scholarly journals Phytochemical Prospection and Modulation of Antibiotic Activity In Vitro byLippia origanoidesH.B.K. in Methicillin ResistantStaphylococcus aureus

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Humberto Medeiros Barreto ◽  
Filipe Cerqueira Fontinele ◽  
Aldeídia Pereira de Oliveira ◽  
Daniel Dias Rufino Arcanjo ◽  
Bernadete Helena Cavalcanti dos Santos ◽  
...  

TheLippia origanoidesH.B.K. ethanol extract (LOEE) and hexane (LOHEX), dichloromethane (LODCM), and ethyl acetate (LOEA) fractions were tested for their antimicrobial activity alone or in combination with antibiotics against a methicillin resistantStaphylococcus aureus(MRSA) strain. The natural products did not show antimicrobial activity against multidrug resistant strain at the clinically significant concentrations tested. However, a modulatory effect in the antibacterial activity of the neomycin and amikacin was verified when LOEE, LOHEX and LODCM were added to the growth medium at subinhibitory concentrations. A similar modulation was found when the natural products were changed for chlorpromazine, an inhibitor of bacterial efflux pumps, suggesting the involvement of resistance mediated by efflux system in the MRSA tested. The fractions LOHEX and LODCM showed a modulatory activity bigger than their majority compounds (carvacrol, thymol, and naringenin), indicating that this activity is not due to their majority compounds only, but it is probably due to a synergism between their chemical components. These results indicate thatL. origanoidesH.B.K. can be a source of phytochemicals able to modify the phenotype of resistance to aminoglycosides in MRSA.

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Kerem Canlı ◽  
Ali Yetgin ◽  
Atakan Benek ◽  
Mustafa Eray Bozyel ◽  
Ergin Murat Altuner

The aim of this study was to test antimicrobial activity of ethanol extract of Lavandula stoechas against 22 bacteria and 1 yeast. Also, biochemical composition of the extract was investigated. A wide range of Gram-positive, Gram-negative microorganisms, and multidrug resistant bacteria were selected to test the antimicrobial activity. As a result, the extract is observed to contain fenchone (bicyclo[2.2.1]heptan-2-one, 1,3,3-trimethyl-, (1R)-) and camphor (+)-2-bornanone) as major components and showed antimicrobial activity against all studied microorganisms except Escherichia coli ATCC 25922 and Klebsiella pneumoniae. The results of the study present that L. stoechas is active against MDR strains too.


2020 ◽  
Vol 9 (1) ◽  
pp. 416-428 ◽  
Author(s):  
Raghad R. Alzahrani ◽  
Manal M. Alkhulaifi ◽  
Nouf M. Al-Enazi

AbstractThe adaptive nature of algae results in producing unique chemical components that are gaining attention due to their efficiency in many fields and abundance. In this study, we screened the phytochemicals from the brown alga Hydroclathrus clathratus and tested its ability to produce silver nanoparticles (AgNPs) extracellularly for the first time. Lastly, we investigated its biological activity against a variety of bacteria. The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy, and energy-dispersive spectroscopy. The biological efficacy of AgNPs was tested against eighteen different bacteria, including seven multidrug-resistant bacteria. Phytochemical screening of the alga revealed the presence of saturated and unsaturated fatty acids, sugars, carboxylic acid derivatives, triterpenoids, steroids, and other components. Formed AgNPs were stable and ranged in size between 7 and 83 nm and presented a variety of shapes. Acinetobacter baumannii, Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), and MDR A. baumannii were the most affected among the bacteria. The biofilm formation and development assay presented a noteworthy activity against MRSA, with an inhibition percentage of 99%. Acknowledging the future of nano-antibiotics encourages scientists to explore and enhance their potency, notably if they were obtained using green, rapid, and efficient methods.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Marwa Reda Bakkar ◽  
Ahmed Hassan Ibrahim Faraag ◽  
Elham R. S. Soliman ◽  
Manar S. Fouda ◽  
Amir Mahfouz Mokhtar Sarguos ◽  
...  

