Diameter Of Growth Inhibition Zone Research Articles

New Insights into Detection of a Dendrobine Compound From a Novel Endophytic Trichoderma longibrachiatum Strain and Its Toxicity Against Phytopathogenic Bacteria.

Dendrobium nobile is the only plant that could produce the natural bioactive dendrobine. No other source of dendrobine has been found to date except from D. nobile and via chemical synthesis. In this study, we aimed to examine the potential fungal endophyte isolated from D. nobile stem segments using the molecular method and to detect dendrobine compound through high-performance liquid chromatography (HPLC), gas chromatography–mass spectrometry (GC-MS), and liquid chromatography with tandem mass spectrometry (LC-MS/MS) and their metabolite for their antibacterial activity. The potential dendrobine producer strain was recognized as Trichoderma longibrachiatum based on molecular DNA sequencing and GenBank databases. The T. longibrachiatum MD33 produced dendrobine and other compounds in a potato dextrose medium (PDM), as confirmed by HPLC retention time peak analysis. The HPLC results revealed that T. longibrachiatum MD33 biomass showed a peak retention time of 5.28 ± 0.2 min, similar to wild D. nobile stem dendrobine (5.32 ± 0.2 min) and standard chemical reference dendrobine (5.30 ± 0.2 min), indicating the presence of dendrobine in the fungal biomass. Results of GC-MS and LC-MS analysis revealed that T. longibrachiatum MD33 produced the same molecular weight (263 in GC-MS and 264.195 in LC-MS) of dendrobine as compared with standard chemical reference dendrobine and D. nobile dendrobine. Antibacterial activity data revealed that T. longibrachiatum MD33 produced the strongest bactericidal activity against Bacillus subtilis, Bacillus mycoides, and Staphylococcus species, and the diameter of the bacterial growth inhibition zone was 12 ± 0.2, 9 ± 0.2, and 8 ± 0.2 mm, respectively. To the best of our knowledge, this was the first study to investigate T. longibrachiatum as a dendrobine producer, and the results revealed that T. longibrachiatum was directly involved in the potential production of a similar bioactive compound to D. nobile (dendrobine). In addition, the T. longibrachiatum metabolite exhibited potent antibacterial activity and can be a potential strain for medical and industrial purposes.

<i>In vitro</i> efficacy of five commercially available herbal preparations used in the treatment of typhoid fever in Bamenda Municipality, Cameroon

Typhoid fever is an infectious disease that has been a public health concern for millennia. The use of herbal preparations is getting popularity, with an estimated 80% of the world’s population still depending on it for the management of various diseases including typhoid fever. However, data concerning their quality, safety and efficacy is not readily available. Our aim was to determine the in vitro efficacy of some commercially available herbal preparations used in the treatment of typhoid fever in Bamenda Municipality. Five herbal preparations indicated for the treatment of typhoid fever (coded P1 to P5) were bought from various outlets of the herbal producers and serial dilutions made and screened for their activities against clinical isolates of Salmonella Typhi and Salmonella Paratyphi using the agar well diffusion and dilution methods. The bacterial growth inhibition zone diameters of the herbal preparations were measured with a transparent ruler and compared with those of some standard antibiotics (ciprofloxacin and ceftriaxone). Two of the herbal preparations (P1 & P2) showed inhibition zone diameters against S. Typhi (20 and 14 mm respectively) while the rest (P3, P4 & P5) were inactive. P1 showed minimal activity on S. Paratyphi while the rest of the herbal preparations (P2, P3, P4 and P5) were inactive at all tested concentrations. The difference between the value of the inhibition zone diameters of the herbal preparations and that of the standard antibiotics on both S. Typhi and S. Paratyphi was statistically significant (p<0.05). It was found out that most of the herbal preparations showed no activity against the tested bacterial isolates contrary to their label bogus claims.Keywords: Antibacterial activity, Typhoid fever, Herbal preparations, in vitro, Bamenda-Cameroon.

