scholarly journals Chitosan nanoparticles loaded with the antimicrobial peptide temporin B exert a long-term antibacterial activity in vitro against clinical isolates of Staphylococcus epidermidis

2015 ◽  
Vol 06 ◽  
Author(s):  
Anna M. Piras ◽  
Giuseppantonio Maisetta ◽  
Stefania Sandreschi ◽  
Matteo Gazzarri ◽  
Cristina Bartoli ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Peptide ◽  
Staphylococcus Epidermidis ◽  
Chitosan Nanoparticles ◽  
Clinical Isolates

scholarly journals Antibacterial Activity Test of Extracts and Fractions of Cassava Leaves (Manihot esculenta Crantz) against Clinical Isolates of Staphylococcus epidermidis and Propionibacterium acnes Causing Acne

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Resmi Mustarichie ◽  
Sulistiyaningsih Sulistyaningsih ◽  
Dudi Runadi
Keyword(s):  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Staphylococcus Epidermidis ◽  
Propionibacterium Acnes ◽  
Ethanol Extract ◽  
Ethyl Acetate Fraction ◽  
Clinical Isolates ◽  
Active Fraction ◽  
Cassava Leaves ◽  
Ethanol Extracts

This study is aimed at determining antibacterial activity from ethanol extracts and the most active fraction of cassava leaves against clinical isolates of Staphylococcus epidermidis and Propionibacterium acnes. Research carried out by the experimental method involved determination of plants, extraction with maceration method, fractionation with liquid-liquid extraction, antibacterial activity testing of extracts and fractions by agar diffusion method, determination of most active fraction from the extract, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) testing of most active fraction by microdilution method. The results showed that ethanol extracts of cassava leaves had antibacterial activity against both bacteria with the most active fraction indicated by ethyl acetate. MIC values of ethyl acetate fraction against S. epidermidis were in the concentration range of 2.5%–5.0% (w/v) and against P. acnes were in the concentration range of 1.25%–2.5% (w/v). The MBC value of ethyl acetate fraction against S. epidermidis was at a concentration of 5% (w/v), while P. acnes was at a concentration of 2.5% (w/v). From the results of this study, it can be concluded that the ethanol extract of cassava leaves (Manihot esculenta Crantz) has antibacterial activity against clinical isolates of Staphylococcus epidermidis as well as on Propionibacterium acnes. The fraction with the best activity from the ethanol extract of cassava leaves to the two test bacteria was shown by ethyl acetate fraction. It is suggested that cassava leaves are possible to be developed into standardized antiacne herbal.

scholarly journals 1293. Sulbactam-durlobactam is active against recent, multi-drug resistant Acinetobacter baumannii clinical isolates from the Middle East

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S662-S662
Author(s):  
Alita Miller ◽  
Sarah McLeod ◽  
Samir Moussa ◽  
Meredith Hackel
Keyword(s):  
Antibacterial Activity ◽  
Middle East ◽  
Acinetobacter Baumannii ◽  
United Arab Emirates ◽  
Blood Stream ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Surveillance Systems ◽  
Spectrum Activity

Abstract Background The incidence of infections caused by multidrug-resistant (MDR) Acinetobacter baumannii (Ab) is increasing at an alarming rate in certain regions of the world, including the Middle East. Sulbactam (SUL) has intrinsic antibacterial activity against Ab; however, the prevalence of β-lactamases in Ab has limited its therapeutic utility. Durlobactam (DUR, formerly ETX2514) is a diazabicyclooctenone β-lactamase inhibitor with broad-spectrum activity against Ambler class A, C and D β-lactamases that restores SUL activity in vitro against MDR Ab. SUL-DUR is an antibiotic designed to treat serious infections caused by Acinetobacter, including multidrug-resistant strains, that is currently in Phase 3 clinical development. In global surveillance studies of >3600 isolates from 2012-2017, the MIC90 of SUL-DUR was 2 mg/L. Although surveillance systems to monitor MDR infections in the Middle East are currently being established, quantitative, prevalence-based data are not yet available. Therefore, the potency of SUL-DUR was determined against 190 recent, diverse Ab clinical isolates from this region. Methods 190 Ab isolates were collected between 2016 - 2018 from medical centers located in Israel (N = 47), Jordan (N = 36), Qatar (N = 13), Kuwait (N = 42), Lebanon (N = 8), Saudi Arabia (N = 24) and United Arab Emirates (N = 20). Seventy-five percent and 20.5% of these isolates were from respiratory and blood stream infections, respectively. Susceptibility to SUL-DUR and comparator agents was performed according to CLSI guidelines, and data analysis was performed using CLSI and EUCAST breakpoint criteria where available. Results This collection of isolates was 86% carbapenem-resistant and 90% sulbactam-resistant (based on a breakpoint of 4 mg/L). The addition of SUL-DUR (fixed at 4 mg/L) decreased the sulbactam MIC90 from 64 mg/L to 4 mg/L. Only 3 isolates (1.6%) had SUL-DUR MIC values of > 4 mg/L. This potency was consistent across countries, sources of infection and subsets of resistance phenotypes. Conclusion SUL-DUR demonstrated potent antibacterial activity against recent clinical isolates of Ab from the Middle East, including MDR isolates. These data support the global development of SUL-DUR for the treatment of MDR Ab infections. Disclosures Alita Miller, PhD, Entasis Therapeutics (Employee) Sarah McLeod, PhD, Entasis Therapeutics (Employee) Samir Moussa, PhD, Entasis Therapeutics (Employee)

