scholarly journals Antibacterial activities of Camellia sinensis plant extracts against uropathogenic E. coli in vitro and in vivo

2020 ◽  
Vol 14 (6) ◽  
pp. 147-155
Author(s):  
J. N. Agbom ◽  
O. Ogbu ◽  
I. R. Iroha ◽  
I. B. Moses ◽  
A. L. Onuora ◽  
...  
2005 ◽  
Vol 49 (10) ◽  
pp. 4185-4196 ◽  
Author(s):  
Yutaka Ueda ◽  
Katsunori Kanazawa ◽  
Ken Eguchi ◽  
Koji Takemoto ◽  
Yoshiro Eriguchi ◽  
...  

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.


Author(s):  
Ruvanthika Pn ◽  
Manikandan S

Objective: The objective of the study was to evaluate whether ethanolic extracts of Nelumbo nucifera (EENN) seedpod and quercetin (active component of NN) possess antibacterial proprieties against Gram (-) bacteria such as Escherichia coli and Pseudomonas aeruginosa and Gram (+) bacteria such as Staphylococcus aureus. Methods: Antibacterial activities of EENN seedpod and quercetin were investigated using disc diffusion method, minimum inhibitory concentration against E. coli and P. aeruginosa and Gram (+) bacteria such as S. aureus. Results: The antibacterial activity of both EENN seedpod and quercetin was found to be increased in dose-dependent manner. The maximum zone of inhibition was exhibited by both EENN seedpod and quercetin against E. coli (14 mm and 15 mm) and P. aeruginosa (13 mm and 15 mm). Gram-negative bacteria were more susceptible to the EENN seedpod extract and quercetin than Gram-positive bacteria.Conclusion: The results of the present study suggested that the effect of EENN seedpod and quercetin against the tested bacteria in vitro may contribute to the in vivo activities of the EENN seedpod and quercetin.


2014 ◽  
Vol 58 (11) ◽  
pp. 6896-6903 ◽  
Author(s):  
Soumitra Maiti ◽  
Sunita Patro ◽  
Sukumar Purohit ◽  
Sumeet Jain ◽  
Shantibhusan Senapati ◽  
...  

ABSTRACTWe successfully produced two human β-defensins (hBD-1 and hBD-2) in bacteria as functional peptides and tested their antibacterial activities againstSalmonella entericaserovar Typhi,Escherichia coli, andStaphylococcus aureusemploying both spectroscopic and viable CFU count methods. Purified peptides showed approximately 50% inhibition of the bacterial population when used individually and up to 90% when used in combination. The 50% lethal doses (LD50) of hBD-1 againstS.Typhi,E. coli, andS. aureuswere 0.36, 0.40, and 0.69 μg/μl, respectively, while those for hBD-2 against the same bacteria were 0.38, 0.36, and 0.66 μg/μl, respectively. Moreover, we observed that bacterium-derived antimicrobial peptides were also effective in increasing survival time and decreasing bacterial loads in the peritoneal fluid, liver, and spleen of a mouse intraperitoneally infected withS.Typhi. The 1:1 hBD-1/hBD-2 combination showed maximum effectiveness in challenging theSalmonellainfectionin vitroandin vivo. We also observed less tissue damage and sepsis formation in the livers of infected mice after treatment with hBD-1 and hBD-2 peptides individually or in combination. Based on these findings, we conclude that bacterium-derived recombinant β-defensins (hBD-1 and hBD-2) are promising antimicrobial peptide (AMP)-based substances for the development of new therapeutics against typhoid fever.