Effect of Addition of Nano-TiO2, Nano-SiO2, and a Combination of Both, on Antimicrobial Activity of an Orthodontic Composite

This study aimed to assess the effect of addition of nano-titanium oxide (nano-TiO2), nano-silicon dioxide (nano-SiO2), and a combination of both, on antimicrobial activity of an orthodontic composite. Molds measuring 0.64 × 0.5 mm were used for the fabrication of composite disks. For this purpose, 0.5% and 1% nano-TiO2, nano-SiO2, and a combination of both (0.5% nano-TiO2 and 0.5% nano-SiO2), were mixed with Transbond XT composite (3M Unitek). A total of 180 composite disks were fabricated for eluted component, disk agar diffusion (DAD), and biofilm inhibition tests. The colony counts of Streptococcus mutans (S. mutans), Streptococcus sanguinis (S. sanguinis), and Lactobacillus acidophilus (L. acidophilus) and the diameters of growth inhibition zones were measured at 3, 15, and 30 days after exposure to the materials. Data were analyzed using one-way ANOVA and a post hoc test. None of the nano-TiO2 and nano-SiO2 concentrations had any significant effect on the growth inhibition zone. All tested concentrations of nano-TiO2 and nano-SiO2 decreased the colony count of all bacteria. The composite sample containing both nano-TiO2 and nano-SiO2 had the greatest efficacy for reduction of S. mutans and S. sanguinis colony counts at all three time points. Also, 1% nano-TiO2 and 1% nano-SiO2 had similar effects on L. acidophilus in eluted component test. Addition of TiO2 and SiO2 nanoparticles conferred antimicrobial property to the tested orthodontic composite. Using orthodontic composite containing nonoparticles with antibacterial activity may prevent dental caries.

Antimicrobial effect of chloroform Hibiscus sabdariffa extract on pathogenic bacteria

Objective: The aim of this study was to determine the antimicrobial effect of Hibiscus sabdariffa extract on oral and dental bacterial pathogens. Materials and Methods: In this study, the extract of H. sabdariffa was isolated by maceration with chloroform and concentrated by a rotary evaporator. The antimicrobial effects were examined using broth microdilution, and minimum inhibitory concentration and minimum bactericidal concentration values were determined. Next, the effect of different concentrations of extract on the growth of Streptococcus pyogenes, Streptococcus mutans, and Streptococcus salivarius was investigated by disc diffusion method. Finally, the data were analyzed using SPSS 16 software (SPSS Inc., 233 South Wacker Drive, 11th Floor, Chicago, IL 60606-6412), and the results were presented as mean (± standard deviation). Results: The results of this study showed that the chloroform extract of H. sabdariffa had inhibitory and bactericidal effects on three bacteria in both broth microdilution and disc diffusion methods. In broth microdilution, S. mutans and S. salivarius were more resistant to H. sabdariffa extract than S. pyogenes. In disc diffusion method, the highest inhibitory effect of the extract was observed on S. pyogenes at 25 μg/ml with a growth inhibition zone diameter of 13.03 ± 0.15 mm. Conclusion: According to the results of this study, it can be argued that the chloroform extract of H. sabdariffa is effective in inhibiting S. pyogenes, S. mutans, and S. salivarius in both broth microdilution and disc diffusion methods.

Cyathea gigantea (Cyatheaceae) as an antimicrobial agent against multidrug resistant organisms

BackgroundRapid emergence of multidrug resistant (MDR) organisms in hospital and community settings often result into treatment failure, thus leading the clinicians with fewer treatment options. Cyathea gigantea, an ethnomedicinally important fern used in cuts and wound infections. So, if this medicinal plant is used in treating the MDR infections then it might bring certain relief in future treatment options.MethodsAntibacterial activity of C. gigantea against MDR bacteria was assed using well diffusion and broth microdilution methods to determine the diameters of growth inhibition zones, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Synergistic activity was also determined with the conventional antibiotics by disc diffusion method followed by FIC index of each of the tested antibiotic was calculated. The active extract was then subjected to fractionation by column chromatography and antibacterial activity was done with each of the collected fractions.ResultsCrude extract of C. gigantea was found to be active against all the tested organisms. The MIC was 200 μg/ml against Gram-positive i.e., Staphylococcus aureus ATCC 25923 and 400 μg/ml against Gram-negative i.e., Escherichia coli ATCC 25922 and Pseudomonas aeruginosa PAO1, while the MBC was 400 μg/ml in case of Gram-positive and 800 μg/ml for Gram-negative. The synergistic activity revealed that the plant extract increased the antibacterial property of the studied antibiotics and the FIC index showed that significant synergistic activity was shown by ciprofloxacin followed by tetracycline, ampicillin and oxacillin. Antibacterial activity with the fractionated extract showed that the FR II, FR III and FR IV were active against both Gram-positive and Gram-negative bacteria, whereas FR I, FR V and FR VI did not show antibacterial property against any of the tested bacteria.ConclusionsExtracts of C. gigantea was found active against both selected Gram-positive and Gram-negative organisms and thus offers the scientific basis for the traditional use of the fern. The present study also provides the basis for future study to validate the possible use against multidrug resistant organisms.

