scholarly journals Nanostructure Mediated Enhancement of Antibacterial Activity of Ampicillin Against Staphylococcus aureus and AFM Analysis of Morphological Changes Occuring Therein

2019 ◽  
Author(s):  
Mumtaz Ali ◽  
Shujat Ali ◽  
Abdul Latif ◽  
Samina Perveen ◽  
Shakil Ahmed ◽  
...  

Staphylococcus aureus is deliberated as one of the most challenging bacteria owing to its ability to develop resistance against antibacterial drugs. In an attempt to explore new approaches for enhancing the activity of antibiotics, here in this work, ampicillin is conjugated to Ag and Au nanoparticles (NPs) and its antibacterial potential was investigated against S. aureus. The antibacterial activity was assessed and the associated changes in the bacterial cell morphology were analyzed using atomic force microscopy (AFM) as well as other characterization techniques. Results showed that the antibacterial activity of ampicillin conjugated to gold and silver NPs was enhanced up to 10 and 5 times respectively, when compared with the non-conjugated antibiotic. The kinetics of the conjugated ampicillin were improved. Bacterial membrane destruction was scarcely evident after treating a cell culture with pure ampicillin for four hours. However, Ag conjugates have severely disrupted the cell membranes and Au conjugates have completely destroyed the cell morphology. The study gave an insight of the enhanced antimicrobial action of ampicillin and can be exploited for the devising nanoparticle’s based antimicrobial agents. More sophisticated approaches such as faster and more efficient diagnostics, non-antimicrobial methodologies to prevent and treat infections and a better understanding of staphylococcal pathogenesis will also be required to forestall the future of the bacterial resistance.

2020 ◽  
Vol 6 (2) ◽  
pp. 246
Author(s):  
Yayuk Bulam Sarifati ◽  
Sjarif Ismail ◽  
Khemasili Kosala

Mekai leaves (Pycnarrhena cauliflora Diels.) (P. cauliflora). Are known to contain flavonoid compounds, tannins and phenolics that act as antibacterial agents and are used in the treatment of eye pain. Staphylococcus aureus (S. aureus) is one of the examples of bacterial diseases of eye pain and also a major cause of many infections in communities and health facilities with cases of resistance to various antimicrobial agents. The purpose of this study was to prove the antibacterial activity of mekai leaves ethanol extract against S. aureus bacteria. This research is an experimental research. The stages of this research began by extracting mekai leaves using maceration method with 96% ethanol solvent. Antibacterial activity was tested by the disc method (Kirby-Bauer) using ethanol extract concentrations of mekai leaves (EPC) 20%, 30%, 40%, 50%, 60%, 70%, and 80%, positive control using 25 μg amoxicillin and negative control using DMSO 10%. The measurement results of inhibition zones of mekai leaf ethanol extract 20%, 30%, 40%, 50%, 60%, 70% and 80% respectively were 8.32 mm, 8.32 mm, 8.32 mm, 8.67 mm, 9.00 mm, 8.67 mm, and 8.33 mm. While the positive control measurement of 25 μg amoxicillin against S. aureus is 28.67 mm and the measurement of 10% negative DMSO control does not produce inhibitory zones, so it can be concluded that the ethanol extract of mekai leaves has antibacterial activity, but the area of ​​inhibition zone produced is smaller than amoxicillin 25 µg. The results of statistical tests using Mann Whitney between negative controls with all EPC concentrations obtained significant differences with p values ​​<0.05, it can be concluded that there is antibacterial activity produced at all EPC concentrations.


Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 89 ◽  
Author(s):  
Shahabe Abullais Saquib ◽  
Nabeeh Abdullah AlQahtani ◽  
Irfan Ahmad ◽  
Mohammed Abdul Kader ◽  
Sami Saeed Al Shahrani ◽  
...  