2018 ◽  
pp. 31-38

Actividad antibacteriana de extractos vegetales frente a cepas intrahospitalarias, Iquitos-Perú Antibacterial activity of plant extracts against nosocomial strains, Iquitos-Peru Ricardo E. Abadie, Ronald Medina O., Lastenia Ruiz, Alvaro Tresierra-Ayala Laboratorio de Microbiología. Centro de Investigación de Recursos Naturales de la Universidad Nacional de la Amazonía Peruana (CIRNA-UNAP). Psje. Los Paujiles S/N, San Lorenzo, distrito de San Juan Bautista, Iquitos-Perú DOI: https://doi.org/10.33017/RevECIPeru2014.0005/  Resumen La región amazónica es una de las áreas que posee la mayor biodiversidad del mundo, albergando varios miles de especies de plantas, muchas de las cuales son utilizadas por sus pobladores como plantas medicinales. Durante los últimos años, el empleo de estos recursos vegetales o de sus productos viene incrementándose de manera importante, lo cual podría deberse a una serie de factores, entre los que destacan el conocimiento de su composición química, y al hecho que en la actualidad se han realizado numerosos ensayos farmacológicos tanto in vivo como in vitro. La aparición de cepas resistentes a los antibióticos comerciales en los últimos tiempos, está creando la necesidad de buscar otras estrategias o alternativas para controlarlas, tal es el caso del uso de las plantas (medicina tradicional), debido a los principios activos que poseen. Se pretende con este trabajo, determinar probables alternativas para combatir infecciones bacterianas de aquellos agentes drogoresistentes, este problema reviste importancia crítica particular en los países en desarrollo, donde quizás no se dispone de antibióticos de segunda línea más costosos o, si los hay, su precio es inasequible. El estudio se realizó en la ciudad de Iquitos, Provincia de Maynas, Departamento de Loreto. Los ensayos microbiológicos se realizaron en el Laboratorio de Microbiología del Centro de Investigación de Recursos Naturales de la Amazonia (CIRNA) de la Universidad Nacional de la Amazonia  Peruana (UNAP). Se determinó la actividad antibacteriana de 6 extractos vegetales (Alchornea triplinervia, Annona muricata, Averrhoa carambola, Brunfelsia grandiflora, Caraipa grandifolia y Cedrela odorata) mediante la técnica de difusión en disco, y a aquellos que presentaron actividad se les determinó la Concentración Inhibitoria Mínima y la Concentración Bactericida Mínima mediante la técnica de macrodilución en caldo. Ninguno de los extractos tuvieron actividad frente a las cepas de E. coli; cuatro extractos tuvieron actividad frente a las cepas de P. aeruginosa, siendo los extractos de Cedrela odorata y Alchornea triplinervia los que tuvieron mayor actividad frente a esta bacteria, con CIM = 15.62 y 62.5 mg/ml, respectivamente; todos los extractos tuvieron actividad frente a las cepas de S. aureus, siendo los extracto de C. odorata, A. triplinervia y Caraipa grandiflora, los de mayor actividad con una CIM = 3.91 mg/ml para cada uno.  Se obtuvieron prometedores resultados de actividad antibacteriana de los extractos en estudio frente a cepas intrahospitalarias, mayormente contra S. aureus. Descriptores: Actividad antibacteriana, extractos vegetales, cepas intrahospitalarias Abstract The Amazon region is one of the areas with the largest biodiversity in the world, hosting several thousand species of plants, many of which are used by its people as medicinal plants. In recent years, the use of these plant resources or products has been increasing significantly, which could be due to a number of factors, among them the knowledge of their chemical composition, and the fact that at present there have been numerous pharmacological tests both in vivo and in vitro. The emergence of antibiotic-resistant strains in recent years, is creating a need for other strategies or ways to control them, as in the case of the use of plants (traditional medicine), because the active ingredients bearing. This work is intended to determine probable alternatives to combat bacterial infections of those agents antibiotic-resistant, this problem is particularly critical in developing countries, where perhaps there are no antibiotics or expensive second line, if any, price is unavailable. The study was conducted in Iquitos city, Province of Maynas, Department of Loreto. Microbiological tests were performed at Microbiology Laboratory of Research Center of Natural Resources of the Amazon (CIRNA) of the National University of the Peruvian Amazon (UNAP). The antibacterial activity of six plant extracts (Alchornea triplinervia, Annona muricata, Averrhoa carambola, Brunfelsia grandiflora, Caraipa grandifolia y Cedrela odorata) by the disk diffusion method was determined, and those that showed activity were determined Minimum Inhibitory Concentration and Minimum Bactericidal Concentration by macrodilution technique. None of the extracts were active against strains of E. coli; four extracts had activity against strains of P. aeruginosa, with Cedrela odorata and Alchornea triplinervia extracts which had greater activity against these bacteria, with MIC = 15.62 and 62.5 mg/ml, respectively; all extracts were active against strains of S. aureus, with the extract of C. odorata, A. triplinervia and Caraipa grandiflora, the most active with an MIC = 3.91 mg/ml for each. Was obtained Promising results of antibacterial activity of the extracts in study against nosocomial strains, mostly against S. aureus. Keywords: Antibacterial activity, plant extracts, nosocomial strains


