scholarly journals Pseudomonas Aeruginosa Lectins As Targets for Novel Antibacterials

Acta Naturae ◽  
2015 ◽  
Vol 7 (2) ◽  
pp. 29-41 ◽  
Author(s):  
A. V. Grishin ◽  
M. S. Krivozubov ◽  
A. S. Karyagina ◽  
A. L. Gintsburg

Pseudomonas aeruginosa is one of the most widespread and troublesome opportunistic pathogens that is capable of colonizing various human tissues and organs and is often resistant to many currently used antibiotics. This resistance is caused by different factors, including the acquisition of specific resistance genes, intrinsic capability to diminish antibiotic penetration into the bacterial cell, and the ability to form biofilms. This situation has prompted the development of novel compounds differing in their mechanism of action from traditional antibiotics that suppress the growth of microorganisms or directly kill bacteria. Instead, these new compounds should decrease the pathogens ability to colonize and damage human tissues by inhibiting the virulence factors and biofilm formation. The lectins LecA and LecB that bind galactose and fucose, as well as oligo- and polysaccharides containing these sugars, are among the most thoroughly-studied targets for such novel antibacterials. In this review, we summarize the results of experiments highlighting the importance of these proteins for P. aeruginosa pathogenicity and provide information on existing lectins inhibitors and their effectiveness in various experimental models. Particular attention is paid to the effects of lectins inhibition in animal models of infection and in clinical practice. We argue that lectins inhibition is a perspective approach to combating P. aeruginosa. However, despite the existence of highly effective in vitro inhibitors, further experiments are required in order to advance these inhibitors into pre-clinical studies.

Author(s):  
Baydaa Hussein ◽  
Zainab A. Aldhaher ◽  
Shahrazad Najem Abdu-Allah ◽  
Adel Hamdan

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.


2016 ◽  
Vol 6 (01) ◽  
pp. 5218
Author(s):  
Laxmi Mohandas ◽  
Anju T. R. ◽  
Sarita G. Bhat*

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.


2021 ◽  
Vol 16 (1) ◽  
pp. 1934578X2098774
Author(s):  
Jinpeng Zou ◽  
Yang Liu ◽  
Ruiwei Guo ◽  
Yu Tang ◽  
Zhengrong Shi ◽  
...  

The drug resistance of Pseudomonas aeruginosa is a worldwide problem due to its great threat to human health. A crude extract of Angelica dahurica has been proved to have antibacterial properties, which suggested that it may be able to inhibit the biofilm formation of P. aeruginosa; initial exploration had shown that the crude extract could inhibit the growth of P. aeruginosa effectively. After the adaptive dose of coumarin was confirmed to be a potential treatment for the bacteria’s drug resistance, “coumarin-antibiotic combination treatments” (3 coumarins—simple coumarin, imperatorin, and isoimperatorin—combined with 2 antibiotics—ampicillin and ceftazidime) were examined to determine their capability to inhibit P. aeruginosa. The final results showed that (1) coumarin with either ampicillin or ceftazidime significantly inhibited the biofilm formation of P. aeruginosa; (2) coumarin could directly destroy mature biofilms; and (3) the combination treatment can synergistically enhance the inhibition of biofilm formation, which could significantly reduce the usage of antibiotics and bacterial resistance. To sum up, a coumarin-antibiotic combination treatment may be a potential way to inhibit the biofilm growth of P. aeruginosa and provides a reference for antibiotic resistance treatment.


2021 ◽  
pp. 1-8
Author(s):  
Soheir A.A. Hagras ◽  
Alaa El-Dien M.S. Hosny ◽  
Omneya M. Helmy ◽  
Mounir M. Salem-Bekhit ◽  
Faiyaz Shakeel ◽  
...  

This study investigated the effect of cefepime at sub-minimum inhibitory concentrations (sub-MICs) on in vitro biofilm formation (BF) by clinical isolates of Pseudomonas aeruginosa. The effect of cefepime at sub-MIC levels (½–1/256 MIC) on in vitro BF by six clinical isolates of P. aeruginosa was phenotypically assessed following 24 and 48 h of challenge using the tissue culture plate (TCP) assay. Quantitative real-time polymeric chain reaction (qRT-PCR) was employed to observe the change in expression of three biofilm-related genes, namely, a protease-encoding gene (lasA), fimbrial protein-encoding gene (cupA1), and alginate-encoding gene (algC), in a weak biofilm-producing strain of P. aeruginosa following 24 and 48 h of challenge with sub-MICs of cefepime. The BF morphology in response to cefepime was imaged using scanning electron microscopy (SEM). The TCP assay showed strain-, time-, and concentration-dependent changes in in vitro BF in P. aeruginosa following challenge with sub-MICs of cefepime, with a profound increase in strains with inherently no or weak biofilm-producing ability. RT-PCR revealed time-dependent upregulation in the expression of the investigated genes following challenge with ½ and ¼ MIC levels, as confirmed by SEM. Cefepime at sub-MICs could upregulate the expression of BF-related genes and enhance BF by P. aeruginosa clinical isolates.


