scholarly journals Combating Pathogenic Microorganisms Using Plant-Derived Antimicrobials: A Minireview of the Mechanistic Basis

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Abhinav Upadhyay ◽  
Indu Upadhyaya ◽  
Anup Kollanoor-Johny ◽  
Kumar Venkitanarayanan

The emergence of antibiotic resistance in pathogenic bacteria has led to renewed interest in exploring the potential of plant-derived antimicrobials (PDAs) as an alternative therapeutic strategy to combat microbial infections. Historically, plant extracts have been used as a safe, effective, and natural remedy for ailments and diseases in traditional medicine. Extensive research in the last two decades has identified a plethora of PDAs with a wide spectrum of activity against a variety of fungal and bacterial pathogens causing infections in humans and animals. Active components of many plant extracts have been characterized and are commercially available; however, research delineating the mechanistic basis of their antimicrobial action is scanty. This review highlights the potential of various plant-derived compounds to control pathogenic bacteria, especially the diverse effects exerted by plant compounds on various virulence factors that are critical for pathogenicity inside the host. In addition, the potential effect of PDAs on gut microbiota is discussed.

2019 ◽  
Author(s):  
KINDU GETA

Abstract Background: Infectious diseases caused by bacteria have a large impact on public health. Increasing in resistant microbial infections intensified the search for new, safer, and more efficacious agents to combat serious microbial infections. Plants have played a central part in combating many diseases in human and domestic animal in many local communities, including Africa. Rhamnus prinoides is Ethiopian medicinal plants that have been used traditionally for the treatment of diverse infectious diseases. Therefore, this research was carried out to evaluate antibacterial activity Rhamnus prinoides extracts against pathogenic bacteria. Methods: The antimicrobial activity tests were carried out by the agar well diffusion method. Broth dilution and streak plate methods were used to determine MIC and MBC of extracts respectively. Results: The results revealed that ethanol extracts of fruits showed the highest antibacterial activity against standard strains of S.aureus with mean inhibition zone of 26±0.58, 28.33±1.2 and 33.33±0.9mm at 25, 50 and 100mg/ml respectively. The lowest mean MIC value (1.04±0.26 mg/ml) was recorded with ethanol extract of fruits against standard strains of S. aureus and the lowest mean MBC value (2.08±0.52 mg/ml) was recorded with ethanol extract of fruits against standard strains and clinical isolates of S. aureu. Conclusion: On the basis of the current findings, Rhamnus prinoides could be a good candidate in the search for new antibacterial agents from natural products against bacterial pathogens. Therefore, further studies are needed to study their toxicology and isolate the bio- active components from this plant.


2019 ◽  
Author(s):  
kindu geta ◽  
Mulugeta Kibret

Abstract Medicinal plants offer a major and accessible source of health care to people living in developing countries. Increasing in resistant microbial infections intensified the search for new, safer, and more efficacious agents to combat serious microbial infections. Acanthus sennii is one of the medicinal plants used traditionally for treatment of different infectious diseases in Ethiopian. Therefore, this research was carried out to evaluate antibacterial activity of Acanthus sennii against pathogenic bacteria. The antimicrobial activity tests of the plant extracts against pathogenic bacteria were carried out by the agar well diffusion method. Broth dilution and streak plate method were used to determine MIC and MBC of extracts respectively. The results revealed that ethanol extracts of leaves showed the highest antibacterial activity against standard strains of S.aureus with inhibition zone of 14±0.58mm and 17±0.67mm at 50mg/ml and at 25mg/ml respectively. Ethanol extracts of buds showed the highest antibacterial activity against standard strains of S.aureus with inhibition zone of 25.67±0.67mm at 100mg/ml. The lowest mean MIC value (2.6±0.52 mg/ml) was recorded with ethanol extract of leaves against standard strains and clinical isolates of S. aureus. The lowest mean MBC value (4.2±1.04 mg/ml) was recorded with ethanol extract of leaves against standard strains of S. aureu. Acanthus sennii could be a good candidate in the search for new antibacterial agents from natural products against bacterial pathogens. Therefore, further studies are needed to study their toxicology and isolate the bio- active components from this plant. Key words: Acanthus sennii, Antibacterial activity, MIC, MBC, pathogenic bacteria