2019 ◽  
Author(s):  
Chem Int

New copper complexes, [Cu(phen)2(Thy)]2Cl and [Cu(phen)2(Ad)]2Cl (phen = 1,10-phenantroline, Ad (Adenine, a purine nucleobase) and Thy (Thymine, a pyrimidine nucleobase)), were synthesized and characterized by atomic absorption spectroscopy (AAS), conductivity measurement, UV-visible and infrared (IR) techniques. The complexes were tested for their antimicrobial activity against two gram positive and two gram negative bacterial strains. The results of in vitro antimicrobial activities were compared with the commercially available antimicrobial agents (ciprofloxacin and chloramphenicol). This comparative study has demonstrated that [Cu(phen)2(Thy)]2Cl inhibited the growth of methicillin resistant Staphylococcus aureous (MRSA), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumonia) better than chloramphenicol by 11.25%, 19.41% and 25.35%, respectively. It also showed better activities than ciprofloxacine on MRSA and K. pneumoniae by 2.50% and 12.13%, respectively. Similarly, [Cu(phen)2(Ad)]2Cl demonstrated better inhibitions than chloramphenicol against MRSA, E. coli and K. pneumoniae by 11.24%, 2.48% and 9.06%, respectively. Therefore, after in vivo cytotoxicity investigations, these complexes could be considered as potential antimicrobial agents.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Atakilt Abebe ◽  
Tizazu Hailemariam

In this work, two complexes of ruthenium(III) ([Ru(phen)2Cl2]Cl·2H2O and [Ru(phen)2(G)Cl]2Cl·H2O) were synthesized from 1,10-phenanthroline alone as well as from both 1,10-phenanthroline and guanide. The synthesis was checked using halide test, conductance measurement, and spectroscopic (ICP-OES, FTIR, and UV/Vis) analysis. Their in vitro antibacterial activities were also investigated on two Gram-positive (Staphylococcus aureus (S. aureus) and methicillin resistant Staphylococcus aureus (MRSA)) and two Gram-negative (Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae)) bacteria. These complexes showed wide-range better activities than the commercially available controls (Chloramphenicol and Ciprofloxacin) against even the most drug resistant K. pneumoniae. [Ru(phen)2(G)Cl]2Cl·H2O inhibited S. aureus, MRSA, E. coli, and K. pneumoniae by 17.5%, 27.4%, 16%, and 52%, respectively, better than Chloramphenicol. It also inhibited these pathogens by 5.9%, 5.1%, 2.3%, and 17.2%, respectively, better than Ciprofloxacin. Similarly, [Ru(Phen)2(Cl)2]Cl·2H2O inhibited these pathogens by 11%, 8.7%, 0.1%, and 31.2%, respectively, better than Chloramphenicol. Therefore, after in vivo cytotoxicity investigations, these compounds can be considered as potential antibiotic drugs.


