2,094 research outputs found
3,4,5,3’,5’-pentabromo-2-(2’-hydroxybenzoyl) pyrrole: a potential lead compound as anti Gram-positive and anti biofilm agent
The activity against Gram-positive bacteria of 3,4,5,3 ,5 -pentabromo-2-(2 -hydroxybenzoyl)pyrrole I, a synthetic anti-bacterial compound
related to pyrrolomycins, was tested in vitro using seven reference bacterial strains and Staphylococcus epidermidis and Staphylococcus
aureus preformed biofilms. Compound I was active against all strains tested, with minimum inhibitory concentration (MIC) values ranging
from 0.002 to 0.097 mg/l and minimum bactericidal concentrations (MBCs) from 0.37 to 12.5 mg/l. Compound I was also active at low
concentrations against preformed S. epidermidis and S. aureus biofilms
Analysis of the influence of tectonics on the evolution of valley networks based on Srtm Dem, Jemma River basin, Ethiopia
The Ethiopian Highlands are a good example of a high plateau landscape formed by a combination of tectonic uplift and episodic volcanism. Deeply incised gorges indicate active fluvial erosion, which leads to instabilities of over-steepened slopes. In this study we focus on the Jemma River basin, which is a left bank tributary of the Abay - Blue Nile in order to assess the influence of neotectonics on the evolution of its river and valley network. Tectonic lineaments, shape of valley networks, direction of river courses and intensity of fluvial erosion were compared in six subregions, which were delineate beforehand by means of morphometric analysis. The influence of tectonics on the valley network is low in the older deep and wide canyons and on the high plateau covered with Tertiary lava flows, whilst in the younger upper part of the canyons it is high. Furthermore, the coincidence of the valley network with the tectonic lineaments differs in the subregions. The direction of the fluvial erosion along the main tectonic zones (NE-SW) made it possible for backward erosion to reach far distant areas in the east. This tectonic zone also separates older areas in the west from the youngest landscape evolution subregions in the east, next to the Rift Valley
Fragments of -thymosin from the sea urchin Paracentrotus lividus as potential antimicrobial peptides against staphylococcal biofilms
The immune mediators in echinoderms can be a potential source of novel antimicrobial peptides (AMPs) applied
toward controlling pathogenic staphylococcal biofilms that are intrinsically resistant to conventional antibiotics.
The peptide fraction <5 kDa from the cytosol of coelomocytes of the sea urchin Paracentrotus lividus (5-CC)
was tested against a group of Gram-positive and Gram-negative pathogen reference strains. The 5-CC of P. lividus
was active against all planktonic-tested strains but also showed antibiofilm properties against staphylococcal strains.
Additionally,wedemonstrated the presenceof three smallpeptides in the5-CCbelonging tosegment 9-41of aP. lividus
-thymosin. The smallest of these peptides in particular, showed the common chemical\u2013physical characteristics of
AMPs. This novel AMP from -thymosin has high potential activity as an antibiofilm agent, acting on slow-growing
bacterial cells that exhibit a reduced susceptibility to conventional antibiotics and represent a reservoir for recurrent
biofilm-associated infections
De novo design of antimicrobial and antibiofilm peptides starting from desert truffle Tirmania pinoyi peptides
With the aim of discovering new routes in the research of antimicrobials, we focused on polypeptide-
enriched extracts derived from edible desert truffle mushroom Tirmania pinoyi. The extracts
showed an interesting activity with MIC=50 ÎĽg/mL against Staphylococcus aureus ATCC 29213
and Pseudomonas aeruginosa ATCC 15442. Through mass spectrometry analysis (RP-HPLC/
nESI-MS/MS) the following eight novel peptides FDVVPKTAANFRAL, AVTVGASTLADERA,
FLVGGASLKPEF, VARIFAVFNDTF, HLVDEPQNLLK, LGEYGFQNALLR, FAVNGGCAKET,
SREDLHPKL were detected. To characterize them online websites were used: IAMPpred,
DPBAAS, Cell-PPD, ToxinPred, HemoPI, PeptideCutter and HLP. The analysis indicated that
some peptides showed negative or neutral charge, hydrophobic ratio between 42% and 67%,
Boman Index < 2.25 kCal/mol. According to the “APD3: Antimicrobial Peptide Calculator and
Predictor” tool of the Antimicrobial Peptide Database (APD) similarities (around 30-40%) with
known antimicrobial peptides (AMPs) identified in amphibians were also detected. In contrast, the
predicted antimicrobial, antifungal and antibiofilm activity was not significant.