scholarly journals Evaluating the Antibacterial Activity and Mode of Action of Thymol-Loaded Chitosan Nanoparticles Against Plant Bacterial Pathogen Xanthomonas campestris pv. campestris

2022 ◽  
Vol 12 ◽  
Author(s):  
Sarangapani Sreelatha ◽  
Nadimuthu Kumar ◽  
Tan Si Yin ◽  
Sarojam Rajani
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Xanthomonas Campestris ◽  
Membrane Damage ◽  
Chitosan Nanoparticles ◽  
Bacterial Pathogen ◽  
Electron Microscopy Analysis ◽  
Rot Disease ◽  
The Impact

The bacterium Xanthomonas campestris pv. campestris (Xcc) causes black rot disease in cruciferous crops, resulting in severe yield loss worldwide. The excessive use of chemical pesticides in agriculture to control diseases has raised significant concern about the impact on the environment and human health. Nanoparticles have recently gained significant attention in agriculture owing to their promising application in plant disease control, increasing soil fertility and nutrient availability. In the current study, we synthesized thymol-loaded chitosan nanoparticles (TCNPs) and assessed their antibacterial activity against Xcc. The synthesis of TCNPs was confirmed by using ultraviolet–visible spectroscopy. Fourier-transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy analysis revealed the functional groups, size, and shape of TCNPs, with sizes ranging from 54 to 250 nm, respectively. The antibacterial activity of TCNPs against Xcc was investigated in vitro by liquid broth, cell viability, and live dead staining assay, and all of them demonstrated the antibacterial activity of TCNPs. Furthermore, TCNPs were found to directly inhibit the growth of Xcc by suppressing the growth of biofilm formation and the production of exopolysaccharides and xanthomonadin. The ultrastructure studies revealed membrane damage in TCNP-treated Xcc cells, causing a release of intracellular contents. Headspace/gas chromatography (GC)–mass spectrometry (MS) analysis showed changes in the volatile profile of Xcc cells treated with TCNPs. Increased amounts of carbonyl components (mainly ketones) and production of new volatile metabolites were observed in Xcc cells incubated with TCNPs. Overall, this study reveals TCNPs as a promising antibacterial candidate against Xcc.

scholarly journals In vitro anti-mycobacterial activity of (E)-N´-(monosubstituted-benzylidene) isonicotinohydrazide derivatives against isoniazid-resistant strains

2012 ◽  
Vol 4 (1) ◽  
pp. 13 ◽  
Author(s):  
Tatiane S. Coelho ◽  
Jessica B. Cantos ◽  
Marcelle L.F. Bispo ◽  
Raoni S.B. Gonçalves ◽  
Camilo H.S. Lima ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Resistant Strain ◽  
Mechanisms Of Action ◽  
Susceptible Strain ◽  
Clinical Isolates ◽  
Coding Region ◽  
Resistant Strains

A series of twenty-three <em>N-acylhydrazones</em> derived from isoniazid (INH 1-23) have been evaluated for their <em>in vitro</em> antibacterial activity against INH- susceptible strain of <em>M. tuberculosis</em> (RG500) and three INH-resistant clinical isolates (RG102, RG103 and RG113). In general, derivatives 4, 14, 15 and 16 (MIC=1.92, 1.96, 1.96 and 1.86 mM, respectively) showed relevant activities against RG500 strain, while the derivative 13 (MIC=0.98 mM) was more active than INH (MIC=1.14 mM). However, these derivatives were inactive against RGH102, which displays a mutation in the coding region of <em>inhA</em>. These results suggest that the activities of these compounds depend on the inhibition of this enzyme. However, the possibility of other mechanisms of action cannot be excluded, since compounds 2, 4, 6, 7, 12-17, 19, 21 and 23 showed good activities against <em>katG</em>-resistant strain RGH103, being more than 10-fold more active than INH.

scholarly journals Fabrication & Characterization of Chitosan Coated Biologically Synthesized TiO2 Nanoparticles against PDR E. coli of Veterinary Origin

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Naheed Zafar ◽  
Bushra Uzair ◽  
Muhammad Bilal Khan Niazi ◽  
Shamaila Sajjad ◽  
Ghufrana Samin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Titanium Dioxide ◽  
Morphological Changes ◽  
Titanium Dioxide Nanoparticles ◽  
Chitosan Nanoparticles ◽  
Diffusion Method ◽  
Potential Threat ◽  
E Coli

