Volatile compounds in the stem bark of Sclerocarya birrea (Anacardiaceae) possess antimicrobial activity against drug-resistant strains of Helicobacter pylori

The emergence of multi-drug resistant strains and limitations of present antimicrobial drugs have led to continuous search for natural products as curative agents for Anti-methicillin resistantinfections. The aim of this study was to evaluate antibacterial activity of an ethanolic extract from Albizia lebbeckstem bark against Anti-methicillin resistant. Methods and Results : The methods of dissemination swab on muller-hinton agar and double dilution were used to evaluate the antibacterial activity of 70 % ethanolic extract of stem bark of Albizia lebbeck.All multi-resistant strains of Staphylococcus aureus and the reference strain (ATCC 25923) were sensitive to 70 % ethanolic extract of the stem bark of Albizia lebbeck. The MBCvary from 0,49 mg/mL to 2mg/mL. Also, the phytochemical screening of this extract revealed the presence of Polyphenols, Gallic tannins, Catechin tanninsand Flavonoids. These findings confirm that an 70 % ethanolic extract from Albizia lebbeck stem bark inhibited growth of Anti-methicillin resistant at low concentration and could be utilised as an alternative Anti-methicillin resistantagent.

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Helicobacter pylori Accumulates Photoactive Porphyrins and Is Killed by Visible Light

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.7.2822-2827.2005 ◽

2005 ◽

Vol 49 (7) ◽

pp. 2822-2827 ◽

Cited By ~ 124

Author(s):

Michael R. Hamblin ◽

Jennifer Viveiros ◽

Changming Yang ◽

Atosa Ahmadi ◽

Robert A. Ganz ◽

...

Keyword(s):

Helicobacter Pylori ◽

Visible Light ◽

Propionibacterium Acnes ◽

Protoporphyrin Ix ◽

Human Stomach ◽

Drug Resistant ◽

Violet Light ◽

Resistant Strains ◽

H Pylori ◽

Drug Resistant Strains

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.

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Rescue therapy with rifabutin regimen for refractory Helicobacter pylori infection with dual drug-resistant strain

10.21203/rs.3.rs-31942/v1 ◽

2020 ◽

Author(s):

Chia-Jung Kuo ◽

Cheng-Yu Lin ◽

Puo-Hsien Le ◽

Pi-Yueh Chang ◽

Chih-Ho Lai ◽

...

Keyword(s):

Helicobacter Pylori ◽

Triple Therapy ◽

Eradication Rate ◽

Rescue Therapy ◽

Univariate Analysis ◽

Drug Resistant ◽

Resistant Strains ◽

H Pylori ◽

Drug Resistant Strains ◽

Dual Drug

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.

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Screening and Characterization of Soil Microbes Producing Antimicrobial Compounds in Makkah Province, Saudi Arabia

Biosciences Biotechnology Research Asia ◽

10.13005/bbra/2954 ◽

2021 ◽

Vol 18 (4) ◽

pp. 719-732

Author(s):

Najwa Menwer Alharbi ◽

Amjad Khalid Alharthi ◽

Alsamadani Alsamadani ◽

Raneem Ahmed Almihmadi ◽

Bothaina Ali Alaidaroos

Keyword(s):

Antimicrobial Activity ◽

Soil Microorganisms ◽

Likelihood Method ◽

Diffusion Method ◽

Group Method ◽

Drug Resistant ◽

Antimicrobial Compounds ◽

Resistant Strains ◽

Inhibition Zones ◽

Drug Resistant Strains

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.

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IBS Therapeutic has Broad Spectrum Antimicrobial Activity

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00443-21 ◽

2021 ◽

Author(s):

Ashley L. Cunningham ◽

Orhi Esarte Palomero ◽

Bradley J. Voss ◽

M. Stephen Trent ◽

Bryan W. Davies

Keyword(s):

Antimicrobial Activity ◽

Irritable Bowel Syndrome ◽

Broad Spectrum ◽

Enteric Pathogens ◽

Drug Resistant ◽

Antibacterial And Antifungal Activity ◽

Resistant Strains ◽

Irritable Bowel ◽

Antibacterial And Antifungal ◽

Drug Resistant Strains

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.

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Potentiation of antimicrobial activity of colistin with antibiotics of different groups against multidrug- and extensively drug-resistant strains of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa

Clinical Microbiology and Antimicrobial Chemotherapy ◽

10.36488/cmac.2020.2.128-136 ◽

2020 ◽

Vol 22 (2) ◽

pp. 128-136

Author(s):

Dmitry V. Tapalskiy ◽

T.A. Petrovskaya ◽

A.I. Kozlova ◽

Mikhail V. Edelstein

Keyword(s):

Pseudomonas Aeruginosa ◽

Antimicrobial Activity ◽

Klebsiella Pneumoniae ◽

Acinetobacter Baumannii ◽

Bactericidal Activity ◽

Drug Resistant ◽

Extensively Drug Resistant ◽

Potentiation Effect ◽

Resistant Strains ◽

Drug Resistant Strains

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.

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Inhibitory and Bactericidal Potential of Crude Acetone Extracts of Combretum molle (Combretaceae) on Drug-resistant Strains of Helicobacter pylori

Journal of Health Population and Nutrition ◽

10.3329/jhpn.v29i5.8897 ◽

2011 ◽

Vol 29 (5) ◽

Cited By ~ 15

Author(s):

Collise Njume ◽

Anthony J Afolayan ◽

Amidou Samie ◽

Roland N Ndip

Keyword(s):

Helicobacter Pylori ◽

Drug Resistant ◽

Combretum Molle ◽

Resistant Strains ◽

Drug Resistant Strains ◽

Acetone Extracts

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Cefiderocol Retains Anti-Biofilm Activity in Multi-Drug Resistant Gram-Negative Pathogens

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01194-20 ◽

2020 ◽

Author(s):

Christine A. Pybus ◽

Christina Felder-Scott ◽

Victor Obuekwe ◽

David E. Greenberg

Keyword(s):

Antimicrobial Activity ◽

Ferric Iron ◽

Potent Inhibitor ◽

Antimicrobial Properties ◽

Drug Resistant ◽

Gram Negative ◽

Resistant Strains ◽

Drug Resistant Strains ◽

Antibiotic Dose ◽

Antibiotic Combination

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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Broad Spectrum Antimicrobial Activity of Licochalcones A and E against MDR (Multidrug Resistant) Strains of Clinical Origin

Natural Product Communications ◽

10.1177/1934578x1701201123 ◽

2017 ◽

Vol 12 (11) ◽

pp. 1934578X1701201 ◽

Cited By ~ 1

Author(s):

Jung-Eun Kim ◽

Goo Yoon ◽

Jung-Hyun Shim ◽

Seung-Sik Cho

Keyword(s):

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Bacterial Infections ◽

Multidrug Resistant ◽

Drug Resistant ◽

Baseline Information ◽

Resistant Strains ◽

Glycyrrhiza Inflata ◽

Drug Resistant Strains ◽

Potential Use

The aim of this study was to evaluate the antibacterial activity of the licochalcones A (1) and E (2) against drug resistant strains of clinical origin. The results indicate that the licochalcones had a broad inhibitory activity against tested bacteria. Compared to vancomycin and teicoplanin, these compounds provided weaker activity against non-MDR Staphylococcus aureus and Enterococcus but broader activity against MRSA and VRE strains. The results provide promising baseline information for the potential use of 1 and 2 from Glycyrrhiza inflata in the treatment of drug resistant bacterial infections.

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