scholarly journals β-Lactamase inhibition profile of new amidine-substituted diazabicyclooctanes

2021 ◽  
Vol 17 ◽  
pp. 711-718
Author(s):  
Zafar Iqbal ◽  
Lijuan Zhai ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Second Generation ◽  
Bacterial Species ◽  
The Other ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
E Coli ◽  
Mic Value

The diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam-based second generation β-lactamase inhibitors. As part of our efforts, we have synthesized a series of DBO derivatives A1–23 containing amidine substituents at the C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds did not show antibacterial activity when tested alone (MIC >64 mg/L), however, they exhibited a moderate inhibition activity in the presence of meropenem by lowering its MIC values. The compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L to 2 mg/L, and is comparable to avibactam against both E. coli strains with a MIC value of <0.125 mg/L.

scholarly journals β-Lactamase inhibition profile of new amidine substituted diazabicyclooctanes

2020 ◽  
Author(s):  
zafar iqbal ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
Jinbo Ji ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Second Generation ◽  
Bacterial Species ◽  
The Other ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
E Coli ◽  
Mic Value

Diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam based second generation β-lactamase inhibitors. As part of our efforts we have synthesized a series of DBO derivatives A1-A23 containing amidine substituents at C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds didn’t show antibacterial activity when alone (MIC, >64 mg/L), however exhibited moderate inhibition activity in the presence of meropenem by lowering its MIC values. Compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L – 2 mg/L, and is comparable to avibactam against both E. coli strains with MIC value of <0.125 mg/L.

Synthesis and Antibacterial Activities of Amidine Substituted Monocyclic β-Lactams

2021 ◽  
Vol 17 ◽  
Author(s):  
Lijuan Zhai ◽  
Lili He ◽  
Yuanbai Liu ◽  
Ko Ko Myo ◽  
Zafar Iqbal ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Lead Target ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Clinical Interest

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.

scholarly journals Design, Synthesis and Antibacterial Activity of Coumarin-1,2,3-triazole Hybrids Obtained from Natural Furocoumarin Peucedanin

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2126 ◽  
Author(s):  
Alla V. Lipeeva ◽  
Danila O. Zakharov ◽  
Liubov G. Burova ◽  
Tatyana S. Frolova ◽  
Dmitry S. Baev ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cycloaddition Reaction ◽  
Bacterial Strains ◽  
Design Synthesis ◽  
Docking Simulations ◽  
E Coli ◽  
Antibiotic Drugs ◽  
In Vitro Antibacterial Activity ◽  
Substituted Coumarins

Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by employing the cross-coupling and copper catalyzed azide-alkyne cycloaddition reaction approaches. The synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, Bacillius subtilis, Actinomyces viscosus and Escherichia coli bacterial strains. Coumarin-benzoic acid hybrids 4с, 42с and 3-((4-acetylamino-3-(methoxycarbonyl)phenyl)ethynyl)coumarin (29) showed promising activity against S. aureus strains, and the 1,2,3-triazolyloct-1-inyl linked coumarin-2,3-furocoumarin hybrid 37c was endowed with high selectivity against B. subtilis and E. coli species. The in vitro antibacterial activity of 4с, 29, 37c and 42с can potentially be compared with that of a number of modern antibiotic drugs used in the clinic, suggesting promising prospects for further research. A detailed study of the molecular interactions with the targeted protein MurB was performed using docking simulations and the obtained results are quite promising.

scholarly journals In vitro Evaluationof the Antimi- crobial Activity of a Topical Skin Preparation Containing 0.1% Polyhexanide vs a Topical Skin Prepa-ration Containing 1% Silver Sulfadiazine

2021 ◽  
Vol 6 (2) ◽  
pp. 1-7
Author(s):  
Barbara Maglione ◽  
Keyword(s):  
Antibacterial Activity ◽  
Positive Control ◽  
Negative Control ◽  
Silver Sulfadiazine ◽  
Bacterial Strains ◽  
Skin Preparation ◽  
E Coli ◽  
Topical Cream ◽  
Significant Difference