Author(s):  
Jitendra K. Patel ◽  
Chetan Kumar Joshi ◽  
Mukesh Kumar Sharma

Medicinal herbs that are in use for centuries to treat infections and other illnesses. Prunella vulgaris L. is traditionally used for its therapeutic attributes for the alleviation of various infectious diseases. The objective of this study on Prunella vulgaris was to reveal relevant pharmaceutical information to understand its beneficial medicinal uses for human beings. The methanolic and petroleum ether extracts after removal of the solvent under reduced pressure from the Prunella vulgaris plants were prepared and these extracts were analyzed in vitro for their activity against B. subtilis, E. coli, S. aureus and S. typhi (with ATCC numbers 6051, 25922, 23235 and 14028 respectively). Likewise, in vivo studies were conducted using the E. coli-induced peritonitis in laboratory rat models where the rats were given allopathic antibiotic ofloxacin and the results were compared with those rats who received plant extracts under controlled conditions. The results were analyzed for the efficacy of the plant extracts was compared with ofloxacin; the methanol extracts exhibited equally if not better results in clearing the pathogen from the system of animals. The petroleum ether extracts exhibited the least antimicrobial activity in comparison to those extracted in methanol isolates. In conclusion, the herbal extract demonstrated significant antibacterial activity both under in-vitro and in-vivo studies which is a major outcome of the study. During this study, all standards and norms were followed as per government animal authority.


1997 ◽  
Vol 41 (12) ◽  
pp. 2652-2663 ◽  
Author(s):  
T Fukuoka ◽  
S Ohya ◽  
Y Utsui ◽  
H Domon ◽  
T Takenouchi ◽  
...  

CS-834 is a novel oral carbapenem antibiotic. This compound is an ester-type prodrug of the active metabolite R-95867. The antibacterial activity of R-95867 was tested against 1,323 clinical isolates of 35 species and was compared with those of oral cephems, i.e., cefteram, cefpodoxime, cefdinir, and cefditoren, and that of a parenteral carbapenem, imipenem. R-95867 exhibited a broad spectrum of activity covering both gram-positive and -negative aerobes and anaerobes. Its activity was superior to those of the other compounds tested against most of the bacterial species tested. R-95867 showed potent antibacterial activity against clinically significant pathogens: methicillin-susceptible Staphylococcus aureus including ofloxacin-resistant strains, Streptococcus pneumoniae including penicillin-resistant strains, Clostridium perfringens, Neisseria spp., Moraxella catarrhalis, most members of the family Enterobacteriaceae, and Haemophilus influenzae (MIC at which 90% of strains are inhibited, < or =0.006 to 0.78 microg/ml). R-95867 was quite stable to hydrolysis by most of the beta-lactamases tested except the metallo-beta-lactamases from Stenotrophomonas maltophilia and Bacteroides fragilis. R-95867 showed potent bactericidal activity against S. aureus and Escherichia coli. Penicillin-binding proteins 1 and 4 of S. aureus and 1Bs, 2, 3, and 4 of E. coli had high affinities for R-95867. The in vivo efficacy of CS-834 was evaluated in murine systemic infections caused by 16 strains of gram-positive and -negative pathogens. The efficacy of CS-834 was in many cases superior to those of cefteram pivoxil, cefpodoxime proxetil, cefdinir, and cefditoren pivoxil, especially against infections caused by S. aureus, penicillin-resistant S. pneumoniae, E. coli, Citrobacter freundii, and Proteus vulgaris. Among the drugs tested, CS-834 showed the highest efficacy against experimental pneumonia in mice caused by penicillin-resistant S. pneumoniae.


2012 ◽  
Vol 7 (8) ◽  
pp. 1934578X1200700
Author(s):  
Hana McFeeters ◽  
Morgan J. Gilbert ◽  
Rachel M. Thompson ◽  
William N. Setzer ◽  
Luis R. Cruz-Vera ◽  
...  

Peptidyl-tRNA Hydrolase (Pth) is a highly conserved, essential enzyme in bacteria. It removes the peptide portion from peptidyl-tRNA, returning free tRNAs to participate in translation. Build-up of peptidyl-tRNAs is toxic and defects in Pth function result in cell death. Herein we use in vitro activity of recombinant E. coli Pth to screen tropical plant extracts for inhibition. Multiple extracts were found to have inhibitory activity with some exhibiting different inhibitory effects depending on extraction conditions. IC50 values ranged from 0.02 to > 53.8 μg of extract per 1 unit of Pth, holding promise for in vivo screening. The inhibitory components in these extracts may serve as lead compounds for development of novel antibacterials.


Sign in / Sign up

Export Citation Format

Share Document