scholarly journals In Vitro Testing of Salicylanilide Derivatives Against Some Fungal and Bacterial Strains

2019 ◽  
Vol 70 (4) ◽  
pp. 1496-1499
Author(s):  
Ioana Maria Carmen Ienascu ◽  
Diana Obistioiu ◽  
Iuliana Maria Popescu ◽  
Mariana Nela Stefanut ◽  
Osser Gyongyi ◽  
...  

In the dental office, disinfection and sterilization are a matter of utmost importance for both the physician, the medical staff and the patient. Twelve N-(2-bromo-phenyl)-2-hydroxy-benzamide and N-(4-bromo-phenyl)-2-hydroxy-benzamide derivatives were synthesized and tested for antimicrobial activity against 6 bacterial and 2 fungal strains using the Disk diffusion method for susceptibility testing. The obtained results indicated that the N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives were more active against the tested microbes, inhibition zones of 6-12 mm being obtained, although the most effective compound against S. pyogenes proved to be N-(4-bromo-phenyl)-2-hydroxy-benzamide (14 mm inhibition zone). The tested compounds presented no effect against S. aureus, S. flexneri, S. typhimurium and C. parapsilopsis at the tested concentration.

2019 ◽  
Vol 2 (1) ◽  
pp. 19
Author(s):  
Murni Halim

A study was carried out to screen for phytochemical constituents and assess the antioxidant and antimicrobial activities of Senna alata and Senna tora leaf extracts. The leaves were first dried at room temperature and 50°C in an oven prior to solvent extraction using ethanol and methanol. The in-vitro qualitative assays showed that both S. alata and S. tora leaf extracts contained bioactive and secondary metabolites components such as tannins, steroids, saponin, terpenoids, glycosides, flavonoids and phenols. The antioxidant activity and capacity test were carried out by conducting free radical of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and Ferric reduction antioxidant plasma (FRAP) assays. Both assays showed S. tora leaf extract has higher antioxidant capacity than S. alata leaf extract. The efficacy of these leaf extracts were tested against skin pathogens through agar well diffusion method. S. alata extract showed an inhibition zone (1.15 – 1.59 mm) against Pseudomonas aeruginosa while S. tora extracts exhibited a strong antimicrobial activity against S. epidermidis (inhibition zone of 12 – 16.94 mm) followed by P. aeruginosa (inhibition zone of 1 – 1.59 mm). Nonetheless, no inhibition zone was observed for S. aureus by both leaf extracts. The phytochemicals and antioxidant constituents as well as inhibitory potential on skin pathogens possessed by S. alata and S. tora leave highlighted their potential utilization in the development of natural drugs or cosmetics to treat skin related diseases or infections.


2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Giovanna Pesavento ◽  
Valentina Maggini ◽  
Isabel Maida ◽  
Antonella Lo Nostro ◽  
Carmela Calonico ◽  
...  

Essential oils (EOs) are known to inhibit the growth of a wide range of microorganisms. Particularly interesting is the possible use of EOs to treat multidrug-resistant cystic fibrosis (CF) pathogens. We tested the essential oil (EO) from Origanum vulgare for in vitro antimicrobial activity, against three of the major human opportunistic pathogens responsible for respiratory infections in CF patients; these are methicillin-resistant Staphylococcus aureus, Stenotrophomonas maltophilia and Achromobacter xylosoxidans. Antibiotic susceptibility of each strain was previously tested by the standard disk diffusion method. Most strains were resistant to multiple antibiotics and could be defined as multi-drug-resistant (MDR). The antibacterial activity of O. vulgare EO (OEO) against a panel of 59 bacterial strains was evaluated, with MIC and MBC determined at 24, 48 and 72 hours by a microdilution method. The OEO was effective against all tested strains, although to a different extent. The MBC and MIC of OEO for S. aureus strains were either lower or equal to 0.50%, v/v, for A. xylosoxidans strains were lower or equal to 1% and 0.50%, v/v, respectively; and for S. maltophilia strains were lower or equal to 0.25%, v/v. The results from this study suggest that OEO might exert a role as an antimicrobial in the treatment of CF infections.


2014 ◽  
pp. 99-116 ◽  
Author(s):  
Jelena Vulic ◽  
Aleksandra Velicanski ◽  
Dragana Cetojevic-Simin ◽  
Vesna Tumbas-Saponjac ◽  
Sonja Djilas ◽  
...  