Treatment of pandrug resistant (PDR) Escherichia coli strain is the leading causative agent of bovine mastitis worldwide. Hence, becoming a potential threat to veterinary and public health. Therefore, to control the infection new nontoxic, biocompatible antimicrobial formulation with enhanced antibacterial activity is massively required. Current study was planned to synthesize chitosan coated titanium dioxide nanoparticles (CS-NPs coated TiO2). Coating was being done by chitosan nanoparticles (CS-NPs) using ionic gelation method. Aqueous solution of Moringa concanensis leaf extract was used to synthesize titanium dioxide nanoparticles (TiO2 NPs). The synthesized nanoformulations were characterized by using XRD, SEM, and FTIR. X-ray diffraction (XRD) analysis indicated the crystalline phase of TiO2 NPs and CS-NPs coated TiO2 NPs. Scanning Electron Microscopy (SEM) confirmed spherical shaped nanoparticles size of chitosan NPs ranging from 19–25 nm and TiO2 NPs 35–50 nm. Thesize of CS-NPs coated TiO2 NPs was in the range of 65–75 nm. The UV-Vis Spectra and band gap values illustrated the red shift in CS-NPs coated TiO2 NPs. Fourier transform infrared (FTIR) spectroscopy confirmed the linkages between TiO2 NPs and chitosan biopolymer, Zeta potential confirmed the stability of CS-NPs coated TiO2 NPs by showing 95 mV peak value. In-vitro antibacterial activity of CS-NPs coated TiO2 NPs and Uncoated TiO2 NPs was evaluated by disc diffusion method against PDR strain of E. coli isolated from mastitic milk samples. The antibacterial activity of all the synthesized nanoformulations were noted and highest antibacterial activity was shown by CS-NPs coated TiO2-NPs against pandrug resistant (PDR) E. coli strain with the prominent zone of inhibition of 23 mm. Morphological changes of E. coli cells after the treatment with MIC concentration (0.78 μg/ml) of CS-NPs coated TiO2 NPs were studied by transmission electron microscopy TEM showedrigorous morphological defectand has distorted the general appearance of the E. coli cells. Cytotoxicity (HepG2 cell line) and hemolytic (human blood) studies confirmed nontoxic/biocompatible nature of CS-NPs coated biologically synthesized TiO2 NPs. The results suggested that biologically synthesized and surface modified TiO2 NPs by mucoadhesive polysaccharides (e.g. chitosan) coating would be an effective and non-toxic alternative therapeutic agent to be used in livestock industry to control drug resistant veterinary pathogens.

scholarly journals Evaluation of Antibacterial Activity of Cymbopogon citratus Ethanolic Leaf Crude Extract against Streptococcus pneumoniae isolated from Kampala International University Teaching Hospital Western Campus, Uganda

2019 ◽  
Vol 7 (1) ◽  
pp. 31-38
Author(s):  
Ibrahim Ntulume ◽  
Ninsiima Victoria ◽  
Abubakar Sunusi Adam ◽  
Adamu Almustapha Aliero
Keyword(s):  
Antibacterial Activity ◽  
Streptococcus Pneumoniae ◽  
Crude Extract ◽  
Clinical Isolates ◽  
University Teaching ◽  
Zone Of Inhibition ◽  
Cymbopogon Citratus ◽  
Alternative Intervention ◽  
Adults And Children

Streptococcus pneumoniae is the common cause of pneumonia, meningitis, bacteremia and Septicemia among adults and children worldwide. Resistance to antimicrobials agents has been reported among S. pneumoniae which necessitate the need for alternative intervention such as ethno-medicinal plants. Cymbopogon citratus is an ethno-medicinal plant which is known to have pharmacological activities including antibacterial activity. This study aimed at determining the in vitro antibacterial activity of C. citratus ethanolic leaves crude extract against clinical isolates of S.  pneumoniae. A fresh leaves of C. citratus were collected early in the morning; shed dried, pulverized and extracted using ethanol (96%) using standard extraction method. The antibacterial activity, Minimum Inhibitory and Minimum Bactericidal Concentrations of C. citratus ethanolic leaves crude extract were determined against clinical isolates of S. pneumoniae. C. citratus ethanolic leaves extract crude showed antibacterial activity against S. pneumoniae at 500mg/ml concentration with mean and standard deviation zone of inhibition (26.33 ± 1.53 mm) in comparison with that of 250mg/ml concentration which gave 20.33 ± 2.08 mm mean and standard zone of inhibition. The minimum inhibitory concentration of the plant crude extract against S. pneumoniae was 15.63 mg/ml while the minimum bactericidal concentration was 125mg/ml. The study found that C. citratus leaves ethanolic crude extract was active against S. pneumoniae. It is recommended that studies should be done focusing on isolation of specific phytochemicals of the C. citratus leaves crude extract and then determines their antibacterial activity against clinical isolates of S. pneumoniae. Int. J. Appl. Sci. Biotechnol. Vol 7(1): 31-38

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