In vitro effectiveness of antimicrobial properties of propolis and chlorhexidine on oral pathogens: A comparative study

2020 ◽  
Vol 1 (3) ◽  
pp. 116-125
Author(s):  
Hadis Tavafi ◽  
Maryam- sadat Sadrzadeh-Afshar ◽  
Soroush Niroomand

Periodontal disease is one of the most prevalent infectious oral conditions in the present century, and it is necessary to conduct research to find a solution to overcome these diseases. A variety of microbial strains of bacteria and fungi are involved in the pathogenesis of periodontal disease. The use of chemical agents such as mouthwashes is one of the strategies to control these diseases. The purpose of the present study was to compare the antimicrobial effects of propolis and chlorhexidine gluconate (CHX) on the bacterial strains of Streptococcus mutans, Streptococcus pyogenes, Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and the yeast strain of Candida albicans using the broth microdilution method. The results showed the inhibitory and microbicidal activities of the two substances against the tested microbial strains. The antibacterial and antifungal effects of CHX were more effective reported in this study than that of propolis against the studied pathogens. The results of this study also indicated that the propolis was less effective in inhibiting bacterial growth than the CHX. In addition, the combination of these two solutions had a synergistic effect on inhibition of other studied strains, with the exception of C. albicans and S. aureus. There is a need for further research on strains isolated from oral biofilm to achieve complementary results.

2021 ◽  
Author(s):  
Jelena S. Katanić Stanković ◽  
◽  
Nikola Srećković ◽  
Vladimir Mihailović

In this study, silver nanoparticles (AgNPs) have been synthesized using the aqueous extract of the aerial parts of B. purpurocaerulea, collected in Serbia. B. purpurocaerulea silver nanoparticles (Bp– AgNPs) synthesis was confirmed using UV-Vis spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The biological potential of synthesized Bp-AgNPs was evaluated in vitro using ABTS assay for determining free radical scavenging potential and microdilution method for analysis of antimicrobial properties. Bp-AgNPs showed high antioxidant activity similar to Bp-extract, comparable to BHT. The synthesized nanoparticles exerted remarkable antibacterial effects, with minimal inhibitory concentration (MIC) values below 20 µg/mL. In the case of some bacterial strains, the results of Bp– AgNPs were comparable or similar to standard antibiotic erythromycin. The antifungal activity of Bp– AgNPs was moderate for most of the used strains. Nevertheless, several fungi were resistant to the NPs action, while two tested Penicillium species were extremely sensitive on Bp-AgNPs with MIC lower than 40 µg/mL. The antimicrobial properties of Bp-AgNPs can be useful for the development of new NPs-containing products.


2021 ◽  
Vol 17 ◽  
Author(s):  
Lijuan Zhai ◽  
Lili He ◽  
Yuanbai Liu ◽  
Ko Ko Myo ◽  
Zafar Iqbal ◽  
...  

Background: Mononcyclic β-lactams are regarded as the most resistant class of β-lactams against a series of β-lactamases though possess limited antibacterial activity. Aztreonam being the first clinically approved monobactam needs broad-spectrum efficacy through structural modification. Objective: We strive to synthesize a number of monocyclic β-lactams by varying the substituents at N1, C3 and C4 positions of azetidinone ring and study the antimicrobial effect on variable bacterial strains. Methods: Seven new monobactam derivatives 23a-g, containing substituted-amidine moieties linked to the azetidinone ring via thiazole linker, were synthesized through multistep synthesis. The final compounds were investigated for their in vitro antibacterial activities using broth microdilution method, against ten bacterial strains of clinical interest. The minimum inhibitory concentrations (MICs) of newly synthesized derivatives were compared with aztreonam, ceftazidime and meropenem, existing clinical antibiotics. Results: All compounds 23a-g showed higher antibacterial activities (MIC 0.25 µg/mL to 64 µg/mL) against tested strains as compared to aztreonam (MIC 16 µg/mL to >64 µg/mL) and ceftazidime (MIC >64 µg/mL). However all compounds, except 23d, exhibited lower antibacterial activity against all tested bacterial strains as compared to meropenem. Conclusion: Compound 23d showed comparable or improved antibacterial activity (MIC 0.25 µg/mL to 2 µg/mL) to meropenem (MIC 1 µg/mL to 2 µg/mL) in case of seven bacterial species. Therefore, compound 23d may be valuable lead target for further investigations against multi-drug resistant Gram-negative bacteria.