Investigating The Antimicrobial Activity Of Different Root Canal Filling Pastes In Deciduous Teeth.

BackgroundThe antiseptic property of root canal filling materials is very important for the removal of residual pathogens from root canals. The aim of the current study was to investigate the antimicrobial activity of mineral trioxide aggregate (MTA), calcium hydroxide (CH), Metapex, zinc oxide eugenol (ZOE), and CEM-cement.Materials and methodsFour standard bacterial strains including Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 29212), Pseudomonas aeruginosa (ATCC 27853), and Bacillus subtilis (ATCC 6633) and Candida albicans (ATCC 10231) were used. On five plates containing Brain Heart Infusion (BHI) agar, five cavities were made. Then, the plates were cultured by 0.1 mL of bacterial suspension with a concentration of 0.5 McFarland. Afterwards, the cavities were filled with the tested materials and were incubated at 37 °C for 24, 48, and 72 hrs. Diameters of microbial inhibition zones were then measured.ResultsThe highest mean diameter of growth inhibition zones was observed around ZOE and then CH and CEM-cement. According to the Kruskal-Wallis test, there was a significant difference among the tested groups (P<0.041).ConclusionConsidering antimicrobial activity, CH was an acceptable alternative to ZOE.

The Effect of Subinhibitory Concentrations of trans-Anethole on Antibacterial and Antibiofilm Activity of Mupirocin Against Mupirocin-Resistant Staphylococcus aureus Strains.

Aim: The aim of this study was to evaluate the effect of subinhibitory concentrations of trans-anethole on antibacterial and antibiofilm properties of mupirocin against mupirocin-resistant Staphylococcus aureus strains. Methods: Following parameters were examined: isolates susceptibility to antibiotics, minimum inhibitory concentration (MIC) of trans-anethole, antibacterial activity of mupirocin/trans-anethole combination, detection of ileS2 gene, genotypic relativity of isolates using pulsed-field gel electrophoresis method, and the influence of mupirocin/trans-anethole combination on S. aureus biofilm formation. Results: Our study revealed that trans-anethole combined with mupirocin increased the growth inhibition zone diameter around the mupirocin disk, independently on S. aureus strains susceptibility to this antibiotic. Moreover, combination of subinhibitory (MIC50) concentration of mupirocin and trans-anethole significantly decreased biofilm biomass. Conclusions: trans-Anethole appeared efficient in increasing susceptibility to mupirocin and decreasing biofilm formation in S. aureus strains used in this study. Reduction of biofilm formation can potentially protect against S. aureus recolonization. Moreover, use of trans-anethole in combination with mupirocin can increase the mupirocin activity against methicillin-resistant and mupirocin-resistant S. aureus strains.

Inhibitory activity of Lactobacillus plantarum ATCC 8014 fermented milk combined with aqueous extract of Moringa oleifera leaves against Streptococcus mutans