The main chemical composition, i.e. the total content of bioactive compounds (phenolics 2209.86 ? 70.32 mg GAE/100g FDR, flavonoids 831.87 ? 12.61 mg R/100g FDR and anthocyanins 144.55 ? 0.39 mg CGE/100g FDR), in freeze-dried raspberry (FDR) was evaluated spectrophotometrically. Vitamin C content was determined by HPLC analysis (88.81 ? 4.38 mg vit C/100g FDR). Antioxidant activities of FDR extract were evaluated spectrophotometrically on stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and by electron spin resonance spectroscopy (ESR) method on hydroxyl radicals (?OH). EC50 values were evaluated. EC50 DPPH? was 0.127 ? 0.013 mg/ml, while EC50 ?OH was 1.366 ? 0.026 mg/ml. Antiproliferative activity of the FDR extract was evaluated in vitro in three human cell lines by colorimetric sulphorhodamine B (SRB) assay. The most pronounced effects were obtained in the breast adenocarcinoma cell line (MCF7). EC50 value was 395.07 ? 96.38 ?g/ml. Antimicrobial activity was determined by disk diffusion method. The FDR extract produced a clear inhibition zone (without visible colonies) only toward Staphylococcus aureus. The minimal inhibitory (MIC) and minimal bactericidal (MBC) concentrations of FDR extract were evaluated. The values MIC were in the range of 4.7 - 100 mg/ml, and of MBC in the range of 6.3 - > 100 mg/ml.


2012 ◽  
Vol 67 (11-12) ◽  
pp. 557-564 ◽  
Author(s):  
Eleanor P. Padla ◽  
Ludivina T. Solis ◽  
Ruel M. Levida ◽  
Chien-Chang Shen ◽  
Consolacion Y. Ragasa

4-(α-L-Rhamnosyloxy)benzyl isothiocyanate (1) and 4-(4’-O-acetyl-α-L-rhamnosyloxy)- benzyl isothiocyanate (2) isolated from Moringa oleifera seeds were screened for their antibacterial activities against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Pseudomonas aeruginosa, and for their antifungal activities against Candida albicans, Trichophyton rubrum, and Epidermophyton floccosum using the disk diffusion method. Isothiocyanates 1 and 2 were found active at the lowest inhibitory concentration of 1 mg/ml against all Grampositive bacteria tested (S. aureus, S. epidermidis, B. subtilis) and against the dermatophytic fungi E. floccosum and T. rubrum. Statistically signifi cant differences were found between the mean inhibition zones (IZ) of 1 and 2 and the standard drugs, ofl oxacin and clotrimazole. The minimum inhibitory concentration (MIC) values confi rmed the good antimicrobial activity of 1 and 2 against S. aureus, good to moderate activity against S. epidermidis, moderate activity against B. subtilis, and weak activity against E. floccosum and T. rubrum. The in vitro bactericidal effect of 1 and 2 against the Gram-positive bacterial strains tested is suggested by MBC:MIC ratios of 2:1.


Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 380
Author(s):  
Jingjing Zhang ◽  
Fang Luan ◽  
Qing Li ◽  
Guodong Gu ◽  
Fang Dong ◽  
...  

Chemical modification is one of the most effective methods to improve the biological activity of chitin. In the current study, we modified C3-OH and C6-OH of chitin (CT) and successfully synthesized 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) through a series of chemical reactions. The structure of NCT and DNCT were characterized by elemental analyses, FT-IR, 13C NMR, XRD, and SEM. The inhibitory effects of CT, NCT, and DNCT against six kinds of phytopathogen (F. oxysporum f. sp. cucumerium, B. cinerea, C. lagenarium, P. asparagi, F. oxysporum f. niveum, and G. zeae) were evaluated using disk diffusion method in vitro. Meanwhile, carbendazim and amphotericin B were used as positive controls. Results revealed that 6-amino-chitin (NCT) and 3,6-diamino-chitin (DNCT) showed improved antifungal properties compared with pristine chitin. Moreover, DNCT exhibited the better antifungal property than NCT. Especially, while the inhibition zone diameters of NCT are ranged from 11.2 to 16.3 mm, DNCT are about 11.4–20.4 mm. These data demonstrated that the introduction of amino group into chitin derivatives could be key to increasing the antifungal activity of such compounds, and the greater the number of amino groups in the chitin derivatives, the better their antifungal activity was.