2014 ◽  
Vol 9 (2) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Dragoljub L. Miladinović ◽  
Budimir S. Ilić ◽  
Tatjana M. Mihajilov-Krstev ◽  
Jovana L. Jović ◽  
Marija S. Marković

The chemical composition and antibacterial activity were examined of Libanotis montana Crantz subsp. leiocarpa (Heuff.) Soó. (Apiaceae) essential oil. Gas chromatography and gas chromatography/mass spectrometry were used to analyze the chemical composition of the oil. The antibacterial activity was investigated by the broth microdilution method against thirteen bacterial strains. The interactions of the essential oil and three standard antibiotics: tetracycline, streptomycin and chloramphenicol toward five selected strains were evaluated using the microdilution checkerboard assay in combination with chemometric methods: principal components analysis and hierarchical cluster analysis. Sesquiterpene hydrocarbons were the most abundant compound class in the oil (67.2%), with β-elemene (40.4%) as the major compound. The essential oil exhibited slight antibacterial activity against the tested bacterial strains in vitro, but the combinations L. montana oil-chloramphenicol and L. montana oil-tetracycline exhibited mostly either synergistic or additive interactions. These combinations reduced the minimum effective dose of the antibiotics and, consequently, minimized their adverse side effects. In contrast, the association of L. montana essential oil and streptomycin was characterized by strong antagonistic interactions against Escherichia coli ATCC 25922. In the PCA and HCA analyses, streptomycin stood out and formed a separate group.


Author(s):  
Prabhakar Walmik ◽  
Basavaraj S Naraboli ◽  
Swathi B ◽  
Somashekhar Ghanti

 Objective: The present study envisage a novel series of thiazole, indole and thiazolidine derivatives, namely, N-((5-Substituted-2-phenyl-1 H-indol-3-yl)methylene)-4,5,6,7-tetrahydro-5,7,-dimethylbenzo [d]thiazole-2-amine (4a-c), 2-(5-substituted-2-phenyl-1H-indol-3-yl)-3-(4,5,6,7- trimethylbenzo[d]thiazol-2-yl)-thiazolidin-4-one (5a-c) and 5-benzylidine-2-(5-substituted-2phenyl-1H-indol-3yl)-3-(4,5,6,7-tetrahydro-5,5,7- trimethylbenzo[d]thiazol-2-yl) thiazolidin-4-one (6a-c).Methods: All the newly synthesized compounds were characterized by infrared, 1H, 13C nuclear magnetic resonance and mass spectral data and elemental analysis and evaluated for in vitro antimicrobial activity.Results: Novel compounds N-((5-Substituted-2-phenyl-1H-indol-3-yl)methylene)-4,5,6,7-tetrahydro-5,7,-dimethylbenzo [d]thiazole-2-amine (4a-c), 2-(5-substituted-2-phenyl-1H-indol-3-yl)-3-(4,5,6,7-trimethylbenzo[d]thiazol-2-yl)-thiazolidin-4-one (5a-c) and 5-benzylidine-2-(5-substituted- 2phenyl-1H-indol-3yl)-3-(4,5,6,7-tetrahydro-5,5,7-trimethyl benzo[d]thiazol-2-yl)thiazolidin-4-one (6a-c) have been made and characterized using spectral and analytical data. The results of antibacterial and antifungal activities showed that some of the synthesized compounds exhibited promising activities.Conclusion: All the newly synthesized compounds were carried out by the broth microdilution method (NCCLS. 2002) in a DMF concentration of 500, 250, 125, and 62.5 μg/ml. Gentamycin and fluconazole are used as reference standards for antibacterial and antifungal activity, respectively. The final results revealed that compounds 4b, 5b, and 6b exhibited potent antimicrobial activity when compared to the standard drugs. 