COVID-19 is a pandemic disease caused by the SARS-CoV-2, which continues to cause global health and economic problems since emerging in China in late 2019. Until now, there are no standard antiviral treatments. Thus, several strategies were adopted to minimize virus transmission, such as social distancing, face covering protection and hand hygiene. Rhamnolipids are glycolipids produced formally by Pseudomonas aeruginosa and as biosurfactants, they were shown to have broad antimicrobial activity. In this study, we investigated the antimicrobial activity of rhamnolipids against selected multidrug resistant bacteria and SARS-CoV-2. Rhamnolipids were produced by growing Pseudomonas aeruginosa strain LeS3 in a new medium formulated from chicken carcass soup. The isolated rhamnolipids were characterized for their molecular composition, formulated into nano-micelles, and the antibacterial activity of the nano-micelles was demonstrated in vitro against both Gram-negative and Gram-positive drug resistant bacteria. In silico studies docking rhamnolipids to structural and non-structural proteins of SARS-CoV-2 was also performed. We demonstrated the efficient and specific interaction of rhamnolipids with the active sites of these proteins. Additionally, the computational studies suggested that rhamnolipids have membrane permeability activity. Thus, the obtained results indicate that SARS-CoV-2 could be another target of rhamnolipids and could find utility in the fight against COVID-19, a future perspective to be considered.


Author(s):  
Amita Shobha Rao ◽  
Shobha Kl ◽  
Prathibha Md’almeida ◽  
Kiranmai S Rai

  Objective: Infections caused by Gram-negative bacteria are important causes of morbidity and mortality. Extracts of plants and herbs such as Clitorea ternatea are used as diuretic. This work attempts to find out antimicrobial activity of aqueous and alcoholic extract of C. ternatea roots against Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), clinical strains of Klebsiella pneumoniae, and Candida albicans.Methods: The agar well-diffusion method was done using Mueller Hinton agar and Sabouraud’s dextrose agar. The microorganism grown in peptone water was inoculated into culture medium. 4 mm diameter well punched into the agar was filled with 20 μl of aqueous and alcoholic root extracts C. ternatea extracts in various concentrations (100-25 μg/ml). The plates were incubated and antimicrobial activity was evaluated.Results: Aqueous root extract of C. ternatea with the concentration of 100 μg/ml showed zone of inhibition against E. coli (ATCC 25922) 18 mm, P. aeruginosa (ATCC 27853) 14 mm, multidrug resistant strain of K. pneumoniae 15 mm. Alcoholic extract of C. ternatea with the concentration of 100 μg/ml showed zone of inhibition of 35 mm against E. coli (ATCC 25922), P. aeruginosa (ATCC 27853) 22 mm, and multidrug resistant strain of K. pneumoniae 28 mm. C. albicanswas resistant to both extract of C. ternatea root. Conclusions: Alcoholic extract of C. ternatea is a better antibacterial agent against multidrug resistant Klebsiella species and other Gram-negative pathogens. Further, studies are required to identify active substances from the alcoholic extracts of C. ternatea for treating infections.


2021 ◽  
Vol 16 (1) ◽  
pp. 52-58
Author(s):  
Elizabeth Winful ◽  
Olanikpekun Idowu ◽  
Opeoluwa O. Fasanya ◽  
Nkechi E. Egbe