2021 ◽  
Vol 20 (6) ◽  
pp. 19-29
Author(s):  
Małgorzata Schollenberger ◽  
Agnieszka Gadomska-Gajadhur ◽  
Ewa Mirzwa-Mróz ◽  
Damian Kret ◽  
Ewa Skutnik ◽  
...  

 The activity of essential oils from Eucalyptus globulus, Pinus silvestris, Lavandula angustifolia, Juniperus virginiana, Rosmarinus officinalis and Citrus paradise against the soft-rot pathogens Pectobacterium carotovorum subsp. carotovorum, Pectobacterium atrosepticum, Pectobacterium parmentieri and Dickeya solani was determined in vitro. The antibacterial activity of the essential oils will be evaluated using the disk-diffusion method by Kirby-Bauer [Bauer et al. 1966]. It was found that all the presented essential oils varied in antimicrobial activity against the four bacterial strains. No differences in the influence of streptomycin on inhibition of growth of the four bacterial strains were observed. Among six tested plants, essential oils from P. sylvestris had the strongest inhibitory effect on the growth of soft rot bacteria from Pectobacterium genus. This paper constitute the first report on the activity of the essential oils obtained from J. virginiana against soft rot bacteria. They are also the first report on the activity of the essential oils obtained from E. globulus, P. silvestris, L. angustifolia and C. paradisi against P. atrosepticum, P. parmentieri and D. solani as well as on the activity of the R. officinalis essential oils against P. atrosepticum and P. parmentieri.


2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Nyoman Mastra

AbstractBackground Staphylococcus aureus is one of causes infection and this bacteria have been resistence for many antibiotic. Bay leaf have antibacterials substance, which stew leaves can be treat infection caused Staphylococcus aureus. The purpose of this study was to determine differences in growth inhibition zone of Staphylococcus aureus at various concentrations of water stew of bay leaf.Method The method of this study is true experiment with posstest only control design, and used Kirby Bauer disk diffusion method with various concentrations of water stewed of bay leaf (20%, 40%, 60%, 80%,100%), positive control (chloramfenicol 30 μg) and negative control (sterile distilled water). Result The result showed that the average diameter of inhibition zone in concentration 20%, 40%, 60%, 80%, and 100% is 7 mm, 8,4 mm, 9,6 mm, 10,5 mm and 11,5 mm. Based on statistical analysis using oneway ANOVA available the value of p (0,000) α (0,05), so the inhibition zone is significant difference of growth inhibition zone of Staphylococcus aureus at various concentrations of stewed water bay leaf. Conclusion Water stew of bay leaf can inhibit the growth of Staphylococcus aureus, and there are differences in growth inhibition zone of Staphylococcus aureus at various concentrations of water stew of bay leaf. Keywords: stew of bay leaf; Staphylococcus aureus; inhibition zone 


2018 ◽  
Vol 9 (3) ◽  
pp. 336
Author(s):  
Ni Luh Budi Artaningsih ◽  
Nur Habibah ◽  
Mastra Nyoman

<p><em>Streptococcus mutans</em> is a positive gram bacteria which cause dental caries. From the several previous studies, Gamal leaf has been predicted as the antibacterial agent because of their active substance such as tannins, alkaloids, saponins, and flavonoids. The objective of the study was to know the antibacterial activity of ethanol extract of Gamal leaf (<em>Gliricidia sepium</em>) for <em>Streptococcus mutans</em> in various concentrations. This study was a true experimental with post-test only control design. The determination of antibacterial activity in this study was conducted by using Kirby Bauer disk diffusion method with the various concentrations, there were 40, 50, 60, 70 and 80%. The positive and negative controls in this study were 30 µg disk diffusion of chloramphenicol and the 96% of ethanol. The average inhibition of zone diameter in the concentrations of 40, 50, 60, 70 and 80% were 11.3, 12.3, 13.4, 15.3 and 19.2 mm, respectively. One Way ANOVA statistical analysis showed that the value of p was 0.000, so there was a difference of growth inhibition zone of <em>Streptococcus mutans</em> in various concentrations of ethanol extract of Gamal leaf (<em>Gliricidia sepium</em>). Based on the result, it can be concluded that the ethanol extract of Gamal leaf (<em>Gliricidia sepium</em>) have strong antibacterial activity, especially to <em>Streptococcus mutans</em> bacteria.</p>