The growth inhibitory activity of Lactobacillus plantarum ATCC 8014 (Lp) fermented milk combined with aqueous extract of Moringa oleifera leaves against Streptococcus mutants has been studied. The preparation is potential developed as healthy food due to its nutritional value as well as its beneficial activities. The well agar diffusion method was applied for the antibacterial assay on nutrient agar media and local strain of Streptococcus mutants was used as a bacterial test. This species often causes infectious in the teeth. Effectiveness of the fermented milk and its combination with aqueous extract preparations against the bacterial test were assessed by minimum inhibitory concentration (MIC) for the potency indication. The aqueous extract of Moringa oleifera leaves was prepared as infuse like according to community daily consumption. Concentration of the extract used in the formulation was higher than the MIC. The result showed that the MIC of the aqueous extract of Moringa oleifera leaves and the L. plantarum fermented milk were 20% and 35% with growth inhibition zone diameter of 11.70 ± 0.28 mm and 12.02 ± 0.83 mm, respectively. The combination of fermented milk and aqueous extract was prepared in various ratio concentration (1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1). The optimum ratio of the combination was 2:8 with growth inhibition zone diameter of 16.53 ±0.32 mm and the MIC value at optimum ratio was 45% with inhibition zone diameter of 11.90 ± 0.86 mm.

Evaluating the Effects of Peracetic Acid and Chlorine Dioxide Disinfectants on Staphylococcus Aureus Isolated from Surfaces of NICU

Introduction: Today, disinfection of surfaces by using antimicrobial agents is critical for the prevention and control of pathogens and reduction of infection in hospital. The aim of this study was to investigate and compare the effects of two disinfectants against Staphylococcus aureus isolated from the NICU of Shahid Sadoughi Hospital of Yazd in 2017. Materials and Methods: In this descriptive cross sectional study, bacterial culture of samples collected from different surfaces of the NICU and S. aureus isolates were identified using conventional biochemical tests. Peracetic acid and chlorine dioxide various concentrations were used as disinfectants. Their effects against Staphylococcus aureus were determined by Standard disc diffusion method. Data were analyzed by linear mixed models in SPSS version 23. Results: 39.39% of samples were found to be S. aureus infected. The mean diameter of growth inhibition zone for peracetic acid 0.1% was significantly lower than that for peracetic acid 0.2%, and peracetic acid 0.1% was significantly higher than that for chlorine dioxide (P &lt; 0.001). The comparison of growth inhibition zone diameters for peracetic acid 0.1% and chlorine dioxide disinfectants showed that the average diameter of the inhibition zone created by peracetic acid 0.1% was significantly higher than that created by chlorine dioxide. The most effective disinfectant on S. aureus strains isolated was peracetic acid 0.2% and the least effective disinfectant was chlorine dioxide. Conclusion: In health care facilities with S. aureus infection, peracetic acid 0.2% can be used effectively to reduce nosocomial infection rate.

The Effect of Efficient Bioactive Nano-Emulsion Formulation Based on Polylophium involucratum on Improving Quality Features of Green Tiger Pawn Fridge Storage

Background: Food industry experts have tried to use these structures in order to integrate the functional food hydrophobic constituents in food networks in recent years. Objectives: The present research is conducted to investigate the effect of a natural emulsion of Polylophium involucratum essential oil and its function in increasing the storage duration of green tiger prawn. Methods: The antimicrobial feature of the nano-emulsions through agar diffusion and the vapor phase, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods are studied. Results: The average size of the 10% nano-emulsion particles prepared was 68.3 nanometers. The average diameter of Staphylococcus aureus and Escherichia coli growth inhibition zone for nano-emulsion in agar diffusion was 10.4 and 9 mm, respectively. The average diameter of growth inhibition zone in vapor phase diffusion for 10% nano-emulsion against both of the mentioned bacteria was zero. MIC and MBC amounts for 10% nano-emulsion obtained 50000 µg/L against S. aureus and 25000 µg/L for E. coli. Moreover, pH, weight decrease percentage, and total viable count (TVC), and psychrotrophic total count (PTC) microbial indices in nano-emulsion treatments underwent fewer changes as compared with the control treatment. In addition, color evaluation results indicated that meaningful changes do not exist between nano-emulsion treatments (P > 0.05). Conclusions: Using 10% nano-emulsion based on Polylophium involucratum is recommended for decreasing the microbial count and enhancing the storage.

