scholarly journals Antibacterial kinetics and phylogenetic analysis of Aloe vera plants

2021 ◽  
Vol 9 (A) ◽  
pp. 946-954
Author(s):  
Paul Akinduti ◽  
Yemisi D. Obafemi ◽  
Patrick O. Isibor ◽  
Rapheal Ishola ◽  
Frank E. Ahuekwe ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Alternative Therapy ◽  
Aloe Vera ◽  
Antibacterial Activities ◽  
Viable Count ◽  
Resistant Bacteria ◽  
Aloe Barbadensis ◽  
Drug Candidates ◽  
Time Kill ◽  
Promising Avenue

Uncontrolled use of antibiotics has resulted in the emergence of resistant bacteria. It has necessitated the evaluation of antibacterial activities and phylo-diversity of Aloe vera (also called Aloe barbadensis) plants as antimicrobial agent in Nigeria. Biotyped enteric bacilli of 251 strains obtained from fecal samples of patients with various gastro-intestinal complications are profiled for antibiogram. Resistant biotypes were assayed for susceptibility to Aloe vera latex and further evaluated for time-kill kinetics and phylo-diversity. More than 30% of enteric bacilli, including Citrobacter freundii, Escherichia coli and Proteus mirabilis were resistant to cotrimoxazole, ciprofloxacin, and tetracycline respectively at MIC >16 µg/ml (p=0.004). Aloe vera latex significantly inhibited 39.5% resistant enteric biotypes with a significant average reduction of the viable count at 1xMIC and 2xMIC to less than 3.0 Log10CFU/mL after 24 hours. Flavonoids, alkaloids, terpenoids and anthraquinine in anti-enteric sap significantly correlated and regressed with antibacterial activity (p<0.05), while two of the antimicrobial Aloe vera plants showed phylogenetic relatedness with other homologous. Anti-bacteria efficacy of some Nigerian Aloe vera latex could provide alternative therapy, while its phylo-diversity and genomic profiling would offer a promising avenue for identification and development of antimicrobial agents as drug candidates for natural antibiotics.

Prospecting Gene Therapy of Implant Infections

2009 ◽  
Vol 32 (9) ◽  
pp. 689-695 ◽  
Author(s):  
William J. Costerton ◽  
Lucio Montanaro ◽  
Naomi Balaban ◽  
Carla Renata Arciola
Keyword(s):  
Gene Therapy ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Knock Out ◽  
Prosthetic Devices ◽  
Drug Candidates ◽  
Bacterial Genes ◽  
Novel Therapeutic Strategies

Infection still represents one of the most serious and ravaging complications associated with prosthetic devices. Staphylococci and enterococci, the bacteria most frequently responsible for orthopedic postsurgical and implant-related infections, express clinically relevant antibiotic resistance. The emergence of antibiotic-resistant bacteria and the slow progress in identifying new classes of antimicrobial agents have encouraged research into novel therapeutic strategies. The adoption of antisense or “antigene” molecules able to silence or knock-out bacterial genes responsible for their virulence is one possible innovative approach. Peptide nucleic acids (PNAs) are potential drug candidates for gene therapy in infections, by silencing a basic gene of bacterial growth or by tackling the antibiotic resistance or virulence factors of a pathogen. An efficacious contrast to bacterial genes should be set up in the first stages of infection in order to prevent colonization of periprosthesis tissues. Genes encoding bacterial factors for adhesion and colonization (biofilm and/or adhesins) would be the best candidates for gene therapy. But after initial enthusiasm for direct antisense knock-out or silencing of essential or virulence bacterial genes, difficulties have emerged; consequently, new approaches are now being attempted. One of these, interference with the regulating system of virulence factors, such as agr, appears particularly promising.

scholarly journals Pharmacodynamic Functions of Synthetic Derivatives for Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) and Mycobacterium tuberculosis

2020 ◽  
Vol 11 ◽  
Author(s):  
Mojdeh Dinarvand ◽  
Malcolm P. Spain ◽  
Fatemeh Vafaee
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Mycobacterium Tuberculosis ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Synthetic Compounds ◽  
Methicillin Resistant ◽  
Chemical Structures ◽  
Time Kill