2019 ◽  
Author(s):  
KINDU GETA

Abstract Background: Infectious diseases caused by bacteria have a large impact on public health. Increasing in resistant microbial infections intensified the search for new, safer, and more efficacious agents to combat serious microbial infections. Plants have played a central part in combating many diseases in human and domestic animal in many local communities, including Africa. Rhamnus prinoides is Ethiopian medicinal plants that have been used traditionally for the treatment of diverse infectious diseases. Therefore, this research was carried out to evaluate antibacterial activity Rhamnus prinoides extracts against pathogenic bacteria. Methods: The antimicrobial activity tests were carried out by the agar well diffusion method. Broth dilution and streak plate methods were used to determine MIC and MBC of extracts respectively. Results: The results revealed that ethanol extracts of fruits showed the highest antibacterial activity against standard strains of S.aureus with mean inhibition zone of 26±0.58, 28.33±1.2 and 33.33±0.9mm at 25, 50 and 100mg/ml respectively. The lowest mean MIC value (1.04 mg/ml) was recorded with ethanol extract of fruits against standard strains of S. aureus and the lowest mean MBC value (2.08 mg/ml) was recorded with ethanol extract of fruits against standard strains and clinical isolates of S. aureu. Conclusion: On the basis of the current findings, Rhamnus prinoides could be a good candidate in the search for new antibacterial agents from natural products against bacterial pathogens. Therefore, further studies are needed to study their toxicology and isolate the bio- active components from this plant. Key words: Antibacterial activity, Escherichia coli, MBC, MIC, Rhamnus prinoides, Staphylococcus aureus


2021 ◽  
Author(s):  
kindu geta ◽  
Mulugeta Kibret

Abstract Background: Infectious diseases caused by bacteria have a large impact on public health. Increasingly resistant microbial infections intensified the search for new, safer, and more efficacious agents to combat serious microbial infections. Plants have played a central part in combating many diseases in human and domestic animals in many local communities, including Africa. Rhamnus prinoides is Ethiopian medicinal plants that have been used traditionally for the treatment of diverse infectious diseases. Therefore, this research was carried out to evaluate the antibacterial activity of Rhamnus prinoides extracts against pathogenic bacteria. Methods: The antimicrobial activity tests were carried out by the agar well diffusion method. Broth dilution and streak plate methods were used to determine MIC and MBC values of extracts respectively. Results: The results revealed that ethanol extracts of fruits showed the highest antibacterial activity against standard strains of S. aureus with mean inhibition zone of 26± 0.58, 28.33±1.2 and 33.33± 0.9 mm at 25, 50 and 100 mg/ml respectively. The lowest mean MIC value (1.04 mg/ml) was recorded with ethanol extract of fruits against the standard strains of S. aureus and the lowest mean MBC value (2.08 mg/ml) was recorded with ethanol extract of fruits against the standard strains and clinical isolates of S. aureus. Conclusion: On the basis of the current findings, Rhamnus prinoides could be a good candidate in the search for new antibacterial agents from natural products against bacterial pathogens. Therefore, further studies are needed to study their toxicology and isolate the bio- active components from this plant.


Planta Medica ◽  
2020 ◽  
Author(s):  
Violette Hamers ◽  
Clément Huguet ◽  
Mélanie Bourjot ◽  
Aurélie Urbain

AbstractInfectious diseases are among the greatest threats to global health in the 21st century, and one critical concern is due to antibiotic resistance developed by an increasing number of bacterial strains. New resistance mechanisms are emerging with many infections becoming more and more difficult if not impossible to treat. This growing phenomenon not only is associated with increased mortality but also with longer hospital stays and higher medical costs. For these reasons, there is an urgent need to find new antibiotics targeting pathogenic microorganisms such as ESKAPEE bacteria. Most of currently approved antibiotics are derived from microorganisms, but higher fungi could constitute an alternative and remarkable reservoir of anti-infectious compounds. For instance, pleuromutilins constitute the first class of antibiotics derived from mushrooms. However, macromycetes still represent a largely unexplored source. Publications reporting the antibacterial potential of mushroom extracts are emerging, but few purified compounds have been evaluated for their bioactivity on pathogenic bacterial strains. Therefore, the aim of this review is to compile up-to-date data about natural products isolated from fruiting body fungi, which significantly inhibit the growth of ESKAPEE pathogenic bacteria. When available, data regarding modes of action and cytotoxicity, mandatory when considering a possible drug development, have been discussed in order to highlight the most promising compounds.


