scholarly journals High-throughput tandem-microwell assay for ammonia repositions FDA-Approved drugs to Helicobacter pylori infection

2021 ◽  
Author(s):  
Fan Liu ◽  
Jing Yu ◽  
Yan-Xia Zhang ◽  
Fangzheng Li ◽  
Qi Liu ◽  
...  

ABSTRACTTo date, little attempt has been made to develop new treatments for Helicobacter pylori (H. pylori), although the community is aware of the shortage of treatments for H. pylori. In this study, we developed a 192-tandem-microwell-based high-throughput-assay for ammonia that is a known virulence factor of H. pylori and a product of urease. We could identify few drugs, i.e. panobinostat, dacinostat, ebselen, captan and disulfiram, to potently inhibit the activity of ureases from bacterial or plant species. These inhibitors suppress the activity of urease via substrate-competitive or covalent-allosteric mechanism, but all except captan prevent the antibiotic-resistant H. pylori strain from infecting human gastric cells, with a more pronounced effect than acetohydroxamic acid, a well-known urease inhibitor and clinically used drug for the treatment of bacterial infection. This study offers several bases for the development of new treatments for urease-containing pathogens and to study the mechanism responsible for the regulation of urease activity.

2016 ◽  
Author(s):  
Yinliang Zhang ◽  
Li Xie ◽  
Lei Xie ◽  
Philip Bourne

Malaria is a disease contracted by over 200 million people each year, mostly in developing countries. The primary causative agent, Plasmodium falciparum (P. falciparum) has shown increased resistance to existing drugs, hence new treatments are needed quickly. To this end we performed a high-throughput systems-level analysis, mapping existing FDA drugs with the potential for repurposing against targets from the P. falciparum structural proteome. The resulting P. falciparum drugome (P.falciparum-drugome) was used to prioritize potential new anti-malaria candidate targets and highlight some novel FDA approved drugs that have apparent anti-malaria effects for possible use as multi-target therapeutics.


2021 ◽  
Vol 35 (11) ◽  
Author(s):  
Fan Liu ◽  
Jing Yu ◽  
Yan‐Xia Zhang ◽  
Fangzheng Li ◽  
Qi Liu ◽  
...  

2021 ◽  
pp. 247255522110006
Author(s):  
Lesley-Anne Pearson ◽  
Charlotte J. Green ◽  
De Lin ◽  
Alain-Pierre Petit ◽  
David W. Gray ◽  
...  

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents a significant threat to human health. Despite its similarity to related coronaviruses, there are currently no specific treatments for COVID-19 infection, and therefore there is an urgent need to develop therapies for this and future coronavirus outbreaks. Formation of the cap at the 5′ end of viral RNA has been shown to help coronaviruses evade host defenses. Nonstructural protein 14 (nsp14) is responsible for N7-methylation of the cap guanosine in coronaviruses. This enzyme is highly conserved among coronaviruses and is a bifunctional protein with both N7-methyltransferase and 3′-5′ exonuclease activities that distinguish nsp14 from its human equivalent. Mutational analysis of SARS-CoV nsp14 highlighted its role in viral replication and translation efficiency of the viral genome. In this paper, we describe the characterization and development of a high-throughput assay for nsp14 utilizing RapidFire technology. The assay has been used to screen a library of 1771 Food and Drug Administration (FDA)-approved drugs. From this, we have validated nitazoxanide as a selective inhibitor of the methyltransferase activity of nsp14. Although modestly active, this compound could serve as a starting point for further optimization.


Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 40
Author(s):  
David Gur ◽  
Theodor Chitlaru ◽  
Emanuelle Mamroud ◽  
Ayelet Zauberman

Yersinia pestis is a Gram-negative pathogen that causes plague, a devastating disease that kills millions worldwide. Although plague is efficiently treatable by recommended antibiotics, the time of antibiotic therapy initiation is critical, as high mortality rates have been observed if treatment is delayed for longer than 24 h after symptom onset. To overcome the emergence of antibiotic resistant strains, we attempted a systematic screening of Food and Drug Administration (FDA)-approved drugs to identify alternative compounds which may possess antibacterial activity against Y. pestis. Here, we describe a drug-repurposing approach, which led to the identification of two antibiotic-like activities of the anticancer drugs bleomycin sulfate and streptozocin that have the potential for designing novel antiplague therapy approaches. The inhibitory characteristics of these two drugs were further addressed as well as their efficiency in affecting the growth of Y. pestis strains resistant to doxycycline and ciprofloxacin, antibiotics recommended for plague treatment.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 845
Author(s):  
Candace Goodman ◽  
Katrina N. Lyon ◽  
Aitana Scotto ◽  
Cyra Smith ◽  
Thomas A. Sebrell ◽  
...  

Helicobacter pylori infection is commonly treated with a combination of antibiotics and proton pump inhibitors. However, since H. pylori is becoming increasingly resistant to standard antibiotic regimens, novel treatment strategies are needed. Previous studies have demonstrated that black and red berries may have antibacterial properties. Therefore, we analyzed the antibacterial effects of black and red raspberries and blackberries on H. pylori. Freeze-dried powders and organic extracts from black and red raspberries and blackberries were prepared, and high-performance liquid chromatography was used to measure the concentrations of anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, a high-throughput metabolic growth assay based on the Biolog system was developed and validated with the antibiotic metronidazole. Biocompatibility was analyzed using human gastric organoids. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. Antimicrobial activity was higher for extracts than powders and appeared to be independent of the anthocyanin concentration. Importantly, human gastric epithelial cell viability was not negatively impacted by black raspberry extract applied at the concentration required for complete bacterial growth inhibition. Our data suggest that black and red raspberry and blackberry extracts may have potential applications in the treatment and prevention of H. pylori infection but differ widely in their MICs. Moreover, we demonstrate that the Biolog metabolic assay is suitable for high-throughput antimicrobial susceptibility screening of H. pylori.