Drug resistant bacteria have emerged, so robust methods are needed to evaluate combined activities of known antibiotics as well as new synthetic compounds as novel antimicrobial agents to treatment efficacy in severe bacterial infections. Marine natural products (MNPs) have become new strong leads in the drug discovery endeavor and an effective alternative to control infections. Herein, we report the bioassay guided fractionation of marine extracts from the sponges Lendenfeldia, Ircinia, and Dysidea that led us to identify novel compounds with antimicrobial properties. Chemical synthesis of predicted compounds and their analogs has confirmed that the proposed structures may encode novel chemical structures with promising antimicrobial activity against the medically important pathogens. Several of the synthetic analogs exhibited potent and broad spectrum in vitro antibacterial activity, especially against the Methicillin-resistant Staphylococcus aureus (MRSA) (MICs to 12.5 μM), Mycobacterium tuberculosis (MICs to 0.02 μM), uropathogenic Escherichia coli (MIC o 6.2 μM), and Pseudomonas aeruginosa (MIC to 3.1 μM). Checkerboard assay (CA) and time-kill studies (TKS) experiments analyzed with the a pharmacodynamic model, have potentials for in vitro evaluation of new and existing antimicrobials. In this study, CA and TKS were used to identify the potential benefits of an antibiotic combination (i.e., synthetic compounds, vancomycin, and rifampicin) for the treatment of MRSA and M. tuberculosis infections. CA experiments indicated that the association of compounds 1a and 2a with vancomycin and compound 3 with rifampicin combination have a synergistic effect against a MRSA and M. tuberculosis infections, respectively. Furthermore, the analysis of TKS uncovered bactericidal and time-dependent properties of the synthetic compounds that may be due to variations in hydrophobicity and mechanisms of action of the molecules tested. The results of cross-referencing antimicrobial activity, and toxicity, CA, and Time-Kill experiments establish that these synthetic compounds are promising potential leads, with a favorable therapeutic index for antimicrobial drug development.

scholarly journals Synergistic action of substituted indole derivatives and clinically used antibiotics against drug-resistant bacteria

2020 ◽  
Vol 15 (8) ◽  
pp. 579-590
Author(s):  
Danielle N Turner ◽  
Leslie Edwards ◽  
Alexander Kornienko ◽  
Liliya V Frolova ◽  
Snezna Rogelj
Keyword(s):  
Mammalian Cells ◽  
Antibacterial Activities ◽  
Resistant Bacteria ◽  
Indole Derivatives ◽  
Bacterial Strains ◽  
Drug Resistant Bacteria ◽  
Diphenyltetrazolium Bromide ◽  
Evolution Of Resistance ◽  
Time Kill ◽  
Current Report

Aim: The current report describes the discovery of indole derivatives that synergize with standard antibiotics. Materials & methods: The antibacterial activities were determined using an optimized time–kill method, while viability of mammalian cells was assessed using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Results: The synergy is observed with methicillin- and vancomycin-resistant Staphylococcus aureus bacterial strains, against which the standard antibiotics show no activities of their own. Our indole derivatives in combination with antibiotics lack toxicity toward mammalian cells, do not promote the evolution of resistance of S. aureus in comparison to clinically established antibiotics, and likely work by permeabilizing bacterial cell membranes. Conclusion: The above-mentioned findings demonstrate the potential clinical applications of our indole derivatives.

scholarly journals Effects of Extracts of Feed Additives Including Rosemary (Rosmarinus officinalis) and Aloe Vera (Aloe barbadensis) on the Growth Performance and Feed Utility of Nile Tilapia (Oreochromis niloticus)

2019 ◽  
Vol 7 (6) ◽  
pp. 866 ◽  
Author(s):  
Ebru Yılmaz ◽  
Deniz Çoban ◽  
Birsen Kırım ◽  
Mehmet Güler
Keyword(s):  
Growth Performance ◽  
Oreochromis Niloticus ◽  
Antimicrobial Agents ◽  
Aloe Vera ◽  
Rosmarinus Officinalis ◽  
Feed Additives ◽  
Rosemary Extract ◽  
Hepatosomatic Index ◽  
Experimental Diet ◽  
Aloe Barbadensis

This study was performed to determine the effects of the extracts of two alternative antimicrobial agents that do not harm the ecosystem (rosemary, Rosmarinus officinalis and aloe vera, Aloe barbadensis) when added to the feed of tilapia (Oreochromis niloticus) on the growth performance, proximate composition, and biometric characteristics. Rosemary extract was added to the experimental diet in ratios of 0.1%, 0.25%, and 0.5% while aloe vera extract was added to the experimental diet in ratios of 0.5%, 1%, and 2.5%. After 90 days of the feeding trial, no change was seen in the weight increase, specific growth rate, feed conversion ratio, condition factor, hepatosomatic index, or viscerosomatic index of the tilapia. The fact that proximate analyses did not differ between groups showed that the plant extracts did not adversely affect the health status of tilapia in the ratios used in this study. As a result, the addition of 0.1%, 0.25%, and 0.5% rosemary extract and the addition of 0.5%, 1%, and 2.5% aloe vera extract to tilapia feeds did not cause changes in the growth performance, biometric indexes, or chemical composition findings of the fish meat.

In vitro activities of U-100592 and U-100766, novel oxazolidinone antibacterial agents.

