scholarly journals Assessment of Antibacterial Activity of Levonadifloxacin against Contemporary Gram-positive Clinical Isolates Collected from Various Indian Hospitals using Disk-Diffusion Assay

2020 ◽  
Vol 38 (3-4) ◽  
pp. 307-312
Author(s):  
Shrikala Baliga ◽  
Dhruv K. Mamtora ◽  
Varsha Gupta ◽  
Priyadarshini Shanmugam ◽  
Sanjay Biswas ◽  
...  
Antibiotics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 272 ◽  
Author(s):  
Ramona Iseppi ◽  
Alessandro Di Cerbo ◽  
Piero Aloisi ◽  
Mattia Manelli ◽  
Veronica Pellesi ◽  
...  

The aim of this study was to analyze the antibacterial activity of four essential oils (EOs), Melaleuca alternifolia, Eucalyptus globulus, Mentha piperita, and Thymus vulgaris, in preventing the development and spread of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, metallo-beta-lactamase (MBL)-producing Pseudomonas aeruginosa and carbapenemase (KPC)-producing Klebsiella pneumoniae. A total of 60 strains were obtained from the stock collection from the Microbiology Laboratory of Hesperia Hospital, Modena, Italy. Twenty ESBL-producing E. coli, 5 K. pneumoniae, 13 KPC-producing K. pneumoniae, and 20 MBL-producing P. aeruginosa were cultured and reconfirmed as ESBL and carbapenamase producers. Polymerase chain reaction was used for the detection of genes responsible for antibiotic resistance (ESBL and KPC/MBL). Antibacterial activity of the EOs was determined using the agar disk diffusion assay, and minimal inhibitory concentrations (MICs) were also evaluated. Lastly, adhesion capability and biofilm formation on polystyrene and glass surfaces were studied in 24 randomly selected strains. M. alternifolia and T. vulgaris EOs showed the best antibacterial activity against all tested strains and, as revealed by agar disk diffusion assay, M. alternifolia was the most effective, even at low concentrations. This effect was also confirmed by MICs, with values ranging from 0.5 to 16 µg/mL and from 1 to 16 µg/mL, for M. alternifolia and T. vulgaris EOs, respectively. The EOs’ antibacterial activity compared to antibiotics confirmed M. alternifolia EO as the best antibacterial agent. T. vulgaris EO also showed a good antibacterial activity with MICs lower than both reference antibiotics. Lastly, a significant anti-biofilm activity was observed for the two EOs (*P < 0.05 and **P < 0.01 for M. alternifolia and T. vulgaris EOs, respectively). A good antibacterial and anti-biofilm activity of M. alternifolia and T. vulgaris EOs against all selected strains was observed, thus demonstrating a future possible use of these EOs to treat infections caused by ESBL/carbapenemase-producing strains, even in association with antibiotics.


Author(s):  
Sukriti Prashar ◽  
Miguel Portales Guemes ◽  
Poorandai Shivbaran ◽  
Eugenia Jimenez Alvarez ◽  
Christopher Soha ◽  
...  

Disk diffusion assays have traditionally been used as a simple and effective way to screen compounds for antibacterial activity and to determine the susceptibility of pathogens to antibiotics; however, they are limited to detecting growth inhibition only. Consequently, antimicrobial agents that inhibit virulence factors, but not growth, would not be detected.


Proceedings ◽  
2020 ◽  
Vol 66 (1) ◽  
pp. 9
Author(s):  
Yoram Gerchman

Plants have been explored and used as sources for antimicrobial extract and compounds for many years, but galls—specialized structures forms on such by diversity of organisms—have been explored much less. Aphid galls host many insects in closed, humid and sugar rich environments for long periods. We have tested the antimicrobial properties of Slavum wertheimae aphid galls on Pistacia atlantica. Secondary metabolites were extracted from leaves and galls with organic solvents, and essential oils with Clevenger, and tested by disk diffusion assay and volatile effect on bacteria and fungi, respectively. The results demonstrated that gall extracts/essential oils had much stronger activity against the diversity of bacteria and fungi. The large diversity of galls suggest they could be explored as source for novel compounds.