2000 ◽  
Vol 14 (10) ◽  
pp. 879-882 ◽  
Author(s):  
Carlo A Fallone

BACKGROUND: The rate ofHelicobacter pyloriresistance to antibiotics determines the cure rate of treatment regimens containing such antibiotics. AIMS: To review the literature to determine the rates ofH pyloriresistance to metronidazole and clarithromycin in Canada, and whether these rates vary in different regions of Canada.METHODS: The literature was reviewed extensively for the prevalence of antibiotic-resistantH pyloriin Canada by searching MEDLINE from January 1980 to May 1999, as well as abstracts of the American Gastroenterology Association Digestive Disease Week, Canadian Digestive Disease Week and The EuropeanH pyloriStudy Group Meetings from January 1995 to May 1999.RESULTS: Eleven studies that estimatedH pyloriresistance to metronidazole resistance and nine that estimated resistance to clarithromycin in Canada were identified. Rates of resistance for metronidazole and clarithromycin varied from 11% to 48% and 0% to 12%, respectively. Studies that obtained their estimates using the E-test and those that did not clearly exclude patients who had undergone previous attempts atH pylorieradication had higher estimates of resistance, accounting for this variability in results.CONCLUSIONS: The prevalence of primaryH pyloriresistance in Canada appears to be 18% to 22% for metronidazole and less than 4% for clarithromycin. These rates appear to be consistent across the different regions studied in Canada, but many regions have not been studied.


2020 ◽  
Author(s):  
Candace Goodman ◽  
Katrina Lyon ◽  
Aitana Scotto ◽  
Mandi M. Roe ◽  
Farimah Moghimpour ◽  
...  

AbstractHelicobacter pylori is an important bacterial pathogen that causes chronic infection of the human stomach, leading to gastritis, peptic ulcer disease and gastric cancer. Treatment with appropriate antibiotics can eliminate H. pylori infection and reduce the risk for severe disease outcomes. However, since H. pylori is becoming increasingly resistant to standard antibiotic regimens, novel treatment strategies are needed. Previous studies have demonstrated that black and red berries may have antibacterial properties. Therefore, we analyzed organic extracts and powders from black and red raspberries and blackberries and determined their antibacterial effects on multiple H. pylori strains. We used high-performance liquid chromatography to measure berry anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, we developed a high-throughput metabolic growth assay based on the OmniLog™ system. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. We next used human gastric epithelial organoids to evaluate biocompatibility of the berry preparations and showed that black raspberry extract, which had the strongest antimicrobial activity, was non-toxic at the concentration required for complete bacterial growth inhibition. To determine whether dietary black raspberry application could eliminate H. pylori infection in vivo, mice were infected with H. pylori and then were placed on a diet containing 10% black raspberry powder. However, this treatment did not significantly impact bacterial infection rates or gastric pathology. In summary, our data indicate that black and red raspberry and blackberry products have potential applications in the treatment and prevention of H. pylori infection, because of their antibacterial effects and good biocompatibility. However, delivery and formulation of berry compounds needs to be optimized to achieve significant antibacterial effects in vivo.


Author(s):  
Salman Sohrabi ◽  
Danielle E. Mor ◽  
Rachel Kaletsky ◽  
William Keyes ◽  
Coleen T. Murphy

AbstractWe recently linked branched-chain amino acid transferase 1 (BCAT1) with the movement disorder Parkinson’s disease (PD), and found that reduction of C. elegans bcat-1 causes abnormal spasm-like ‘curling’ behavior with age. Here, we report the development of a high-throughput automated curling assay and its application to the discovery of new potential PD therapeutics. Four FDA-approved drugs were identified as candidates for late-in-life intervention, with metformin showing the greatest promise for repurposing to PD.


1998 ◽  
Vol 66 (10) ◽  
pp. 4832-4837 ◽  
Author(s):  
Hiroki Nakamura ◽  
Hironori Yoshiyama ◽  
Hiroaki Takeuchi ◽  
Tomoko Mizote ◽  
Kiwamu Okita ◽  
...  

ABSTRACT Helicobacter pylori exhibits chemotactic responses to urea, flurofamide, acetohydroxamic acid, and sodium bicarbonate. In buffer, the chemotactic activities of a urease-positive strain were higher than those of the isogenic urease-negative strain. Moreover, the chemotactic activities of the urease-positive strain were increased in a viscous solution containing 3% polyvinylpyrrolidone, whereas those of the urease-negative mutant were not. These results are in accordance with the fact that the mutant strain did not show swarming in motility agar regardless of having flagella. Incubation of the wild-type strain with flurofamide resulted in partial inhibition of the chemotactic activities in the viscous solution. In addition, incubation with acetohydroxamic acid, a low-molecular-weight, diffusible urease inhibitor, resulted in complete loss of chemotactic activity in the viscous solution. The inhibition of the chemotactic activity by urease inhibitors paralleled the inhibition of urease. The chemotactic activity of H. pylori was also inhibited by the proton carrier carbonyl cyanide m-chlorophenylhydrazone, showing that H. pylori utilizes proton motive force for motility. These results indicate that cytoplasmic urease plays an important role in the chemotactic motility of H. pylori under a condition that mimics the ecological niche of the bacterium, the gastric mucous layer.


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