2020 ◽  
Vol 13 (4) ◽  
pp. 2003-2014
Author(s):  
Arun Kumar ◽  
Yashika Garg

Background:Calophylluminophyllum is an evergreen tree with ethno-medical value growing along the seashores and islands of the Pacific and Indian Ocean. All parts of the plant such as bark, seeds and leaves have diverse medicinal uses such as an antiseptic, analgesic in wound healing, astringent, diuretic, purgative and expectorant. Although many species of calophyllum have been studied phytochemically for pharmacological properties, reports on inophyllum species are scanty. Aim of the study:Keeping inview it’s medical importance and availability in India as well as the rapid development of resistance by pathogens to the commonly used synthetic antibiotics,the pharmacological effects of C. inophyllum leaf extract (CIE) on HIV, bacteria and fungi causative of many human diseases was assessed in this study. Material and Methods: Isolation of the pure compounds from the ethanolic CIE was performed by gross column chromatography and tested against lyophilized forms of 8 fungal and 14 bacterial strains grown on Sabouraud’s dextrose agar and nutrient agar media respectively. Fractions and pure compounds isolated from CIE were evaluated against HIV by the HIV-RT inhibition assay by using the RT assay kit(Roche). The results were tabulated and analysed. Results: Among the purified compounds, Inophyllum C & E exhibited significant antibacterial and antifungal properties. Moreover, Inophyllum E was more potent than Inophyllum C in inhibiting the tested strains of bacteria and fungi whereasInophyllum B shows highest antiretroviral activity. Conclusion:We conclude that CIEis aneffective antimicrobial agent against common human pathogens tested in this in-vitro pharmacological evaluation of CIE.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7400
Author(s):  
José B. de Araújo-Neto ◽  
Maria M. C. da Silva ◽  
Cícera D. de M. Oliveira-Tintino ◽  
Iêda M. Begnini ◽  
Ricardo A. Rebelo ◽  
...  

The search for new antibacterial agents has become urgent due to the exponential growth of bacterial resistance to antibiotics. Nitrogen-containing heterocycles such as 1,8-naphthyridine derivatives have been shown to have excellent antimicrobial properties. Therefore, the purpose of this study was to evaluate the antibacterial and antibiotic-modulating activities of 1,8-naphthyridine derivatives against multi-resistant bacterial strains. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of the following compounds: 7-acetamido-1,8-naphthyridin-4(1H)-one and 3-trifluoromethyl-N-(5-chloro-1,8-naphthyridin-2-yl)-benzenesulfonamide. The antibiotic-modulating activity was analyzed using subinhibitory concentrations (MIC/8) of these compounds in combination with norfloxacin, ofloxacin, and lomefloxacin. Multi-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used in both tests. Although the compounds had no direct antibacterial activity (MIC ≥ 1.024 µg/mL), they could decrease the MIC of these fluoroquinolones, indicating synergism was obtained from the association of the compounds. These results suggest the existence of a structure–activity relationship in this group of compounds with regard to the modulation of antibiotic activity. Therefore, we conclude that 1,8-naphthyridine derivatives potentiate the activity of fluoroquinolone antibiotics against multi-resistant bacterial strains, and thereby interesting candidates for the development of drugs against bacterial infections caused by multidrug resistant strains.


1999 ◽  
Vol 43 (9) ◽  
pp. 2251-2255 ◽  
Author(s):  
M. L. Peterson ◽  
L. B. Hovde ◽  
D. H. Wright ◽  
A. D. Hoang ◽  
J. K. Raddatz ◽  
...  

