ZL-2, a cathelicidin-derived antimicrobial peptide, has a broad antimicrobial activity against gram-positive bacteria and gram-negative bacteria in vitro and in vivo

2015 ◽  
Vol 38 (10) ◽  
pp. 1802-1809 ◽  
Author(s):  
Jiancheng Tu ◽  
Geping Wu ◽  
Yun Zuo ◽  
Lei Zhao ◽  
Shusheng Wang
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.


2000 ◽  
Vol 68 (3) ◽  
pp. 1600-1607 ◽  
Author(s):  
Andreas Sing ◽  
Thomas Merlin ◽  
Hans-Peter Knopf ◽  
Peter J. Nielsen ◽  
Harald Loppnow ◽  
...  

ABSTRACT We investigated the reason for the inability of lipopolysaccharide (LPS)-resistant (Lps-defective [Lpsd ]) C57BL/10ScCr mice to produce beta interferon (IFN-β) when stimulated with bacteria. For this purpose, the IFN-β and other macrophage cytokine responses induced by LPS and several killed gram-negative and gram-positive bacteria in LPS-sensitive (Lps-normal [Lpsn ]; C57BL/10ScSn and BALB/c) and Lpsd (C57BL/10ScCr and BALB/c/l) mice in vitro and in vivo were investigated on the mRNA and protein levels. In addition, double-stranded RNA (dsRNA) was used as a nonbacterial stimulus. LPS and all gram-negative bacteria employed induced IFN-β in the Lpsn mice but not in theLpsd mice. All gram-positive bacteria tested failed to induce significant amounts of IFN-β in all four of the mouse strains used. As expected, all other cytokines tested (tumor necrosis factor alpha, interleukin 1α [IL-1α], IL-6, and IL-10) were differentially induced by gram-negative and gram-positive bacteria. Stimulation with dsRNA induced IFN-β and all other cytokines mentioned above in all mouse strains, regardless of their LPS sensitivities. The results suggest strongly that LPS is the only bacterial component capable of inducing IFN-β in significant amounts that are readily detectable under the conditions used in this study. Consequently, in mice, IFN-β is inducible only by gram-negative bacteria, but not in C57BL/10ScCr or other LPS-resistant mice.


Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3532-3543 ◽  
Author(s):  
Geoff P. Doherty ◽  
Mark J. Fogg ◽  
Anthony J. Wilkinson ◽  
Peter J. Lewis

Bacterial RNA polymerases (RNAPs) contain several small auxiliary subunits known to co-purify with the core α, β and β′ subunits. The ω subunit is conserved between Gram-positive and Gram-negative bacteria, while the δ subunit is conserved within, but restricted to, Gram-positive bacteria. Although various functions have been assigned to these subunits via in vitro assays, very little is known about their in vivo roles. In this work we constructed a pair of vectors to investigate the subcellular localization of the δ and ω subunits in Bacillus subtilis with respect to the core RNAP. We found these subunits to be closely associated with RNAP involved in transcribing both mRNA and rRNA operons. Quantification of these subunits revealed δ to be present at equimolar levels with RNAP and ω to be present at around half the level of core RNAP. For comparison, the localization and quantification of RNAP β′ and ω subunits in Escherichia coli was also investigated. Similar to B. subtilis, β′ and ω closely associated with the nucleoid and formed subnucleoid regions of high green fluorescent protein intensity, but, unlike ω in B. subtilis, ω levels in E. coli were close to parity with those of β′. These results indicate that δ is likely to be an integral RNAP subunit in Gram-positives, whereas ω levels differ substantially between Gram-positives and -negatives. The ω subunit may be required for RNAP assembly and subsequently be turned over at different rates or it may play roles in Gram-negative bacteria that are performed by other factors in Gram-positives.


Author(s):  
J. A. Melo1 ◽  
K. M. M. Aroucha1 ◽  
L. P. M. Santos ◽  
C. M. Moraes ◽  
J A. Takahashi ◽  
...  