Antimicrobial resistance has become a global health problem. Although a wide range of chemotherapeutic antimicrobials are available for treatment of microbial related infections and diseases, development of resistance to these chemotherapeutic agents is rapidly on the increase. Extracts from some plants have shown some promise in antimicrobial activity. This has led to the screening of several medicinal plants for their potential antimicrobial activity. Therefore, this study was aimed at evaluating the antimicrobial effect of ethanolic and aqueous extracts of Garcinia kola against Klebsiella pneumonia and Candida albicans in vitro. The Garcinia kola seeds extracts were obtained using 70% ethanol and distilled water respectively. Phytochemical screening of Garcinia kola revealed the presence of various potent phytochemicals such as tannins, saponins, flavonoids, alkaloids and glycosides. Both extracts of the seeds were investigated for antimicrobial activity using disc diffusion and agar well diffusion sensitivity tests. The ethanol extract produced zones of inhibition of about 7.3 mm for Candida albicans only at a concentration of 800mg/ml for the disc diffusion test. For the agar well diffusion test, the aqueous extract produced zones of inhibition of about 9.5 mm, while the ethanol extract produced zone of inhibition of 19 mm against Candida albicans at a concentration of 800 mg/ml. However, at the same concentration, the ethanol extract produced zones of inhibition of about 8.5 mm against Klebsiella pneumoniae. The findings of this study revealed that Garcinia kola was not effective in treating Klebsiella pneumonia infections but has potential in treating Candida albicans infections. Keywords: Garcinia kola, Klebsiella pneumonia, Candida albicans


2014 ◽  
Vol 73 (1) ◽  
pp. 303-311 ◽  
Author(s):  
Saulo R. Tintino ◽  
Celestina E. S. Souza ◽  
Gláucia M. M. Guedes ◽  
Jaqueline I. V. Costa ◽  
Francisco M. Duarte ◽  
...  

AbstractThe side effects of certain antibiotics have been a recent dilemma in the medical arena. Due this fact, the necessity of natural product discovery could provide important indications against several pharmacological targets and combat many infectious agents. Piper arboreum Aub. (Piperaceae) has been used by Brazilian traditional communities against several illnesses including rheumatism, bronchitis, sexually transmitted diseases and complaints of the urinary tract. Medicinal plants are a source of several remedies used in clinical practice to combat microbial infections. In this study, ethanol extract and fractions of Piper arboreum leaves were used to assay antimicrobial and modulatory activity. The minimum inhibitory concentration (MIC) was determined using microdilution method of ethanol extract and fractions from the leaves of P. arboreum ranging between 8 and 1024 μg mL-1. The capacity of these natural products to enhance the activity of antibiotic and antifungal drugs was also assayed. In these tests, natural products were combined with drugs. The natural products assayed did not demonstrate any clinically relevant antimicrobial activity (MIC ≥ 1024 μg mL-1). However, the modulation of antibiotic activity assay observed a synergistic activity of natural products combined with antifungal (such as nystatin and amphotericin B) and antibiotic drugs (such as amikacin, gentamicin and kanamycin). According to these results, these natural products can be an interesting alternative not only to combat infectious diseases caused by bacteria or fungi, but also to combat enhanced resistance of microorganisms to antibiotic and antifungal drugs.


2006 ◽  
Vol 50 (2) ◽  
pp. 806-809 ◽  
Author(s):  
Giuseppantonio Maisetta ◽  
Giovanna Batoni ◽  
Semih Esin ◽  
Walter Florio ◽  
Daria Bottai ◽  
...  

ABSTRACT The antimicrobial activity of human β-defensin 3 (hBD-3) against multidrug-resistant clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, and Acinetobacter baumannii was evaluated. A fast bactericidal effect (within 20 min) against all bacterial strains tested was observed. The presence of 20% human serum abolished the bactericidal activity of hBD-3 against gram-negative strains and reduced the activity of the peptide against gram-positive strains.


2020 ◽  
Vol 8 (2) ◽  
pp. 739-745 ◽  
Author(s):  
Weinan Jiang ◽  
Ximian Xiao ◽  
Yueming Wu ◽  
Weiwei Zhang ◽  
Zihao Cong ◽  
...  

Host defense peptide mimicking peptide polymer displayed potent in vitro and in vivo antimicrobial activity against clinically isolated multidrug resistant Pseudomonas aeruginosa.


Sign in / Sign up

Export Citation Format

Share Document