Antifungal and growths regulation activity of new metal-organic compounds

The aim of present paper is to study the antifungal activity of the new platinum, palladium and copper chelate complexes with different organic ligands against Fusarium strains and to determine the influence of these compounds on the germination energy and seed germination of investigated grain crops. Methods. In vitro antifungal activities of new chelate complexes were studied by the agar disk diffusion method. New complexes were tested against pathogenic Fusarium strains such as — F. culmorum 3260/4, F. verticillioides and F. sporotrichioides. The toxic effect of new complexes was evaluated according to changes in germination power and seed germination of grain crops — winter wheat, vernal barley and maize. The determination of these characteristics was carried out in accordance with the standard demands. Results. Our results revealed that palladium complex H exhibited fungicidal activity against F. culmorum 3260/4 and fungistatic activity against F. verticillioides with growth inhibition zone diameter 25 mm ad 20 mm respectively. Copper complex 2 showed a moderate fungicidal effect against F. culmorum 3260/4 strain (inhibition zone diameter 12 mm). The treatment of grain crops seeds with the H and 2 complexes demonstrated the less toxicity than standard agent — commercial fungicide tebuconazol. These complexes had also less negative influence on the germination power for all test cultures than tebuconazol. Copper complex 2 showed a noticeable growth promoting effect on studied seeds compared to seeds under conditions without treatment. Conclusions. Thus, the studied complexes can be considered as promising antifungal agents with growth regulating properties. The directional modification of the complexes to obtain the more potent derivatives will be performed.Keywords: metal-organic compounds, antifungal, growths regulation activity.

Bioactive compounds, antioxidant and antimicrobial activities of Arum maculatum leaves extracts as affected by various solvents and extraction methods.

The different species of Arum maculatum plant can be found in all over the world, and a wide range of medicinal applications has been mentioned for them. Thus, it can also be valued as a source of natural compounds with antioxidant and antimicrobial activities. In this study, the effect of solvents (water, ethanol, ethanol:water (50:50)) and extraction methods (maceration and ultrasound) on the extraction yields and bioactive properties of extracts were analyzed. The antioxidant capacity of Arum maculatum leaves extracts was investigated, and the concentrations of total phenolics, tocopherols, tannins and flavonoids were determined. 1,1‐diphenyl 2‐picrylhydrazyl free radical (DPPH), β‐Carotene bleaching, and oxidative stability index (OSI) were used to determine antioxidant activity. The ability to scavenge radicals was measured in these experiments by the discoloration of the solution. Also, the antimicrobial activity of different extracts against Gram‐positive (Staphylococcus aureus and Listeria monocytogenes) and Gram‐negative bacteria (Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa) was evaluated by using of microdilution and agar diffusion assays. The results demonstrated that ultrasonic extracts (especially ethanol:water (50:50) solvent) had the higher extraction yield and antioxidant potential than maceration extracts. All extracts were effective against all tested bacteria, and Listeria monocytogenes was the most sensitive bacterium with lowest MIC value (12.5 mg/ml) and biggest diameter of growth inhibition zone (13.77 mm). Generally, this Arum maculatum leaves extracts can be suggested as an economical source of antioxidant and antimicrobial agents and can be a suitable substitute for artificial and chemical food preservatives.

The Antifungal Effects of Two Herbal Essences in Comparison with Nystatin on the Candida Strains Isolated from the Edentulous Patients

The aim of this study is to evaluate the anticandidal effects of essential oils derived from fennel (Foeniculum vulgare) and cumin (Cuminum cyminum) on Candida strains isolated from edentulous patients. Candida samples were isolated from 30 edentulous patients and the strains were identified using the CHROMagar method. Using the macro-broth dilution method and punched-hole tests, the effectiveness of fennel and cumin essential oils (prepared through distillation by water) was clarified. Nystatin was used as a positive control. Nystatin (44 μg/mL) had the strongest antifungal effect, followed by cumin [minimum inhibitory concentration (MIC) = 662 μg/mL; minimum fungicidal concentration (MFC) = 630 μg/mL] and fennel (MIC = 1,074 μg/mL; MFC = 1,227 μg/mL). The average diameter of the fungal growth inhibition zone was 23 mm for Nystatin, 14 mm for cumin essential oil, and 5 mm for fennel essential oil. The anti-Candida effects of fennel and cumin show promise as alternatives to conventional drugs for the treatment of Candida infections.