Background: In the past few decades focus of research has been toward herbal medicines because of growing bacterial resistance and side effects of antimicrobial agents. The extract derived from the plants may increase the efficacy of antibiotics when used in combination against pathogenic bacteria. In the current study, the synergistic antibacterial efficacy of plant extracts in combination with antibiotics has been assessed on selected periodontal pathogens. Methods: Ethanolic extracts were prepared from Salvadora persica (Miswak) and Cinnamomum zeylanicum (Ceylon cinnamon), by the soxhalate method. Plaque samples were collected from clinical periodontitis patients to isolate and grow the periodontal pathobionts under favorable conditions. Susceptibility of bacteria to the extracts was assessed by gauging the diameter of the inhibition zones. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of plant extracts were determined against each bacterium. Synergistic activity of plants extract in combination with antibiotics against the bacteria was also assessed by measuring the diameter of the inhibition zones. Results: Ethanolic extract of both the plants showed an inhibitory effect on the proliferation and growth of all four strains of periodontal pathobionts. Maximum antibacterial activity was exhibited by C. zeylanicum against Tannerella forsythia (MIC = 1.56 ± 0.24 mg/mL, MBC = 6.25 ± 0.68 mg/mL), whereas among all the studied groups the minimum activity was reported by C. zeylanicum against Aggregatibacter actinomycetemcomitans the (MIC = 12.5 ± 3.25 mg/mL, MBC = 75 ± 8.23 mg/mL). Combination of herbal extracts with different antibiotics revealed a synergistic antibacterial effect. The best synergism was exhibited by S. persica with metronidazole against A. actinomycetemcomitans (27 ± 1.78). Conclusions: Current in vitro study showed variable antibacterial activity by experimented herbal extracts against periodontal pathobionts. The synergistic test showed significant antibacterial activity when plant extracts were combined with antibiotics.


Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3513 ◽  
Author(s):  
Kun Zhang ◽  
Heng Zhang ◽  
Chunyu Gao ◽  
Ruibo Chen ◽  
Chunli Li

Antimicrobial peptides (AMPs) show high antibacterial activity against pathogens, which makes them potential new therapeutics to prevent and cure diseases. Porcine beta defensin 2 (pBD2) is a newly discovered AMP and has shown antibacterial activity against different bacterial species including multi-resistant bacteria. In this study, the functional mechanism of pBD2 antibacterial activity against Staphylococcus aureus was investigated. After S. aureus cells were incubated with different concentrations of pBD2, the morphological changes in S. aureus and locations of pBD2 were detected by electron microscopy. The differentially expressed genes (DEGs) were also analyzed. The results showed that the bacterial membranes were broken, bulging, and perforated after treatment with pBD2; pBD2 was mainly located on the membranes, and some entered the cytoplasm. Furthermore, 31 DEGs were detected and confirmed by quantitative real-time PCR (qRT-PCR). The known functional DEGs were associated with transmembrane transport, transport of inheritable information, and other metabolic processes. Our data suggest that pBD2 might have multiple modes of action, and the main mechanism by which pBD2 kills S. aureus is the destruction of the membrane and interaction with DNA. The results imply that pBD2 is an effective bactericide for S. aureus, and deserves further study as a new therapeutic substance against S. aureus.


Author(s):  
Susan Christina Braga Domingos ◽  
Victor Hugo Clebis ◽  
Gerson Nakazato ◽  
Admilton Gonçalves Oliveira ◽  
Renata Katsuko Takayama Kobayashi ◽  
...  

2001 ◽  
Vol 7 (2) ◽  
pp. 155-158 ◽  
Author(s):  
M. Garcia ◽  
C. Perez-Arquillue ◽  
T. Juan ◽  
M. I. Juan ◽  
A. Herrera

Antibacterial activity of twenty-five samples of honey from different botanical origin was evaluated. Staphylococcus aureus ATCC 25923 was used as the resistant microorganism. Pollen analysis revealed different botanical origins: Labiatae, rosemary, eucalyptus, heather and multifloral. The pH and acidity values were in the normal range, except for four samples that showed acidity values over 40 meq/kg, but none exhibited a state of fermentation. We have not found correlation between antibacterial activity and free acidity in the samples. Labiatae and rosemary honeys have exhibited the largest inhibition against Staphylococcus aureus ATCC, conversely to heather honeys, which showed lowest inhibition ability against this microorganism. Our results may indicate the presence of antimicrobial agents in Labiatae and rosemary honeys that have inhibited the growth of Staphylococcus aureus ATCC. Likewise, the free acids of heather honeys have not shown inhibitory activity over this microorganism.