Aim: The effective in vitro antibacterial activity on Staphylococcus aureus (S.aureus), Pseudomonas aeruginosa (P.aeruginosa), Klebsiella pneumoniae (K.pneumoniae),Escherichia coli (E.Coli) and the combination of S.aureus and K. pneumonia of a topical cream based on 0.1% polyhexanidewas compared to a topical cream based on 1% silver sulfadiazine.A topical cream containing 0,1% gentamicin was used as a positive control and a white blank topical cream was used as negative control. Materials and Methods: The in vitro antibacterial activities were determined by agar well-diffusion assay. Two-way Analysis of Variance (ANOVA) was used to test, by calculation of P-values, for significant antiseptic activity in bacteria treated with 0.1% polyhexanide topical cream compared to 1% silver sulfadiazine and to the negative and positive controls. Results: Among the derivatives tested, all the active topical creams analyzed were able to reduce microbial strains. The topical cream based on 0.1% polyhexanide showed a significantly higher antibacterial efficacy in comparison to the topical cream based on 1% silver sulfadiazine on S. aureus and K. pneumonia and on the combination of S. aureus and K. pneumoniae,while no significant difference was detected between the antibacterial activity of the two topical creams against P. aeruginosa and E. coli. Conclusion: These results provide a further insight into the antibacterial activity of polyhexanide and its non-inferiority compared to silver sulfadiazine towards certain bacterial strains (P. aeruginosa and E. coli) and superiority towards other (S. aureus and K. pneumoniae)and support the use of 0.1% Polyhexanide topical preparation for the treatment of wounds that are infected or at risk of infection.

In-vitro evaluation of cisplatin nanoparticles encompass natural polymer

2020 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Bhavani J ◽  
Sunil Kumar Prajapati ◽  
Ravichandran S
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Research Work ◽  
Dilution Method ◽  
Bacterial Strains ◽  
Active Components ◽  
Synthetic Drugs

Opportunistic bacterial infections are common in the various parts of human body. In recent years bacterial species have shown resistance against a number of synthetic drugs. This study measured the antibacterial activity of bacterial strains against five common pathogenic bacteria related strains. Cup plate method and two fold serial dilution method were used to evaluated by antibacterial activity by the help of different bacterial related strains. The results revealed that Cisplatin (CIP) using natural as a polymer showed a minimum inhibitory concentration (MIC) at 250 mg/ml to 500 mg/ml of the broth against all bacterial strains. CIP using natural as a polymer was prepared different doses1000 μg/ml and 2000 μg/ ml and measured zone of inhibition dose dementedly reduced when compared to standard. The CIP using natural as a polymer exhibited strong anti-bacterial activity against five different species of bacteria and this may be attributed to various active components. Our research work has been indicated Nanoparticles containing CIP using natural as a polymer formulated for the enhanced anti-cancer activity through antimicrobial mechanism. 

scholarly journals MIC-Based Interspecies Prediction of the Antimicrobial Effects of Ciprofloxacin on Bacteria of Different Susceptibilities in an In Vitro Dynamic Model

1998 ◽  
Vol 42 (11) ◽  
pp. 2848-2852 ◽  
Author(s):  
Alexander A. Firsov ◽  
Sergey N. Vostrov ◽  
Alexander A. Shevchenko ◽  
Stephen H. Zinner ◽  
Giuseppe Cornaglia ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Bacterial Species ◽  
Maximal Effect ◽  
Bacterial Strains ◽  
Time Curve ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Kill Curve ◽  
Time Kill

