SEARCH FOR ANTIMICROBIAL AGENTS: QUINOXALINE AS A PROMISING TARGET

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (07) ◽  
pp. 5-9
Author(s):  
R. G Ingle ◽  
◽  
S. J. Wadher
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
E Coli ◽  
Promising Target ◽  
Quinoxaline Derivatives

A set of ten new 2,3-diphenyl-6-sulfonamido quinoxaline derivatives was synthesized and screened for antimicrobial activity by disk diffusion method. Test derivatives R3, R5, R’’1 and R’’2 show promising results against bacterial strains S. aureus gram positive and E. coli gram negative organism with the concentration 1000 μg/mL in disk diffusion method. Rest of the derivatives show sensitivity against the same organisms. All the synthesized derivatives were confirmed by their spectral data.

scholarly journals An Efficient Approach to the Synthesis of Novel Oxazolidinones as Potential Antimicrobial Agents

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Kavita Devi ◽  
Yumna Asmat ◽  
Sonika Jain ◽  
Swapnil Sharma ◽  
Jaya Dwivedi
Keyword(s):  
Medicinal Chemistry ◽  
Antimicrobial Agents ◽  
Biological Activities ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Efficient Approach ◽  
Fungal Strains

Oxazolidinone, either mononuclear or condensed with other heterocyclics, has established its importance in medicinal chemistry. A variety of biological activities have been reported by oxazolidinone derivatives. The present work describes the synthesis of several oxazolidinone derivatives, 3-(2-(7-chloroquinoline-4-ylamino)ethyl)-2-imino-5-(4-chloro/nitro/methoxy benzylidene)oxazolidin-4-one 4(a–c) and 4-(2-(7-chloroquinolin-4-ylamino)ethyl)-2(4-chloro/nitro/methoxy-benzylidene)-1,6-diox-4,9-di-azaspiro[4,4]nonane-3,8-dione 5(a–c). Synthesized compounds (1, 3, 4a, 5a, and 5c) were screened against bacterial strains such asS. aureus(MTCC 96) andE. coli(MTCC119) and fungal strainsA. niger(MTCC 1344) andC. albicans(MTCC 871) compared with penicillin for bacteria and fluconazole for fungi as reference drugs by disk diffusion method. All synthesized compounds were identified by the means of IR, NMR, and MS.

scholarly journals STUDY OF VARIOUS FIVE EXTRACTS OF TRACHYSPERMUM AMMI SEEDS ON SELECTED FOUR GRAM-NEGATIVE COOKED FOOD SPOILAGE BACTERIAL STRAINS BY DISK DIFFUSION METHOD

2015 ◽  
Vol 3 (9SE) ◽  
pp. 1-3
Author(s):  
Usha Masih
Keyword(s):  
Antimicrobial Activity ◽  
Cold Water ◽  
Bacterial Species ◽  
Antibacterial Properties ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
E Coli ◽  
Trachyspermum Ammi

Bacterial foodborne diseases are caused by consumption of foods contaminated with bacteria or their toxins. This study evaluated antibacterial properties of Trachyspermum ammi Acetone, ethanol, methanol, cold water and hard water extracts of spice (Ajowan) seeds against four gram negative strains of pathogenic foodborne bacteria, E. coli O157:H7   ATCC 43888, ATCC 25922, ATCC 8739 and ATCC 43895 that cause infection and intoxication. E. coli ATCC 43888 was observed to be highly susceptible to all extracts of ajowan with absolute zones of inhibition in the range of 16mm – 23mm in diameter. This study demonstrated that spice extracts have antimicrobial activity against food-borne bacterial species and should be considered as potential antibacterial agents for addition to ready meals. The spice contain high amount of secondary metabolites due to these metabolites they have high antimicrobial activity and it can be used as good bio- preserver and it can also use for medicinal purpose.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

scholarly journals ANTIMICROBIAL ACTIVITY OF METHANOLIC EXTRACT OF LUDWIGIA PARVIFLORA L. AGAINST STANDARD BACTERIAL STRAINS AND COMPARISON OF ITS ACTIVITY WITH THAT OF STANDARD ANTIBIOTICS

