scholarly journals Aqueous and Organic Solvent-Extracts of Selected South African Medicinal Plants Possess Antimicrobial Activity against Drug-Resistant Strains of Helicobacter pylori: Inhibitory and Bactericidal Potential

2011 ◽  
Vol 12 (9) ◽  
pp. 5652-5665 ◽  
Author(s):  
Collise Njume ◽  
Afolayan A. Jide ◽  
Roland N. Ndip
2005 ◽  
Vol 49 (7) ◽  
pp. 2822-2827 ◽  
Author(s):  
Michael R. Hamblin ◽  
Jennifer Viveiros ◽  
Changming Yang ◽  
Atosa Ahmadi ◽  
Robert A. Ganz ◽  
...  

ABSTRACT Helicobacter pylori colonizes the mucus layer of the human stomach and duodenum, causes chronic gastritis, gastric ulcer, and is a risk factor for gastric adenocarcinoma. There is a 20% failure rate in antibiotic therapy, which is increasingly due to antibiotic resistance and necessitates the search for alternative antimicrobial methods. We have discovered that H. pylori when cultured in liquid medium, accumulates significant quantities of coproporphyrin and protoporphyrin IX, both in the cells and secreted into the medium. These photoactive porphyrins lead to cell death (up to 5 logs) by photodynamic action upon illumination with low doses of visible light, with blue/violet light being most efficient. The degree of killing increases with the age of the culture and is greater than that found with Propionibacterium acnes (another bacterium known to be photosensitive due to porphyrin accumulation). Both virulent and drug-resistant strains are killed. The data suggest that phototherapy might be used to treat H. pylori infection in the human stomach.


2020 ◽  
Author(s):  
Chia-Jung Kuo ◽  
Cheng-Yu Lin ◽  
Puo-Hsien Le ◽  
Pi-Yueh Chang ◽  
Chih-Ho Lai ◽  
...  

Abstract Background: There is no current standard rescue treatment for dual drug-resistant strains of Helicobacter pylori. This aim of this study was to investigate the efficacy of rifabutin-based triple therapy for patients infected with dual drug-resistant strains to clarithromycin and levofloxacin.Methods: After two or three H. pylori treatment failures, patients underwent upper endoscopy with tissue biopsies. Phenotypic and genotypic resistance was determined using agar dilution test and polymerase chain reaction with direct sequencing, respectively. Patients infected with dual drug-resistant (clarithromycin and levofloxacin) strains and received rifabutin based triple therapy (rifabutin 150 mg bid, amoxicillin 1 g bid and esomeprazole 40 mg bid for 10 days) were enrolled. Eradication status was determined by 13C-urea breath test four weeks after treatment completion. Results: A total of 39 patients infected with dual drug-resistant strains were enrolled in this study, with a mean age of 55.9 years. The eradication rate was 79.5% (31/39). Adverse event was reported in 23.1% (9/39) of patients but mild and tolerable. In univariate analysis, no factor was identified as an independent predictor of eradication failure. Conclusions: Our current study demonstrated that rifabutin-based triple therapy was well tolerated and yielded an acceptable eradication rate for patients infected with dual drug-resistant strains of H. pylori.


2021 ◽  
Vol 18 (4) ◽  
pp. 719-732
Author(s):  
Najwa Menwer Alharbi ◽  
Amjad Khalid Alharthi ◽  
Alsamadani Alsamadani ◽  
Raneem Ahmed Almihmadi ◽  
Bothaina Ali Alaidaroos

This study aimed to investigate a method to manage antimicrobial resistance (AMR) issues by exploring soil microorganisms that are capable of producing bioactive compounds. Eight different types of soil were selected from three locations to screen, isolate, and identify microorganisms that are capable of producing antimicrobial compounds. The multi-drug resistant strains are Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans were selected for primary and secondary screening using the crowded plate method and the agar well diffusion method. Inhibition zones were measured, and data were assessed using statistical tests to check for normality and differences between parametric variables and nonparametric data. This was followed by biochemical characterization, DNA isolation, and polymerase chain reaction (PCR). Molecular identification was performed using 16S rRNA amplification and sequencing. Here, 86 isolates containing bacteria and fungi were successfully extracted from soil samples. Further, 49 of 86 microbes showed possible antimicrobial activity, but only 12 isolates resulted in distinct inhibition zones with the selected multi-drug resistant strains. The following different taxa were identified: Firmicutes (nine strains), Proteobacteria (one strain), Actinobacteria (one strain), and Azotobacter (one strain). Species are represented in a phylogenetic tree, which was constructed using the unweighted pair-group method with arithmetic mean (UPGMA) method. The evolutionary distances were computed using the Maximum Composite Likelihood method. The identified microorganisms showed antimicrobial activity, confirming that soil microorganisms have great potential to address AMR issues.