Popularly known as red mandioqueira, ‘mandioqueira vermelha’, Qualea paraensis Ducke is a plant species belonging to the family Vochysiaceae, with a natural distribution in the Amazon region. It is used in traditional medicine, by native communities of the Amazon and Bolivia, for the treatment of skin lesions caused by microorganisms. Previous studies of the species have found antimalarial activity in vivo assays. However, studies involving the investigation of numerous biological activities of Q. paraensis are incipient. Biological assays already performed with plants of other species of the genus Qualea have shown promising biological activities. Therefore, this study describes the evaluation of the biological activities (bactericide, fungicide, toxicity, and anticholinesterase) of an ethanolic extract of the bark of Q. paraensis from the state of Roraima, Brazil. For the evaluation of the toxicity of the extract, a system with microcrustacean Artemia salina was used. Antimicrobial activity was tested for the pathogenic groups of fungi (Aspergillus flavus and Fusarium proliferatum), Gram-negative bacteria (Escherichia coli and Salmonella tiphymurium), and Gram-positive bacteria (Staphylococcus aureus and Streptococcus sanguinis). The potential of the extract for the inhibition of the enzyme acetylcholinesterase (AChE) was also evaluated. The assays for determining the antimicrobial activity for Gram-positive bacteria revealed satisfactory IC50 (29.98μg/mL) inhibition values for S. sanguinis strains, showing inhibition of 64.6% of their growth. The assay for S. aureus, however, presented low inhibition. For Gram-negative bacteria, there was moderate inhibition of E. coli strains. The extract showed low toxicity to A. salina and inhibition of 23.66% of the AChE enzyme.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Rajesh K. Joshi ◽  
Vijaylaxmi Badakar

The essential oil of the flowers of Tridax procumbens L. was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twenty-six compounds were identified, which comprised 90.6% of the total constituents. The most abundant compound was ( Z)-falcarinol (25.9%), followed by α-selinene (15.3%), limonene (8.3%) and zerumbone (4.3%). Antimicrobial activity was tested against six Gram-positive and eight Gram-negative bacteria, and three fungi. The oil was active against the tested Gram-positive bacteria at a concentration range of 0.14 ± 0.03 - 0.57±0.05 mg/mL, while 0.67 ± 0.12 - 4.58 ± 0.41 mg/mL was effective against the studied Gram-negative bacteria. Remarkable antifungal activity was found against the tested fungi at a concentration range of 0.06 ± 0.008 - 0.10 ± 0.01 mg/mL.


2021 ◽  
Vol 47 ◽  
pp. e645
Author(s):  
Jaqueline da Rosa COELHO ◽  
Karolina Victória ROSA ◽  
Jamilly Sousa ROCHA ◽  
Norha Constanza Bolívar RAMÍREZ ◽  
Marcelo MARASCHIN ◽  
...  

This study aimed to evaluate the in vitro effect of carvacrol on different microorganisms of importance in shrimp farming, as well as its in vivo effect on zootechnical, immunological and microbiological performance, as well as resistance, of Litopenaeus vannamei challenged with Vibrio parahaemolyticus. In particular, the antimicrobial activity of carvacrol was evaluated in vitro by analysis of the minimum inhibitory concentration (MIC) and by agar diffusion disc with Gram-negative and Gram-positive bacteria. The in vivo experiment was conducted using different concentrations of carvacrol (1, 3, 4 and 6 mg mL-1) added to shrimp feed, together with a control diet without carvacrol. After four weeks, zootechnical, immunological and microbiological parameters, as well as resistance, of animals challenged with V. parahaemolyticus were evaluated. The MIC of Vibrio alginolyticus and Vibrio harveyi was 0.078 mg mL-1, while for the other bacteria, it was 0.156 mg mL-1 of carvacrol. The greatest halos of inhibition were observed in V. parahaemolyticus and Vibrio harveyi with significant differences demonstrated for the other microorganisms, except Escherichia coli. The in vivo results showed no significant differences among treatments. In conclusion, the antimicrobial activity of carvacrol was confirmed with Gram-negative and Gram-positive bacteria, and it is suggested that its antimicrobial potential is more effective against Vibrio spp. However, the concentrations of carvacrol used in vivo did not affect the parameters evaluated.