2019 ◽  
pp. 430-432
Author(s):  
SHIBU GEORGE ◽  
MEVLIN JOY
Keyword(s):  
Antimicrobial Activity ◽  
Bacterial Infections ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Whole Plant ◽  
The Common ◽  
Susceptibility Tests

Objective: The objective of this study was to evaluate the antimicrobial activity of methanolic extract of Ludwigia parviflora L. using standard bacterial strains and compare its activity with that of standard antibiotics. Methods: The antibacterial activity and antibiotic susceptibility tests were done by disk diffusion method using MTCC bacterial strains. Results: The study revealed that the methanolic extract of the whole plant of L. parviflora L. was effective to inhibit the growth of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Among the tested strains, S. aureus, P. aeruginosa, K. pneumoniae, and E. coli were more susceptible to the methanolic extract of L. parviflora than the commonly using antibiotic tetracycline 30 mcg. The activity of methanolic extract was also higher than the activity of gentamicin 10 mcg against the P. aeruginosa. Conclusion: The study concluded that the crude methanolic extract of the whole plant of L. parviflora L. is a good source for antibacterial agent against S. aureus, P. aeruginosa, K. pneumoniae, and E. coli. Hence, this plant can be used as a natural alternative to the common antibiotics such as gentamicin and tetracycline against common bacterial infections after validating its pharmacological and toxicological activities.

scholarly journals In vitro Synergistic Antimicrobial Activity of Romanian Propolis and Antibiotics against Escherichia coli Isolated from Bovine Mastitis

2015 ◽  
Vol 43 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Mihaela NICULAE ◽  
Laura STAN ◽  
Emoke PALL ◽  
Anamaria Ioana PAȘTIU ◽  
Iulia Maria BALACI ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Bovine Mastitis ◽  
Antibacterial Properties ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Ethanolic Extracts

The study was aimed to characterize the chemical composition and the antimicrobial activity of Romanian propolis ethanolic extracts (EEP) against antibiotic-sensitive and antibiotic-resistant E. coli strains isolated from bovine mastitis. The preliminary antimicrobial screening was performed by a disk diffusion method, followed by determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) based on broth microdilution assay; further, the synergistic action of propolis with antimicrobial drugs was assessed by a disk diffusion method on agar containing subinhibitory concentrations of propolis. For the chemical characterisation of EEP, the flavonoids (flavones/flavonols, flavanones/dihydroflavonols) and total phenolics were evaluated by spectrophotometric methods. The phenolic compounds of these extracts were also determined using HPLC. The results indicated for Romanian propolis ethanolic extracts the typical poplar composition profile with flavonoids and phenolic acids as main biological active compounds, with chromatographic analysis data confirmed also spectrophotometrically. In addition, positively correlated with the chemical composition, a strong antimicrobial efficacy was exhibited towards E. coli strains, along with interesting synergistic interaction with antibiotics that can be further investigated to obtain propolis-based formulation with antibacterial properties. Subsequent in vitro and in vivo studies evaluating the safety and efficacy are intended to consider propolis in veterinary therapeutic protocols.

scholarly journals Resistance to multiple first-line antibiotics among Escherichia coli from poultry in Western Algeria

2020 ◽  
Vol 13 (2) ◽  
pp. 290-295
Author(s):  
Meki Boutaiba Benklaouz ◽  
Hebib Aggad ◽  
Qada Benameur
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
First Line ◽  
Resistance Level ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Mueller Hinton Agar ◽  
Western Algeria