Antioxidant activity and antibacterial evaluation of new thiazolin-4-one derivatives as potential tryptophanyl-tRNA synthetase inhibitors

The rapid emergence of bacterial resistance to antibiotics currently available for treating infectious diseases requires effective antimicrobial agents with new structural profiles and mechanisms of action. Twenty-three thiazolin-4-one derivatives were evaluated for their antibacterial activity by determining the growth inhibition zone diameter, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC), against gram-positive and gram-negative bacteria. Compounds 3a–c, 3e–h, 6b–c and 9a–c expressed better MIC values than moxifloxacin, against Staphylococcus aureus. Compounds 3h and 9b displayed similar effect to indolmycin, a tryptophanyl-tRNA ligase inhibitor. Due to their structural analogy to indolmycin, all compounds were subjected to molecular docking on tryptophanyl-tRNA synthetase. Compounds 3a–e, 6a–e, 8 and 9a–e exhibited better binding affinities towards the target enzymes than indolmycin. The antioxidant potential of the compounds was evaluated by four spectrophotometric methods. Thiazolin-4-ones 3e, 6e and 9e presented better antiradical activity than ascorbic acid, trolox and BHT, used as references.

Comparative study of antimicrobial activity of composite semisolid dosage forms for differentiated therapy of foot mycosis

The aim of work is the study of antimicrobial activity of composite semisolid dosage forms for differentiated therapy of foot mycosis with 2-mercaptobenzthiazol and chinozol, namely the paste on emulsive base and the ointment on hydrophilic delivery vehicle. Materials and methods . As the objects of investigation, the paste on emulsive base and the ointment on methylcellulose glycerogel, providing optimal releasing of 2-mercaptobenzthiazol and chinozol from the delivery vehicle and also appropriate semisolid dosage forms (placebo) were used. Antimicrobial activity of paste for nails, ointment for external use and their delivery vehicle was determined for Candida albicans fungi by diffusion into agar method. Candida albicans fungi take second place by the frequency of foot mycosis occurrence after dermatophytes and gram-positive ( Staphylococcus aureus ), gram-negaitive ( Pseudomonas aeruginosa ) pathogenic bacteria because of high frequency of mixtinfection joining the foot mycosis. As the references the well-known antimycotic medications which are registered in Ukraine and for enough time have been used in practice of foot mycosis therapy – cream “Clotrimazole 1 %” (Salutas Pharma, Germany), cream “Exoderil 1 %” (GlaxoSmithKline Pharmaceuticals S.A., Poland), ointment “Kanespor 1 %” (Kern Pharma S.L., Spain) were used. Results . It was revealed that investigated pharmacotherapeutic medicines are characterized by high efficacy for above mentioned microflora. Bases of experimental dosage form have a moderate antimycotic and antibacterial activity caused by onycholytics (salicylic and benzoic acids) and keratolytic (carbamide) presence in formulations. In comparative microbiological studies it was established that the experimental paste for onychomycosis therapy, which contains the composition of nonspecific antimycotics and onycholytics, noticeably surpasses one of the most effective medications – ointment “Kanespor” by the area of growth inhibition zone for pathogenic fungi Candida albicans and gram-negaitive bacteria Escherichia coli and Pseudomonas aeruginosa . It was revealed that by the diameter of growth inhibition zone for above mentioned microorganisms the developed ointment surpasses such modern remedies as cream “Clotrimazole 1 %” and cream “Exoderil 1 %”, which are widely used in topical treatment of dermatological mycosis. Conclusions . Obtained results of antimicrobial activity study of composite semisolid dosage forms for differentiated therapy of foot mycosis on the base of combination of 2-mercaptobenzthiazol and chinozol allow to predict their high clinical value and possibility of providing the domestic dermatology with affordable and effective pharmacotherapeutic medicines, creating the real alternative to import products.