Author(s):  
Nandan Sarkar ◽  
Yadu Nandan Dey ◽  
Dharmendra Kumar ◽  
Mogana R

: Effective treatment of tuberculosis has been hindered by the emergence of drug-resistant strains of Mycobacterium therapeutic facilities tuberculosis. With the global resurgence of tuberculosis with the development of multidrug-resistant cases, there is a call for the development of new drugs to combat these diseases. Throughout history, natural products have afforded a rich source of compounds that have found many applications in the fields of medicine, pharmacy and biology, and continued to play a significant role in the drug discovery and development process. This review article depicts the various potential plant extracts as well as plant-derived phytoconstituents against the H37rv, the most persistent strains of Mycobacterium tuberculosis and its multidrug strains.


Author(s):  
Ashley L. Cunningham ◽  
Orhi Esarte Palomero ◽  
Bradley J. Voss ◽  
M. Stephen Trent ◽  
Bryan W. Davies

Otilonium bromide is a poorly absorbed oral medication used to control irritable bowel syndrome. It is thought to act as a muscle relaxant in the intestine. Here we show that otilonium bromide has broad-spectrum antibacterial and antifungal activity, including against multi-drug resistant strains. Our results suggest otilonium bromide could act on enteric pathogens and may offer a new scaffold for poorly absorbed intestinal antimicrobial therapy.


2015 ◽  
Vol 5 ◽  
pp. S151-S154
Author(s):  
Rafiqul Islam ◽  
Md. Shahedur Rahman ◽  
Riad Hossain ◽  
Nazmun Nahar ◽  
Belal Hossin ◽  
...  

2020 ◽  
Vol 22 (2) ◽  
pp. 128-136
Author(s):  
Dmitry V. Tapalskiy ◽  
T.A. Petrovskaya ◽  
A.I. Kozlova ◽  
Mikhail V. Edelstein

Objective. To reveal antibiotics being capable of potentiating the antimicrobial activity of colistin against multidrug- and extensively drug-resistant strains of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. Materials and Methods. The minimum inhibitory concentrations (MIC) of colistin alone and in combination with fixed concentrations of antibiotics of different groups were determined for 272 multidrug- and extensively drug-resistant strains of K. pneumoniae, A. baumannii and P. aeruginosa. Bactericidal activity of colistin, carbapenems, clarithromycin and their combinations were also determined at fixed PK/PD breakpoint concentrations of antibiotics. Results. Potentiation of colistin antibacterial activity in the presence of fixed concentration of rifampicin (0.5 mg/L) was observed as a 4–16-fold MIC decrease for K. pneumoniae and A. baumannii. In the presence of fixed concentrations of azithromycin (2 mg/L) or clarithromycin (1 mg/L), the colistin MICs decreased 64–512 times for K. pneumoniae, 4–32 times for A. baumannii, 16–64 times for P. aeruginosa. Two- or more-fold reduction of MIC of colistin in the presence of 1 mg/L clarithromycin was observed for 85.2% of K. pneumoniae, 86.3% of A. baumannii and 60.2% of P. aeruginosa strains. In the presence of 1 mg/L clarithromycin and 8 mg/L meropenem, the potentiation effect was enhanced and was observed for an even larger percent of isolates: 96.1% K. pneumoniae, 98.0% A. baumannii and 61.3% P. aeruginosa. Colistin-based combinations with clarithromycin-meropenem and clarithromycin-doripenem were bactericidal against most isolates of A. baumannii and P. aeruginosa (91.4–100%), and against colistin-sensitive K. pneumoniae (95.3%) and colistin-resistant K. pneumoniae (79.1%). Conclusions. The ability of macrolides to significantly potentiate the colistin antimicrobial activity against both colistin-sensitive and colistin-resistant strains of K. pneumoniae, A. baumannii and P. aeruginosa was shown. This potentiation effect was enhanced in the presence of carbapenems. The most potent bactericidal activity was revealed with dual and triple combinations of colistin-clarithromycin and colistinclarithromycin-carbapenems.


Author(s):  
Christine A. Pybus ◽  
Christina Felder-Scott ◽  
Victor Obuekwe ◽  
David E. Greenberg

Cefiderocol is a siderophore cephalosporin with potent antibacterial activity against a broad range of Gram-negative pathogens, including multi-drug resistant strains. Siderophore antibiotics bind ferric iron and utilize iron transporters to cross the cell membrane. In the biofilm setting, where antibiotic resistance is high but iron scavenging is important, cefiderocol may have advantageous antimicrobial properties. In this study, we compared the antimicrobial activity of cefiderocol to seven commonly used antibiotics in well-characterized multi-drug resistant pathogens, then determined their efficacy in the biofilm setting. MIC90 values were consistently lower for cefiderocol in all strains tested compared to other antibiotics (ceftolozane-tazobactam, ceftazidime-avibactam, ceftazidime, piperacillin-tazobactam, imipenem, tobramycin, clarithromycin). Cefiderocol treatment displayed a superior reduction in Pseudomonas aeruginosa biofilm (93%, p<0.0001) compared to other antibiotics (49-82%). Cefiderocol was generally as effective or superior in reducing biofilm in other pathogens depending on the pathogen-antibiotic combination. There was a trend towards greater biofilm reduction when the antibiotic dose was increased or with increased frequency of antibiotic treatment. We conclude that cefiderocol effectively reduces biofilm and is a potent inhibitor of planktonic growth across a range of Gram-negative medically important pathogens.


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