.Conclusion:When compared to the most potent known HpIMPDH inhibitor molecule C91, 1 was only four-fold less potent and can be a good lead for further development of selective and potent inhibitors of HpIMPDH.

Synthesis, Molecular Modelling and Antibacterial Activity Against Helicobacter pylori of Novel Diflunisal Derivatives as Urease Enzyme Inhibitors

2019 ◽  
Vol 16 (4) ◽  
pp. 392-400 ◽  
Author(s):  
Göknil Pelin Coşkun ◽  
Teodora Djikic ◽  
Sadık Kalaycı ◽  
Kemal Yelekçi ◽  
Fikrettin Şahin ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Enzyme Inhibitors ◽  
Binding Modes ◽  
Bacterial Strains ◽  
Urease Enzyme ◽  
H Pylori ◽  
Ulcer Treatment ◽  
Main Factor

Background:The main factor for the prolongation of the ulcer treatment in the gastrointestinal system would be Helicobacter pylori infection, which can possibly lead to gastrointestinal cancer. Triple therapy is the treatment of choice by today's standards. However, observed resistance among the bacterial strains can make the situation even worse. Therefore, there is a need to discover new targeted antibacterial therapy in order to make success in the eradication of H. pylori infections.Methods:The targeted therapy rule is to identify the related macromolecules that are responsible for the survival of the bacteria. Thus, 2-[(2',4'-difluoro-4-hydroxybiphenyl-3-yl)carbonyl]-N- (substituted)hydrazinocarbothioamide (3-13) and 5-(2',4'-difluoro-4-hydroxybiphenyl-3-yl)-4- (substituted)-2,4-dihydro-3H-1,2,4-triazole-3-thiones (14-17) were synthesized and evaluated for antibacterial activity in vitro against H. pylori.Results:All of the tested compounds showed remarkable antibacterial activity compared to the standard drugs (Ornidazole, Metronidazole, Nitrimidazin and Clarithromycin). Compounds 4 and 13 showed activity as 2µg/ml MIC value.Conclusion:In addition, we have investigated binding modes and energy of the compounds 4 and 13 on urease enzyme active by using the molecular docking tools.

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