ABSTRACT Multiple predictors of fluoroquinolone antimicrobial effects (AMEs) are not usually examined simultaneously in most studies. To compare the predictive potentials of the area under the concentration-time curve (AUC)-to-MIC ratio (AUC/MIC), the AUC above MIC (AUCeff), and the time above MIC (T eff), the kinetics of killing and regrowth of four bacterial strains exposed to monoexponentially decreasing concentrations of ciprofloxacin were studied in an in vitro dynamic model. The MICs of ciprofloxacin for clinical isolates ofStaphylococcus aureus, Escherichia coli11775 (I) and 204 (II), and Pseudomonas aeruginosa were 0.6, 0.013, 0.08, and 0.15 μg/ml, respectively. The simulated values of AUC were designed to provide similar 1,000-fold (S. aureus, E. coli I, and P. aeruginosa) or 2,000-fold (E. coli II) ranges of the AUC/MIC. In each case except for the highest AUC/MIC ratio, the observation periods included complete regrowth in the time-kill curve studies. The AME was expressed by its intensity,I E (the area between the control growth and time-kill and regrowth curves up to the point where the viable counts of regrowing bacteria are close to the maximum values observed without drug). For most AUC ranges the I E-AUC curves were fitted by an E max (maximal effect) model, whereas the effects observed at very high AUCs were greater than those predicted by the model. The AUCs that produced 50% of maximal AME were proportional to the MICs for the strains studied, but maximal AMEs (I E max ) and the extent of sigmoidicity (s) were not related to the MIC. BothT eff and log AUC/MIC correlated well withI E (r 2 = 0.98 in both cases) in a species-independent fashion. UnlikeT eff or log AUC/MIC, a specific relationship between I E and log AUCeff was inherent in each strain. Although each I E and log AUCeff plot was fitted by linear regression (r 2 = 0.97 to 0.99), these plots were not superimposed and therefore are bacterial species dependent. Thus, AUC/MIC and T eff were better predictors of ciprofloxacin’s AME than AUCeff. This study suggests that optimal predictors of the AME produced by a given quinolone (intraquinolone predictors) may be established by examining its AMEs against bacteria of different susceptibilities.T eff was shown previously also to be the best interquinolone predictor, but unlike AUC/MIC, it cannot be used to compare different quinolones. AUC/MIC might be the best predictor of the AME in comparisons of different quinolones.

scholarly journals In Vitro Antibacterial Activity of Selected Medicinal Plants in the Traditional Treatment of Skin and Wound Infections in Eastern Ethiopia

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bahar Mummed ◽  
Ashebr Abraha ◽  
Teka Feyera ◽  
Adugna Nigusse ◽  
Solomon Assefa
Keyword(s):  
Antibacterial Activity ◽  
Medicinal Plants ◽  
Wide Spectrum ◽  
Bacterial Species ◽  
Wound Infections ◽  
Bacterial Strains ◽  
Traditional Use ◽  
Eastern Ethiopia ◽  
Cissus Quadrangularis

Background. External infections involving the skin and wound are the most frequent complications affecting humans and animals. Medicinal plants play great roles in the treatment of skin and wound infections. This study was aimed to evaluate thein vitroantibacterial activity of crude methanolic extracts of nine medicinal plants.Methods. Agar well diffusion and broth dilution methods were used to determine the antibacterial activity of nine Ethiopian plants against four bacterial species includingStaphylococcus aureus,Pseudomonas aeruginosa,Escherichia coli, andKlebsiella pneumoniae.Results. Among the tested plants, seven (Cissus quadrangularis,Commelina benghalensis,Euphorbia heterophylla,Euphorbia prostrate,Momordica schimperiana,Trianthemaspp., andSolanum incanum) were found to exhibit considerable antibacterial activity against at least one of the test bacteria. The extracts ofC. quadrangularis,E. heterophylla, andE. prostratahad a wide spectrum of antibacterial activities against test bacterial strains while the extracts ofGrewia villosaandSchinus molledid not show any inhibitory activity. Clinical isolate and laboratory strain of S.aureusshowed the highest susceptibility to highest concentration (780 mg/mL) ofE. prostratawith a zone of inhibition of 21.0mm and 22.3mm, respectively.Conclusion. This study indicates clear evidence supporting the traditional use of seven plants in treating skin and wound infections related to bacteria.

scholarly journals Design, Synthesis, and Antibacterial Screening of Some Novel Heteroaryl-Based Ciprofloxacin Derivatives as DNA Gyrase and Topoisomerase IV Inhibitors