Biodiversity and antibacterial screening of endophytic fungi isolated from Pelargonium sidoides

To investigate the biodiversity of endophytic fungi isolated from indigenous Pelargonium sidoides plants using morphological and molecular techniques and also screen isolates for antibacterial activities.In the present study, a total of 50 Pelargonium sidoides plants were collected and the roots were analysed for the presence of endophytic fungi. The fungi were initially sorted according to morphological characteristics. Fungal identities were further confirmed through amplification of sequences encoding Translation Elongation Factor-1α (TEF-1α) gene for Fusarium species and Internal Transcribed Spacer (ITS) regions for all other fungi. Fungi were screened for antibacterial activity by adopting the standard Kirby-Bauer agar disc diffusion method using a pathogenic Escherichia coli strain (Code from the collection) previously isolated from cattle. A total of 133 fungi belonging to 32 genera were successfully isolated and identified in the study based morphological analyses. Fungi belonging to the genus Penicillium were dominant (23%) among the isolates when compared with Fusarium species (12%) as well as Alternaria and Aspergillus that were detected at 11% respectively. Antibacterial agent producing data revealed that Aspergillus sp. (KM458796.1), Penicillium expansum (LC015096.1) and Aspergillus niger (KP172477.1) produced the strongest bactericidal activity against the E. coli strain with growth inhibition zone diameter data of 11mm, 5mm and 4mm respectively. To the best of our knowledge, this is the first study in which the diversity of fungi from Pelargonium sidoides has been assessed and the findings revealed that fungal diversity is directly related to their potential to produce bioactive compounds.

Antibacterial Evaluation and Virtual Screening of New Thiazolyl-Triazole Schiff Bases as Potential DNA-Gyrase Inhibitors.

The global spread of bacterial resistance to drugs used in therapy requires new potent and safe antimicrobial agents. DNA gyrases represent important targets in drug discovery. Schiff bases, thiazole, and triazole derivatives are considered key scaffolds in medicinal chemistry. Fifteen thiazolyl-triazole Schiff bases were evaluated for their antibacterial activity, measuring the growth inhibition zone diameter, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC), against Gram-positive (Staphylococcus aureus, Listeria monocytogenes) and Gram-negative (Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa) bacteria. The inhibition of S. aureus and S. typhimurium was modest. Compounds B1, B2, and B9 showed a similar effect as ciprofloxacin, the antimicrobial reference, against L. monocytogenes. B10 displayed a better effect. Derivatives B1, B5–7, B9, and B11–15 expressed MIC values lower than the reference, against L. monocytogenes. B5, B6, and B11–15 strongly inhibited the growth of P. aeruginosa. All compounds were subjected to an in silico screening of the ADMET (absorption, distribution, metabolism, elimination, toxicity) properties. Molecular docking was performed on the gyrA and gyrB from L. monocytogenes. The virtual screening concluded that thiazolyl-triazole Schiff base B8 is the best drug-like candidate, satisfying requirements for both safety and efficacy, being more potent against the bacterial gyrA than ciprofloxacin.

A COMPARATIVE STUDY OF THE PHYTOCHEMICALS, ANTIOXIDANT AND ANTIBACTERIAL POTENTIAL OF METHANOLIC EXTRACTS OF TRICHOSANTHES CUCUMERINA (L.) VAR. CUCUMERINA UNDER IN VITRO CULTURE AND NATURAL CONDITIONS