Background and Aim: Escherichia coli can cause a number of serious infections both in human and veterinary medicine. Their management is increasingly complicated by the emergence and dissemination of multiresistance to various first-line antimicrobial agents. This study aimed to evaluate the resistance level to the commonly used antibiotics, with a focus on the first-line antimicrobial agents, in E. coli strains isolated from poultry in Western Algeria. Materials and Methods: E. coli culture was done on MacConkey agar and their identification was determined by AP20E system. For susceptibility testing, disk diffusion method to 14 antimicrobials, including first-line antibiotics, was used according to Kirby–Bauer disk diffusion method in Mueller-Hinton agar and the results were interpreted according to the Clinical and Laboratory Standards Institute guidelines. E. coli isolates were considered as multidrug resistance (MDR) when found resistant to at least one antimicrobial agent of three different families of antibiotics. Double-disk synergy and combination disk tests were used for initial screening and confirmation for extended-spectrum β-lactamases (ESBLs) production, respectively. Results: A total of 145 E. coli strains were isolated in this study. High resistance levels to various antibiotics, including commonly used first-line antimicrobial agents, were recorded in this study. The highest resistance level was observed against nalidixic acid (90.34%, n=131), followed by tetracycline (86.89%, n=126), ampicillin (82.75%, n=120), enrofloxacin (80.68%, n=117) and neomycin (80.68%, n=117), trimethoprim/sulfamethoxazole (73.79%, n=107), norfloxacin (72.41%, n=105) and cephalothin (72.41%, n=105), amoxicillin/clavulanic acid (51.72%, n=75), chloramphenicol (22.75%, n=33), nitrofurantoin (17.24%, n=25), gentamicin (13.10%, n=19), and ceftiofur (3.44%, n=5). Moreover, resistance to multiple first-line antibiotics was also demonstrated in the present study. Overall, 139 out of 145 isolates (95.86%) demonstrated MDR (resistant to at least three antibiotics). In addition, five E. coli isolates (3.44%) were confirmed to be ESBL producers. Conclusion: The alarming rate of E. coli resistant to multiple first-line antibiotics in poultry demands intensified surveillance. These results call for taking drastic measures to preserve antibiotic effectiveness and reduce the emergence risks of extensively drug-resistant and pandrug-resistant E. coli isolates.

scholarly journals Optimization of antimicrobial efficiency of silver nanoparticles against three oral microorganisms in irreversible hydrocolloid impressions

2021 ◽  
Author(s):  
Ahmad Jafari ◽  
Ramin Mazaheri Nezhad Fard ◽  
Sima Shahabi ◽  
Farid Abbasi ◽  
Golshid Javdani Shahedin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Ag Nps ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Irreversible Hydrocolloid ◽  
Predicted Model ◽  
Water Ratio

Background and Objectives: Silver nanoparticles (Ag-NPs) are potent antimicrobial agents, which have recently been used in dentistry. The aim of the current study was to optimize antimicrobial activity of Ag-NPs used in preparing irre- versible hydrocolloid impressions against three microorganisms of Escherichia coli, Streptococcus mutans and Candida albicans. Materials and Methods: After assessing antimicrobial activity of the compound using disk diffusion method, three parame- ters of concentration of Ag-NPs (250-1000 ppm), ratio of hydrocolloid impression material powder to water (0.30-0.50) and time of mixing (20.0-60.0 s), affecting antimicrobial activity of irreversible hydrocolloid impression materials against the three microorganisms, were optimized. This combined process was successfully modeled and optimized using Box-Behnken design with response surface methodology (RSM). Decreases in colony number of E. coli, S. mutans and C. albicans were proposed as responses. Results: Qualitative antimicrobial assessments respectively showed average zone of inhibition (ZOI) of 3.7 mm for E. coli, 3.5 mm for S. mutans and 4 mm for C. albicans. For all responses, when the mixing duration and powder-to-water ratio increased, the circumstances (mixing duration of 59.38 s, powder-to-water ratio of 0.4 and Ag-NP concentration of 992 response) increased. Results showed that in optimum ppm, the proportion of decreases in colony numbers was maximum (89.03% for E. coli, 87.08% for S. mutans and 74.54% for C. albicans). Regression analysis illustrated a good fit of the ex- perimental data to the predicted model as high correlation coefficients validated that the predicted model was well fitted with data. Values of R2Adj with R2Pred were associated to the accuracy of this model in all responses. Conclusion: Disinfection efficiency dramatically increased with increasing of Ag-NP concentration, powder-to-water ratio and mixing time.

scholarly journals Anti-microbial activity of heterocyclic cationic surface-active substances

2020 ◽  
Vol 24 (1) ◽  
pp. 36-40
Author(s):  
V. V. Pantyo ◽  
M. M. Fizer ◽  
O. I. Fizer ◽  
G. M. Koval ◽  
E.M. Danko
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Pathogenic Microorganisms ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Quantitative Studies ◽  
Ionic Associates ◽  
Surface Active