2021 ◽  
Vol 14 (5) ◽  
pp. 399
Author(s):  
Lamya H. Al-Wahaibi ◽  
Amer A. Amer ◽  
Adel A. Marzouk ◽  
Hesham A.M. Gomaa ◽  
Bahaa G. M. Youssif ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Dna Gyrase ◽  
Bacterial Strains ◽  
Topoisomerase Iv ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Screening ◽  
Ic50 Values

A novel series of ciprofloxacin hybrids comprising various heterocycle derivatives has been synthesized and structurally elucidated using 1H NMR, 13C NMR, and elementary analyses. Using ciprofloxacin as a reference, compounds 1–21 were screened in vitro against Gram-positive bacterial strains such as Staphylococcus aureus and Bacillus subtilis and Gram-negative strains such as Escherichia coli and Pseudomonas aeruginosa. As a result, many of the compounds examined had antibacterial activity equivalent to ciprofloxacin against test bacteria. Compounds 2–6, oxadiazole derivatives, were found to have antibacterial activity that was 88 to 120% that of ciprofloxacin against Gram-positive and Gram-negative bacteria. The findings showed that none of the compounds tested had antifungal activity against Aspergillus flavus, but did have poor activity against Candida albicans, ranging from 23% to 33% of fluconazole, with compound 3 being the most active (33% of fluconazole). The most potent compounds, 3, 4, 5, and 6, displayed an IC50 of 86, 42, 92, and 180 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). Compounds 4, 5, and 6 showed IC50 values (1.47, 6.80, and 8.92 µM, respectively) against E. coli topo IV in comparison to novobiocin (IC50 = 11 µM).

scholarly journals Antibacterial Activity of Floral Petals of Some Angiosperms

2019 ◽  
pp. 1-5 ◽  
Author(s):  
L. Rajanna ◽  
N. Santhosh Kumar ◽  
N. S. Suresha ◽  
S. Lavanya
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Bacterial Strains ◽  
Inhibitory Zone ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Assay

The in vitro antibacterial assay was carried out against both Gram positive (B. cerus and S. aureus) and Gram negative (E. coli and K. pneumoniae) bacteria. Floral petals of 20 different species of plants were collected and tested for antibacterial activity. The result showed that the petals were active against both Gram positive and Gram negative. Out of 20 floral petals tested, 19 floral petals exhibited antibacterial activity against selected bacterial strains. The minimal inhibitory zone of floral petal discs against human pathogenic bacteria varies from 2 – 6 mm. Rosa carolina and Ruellia tuberosa showed significance inhibition zone for all the bacterial strains while Lantana camara does not show inhibition zone for any of these pathogenic bacteria.

scholarly journals In Vitro, Controlling the Establishment of Xanthomonas Campestris with different Bacterial Bioagents

2016 ◽  
Vol 29 (1) ◽  
pp. 37-40
Author(s):  
Amna Ali ◽  
M Saleem Haider ◽  
Sobia Mushtaq ◽  
Ibatsam Khokhar ◽  
Irum Mukhtar ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Fruits And Vegetables ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Diffusion Technique

The antimicrobial agents of bacteria isolated from different rhizosphere of fruits and vegetables soil in Lahore. Of ten species, five were gram-negative (Escherichia coli, Pseudomonas fluorescence, Klebsiella pneumoniae, Salmonella typhii, Brachybacterium faecium); other five were gram positive and identified as Bacillus farraginis, Kurthia gibsonii, Aureobacterium liquefaciens, Curtobacterium albidum, Micrococcus lylae. The antagonistic potential of bacterial strains was assessed by the well diffusion technique and results indicating varying degree of biocontrol activity against pathogenic strain of X. campestris. Out of ten bacterial species, E. coli (gram negative) and C. albidum (gram positive) showed a high prevalence of resistance with reduction of 4.2cm and 4.1cm zone diameter respectively. The minimum inhibitory volume (MIV) to two bio-agents was determined for X. campestris from range 10-100 ?L. E. coli (volume required to inhibit < 20 ?L) and C. albidum (volume required to inhibit < 40 ?L) exhibited good activity against pathogen. These results provide information on the prevalence of resistant bacterial strains with the MIV of organisms and indicate the possibility of using these bacterial species as bio-agent against X. campestris.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 37-40

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