Objective: To compare the phytochemicals, antioxidative capacity and antibacterial profile of methanolic extracts of callus and naturally propagated plant species-Trichosanthes cucumerina (L.) var. cucumerina and to optimize an ideal protocol for in vitro callus and shoot induction.Methods: The sterilized seeds of Trichosanthes cucumerina (L.) var. cucumerina were inoculated in half Murashige and Skoog (MS) basal medium devoid of growth hormones to raise aseptic seedlings. Explants from aseptic seedlings used for callus induction in MS medium fortified with varying combinations of N6–Benzyl amino purine (BAP), 1-Naphthalene acetic acid (NAA) and 2,4–Dichlorophenoxy acetic acid (2,4-D). For in vitro soot induction, MS medium supplemented with different concentrations of 2,4-D, BAP and Kinetin-either alone or in combinations were employed. The callus harvested on 21st and 45th days were analyzed for a comparison of the influence of age of callus on the quantity of secondary metabolites. For a comparison with the naturally grown plant, all experiments were carried out with extracts from callus and wild plants. The antioxidant capacity of methanolic extracts was evaluated by 2,2-Diphenyl-1 Picryl Hydrazyl (DPPH) free radical scavenging assay and Ferric Reducing Antioxidant Power (FRAP) analysis. The antibacterial activity of were screened by the agar diffusion method using pathogenic bacteria such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus and documented through measurement of the diameter of growth inhibition zone (IZ). Results: The results on in vitro culture indicated that MS medium with BAP (0.5 mg/l) and 2,4-D (1 mg/l) was ideal for callus induction. For shoot induction, supplementation of MS medium with BAP-0.5 mg/l, 2,4,D-1.0 mg/l and Kinetin-0.5 mg/l was found to be most favourable. Direct root induction from the callus was found to occur in medium fortified with BAP-0.5 mg/l, 2,4, D-0.5 mg/l and NAA-1.0 mg/l. The phytoconstituents quantified were alkaloids, flavonoids, tannins, phenols and terpenoids and their levels were higher in wild plant in comparison to callus. Naturally grown plant possesses higher free radical scavenging ability and ferric reducing power than callus. Results of antibacterial activity indicated that the Gram-positive strain (Staphylococcus aureus) was more sensitive than the Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The highest antibacterial activity recorded for naturally propagated plant extract against S. aureus (IZ = 13 mm) and was quite comparable with standard antibiotic cephatoxim (IZ = 20 mm) at 100mg concentration.Conclusion: Results concluded that this overexploited medicinal plant with lesser seed longevity could be successfully propagated by in vitro methods. The phytoconstituents with antioxidative and antibacterial potential were more abundant in naturally propagated plants than undifferentiated callus tissue. The extracts are potent antibacterial agents.

In Vitro Study the Effects of Anti-Fungal Agents on the Mycelial Growth of Aspergillus Niger

The purpose of this study was to determine the sensitivity of Aspergillus niger to antifungal agents (Terbinafine, Nystatin and Clotrimazole) by using several parameter include minimum inhibitory concentration (MIC), inhibition zone diameter and spores growth test. MIC value of Terbinafine showed highly effect compere with Clotrimazole and Nystatin. The in vitro study revealed that the Terbinafine have the potential to inhibit mycelial growth (inhibition zone diameter) of Aspergillus niger at concentrations of 1%, whereas Clotrimazole and Nystatin have lowest effect to inhibit mycelial growth of Aspergillus niger at concentrations of 1% and 100000 IU/ml respectively. Spore growth test for Terbinafine showed no growth of Aspergillus niger spores on SDA media through incubation in SDA at 28oC for 5 days, While Clotrimazole showed no growth of Aspergillus niger spores on SDA media in the 3ed days of incubation, and Nystatin showed no growth of Aspergillus niger spores in the 5th day of incubation at same condition.

A Comparative Evaluation of Antimicrobial Effect of Thymus capitatus Ethanolic Extract on the Different Respiratory Tract Infections Isolates

Natural components, particularly those derived from medicinal plants, provide a promising source of new antimicrobial agents for the treatment of respiratory infections. In this work, we studied the antimicrobial potency of Thymus capitatus ethanolic extract against nine microorganisms isolated from clinical material obtained from patients admitted to hospitals in Egypt and Germany with infections of the respiratory tract (bacterial sinusitis, laryngitis, pharyngitis and bronchitis) using the disc diffusion assay and minimum inhibitory concentration (MIC) values. All isolates obtained from the Giessen University Clinic (Germany) exhibit susceptibility of different extent to the plant extract tested. The growth inhibition zone diameters for nine strains were in the range of 13–15.5 mm at a concentration of 5 mg/disc. The extract produced large inhibition zones of 14–17 mm diameters for seven microbial strains obtained in Egypt although it failed to inhibit the growth of isolates of Staphylococcus epidermidis and Enterococcus faecalis. In fact, most of the respiratory tract infections isolates from Egypt were generally more susceptible to the ethanolic extract of Thymus capitatus at lower MIC values than those obtained from Giessen University Clinic MIC values. The results of this study suggest that further delineation of bioactive phytomolecules of Thymus capitatus ethanolic extract will improve their potential application for the treatment of respiratory tract diseases.