1996 ◽  
Vol 40 (4) ◽  
pp. 839-845 ◽  
Author(s):  
G E Zurenko ◽  
B H Yagi ◽  
R D Schaadt ◽  
J W Allison ◽  
J O Kilburn ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Spontaneous Mutation ◽  
Antibacterial Activities ◽  
Bactericidal Effect ◽  
Human Pathogens ◽  
Serial Transfer ◽  
Methicillin Resistant ◽  
Time Kill ◽  
Bacterial Protein Synthesis

Oxazolidinones make up a relatively new class of antimicrobial agents which possess a unique mechanism of bacterial protein synthesis inhibition. U-100592 (S)-N-[[3-[3-fluoro-4-[4-(hydroxyacetyl)-1-piperazinyl]- phenyl]-2-oxo-5-oxazolidinyl]methyl]-acetamide and U-100766 (S)-N-[[3-[3-fluoro-4-(4-morpholinyl)phenyl]- 2-oxo-5-oxazolidinyl]methyl]-acetamide are novel oxazolidinone analogs from a directed chemical modification program. MICs were determined for a variety of bacterial clinical isolates; the respective MICs of U-100592 and U-100766 at which 90% of isolates are inhibited were as follows: methicillin-susceptible Staphylococcus aureus, 4 and 4 micrograms/ml; methicillin-resistant S. aureus, 4 and 4 micrograms/ml; methicillin-susceptible Staphylococcus epidermidis, 2 and 2 micrograms/ml; methicillin-resistant S. epidermidis, 1 and 2 micrograms/ml; Enterococcus faecalis, 2 and 4 micrograms/ml; Enterococcus faecium, 2 and 4 micrograms/ml; Streptococcus pyogenes, 1 and 2 micrograms/ml; Streptococcus pneumoniae, 0.50 and 1 microgram/ml; Corynebacterium spp., 0.50 and 0.50 micrograms/ml; Moraxella catarrhalis, 4 and 4 micrograms/ml; Listeria monocytogenes, 8 and 2 micrograms/ml; and Bacteroides fragilis, 16 and 4 micrograms/ml. Most strains of Mycobacterium tuberculosis and the gram-positive anaerobes were inhibited in the range of 0.50 to 2 micrograms/ml. Enterococcal strains resistant to vancomycin (VanA, VanB, and VanC resistance phenotypes), pneumococcal strains resistant to penicillin, and M. tuberculosis strains resistant to common antitubercular agents (isoniazid, streptomycin, rifampin, ethionamide, and ethambutol) were not cross-resistant to the oxazolidinones. The presence of 10, 20, and 40% pooled human serum did not affect the antibacterial activities of the oxazolidinones. Time-kill studies demonstrated a bacteriostatic effect of the analogs against staphylococci and enterococci but a bactericidal effect against streptococci. The spontaneous mutation frequencies of S. aureus ATCC 29213 were <3.8 x 10(-10) and <8 x 10(-11) for U-100592 and U-100766, respectively. Serial transfer of three staphylococcal and two enterococcal strains on drug gradient plates produced no evidence of rapid resistance development. Thus, these new oxazolidinone analogs demonstrated in vitro antibacterial activities against a variety of clinically important human pathogens.

scholarly journals Aloe Vera (Aloe barbadensis Miller) Extract as a Natural Antimicrobial Agent in Hand-Washing Liquid Soap

2019 ◽  
Vol 1 ◽  
pp. 96-107
Author(s):  
A T Tyowua ◽  
T B Vitalis ◽  
M M Terhemen ◽  
E M Mbaawuaga
Keyword(s):  
Antimicrobial Agent ◽  
Antimicrobial Agents ◽  
Soap Solution ◽  
Skin Irritation ◽  
Aloe Vera ◽  
Coconut Oil ◽  
Hand Washing ◽  
Liquid Soap ◽  
Aloe Barbadensis