2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Vladimir Baturin ◽  
M. Selimov ◽  
Albert Bolatchiev ◽  
Roman Budkevich ◽  
Vladimir Sadovoy ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Martin Krátký ◽  
Jarmila Vinšová ◽  
Vladimír Buchta

The resistance to antimicrobial agents brings a need of novel antimicrobial agents. We have synthesized and found thein vitroantibacterial activity of salicylanilide esters with benzoic acid (2-(phenylcarbamoyl)phenyl benzoates) in micromolar range. They were evaluatedin vitrofor the activity against eight fungal and eight bacterial species. All derivatives showed a significant antibacterial activity against Gram-positive strains with minimum inhibitory concentrations ≥0.98 μmol/L including methicillin-resistantStaphylococcus aureusstrain. The most active compounds were 5-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl benzoate and 4-chloro-2-(4-(trifluoromethyl)phenylcarbamoyl)phenyl benzoate. The antifungal activity is significantly lower.


2018 ◽  
Vol 23 (3) ◽  
pp. 131
Author(s):  
Suzana Kristy Satriani Fofied ◽  
Agus Sabdono ◽  
Diah Permata Wijayanti

Staphylococcus aureus and Escherichia coli are pathogenic bacteria agent of many human diseases. Those bacteria infect in various levels and also been antibiotic resistants. Bacterial resistance has become a serious global problem. The purposes of this study were to isolate and identify the symbiotic bacteria of the Sea Urchin that have an antibacterial activity of the Strain Multi-Drug Resistant (MDR) against Staphylococcus aureus and Escherichia coli. Sea Urchin was taken from Panjang island, Jepara Indonesia at 2-3 m depth. The symbiotic bacteria were isolated from Sea Urchin by using dilution method and spread plate method. Phenotypic characteristics was observed on colony shape, color and texture of growing bacteria. While the streak method was used to purify bacterial symbion. The antibacterial activity test was performed using overlay method. The results showed that 3 out of 37 isolates have antibacterial activity against Staphylococcus aureus and Escherichia coli. The BB.03.35 isolate was selected for molecular identification due to the largest inhibitory zone diameter. The sequence of this bacterium showed 97% homology and closely related to Pseudoalteromonas flavipulchra.


2020 ◽  
Vol 8 (4) ◽  
pp. 468 ◽  
Author(s):  
Adriana Vollaro ◽  
Anna Esposito ◽  
Eleni Antonaki ◽  
Vita Dora Iula ◽  
Daniele D’Alonzo ◽  
...  

In this work, the antibacterial activity of deflazacort and several of its synthetic precursors was tested against a panel of bacterial pathogens responsible for most drug-resistant infections including Staphylococcus aureus, Enterococcus spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterobacter spp. The derivative of deflazacort, PYED-1 (pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1) showed the best antibacterial activity in a dose-dependent way. We focused on the action of PYED-1 against S. aureus cells. PYED-1 exhibited an additive antimicrobial effect with gentamicin and oxacillin against the methicillin-resistant S. aureus isolate 00717. In addition to its antimicrobial effect, PYED-1 was found to repress the expression of several virulence factors of S. aureus, including toxins encoded by the hla (alpha-haemolysin), hlb (beta-haemolysin), lukE-D (leucotoxins E-D), and sea (staphylococcal enterotoxin A) genes, and cell surface factors (fnbB (fibronectin-binding protein B) and capC (capsule biosynthesis protein C)). The expression levels of autolysin isaA (immunodominant staphylococcal antigen) were also increased.


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