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 552
Author(s):  
Suraj Arora ◽  
Shahabe Saquib ◽  
Youssef Algarni ◽  
Mohammed Kader ◽  
Irfan Ahmad ◽  
...  

Background and objectives: This study aimed to evaluate the synergistic antimicrobial activity of extracts obtained from Salvadora persica (Miswak), Commiphora molmol (myrrh) and Azadirachta indica (neem) in combination with commercially available antimicrobial agents: penicillin, tetracycline, ofloxacin and fluconazole on endodontic pathogens such as Enterococcus faecalis, Streptococcus mitis, Actinomyces naeslundii and Candida albicans. Materials and Methods: Microbiological samples from the root canals of the teeth undergoing retreatment were taken using sterile paper points kept at full length in the canal for 30 seconds. The disc diffusion method was used to check the susceptibility of microbes to the plant extracts and antimicrobials by measuring the diameter of the inhibition zones. Against the microbes, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of the plant extracts were assessed. The fractional inhibitory concentration index (FICI) was used to estimate the synergistic effect of plant extracts combined with antimicrobials against the resistant endodontic microbes. Results: The findings clearly indicate the effectiveness of all the three plant extracts, Commiphora molmol, Azadirachta indica, Salvadora persica, against all the experimental pathogenic microorganisms except for the ineffectiveness of Azadirachta indica, Salvadora persica against Candida albicans. Maximum antimicrobial activity was displayed by Azadirachta indica against Enterococcus faecalis (MIC = 0.09 ± 1.2 mg/mL, MBC = 0.78 ± 1.25 mg/mL) and the minimum antimicrobial activity was displayed by Commiphora molmol against Actinomyces naeslundii (MIC = 12.5 ± 3.25 mg/mL, MBC = 100 ± 3.75 mg/mL). The best synergy was displayed by Commiphora molmol with fluconazole against Candida albicans (FICI = 0.45). Conclusions: The current study delineates the variable antimicrobial activity of plant extracts against the experimental endodontic pathogenic microorganisms. Plant extracts in conjunction with various antimicrobials can be valuable aids in combating relatively resistant endodontic microorganisms that have been the cause of worry in recent years, leading to failure even in treatment procedures following all required protocols.


1974 ◽  
Vol 83 (4) ◽  
pp. 550-554 ◽  
Author(s):  
Gary D. Becker ◽  
Alexander M. Wernicke

Four cases of gonococcal pharyngotonsillitis have been presented, along with a review of the world literature. This entity is most commonly seen in those individuals practicing fellatio, i.e., females and homosexual males. The infection may be passed to the newborn by the infected genitals of the mother during birth, to the infant from adult molestation, or among sexually promiscuous children. Most gonococcal pharyngeal infections result in a carrier state, and as such, are possible reservoirs of propagated infections. When symptomatic, the most frequent complaint is a sore throat. Physical finding among symptomatic patients reveal a wide spectrum ranging from mild hyperemia of the pharynx or tonsils, to exudative tonsillitis with tender cervical lymph nodes and moderate elevation of temperature. Most authorities agree that the preferred treatment is 4.8 million units of procaine penicillin G I.M., with one gm of probenecid by mouth thirty minutes before the injection. If allergic to penicillin, tetracycline should be given, 1.5 gm by mouth stat, then 0.5 gm four times a day for a total of 9 gm. A routine blood agar culture of the throat will not reveal the presence of the gonococcus. Thayer-Martin (or Transgrow) media must be used. Failure to detect pathogenic bacteria in a routine culture may lead to either no treatment or improper treatment of a gonococcal pharyngotonsillar infection. This may result in a carrier state, or even worse, to a disseminated gonococcal infection.