ABSTRACT In vitro pharmacodynamic studies investigating the antimicrobial properties of five fluoroquinolones, (trovafloxacin, sparfloxacin, clinafloxacin, levofloxacin, and ciprofloxacin) againstBacteroides fragilis ATCC 23745 were conducted. The times required to reduce the viable counts by 3 log units were as follows: clinafloxacin, 2.9 h; levofloxacin, 4.6 h; trovafloxacin, 6 h; and sparfloxacin, 10 h. Exposure to ciprofloxacin did not achieve a 3-log decrease in viable counts. The susceptibility ofB. fragilis was determined both prior to exposure and following 24 h of exposure to each of the five fluoroquinolones tested. The MICs of clinafloxacin, levofloxacin, trovafloxacin, sparfloxacin, ciprofloxacin, metronidazole, cefoxitin, chloramphenicol, and clindamycin were determined by the broth microdilution method. The MICs for B. fragilis preexposure were as follows: clinafloxacin, 0.25 μg/ml; trovafloxacin, 0.5 μg/ml; sparfloxacin, 2 μg/ml; levofloxacin, 2 μg/ml; and ciprofloxacin, 8 μg/ml. Similar pre- and postexposure MICs were obtained for cultures exposed to trovafloxacin, clinafloxacin, levofloxacin, and ciprofloxacin. However, following 24 h of exposure to sparfloxacin, a fluoroquinolone-resistant strain emerged. The MICs for this strain were as follows: clinafloxacin, 1 μg/ml; trovafloxacin, 4 μg/ml; sparfloxacin, 16 μg/ml; levofloxacin, 16 μg/ml; and ciprofloxacin, 32 μg/ml. No changes in the susceptibility of B. fragilispre- and postexposure to sparfloxacin were noted for metronidazole (MIC, 1 μg/ml), cefoxitin (MIC, 4 μg/ml), chloramphenicol (MIC, 4 μg/ml), and clindamycin (MIC, 0.06 μg/ml). Resistance remained stable as the organism was passaged on antibiotic-free agar for 10 consecutive days. Mutant B. fragilis strains with decreased susceptibility to clinafloxacin, trovafloxacin, sparfloxacin, levofloxacin, and ciprofloxacin were selected on brucella blood agar containing 8× the MIC of levofloxacin at a frequencies of 6.4 × 10−9, 4× the MICs of trovafloxacin and sparfloxacin at frequencies of 2.2 × 10−9 and 3.3 × 10−10, respectively, and 2× the MIC of clinafloxacin at a frequency of 5.5 × 10−11; no mutants were selected with ciprofloxacin. The susceptibilities of strains to trovafloxacin, levofloxacin, clinafloxacin, sparfloxacin, and ciprofloxacin before and after exposure to sparfloxacin were modestly affected by the presence of reserpine (20 μg/ml), an inhibitor of antibiotic efflux. The mechanism of fluoroquinolone resistance is being explored, but it is unlikely to be efflux due to a lack of cross-resistance to unrelated antimicrobial agents and to the fact that the MICs for strains before and after exposure to sparfloxacin are minimally affected by reserpine.


Biologia ◽  
2006 ◽  
Vol 61 (3) ◽  
Author(s):  
Premysl Landa ◽  
Petr Marsik ◽  
Tomas Vanek ◽  
Vojtech Rada ◽  
Ladislav Kokoska

AbstractCrude methanol extracts from callus cultures of Nigella arvensis, N. damascena, N. hispanica, N. integrifolia, and N. sativa were investigated for their anti-microbial activity. Growth inhibition was determined in Gram-positive and Gram-negative bacterial strains as well as in yeast by using a broth-microdilution method. The results showed that the extracts of all calli tested exhibited significant anti-microbial activity, especially against Bacillus cereus, Staphylococcus aureus and Staphylococcus epidermidis. Compared with other Nigella species, a callus culture of N. hispanica was the most effective against the microorganisms used in this study.


2013 ◽  
pp. 333-340 ◽  
Author(s):  
Daniela Nikolovska-Nedelkoska ◽  
Natalija Atanasova-Pancevska ◽  
Haris Amedi ◽  
Dafina Veleska ◽  
Emilija Ivanova ◽  
...  

Regarding the development of novel safe antimicrobials of natural origin, macrofungi became attractive for the researchers in the last decade. In this study, antimicrobial potential of methanolic extracts of six wild macromycetes (Boletus lupinus, Flammulina velutypes, Phellinus igniarius, Sarcodon imbricatus, Tricholoma aurantium, Xerocomus ichnusanus) was evaluated. In vitro antimicrobial activity was investigated by the microdilution method and minimum inhibitory concentration (MIC) was determined. Testing was conducted against eleven microorganisms, including six strains of bacteria and five species of fungi. Extracts showed selective antimicrobial properties while the activities depended both on the species of microorganism and on the type and concentration of extract. The evaluated extracts demonstrated antimicrobial activity, exhibiting more potent inhibitory effects on the growth of bacteria than on fungi. The highest antibacterial and antifungal activity was observed in methanolic extract of polypore fungus P. igniarius.


2021 ◽  
pp. 109-118
Author(s):  
Gautam M. Dhuda ◽  
Khushal M. Kapadiya ◽  
Paresh D. Ladwa ◽  
Jayesh J. Modha

To generate a new class of scaffolds with amended anti-microbial potency, synthesis and in vitro biological evaluation of a series of 2-((5-(3-nitrophenyl)-1,3,4-oxadiazol-2-yl)methylthio)-5-substitutedphenyl-1,3,4-oxadiazole (5a-5o) having S-Methylene linkage between the two 1,3,4-diisoxazole rings is reported. Anti-microbial properties of the entire compounds were investigated in a broad panel of some selected gram-positive bacterial strains, gram-negative bacterial strain, and fungal strains using the broth microdilution method. The results were dominant on –Cl and –NO2 functionality than the used standard drug.


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