In order to improve biological and physico-chemical properties, the sequences of natural peptides
were modified using APD3, by replacing some hydrophilic and negative charged amino acids
with hydrophobic and positive ones. The derivative sequences (GWDVVPKTWWKFRAL,
KWTWGASTLAKKRA, FLRGGWSLKPKF, KWRIFWVFNKTF, HLVKRWQNLLK,
KGKYRFWNALLR, FARWGGCAKRT, SRKWLHPWL) showed net positive charge between
+2 and +4, hydrophobic ratio between 42% and 48%, Boman Index < 2.25 kCal/mol and high
stability. Moreover, the predicted antimicrobial, antifungal and antibiofilm activity was high, without
toxic or hemolytic effects.
In conclusion, bioinformatic analysis has demonstrated that novel peptides discovered in T. pinoyi
may be considered new platforms for the design of novel antimicrobial and antibiofilm peptides to
counteract multi-drug resistant pathogens
A High Sensitive Nested PCR for Toxoplasma gondii Detection in Animal and Food Samples
Toxoplasma gondii is a major food and waterborne transmitted parasite world-wide. The tissues and meat
samples of many warm blooded animals can contain tissues cysts from chronic toxoplasmosis. Water and vegetable
can be contaminated by the parasitic oocysts shed through the feces of infected cats, representing the definitive
host of the parasite.
A sensitive PCR for Toxoplasma gondii detection is described. The first step amplified the region between the
28S and 18S rDNA in the closely related T. gondii and Neospora caninum; RFLP analysis distinguished the DNA
from the two morphologically identical parasites. Although N. caninum is not involved in human transmission, so far,
it is important for animal health since is a major responsible for abortion in cattle.
The nested PCR was used in a dilution assay in pork sausage samples spiked with T. gondii parasitic DNA. The
analysis showed that up to 200fg equivalent to two single parasites only, could be detected. Similar detection limit
for T. gondii can be obtained with real-time PCRs, but real time methods need special consumables and expensive
equipment
A very promising antibiofilm activity against Candida albicans from an in vitro screening for antimicrobial, antibiofilm and antiproliferative activity of new synthesized 4-cinnamamido- and 2-phenoxyacedamido-1H-pyrazol-5-yl)benzamides
Several new synthesized 4-cinnamamido- and 2-phenoxyacedamido-(1H-pyrazol-5-yl)benzamides were obtained by two
multi step different synthetic routes in order to maximize their yield. The new derivatives were screened to determine the
antiproliferative, antimicrobial and antibiofilm activity. The biological results showed how, respect to the antiproliferative
and antimicrobial activities, the compounds have a low to missing activity. Different are the results obtained concerning the
antibiofilm activity, especially towards Candida albicans. Most of the synthesized compounds showed a good percentage
inhibition of biofilm formation ranging from 60 to 73% with a Biofilm Inhibition Concentration 50% (BIC50) from 0.13 to
0.01 ÎĽM. Among the synthesized compounds the ethyl 5-(4-(2-(4-chlorophenoxy)acetamido)benzamido)-1-methyl-1Hpyrazole-
4-carboxylate (27c) resulted the most active molecule with a BIC50 of 0.01 ÎĽM. According to the results obtained,
such compound could be considered a lead subject of further studies to obtain novel and more effective antibiofilm agents
against C. albicans
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