2020 ◽  
Vol 148 (3-4) ◽  
pp. 196-202
Author(s):  
Snjezana Petrovic ◽  
Jasmina Basic ◽  
Zoran Mandinic ◽  
Dragana Bozic ◽  
Marina Milenkovic ◽  
...  

Introduction/Objective. Biofilm and pyocyanin production are essential components of Pseudomonas aeruginosa virulence and antibiotic resistance. Our objective was to examine inhibitory effect of synthetized propafenone derivatives 3-(2-Fluorophenyl)- 1-(2- (2-hydroxy-3-propylamino-propoxy)-phenyl)-propan-1-one hydrochloride (5OF) and3-(2- Trifluoromethyl-phenyl)-1-(2-(2-hydroxy-3-propylamino-propoxy)-phenyl)-propan-1-one hydrochloride (5CF3) on biofilm and pyocyanin in Pseudomonas aeruginosa clinical strains. Methods. Effects were tested on nine clinical isolates and one control laboratory strain of P. aeruginosa. In vitro analysis of biofilm growing was performed by incubating bacteria (0.5 McFarland) with 5OF and 5CF3 (500?31.2 ?g/ml) and measuring optical density (OD) at 570 nm. Bacteria in medium without compounds were positive control. Blank medium (an uninoculated medium without test compounds) was used as negative control. Pyocyanin production was estimated by OD at 520 nm, after bacteria incubated with 5CF3 and 5OF (250 and 500 ?g/ml), treated with chloroform, and chloroform layer mixed with HCl. Results. A total of 500 ?g/ml of 5OF and 5CF3 completely inhibited biofilm formation in 10/10 and 4/10 strains, respectively. A total of 250 ?g/ml of 5OF and 5CF3 strongly inhibited biofilm formation in 7/10 strains, while inhibition with 125 ?g/ml of 5OF and 5CF3 was moderate. Lower concentrations had almost no effect on biofilm production. Pyocyanin production was reduced to less than 40% of the control value in 6/9, and less than 50% of the control in 7/9 strains with 500 ?g/ml of 5OF and 5CF3, respectively. At 250 ?g/ml 5OF and 5CF3, most strains had pyocyanin production above 50% of the control value. Conclusion. Synthetized propafenone derivatives, 5OF and 5CF3, inhibited biofilms and pyocyanin production of Pseudomonas aeruginosa clinical strains. Presented results suggest that propafenone derivatives are potential lead-compounds for synthesis of novel antipseudomonal drugs.


2000 ◽  
Vol 11 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Olaf Weber ◽  
Jürgen Reefschläger ◽  
Helga Rübsamen-Waigmann ◽  
Siegfried Raddatz ◽  
Matthias Hesseling ◽  
...  

Novel peptide aldehydes (PAs) were identified as potent inhibitors of human cytomegalovirus (HCMV) in vitro. Although these compounds were highly effective against HCMV, they did not exhibit any activity against murine cytomegalovirus (MCMV). The purpose of this study was to test the antiviral activity of PA 8 as a representative of this novel class of inhibitors against HCMV in vivo. Because of the strict species specificity of HCMV we had to use two artificial animal models. In the first model, HCMV-infected human cells were entrapped into agarose plugs and transplanted into mice. In the second model, SCID mice were transplanted with human tissues that were subsequently infected with a clinical isolate of HCMV. In these two models the antiviral activity of PA 8 was clearly demonstrated, ganciclovir only being slightly superior in its in vivo antiviral activity.


2021 ◽  
Vol 151 ◽  
pp. 106058
Author(s):  
Felix LewisOscar ◽  
Chari Nithya ◽  
Sasikumar Vismaya ◽  
Manivel Arunkumar ◽  
Arivalagan Pugazhendhi ◽  
...  

Author(s):  
Valeria Chiono

Since its adhesion to Centro3R, Politecnico di Torino has approached 3R teaching through a new Master course, entitled “New advances in alternative preclinical trials”. This is a multidisciplinary optional course for Master students in Biomedical Engineering, with the contribution of different teachers, who are experts on different aspects of preclinical testing of biomedical devices: European Standards for preclinical experimentation; preclinical animal models; protection of animal welfare in the European legislation; the role of statistics on the application of the 3R principle; preclinical experimental models in vitro; in silico models. This contribution describes the subjects faced by the course and their importance in the context of the 3R Principle.


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