Author(s):  
Fatemeh Mirhosseini ◽  
Motahareh Amiri ◽  
Alireza Daneshkazemi ◽  
Hengameh Zandi ◽  
Zoleikha Sadat Javadi

Objectives: The purpose of the present study was to evaluate the antimicrobial effect of various sizes and concentrations of zinc oxide (ZnO) nanoparticles on Streptococcus mutans (S. mutans), Enterococcus faecalis (E. faecalis), Lactobacillus fermentum (L. fermentum), and Candida albicans (C. albicans). Materials and Methods: Solutions at the concentration of 10 µg/ml were prepared using 20-nm, 40-nm, and 140-nm nano ZnO (nZnO) powder. The antimicrobial     effect of nZnO was determined using the disk diffusion method. The inhibition       zone (mm) was measured using a ruler. Data were analyzed by analysis of variance (ANOVA) and the Bonferroni correction. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of nZnO were      determined using the broth microdilution method in Mueller-Hinton Agar (MHA) for S. mutans and E. faecalis, De Man, Rogosa, and Sharpe (MRS) agar, and Sabouraud Dextrose Agar (SDA). Results: The greatest inhibition zones were observed against S. mutans with 20-nm and 40-nm nZnO, while 140-nm nZnO formed the greatest inhibition zones against S. mutans and E. faecalis. The smallest inhibition zones were observed against C. albicans with the three nZnO particle sizes. The MICs for C. albicans with 40-nm and 140-nm particles and for L. fermentum with 140-nm particles were higher than 10 µg/ml. A significant correlation was found between the particle size and the antibacterial activity against S. mutans (P=0.00), L. fermentum, and E. faecalis (P<0.02).   Conclusion: The antimicrobial activity of nZnO increases with decreasing the particle size. The greatest antimicrobial effect was observed against S. mutans and E. faecalis. S. mutans is more sensitive to the changes in the particle size compared to other bacteria.


2020 ◽  
Vol 22 (4) ◽  
pp. 314-320
Author(s):  
Svetlana A. Egorova ◽  
L.A. Kaftyreva

Objective. To evaluate effectiveness of the various approaches to fluoroquinolone susceptibility testing of Salmonella, including S. typhi, taking into account molecular resistance mechanisms. Materials and Methods. The MIC values of ciprofloxacin were compared with the inhibition zone for pefloxacin disc, 5 mg (310 isolates) and nalidixic acid, 30 mg (420 isolates). MIC of ciprofloxacin was determined by gradient diffusion test and broth microdilution method. Muller – Hinton agar and Muller – Hinton broth, antibiotic discs and MICE-tests (Oxoid, UK) were used. Chromosomal mutations in QRDR of gyrA, gyrB, parC, and parE genes and plasmid-mediated quinolone resistance genes (qnr, aac-(6’)-1b etc.) were detected in 19 Salmonella isolates by analysis using ResFinder service (Center of Genomic Epidemiology). Genomic DNA libraries were prepared using the MiSeq Nextera XT Library Preparation Kit (Illumina, USA). WGS was performed on MiSeq (Illumina, USA) with MiSeq Reagent Kit v3 600 cycles (Illumina, USA). Genome assembly and analysis were performed using CLC Genomics Workbench 8.0 (Qiagen, USA). Results. Despite the high concordance of ciprofloxacin MIC values and the results of disc diffusion screening with pefloxacin (96.5% of isolates) and nalidixic acid (98.1% of isolates), the results obtained for some resistant isolates were inconsistent. When those isolates were tested by a single method, there was a possibility of incorrect susceptibility categorization. Discordant results were obtained for 19 isolates and had the objective reason (paradoxical resistance phenotype due to the plasmid-mediated resistance, qnrS) in 3 cases. Other discrepancies were noted when the values were equal to the clinical breakpoints: ciprofloxacin MIC – 0.06 mg/l, inhibition zone for pefloxacin – 24 mm. Repeated testing revealed the variations around the clinical breakpoints: the MIC values of 0.06–0.12 mg/l, and inhibition zone of 23 to 25 mm. Conclusions. When performing fluoroquinolone susceptibility testing of Salmonella, it is reasonable to add the category “Area of Technical Uncertainty”: ciprofloxacin MIC value of 0.06 mg/l, and inhibition zone for pefloxacin of 23 to 25 mm. Two discs (pefloxacin and nalidixic acid) should be used for fluoroquinolone resistance screening by disk diffusion method.


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