Author(s):  
Halah A. Sahib ◽  
Mohammed H. Mohammed

A A new series of bases of Schiff (H2-H4) derived from phthalic anhydrideweresynthesized. These Schiff bases were prepared by the reaction of different amines (tyrosine methyl ester, phenylalanine methyl ester, and isoniazid) with the phthalimide derived aldehyde with the aid of glacial acetic acid or triethylamine ascatalysts. All the synthesized compounds were characterized by (FT-IR and 1HNMR) analyses and were in vitro evaluated for their antimicrobial activity against six various kinds of microorganisms. All the synthesized compounds had been screened for their antimicrobial activity against two Gram-positive bacteria “Staph. Aureus, and Bacillus subtilis”, two Gram-negative bacteria “Escherichia coli, and Klebsiella pneumoniae”, and two fungi species “Candida tropicalis and Candida albicans” using concentrations of 62.5, 125 and 250 µg\mLof derivative in dimethyl sulfoxide(DMSO). All the synthesized compounds showed no activity at all against Gram-positive bacteria, for Gram-negative bacteria and fungi they showed moderate or no activity except compound H1revealedhigh antifungal activityagainstCandida tropicalisat concentrations 125 and 250 µg\ mL. Keywords: Schiff base, phthalic anhydride, antimicrobial.  


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2987 ◽  
Author(s):  
Cornelius Domhan ◽  
Philipp Uhl ◽  
Christian Kleist ◽  
Stefan Zimmermann ◽  
Florian Umstätter ◽  
...  

Infections caused by multidrug-resistant bacteria are a global emerging problem. New antibiotics that rely on innovative modes of action are urgently needed. Ranalexin is a potent antimicrobial peptide (AMP) produced in the skin of the American bullfrog Rana catesbeiana. Despite strong antimicrobial activity against Gram-positive bacteria, ranalexin shows disadvantages such as poor pharmacokinetics. To tackle these problems, a ranalexin derivative consisting exclusively of d-amino acids (named danalexin) was synthesized and compared to the original ranalexin for its antimicrobial potential and its biodistribution properties in a rat model. Danalexin showed improved biodistribution with an extended retention in the organisms of Wistar rats when compared to ranalexin. While ranalexin is rapidly cleared from the body, danalexin is retained primarily in the kidneys. Remarkably, both peptides showed strong antimicrobial activity against Gram-positive bacteria and Gram-negative bacteria of the genus Acinetobacter with minimum inhibitory concentrations (MICs) between 4 and 16 mg/L (1.9–7.6 µM). Moreover, both peptides showed lower antimicrobial activities with MICs ≥32 mg/L (≥15.2 µM) against further Gram-negative bacteria. The preservation of antimicrobial activity proves that the configuration of the amino acids does not affect the anticipated mechanism of action, namely pore formation.


Author(s):  
Shipra Baluja ◽  
Sumitra Chanda ◽  
Paras Ramavat

A series of oxadiazole derivatives were synthesized and were characterized by IR, 1H NMR and mass spectroscopy. All these synthesized compounds were tested for in vitro antimicrobial against four Gram positive bacteria, four Gram negative bacteria and four fungal strains in DMSO and DMF.


2012 ◽  
Vol 9 (4) ◽  
pp. 2079-2088 ◽  
Author(s):  
Vishakha Bansode ◽  
Meenakshi N. Deodhar

A series of the title compounds 3-(4-(4, 5-dihydro-5-(substituted phenyl)-1H-3-pyrazolyl) phenylimino) methyl)-4-chloro-2H-chromen-2-one 5(a-g) have been synthesized. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive bacteria, gram negative bacteria and fungi. The compound (5b) was found to be the most active with MIC of 20 µg/ml against all the tested organisms.


Sign in / Sign up

Export Citation Format

Share Document