Author(s):  
E. A. Selivanova ◽  
Yu. A. Khlopko ◽  
N. E. Gogoleva ◽  
A. O. Plotnikov

Aim. To indicate potentially pathogenic bacteria in plankton of the brackish rivers flowing into the Elton Lake by high-throughput sequencing of 16S ssuRNA gene. Materials and methods. The water samples from brackish rivers Lantsug and Chernavka, flowing into the Elton Lake, were taken up in a volume of 50 ml, filtered through membrane filters (pore diameter - 0.22 pm). Total DNAwas obtained by phenol-chloroform extraction with preliminary homogenization and enzymatic lysis. DNA libraries for sequencing were created by protocol Illumina with primers to a variable V3-V4 region of 16S ssuRNA gene. Sequencing was performed on a platform MiSeq («Illumina», США). Results.There were found the phylotypes of potentially pathogenic bacteria of Proteobacteria phylum from the families Enterobacteriaceae, Pseudomonadaceae, Campylobacteraceae, Vibrionaceae, Aeromonadaceae, Moraxellaceae, Legionellaceae, Alcaligenaceae, Campylobacteraceae, and also of Firmicutes, Bacteroidetes, Actinobacteria phyla in the plankton samples of the brackish rivers. Probable source of bacterial contamination is large and small cattle. Conclusion. These data demonstrate that the continental brackish waters, along with freshwater and marine habitats perform a reservoir function to potentially pathogenic microorganisms. High-throughput sequencing can be used to screen the presence of pathogens in water.


Author(s):  
N. S. Chervyakova ◽  
T. V. Valova ◽  
A. V. Osin

By the example of Martin Christ Epsilon 2-6D device carried out was assessment of the possibility to use freeze-dryers of the chamber type for conservation of pathogenic microorganisms collection strains. Elaborated was algorithm of lyophilisation of the III-IV pathogenicity groups bacteria, which incorporated conditions of freeze-drying and biological safety provision of this process. Indices of viability and survivability were defined for freeze-dried cells of pathogenic bacteria strains. Using thermostability test calculated were predicted timelines of storage of collection strains preparations freeze-dried in the flasks in Martin Christ Epsilon 2-6D. It was determined that in the collections of pathogenic microorganisms freeze-dryers of the chamber type could be used most prospectively for the III-IV pathogenicity groups bacteria conservation requiring mass reproduction and not intended for long storage. At the same time their application for freeze-drying of the strains of the I-II pathogenicity groups bacteria intended for a long storage, requires further adaptation of these devices as regards biological safety provision and prolongation of the shelf life.


Author(s):  
Ulrike Friedlein ◽  
Samart Dorn-In ◽  
Karin Schwaiger

The application of plant extracts (PEs) could be a promising option to satisfy consumers’ demand for natural additives to inhibit growth of variable pathogenic bacteria. Thus, the aim of this study was to develop a standardized microdilution method to examine the antimicrobial effects of ten hydrophilic plant extracts against two strains of C. perfringens facing various food-relevant influencing factors. Due to the high opacity of PEs, resazurin was used as an indicator for bacterial growth instead of pellet formation. The highest value of the minimum inhibitory concentration (MIC) of the replications of each PE was defined as effective plant extract concentration (EPC), whereas the next concentration beneath the lowest MIC value was defined as the ineffective plant extract concentration (IEPC). The EPC of seven PEs: allspice, cardamom, cinnamon, clove, coriander, ginger and mace were between 0.625 - 10 g/kg, whereas extracts of caravey, nutmeg and thyme showed no antimicrobial activity up to the maximum concentration tested (10 g/kg) against C. perfringens in vitro. Two intrinsic factors, sodium chloride and sodium nitrite, displayed either synergistic/additive effects or no interaction with most PEs. By combination with PEs at its ineffective plant concentration (IEPC, 0.08 – 1.25 g/kg), MIC of NaCl and NaNO2 decreased from 25 – 50 g/kg to 6 – 25 g/kg and > 200 mg/kg to 0.2 – 100 mg/kg respectively. On the contrary, lipid (sun flower oil) at a low concentration inhibited the antimicrobial effects of all tested PEs. For extrinsic factors, only allspice, ginger and coriander could maintain their antimicrobial effects after being heated to 78 °C for 30 min. The synergistic effect between PEs and pH values (5.0 and 5.5) was also found for all PEs. The established screening method with resazurin and defining EPC and IEPC values allows the verification of antimicrobial effects of PEs under various food-relevant influencing factors in a fast and reproducible way.


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