Annotation. The development and rapid pace of the spread of resistance to antimicrobial agents predetermines the search for new methods of counteracting pathogenic and conditionally pathogenic microorganisms. In this context, studies of the antimicrobial activity of newly synthesized chemicals, which in the future can be considered as candidates for antiseptic and disinfectants, are relevant. The aim of the work was to determine the antimicrobial activity of new ionic associates based on the surface-active cetylpyridinium cation with respect to certain opportunistic microorganisms. The antimicrobial activity of four ionic associates based on the cetylpyridinium cation with respect to clinical isolates of E. coli, P. vulgaris, K. pneumonia, P. aeruginosa, S. aureus, as well as the collection test strains of S. aureus ATCC 25923, E. coli ATCC 29522 and P. aeruginosa ATCC 27853 was studied. Screening studies were performed by the disk diffusion method. With substances that showed an antimicrobial effect, quantitative studies were carried out by the method of serial macro-dilutions in a liquid nutrient media. Screening studies revealed the antibacterial activity of the substances against E. coli ATCC 25923, E. coli (clinical isolate), P. vulgaris and K. pneumonia. With these microorganisms quantitative studies were carried out with the determination of the minimum inhibitory and minimum bactericidal concentrations. The most pronounced antimicrobial activity for the investigated microflora was shown by tetraphenylborate and cetylpyridinium perchlorate. The MIC and MBC values of these substances ranged between 1.625–3.125 mmol / L and 3.125–12.5 mmol / L, respectively. The studied associates showed high antimicrobial activity against representatives of the Enterobacteriaceae family in in vitro studies. Promising is the further study of the effect of the counter-anion associates of cationic surfactants on the biofilm formation of conditionally pathogenic microorganisms.

scholarly journals Invitro antibacterial activity of Cassia fistula Linn methanolic leaf extracts

2019 ◽  
Vol 8 (2) ◽  
pp. 270
Author(s):  
Bindhu R. Kamath ◽  
Sabeena Kizhedath
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Cassia Fistula ◽  
Leaf Extracts ◽  
E Coli

Background: Cassia fistula Linn is a plant which is widely grown in India and is used for medicinal purposes. The study was carried out with an objective to demonstrate the antimicrobial activity of leaves of Cassia fistula Linn. The aim of the study is to assess antibacterial and antifungal activity of methanolic leaf extract of Cassia fistula Linn against selected clinical isolates.Methods: The antimicrobial activity of methanolic extract of Cassia fistula was evaluated using agar well diffusion method and to zone of inhibition of extract was determined. Clinical isolates of Staphyloccocus aureus, MRSA, Pseudomonas aeruginosa, E. coli and Proteus were screened.Results: The methanolic extracts exhibited antibacterial activity against Staphylococcus aureus. The extract was not active against E. coli, Proteus, MRSA, Pseudomonas aeruginosa. The extract also failed to demonstrate antifungal activity against Candida albicans and Aspergillus niger.Conclusions: The global emergence of multidrug resistant bacterial strains is increasing, limiting the effectiveness of current drugs and treatment failure of infections. A novel approach to the prevention of antibiotic resistance of pathogenic species is the use of new compounds that are not based on existing synthetic antimicrobial agents.

scholarly journals Determination of antibiotic resistance sensitivity of Aeromonas sobria isolated from Green terror (Andinoacara rivulatus)

2019 ◽  
Vol 36 (3) ◽  
pp. 265-269 ◽  
Author(s):  
Ayşe Gül Şahin ◽  
Ahmet Turan San ◽  
Selahattin Gürçay ◽  
Serhat Murat Alkan
Keyword(s):  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Aeromonas Species ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
Aeromonas Sobria ◽  
Freshwater Bacteria ◽  
Vitek 2

Motil Aeromonas species are responsible for the formation of significant hemorrhagic septicemia in freshwater fish. Aeromonas are characteristic freshwater bacteria. They are often found in the ecosystem due to their being mobile. It is pathogenic in water, in various water creatures and in humans. In this study, it was determined that the bacterial strains obtained from Green terror (Andinoacara rivulatus) were Gram-negative, rod-shaped. VITEK-2 compact system is used for identification. Species have been identified as Aeromonas sobria. Aeromonas isolates were evaluated by 12 different antimicrobial agents in antimicrobial activity against the disk diffusion method. While cefquinome was found to be the most effective in the tested antimicrobials, the lowest sensitivity was determined against trimethoprim / sulphamethoxazole.

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