Synthetic antimicrobial agents, like triclosan, used in many cosmetics are now associated with serious health problems, beginning with skin irritation to cancer. This calls for alternative antimicrobial agents. Many plant extracts have the potential to inhibit the growth of microorganisms and perhaps kill them and thus can serve as alternative antimicrobial agents in cosmetic formulations. To demonstrate this, a hand-washing liquid soap was prepared in the presence of varying concentrations of aloe vera extract and tested in-vitro against common skin microbes. First, a liquid soap paste was prepared by saponifying a vegetable oil blend containing olive oil (80.0 %w/w), coconut oil (14.3 %w/w) and castor oil (5.7 %w/w) with aqueous KOH solution (22.5 %w/w) at a relatively high temperature (200 °C). Second, the soap paste was diluted with distilled water in the presence of varying concentrations (0 to 66.67 %w/w) of aloe vera extract to obtain hand-washing liquid soap samples, with the extract acting as an antimicrobial agent. Third, the liquid soap solutions were characterised in terms of foaming, wetting and cleansing abilities and the ability to inhibit the growth of Staphylococcus aureus, Pseudomonas aeruginosa and the fungus Aspergillus flavus. These were compared with those of a commercial (Astonish) hand-washing liquid soap sample containing triclosan (0.1 %w/w) as an antimicrobial agent. The liquid soap solutions exhibited excellent foaming, wetting and cleansing abilities, similar to the commercial liquid soap solution. In addition, the liquid soap solutions gave an average zone of inhibition between 9.0±0.3 mm and 11.0±0.2 mm for S. aureus, 7.0±0.1 mm and 10.0±0.2 mmfor P. aeruginosa and also inhibited the growth of the fungus A. flavus. These results compare favourably ( p= 0.05)with the commercial liquid soap solution, which gave an average inhibition zone of 9.00±1 mmfor both bacteria and also inhibited the growth of the fungus. This indicates that aloe vera extract can be used as an antimicrobial agent in the formulation of antimicrobial hand-washing liquid soap and other related products, rather than synthetic agents which are inherently harmful.

Medicinal Plants: Antibacterial Effects and Chemical Composition of Essential Oil of Foeniculum vulgare

2017 ◽  
Vol 8 (01) ◽  
Author(s):  
Azadeh Foroughi ◽  
Pouya Pournaghi ◽  
Fariba Najafi ◽  
Akram Zangeneh ◽  
Mohammad Mahdi Zangeneh ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Medicinal Plants ◽  
Essential Oil ◽  
Antibacterial Properties ◽  
Screen Test ◽  
Antibacterial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Resistant Bacteria ◽  
Antibacterial Effects ◽  
Foeniculum Vulgare

Medicinal plants are considered modern resources for producing agents that could act as alternatives to antibiotics in demeanor of antibiotic-resistant bacteria. The aim of the study was to evaluate the chemical composition and antibacterial activities of essential oil of Foeniculum vulgare (FV) against Pseudomonas aeruginosa and Bacillus subtilis. Gas chromatography mass spectrometry was done to specify chemical composion. As a screen test to detect antibacterial properties of the essential oil, agar disk and agar well diffusion methods were employed. Macrobroth tube test was performed to determinate MIC. The results indicated that the most substance found in FV essential oil was Trans-anethole (47.41 %), also the essential oil of FV with 0.007 g/ml concentration has prevented P. aeruginosa and with 0.002 g/ml concentration has prevented B. subtilis from the growth. Thus, the research represents the antibacterial effects of the medical herb on test P. aeruginosa and B. subtilis. We believe that the article provide support to the antibacterial properties of the essential oil. The results indicate the fact that the essential oil from the plant can be useful as medicinal or preservatives composition.

Inhibition of Bacterial Biofilm Formation by Phytotherapeutics with Focus on Overcoming Antimicrobial Resistance

2020 ◽  
Vol 26 (24) ◽  
pp. 2807-2816 ◽  
Author(s):  
Yun Su Jang ◽  
Tímea Mosolygó
Keyword(s):  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Biofilm ◽  
Experimental Investigations ◽  
Resistant Bacteria ◽  
Salmonella Spp ◽  
Food Borne ◽  
High Prevalence ◽  
Scientific Attention

: Bacteria within biofilms are more resistant to antibiotics and chemical agents than planktonic bacteria in suspension. Treatment of biofilm-associated infections inevitably involves high dosages and prolonged courses of antimicrobial agents; therefore, there is a potential risk of the development of antimicrobial resistance (AMR). Due to the high prevalence of AMR and its association with biofilm formation, investigation of more effective anti-biofilm agents is required. : From ancient times, herbs and spices have been used to preserve foods, and their antimicrobial, anti-biofilm and anti-quorum sensing properties are well known. Moreover, phytochemicals exert their anti-biofilm properties at sub-inhibitory concentrations without providing the opportunity for the emergence of resistant bacteria or harming the host microbiota. : With increasing scientific attention to natural phytotherapeutic agents, numerous experimental investigations have been conducted in recent years. The present paper aims to review the articles published in the last decade in order to summarize a) our current understanding of AMR in correlation with biofilm formation and b) the evidence of phytotherapeutic agents against bacterial biofilms and their mechanisms of action. The main focus has been put on herbal anti-biofilm compounds tested to date in association with Staphylococcus aureus, Pseudomonas aeruginosa and food-borne pathogens (Salmonella spp., Campylobacter spp., Listeria monocytogenes and Escherichia coli).

Sign in / Sign up

Export Citation Format

Share Document