2010 ◽  
Vol 48 (10) ◽  
pp. 3750-3752 ◽  
Author(s):  
E. I. Nweze ◽  
P. K. Mukherjee ◽  
M. A. Ghannoum

2018 ◽  
Vol 13 (6s) ◽  
pp. 3-19 ◽  
Author(s):  
Rafael Canton ◽  
Ian Morrissey ◽  
Jordi Vila ◽  
Marta Tato ◽  
María García-Castillo ◽  
...  

2021 ◽  
Vol 22 (6) ◽  
Author(s):  
Laid Ziane ◽  
MOHAMMED DJELLOULI ◽  
ABDELAZIZ BERGHIOUA

Abstract. Ziane L, Djellouli M, Berghioua A. 2021. Short Communication: Chemical composition, antioxidant and antimicrobial activity of Fagonia longispina (Zygophyllaceae) of Algerian. Biodiversitas 22: 3448-3453. The study's aim is to discover the antioxidant, antibacterial efficacy and identifying the main constituents of the essential oil of Fagonia longispina from southwest of Algeria. The essential oil from the aerial parts of the endemic plant Fagonia longispina collected from the region of Sahara southwest of Algeria was isolated by hydrodistillation and analyzed by gas chromatography-mass spectrometry.  Our work was designed then, to evaluate the antioxidant activity of the essential oil of Fagonia longispina by DPPH free radical scavenging and HPTLC techniques. Antibacterial potency of essential oil from this plant has been tested against Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), and Bacillus cereus (ATCC11778) by disk diffusion assay. We found that the chemical profile of the essential oil revealed the presence of 14 compounds: Trans–Pinocarveol (3.14 %), Panisaldehyd (4.24 %), Trans geraniol (3.05 %), carvacrol 18.72 %), Elemicin (22.85 %), (Z,E) Farnesol (15.69 %), Caryophyllene oxide (2.68 %), Alpha-curcumene (1.75 %), Germacrene D (4.22 %), longipinane (2.89 %) and ?-Terpinine (2.74 %). The antioxidant assay showed that the essential oil could scavenge DPPH (IC50 values of 2.1959 mg/mL free radical. The essential oil exhibits very effective antimicrobial activity using disk diffusion assay method with minimum inhibitory concentration ranging from 0.75 ?L/mL to 1.9714 ?L/mL. These results showed that this native plant may be a good candidate for further biological and pharmacological investigations.


Biosynthesis of silver nanoparticles, especially fungal mediated method is given attention in the development of new drugs for resistance pathogens, molecular diagnosis, drug delivery therapy and in catalytic sensor due to its cost effective, none toxicity and eco-friendly. The present study focused on the fungal mediated biosynthesis of silver nanoparticles using Aspergillus terrues strain (MTCC 9618). The synthesized nanoparticles was monitored by spectrophotometer SEM, XRD and its band gap was determined by Tuac equation. After while the fungal crude cells was exposed to 5mM silver nitrate the reduction reaction was recorded according to red shift colorchange. Based on ultra violet spectrophotometeran absorbance was recorded in a distinct pick around 430nm - 450nm and also the band gab was determined using Tuac equationsuch that 2.08eV, 2.02eV, 2.0eV and 1.96eV at about 10min, 30min, 12h and 24h respectively. The AgNPs coated cotton fabrics was developed through direct exposed to extracellular metabolites and 100ppm colloidal solution of AgNPs. The antimicrobial efficacy of the synthesized AgNPs coted cotton fabrics against gram positive Hospital staphylococcus aureus pathogenstrains was conducted by disk diffusion assay. In which the antimicrobial efficacy of coated cotton-Ag against human pathogens was proofed how the staphylococcus aureus had susceptible too and (16mm) zone of inhibition was recorded. Based on disk diffusion assay at 10ug/mL minimum inhibition concentration (MIC)10.5 mm inhibition zone was noted consequently, this study accomplished that Aspergillus terreus strain mediated biosynthesis of silver nanoparticles is cost effective, time saving, eco-friendly and small spherical (<10nm) had produced against to Physio-chemical means. The bio-synthesized silver nanoparticles cotton fabrics publicized that a higher efficacy of antimicrobial activity against staphylococcus aureus and the result was considerable suggested in widely range used in textile and pharmaceutical industries to enrich durability, strength, quality of products against a clinical pathogens application as well bad odor and spoilage of dusts from fabrics.


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