Zinc oxide microrods and nanorods: different antibacterial activity and their mode of action against Gram-positive bacteria

RSC Advances ◽  
2014 ◽  
Vol 4 (99) ◽  
pp. 56031-56040 ◽  
Author(s):  
Ilaria Rago ◽  
Chandrakanth Reddy Chandraiahgari ◽  
Maria P. Bracciale ◽  
Giovanni De Bellis ◽  
Elena Zanni ◽  
...  

ZnO micro and nanorods, produced through simple and inexpensive techniques, resulted to be strong antimicrobials against Gram-positive bacteria, in vitro as well as in vivo, by altering cell outer structures like membrane and exopolysaccharides.

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.


2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.


2015 ◽  
Vol 25 (2-3) ◽  
pp. 79-93 ◽  
Author(s):  
Joseph W. Lengeler

<b><i>Past:</i></b> The title ‘PTS 50 or The PTS after 50 years' relies on the first description in 1964 of the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system (PTS) by Kundig, Gosh and Roseman [Proc Natl Acad Sci USA 1964;52:1067-1074]. The system comprised proteins named Enzyme I, HPr and Enzymes II, as part of a novel PTS for carbohydrates in Gram-negative and Gram-positive bacteria, whose ‘biological significance remained unclear'. In contrast, studies which would eventually lead to the discovery of the central role of the PTS in bacterial metabolism had been published since before 1942. They are primarily linked to names like Epps and Gale, J. Monod, Cohn and Horibata, and B. Magasanik, and to phenomena like ‘glucose effects', ‘diauxie', ‘catabolite repression' and carbohydrate transport. <b><i>Present:</i></b> The pioneering work from Roseman's group initiated a flood of publications. The extraordinary progress from 1964 to this day in the qualitative and in vitro description of the genes and enzymes of the PTS, and of its multiple roles in global cellular control through ‘inducer exclusion', gene induction and ‘catabolite repression', in cellular growth, in cell differentiation and in chemotaxis, as well as the differences of its functions between Gram-positive and Gram-negative bacteria, was one theme of the meeting and will not be treated in detail here. <b><i>Future:</i></b> At the 1988 Paris meeting entitled ‘The PTS after 25 years', Saul Roseman predicted that ‘we must describe these interactions [of the PTS components] in a quantitative way [under] in vivo conditions'. I will present some results obtained by our group during recent years on the old phenomenon of diauxie by means of very fast and quantitative tests, measured in vivo, and obtained from cultures of isogenic mutant strains growing under chemostat conditions. The results begin to hint at the problems relating to future PTS research, but also to the ‘true science' of Roseman.


2019 ◽  
Vol 7 (12) ◽  
pp. 5097-5111 ◽  
Author(s):  
Chunyi Tong ◽  
Li Li ◽  
Feng Xiao ◽  
Jialong Fan ◽  
Xianghua Zhong ◽  
...  

rGO was used for simultaneously anchoring AgNPs and Daptomycin to prepare rGO@Ag@Dap for anti-bacterium. The new nanomaterial showed strong Gram-positive bacteria killing ability in vitro and enhanced wound healing infected with S. aureus in vivo.


2011 ◽  
Vol 79 (9) ◽  
pp. 3596-3606 ◽  
Author(s):  
Chris S. Rae ◽  
Aimee Geissler ◽  
Paul C. Adamson ◽  
Daniel A. Portnoy

ABSTRACTListeria monocytogenesis a Gram-positive intracellular pathogen that is naturally resistant to lysozyme. Recently, it was shown that peptidoglycan modification by N-deacetylation or O-acetylation confers resistance to lysozyme in various Gram-positive bacteria, includingL. monocytogenes.L. monocytogenespeptidoglycan is deacetylated by the action ofN-acetylglucosamine deacetylase (Pgd) and acetylated byO-acetylmuramic acid transferase (Oat). We characterized Pgd−, Oat−, and double mutants to determine the specific role ofL. monocytogenespeptidoglycan acetylation in conferring lysozyme sensitivity during infection of macrophages and mice. Pgd−and Pgd−Oat−double mutants were attenuated approximately 2 and 3.5 logs, respectively,in vivo. In bone-marrow derived macrophages, the mutants demonstrated intracellular growth defects and increased induction of cytokine transcriptional responses that emanated from a phagosome and the cytosol. Lysozyme-sensitive mutants underwent bacteriolysis in the macrophage cytosol, resulting in AIM2-dependent pyroptosis. Each of thein vitrophenotypes was rescued upon infection of LysM−macrophages. The addition of extracellular lysozyme to LysM−macrophages restored cytokine induction, host cell death, andL. monocytogenesgrowth inhibition. This surprising observation suggests that extracellular lysozyme can access the macrophage cytosol and act on intracellular lysozyme-sensitive bacteria.


Author(s):  
G. D. Shermatova

Abstract: The leaves and roots of Rumex confertus Willd were tested in vitro for antibacterial and fungal activity in the fractions of gasoline, chloroform, ethyl acetate and butanol. As a result, it was found that the leaves of the Rumex confertus Willd plant, chloroform and ethyl acetate fractions of the root part have antibacterial activity against fungi and gram-positive bacteria. Keywords: Rumex confertus Willd, fractions, extracts, antibacterial, antifungal


2020 ◽  
Vol 10 (5) ◽  
pp. 274-292
Author(s):  
Rohit Kumar ◽  
Sushil Kumar ◽  
Mohammad Asif Khan

Recently a series of Schiff bases of diphenylamine derivatives have been synthesized and evaluated in vitro for their antibacterial activity against pathogenic both Gram-positive bacteria B. subtitles and Gram-negative bacteria E. coli using ciprofloxacin as standard drug at conc. of 50 μg/ml and 100 μg/ml. Literature review revels that chalcones possesses various biological activities like antimicrobial, antiviral, anti-inflammatory, anticancer and sedative etc. Therefore the present study was designed on synthesis and pharmacological evaluation of 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides. Target compound was synthesized by reaction of chloroacetylchloride with diphenylamine to afford 2-chloro-N, N-diphenylacetamide which further by reaction with substituted Chalcones and characterized following recrystallization and evaluated for anti-microbial potential through cup-diffusion method. In results, the target compounds were tested for activity against B. Subtilis, E.Coli and C. albicans. The chalcones having the lipophilic 4-chloro group (RKCT2) showed the greatest antimicrobial activity (zone of inhibition 20 & 22 mm against. B. subtilis, E. Coli, C. Albicans respectively. It suggests further researchers to go through anti-microbial evaluations against a more varieties of bacteria and fungi. Keywords: Schiff bases of diphenylamine derivatives, antibacterial activity, Gram-positive bacteria, 2-(4-(3 (Substituted Phenyl) Acryloyl) Phenoxy)-N, N Diphenylacetamides


Sign in / Sign up

Export Citation Format

Share Document