Rhamnolipid biosurfactant adsorption on a plasma-treated polypropylene surface to induce antimicrobial and antiadhesive properties

RSC Advances ◽  
2015 ◽  
Vol 5 (42) ◽  
pp. 33089-33097 ◽  
Author(s):  
Hamidreza Hajfarajollah ◽  
Saeid Mehvari ◽  
Mahmoud Habibian ◽  
Babak Mokhtarani ◽  
Kambiz Akbari Noghabi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Polypropylene Film ◽  
Polymeric Surface ◽  
Rhamnolipid Biosurfactant ◽  
First Time

A glycolipid type of biosurfactant (rhamnolipid), which is obtained fromPseudomonas aeruginosaMA01, was adsorbed on a polypropylene film to produce an antimicrobial and antiadhesive polymeric surface for the first time.

Production of Rhamnolipid Biosurfactant from Fed Batch Culture by Pseudomonas aeruginosa using Multiple Substrates

2020 ◽  
Vol 16 (6) ◽  
pp. 928-933
Author(s):  
Jujjavarapu S. Eswari
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Batch Process ◽  
Time Interval ◽  
Fed Batch ◽  
Multiple Substrates ◽  
Surface Active Agents ◽  
Limiting Nutrients ◽  
Limiting Nutrient ◽  
Surface Active ◽  
Rhamnolipid Biosurfactant

Objective: Biosurfactants are the surface active agents which are used for the reduction of surface and interfacial tensions of liquids. Rhamnolipids are the surfactants produced by Pseudomonas aeruginosa. It requires minimum nutrition for its growth as it can also grow in distilled water. The rhamnolipids produced by Pseudomonas aeruginosa are extra-cellular glycolipids consisting of L-rhamnose and 3-hydroxyalkanoic acid. Methods: The fed-batch method for the rhamnolipid production is considered in this study to know the influence of the carbon, nitrogen, phosphorous substrates as growth-limiting nutrients. Pulse feeding is employed for limiting nutrient addition at particular time interval to obtain maximum rhamnolipid formation from Pseudomonas aeruginosa compared with the batch process. Results: Out of 3 fed batch strategies constant glucose fed batch strategy shows best and gave maximum rhamnolipid concentration of 0.134 g/l.

scholarly journals Rhamnolipid Biosurfactant Production by Strains of Pseudomonas aeruginosa Using Low-Cost Raw Materials

2002 ◽  
Vol 18 (6) ◽  
pp. 1277-1281 ◽  
Author(s):  
K.S.M. Rahman ◽  
T.J. Rahman ◽  
S. McClean ◽  
R. Marchant ◽  
I.M. Banat
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Raw Materials ◽  
Low Cost ◽  
Biosurfactant Production ◽  
Rhamnolipid Biosurfactant

scholarly journals Production and characterization of rhamnolipids from Pseudomonas aeruginosa san ai

2012 ◽  
Vol 77 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Milena Rikalovic ◽  
Gordana Gojgic-Cvijovic ◽  
Miroslav Vrvic ◽  
Ivanka Karadzic
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Response Surface Methodology ◽  
Nitrogen Source ◽  
Testing Effect ◽  
Carbon And Nitrogen ◽  
Rhamnolipid Production ◽  
Proteose Peptone ◽  
Isolated Compound ◽  
Rhamnolipid Biosurfactant

Production and characterization of rhamnolipid biosurfactant obtained by strain Pseudomonas aeruginosa san ai was investigated. With regard to carbon and nitrogen source several media were tested to enhance production of rhamnolipids. Phosphate-limited proteose peptone-ammonium salt (PPAS) medium supplemented with sun flower oil as a source of carbon and mineral ammonium chloride and peptone as a nitrogen source greatly improved rhamnolipid production, from 0.15 on basic PPAS (C/N ratio 4.0), to 3 g L-1, on optimized PPAS medium (C/N ratio 7.7). Response surface methodology analysis was used for testing effect of three factors: temperature, concentration of carbon and nitrogen source (w/w), in optimized PPAS medium on rhamnolipid production. Isolated rhamnolipids were characterized by IR and ESI-MS. IR spectra confirmed that isolated compound corresponds to rhamnolipid structure, whereas MS indicated that isolated preparation is a mixture of mono-rhamno-mono-lipidic, mono-rhamno-di-lipidic- and dirhamno- di-lipidic congeners.

scholarly journals Pseudomonas aeruginosa Requires the DNA-Specific Endonuclease EndA To Degrade Extracellular Genomic DNA To Disperse from the Biofilm

2019 ◽  
Vol 201 (18) ◽  
Author(s):  
Kathryn E. Cherny ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Genomic Dna ◽  
Early Stage ◽  
Content Type ◽  
Biofilm Dispersion ◽  
Biofilm Structure ◽  
First Time ◽  
Biofilm Matrix ◽  
Dispersed Cells

ABSTRACT The dispersion of biofilms is an active process resulting in the release of planktonic cells from the biofilm structure. While much is known about the process of dispersion cue perception and the subsequent modulation of the c-di-GMP pool, little is known about subsequent events resulting in the release of cells from the biofilm. Given that dispersion coincides with void formation and an overall erosion of the biofilm structure, we asked whether dispersion involves degradation of the biofilm matrix. Here, we focused on extracellular genomic DNA (eDNA) due to its almost universal presence in the matrix of biofilm-forming species. We identified two probable nucleases, endA and eddB, and eddA encoding a phosphatase that were significantly increased in transcript abundance in dispersed cells. However, only inactivation of endA but not eddA or eddB impaired dispersion by Pseudomonas aeruginosa biofilms in response to glutamate and nitric oxide (NO). Heterologously produced EndA was found to be secreted and active in degrading genomic DNA. While endA inactivation had little effect on biofilm formation and the presence of eDNA in biofilms, eDNA degradation upon induction of dispersion was impaired. In contrast, induction of endA expression coincided with eDNA degradation and resulted in biofilm dispersion. Thus, released cells demonstrated a hyperattaching phenotype but remained as resistant to tobramycin as biofilm cells from which they egress, indicating EndA-dispersed cells adopted some but not all of the phenotypes associated with dispersed cells. Our findings indicate for the first time a role of DNase EndA in dispersion and suggest weakening of the biofilm matrix is a requisite for biofilm dispersion. IMPORTANCE The finding that exposure to DNase I impairs biofilm formation or leads to the dispersal of early stage biofilms has led to the realization of extracellular genomic DNA (eDNA) as a structural component of the biofilm matrix. However, little is known about the contribution of intrinsic DNases to the weakening of the biofilm matrix and dispersion of established biofilms. Here, we demonstrate for the first time that nucleases are induced in dispersed Pseudomonas aeruginosa cells and are essential to the dispersion response and that degradation of matrix eDNA by endogenously produced/secreted EndA is required for P. aeruginosa biofilm dispersion. Our findings suggest that dispersing cells mediate their active release from the biofilm matrix via the induction of nucleases.

scholarly journals Molecular Epidemiology of Multi-Drug Resistant Pseudomonas aeruginosa Isolates from Hospitalized Patients in Greece

2020 ◽  
Vol 8 (11) ◽  
pp. 1652
Author(s):  
Olga Pappa ◽  
Anastasia Maria Kefala ◽  
Kyriaki Tryfinopoulou ◽  
Marios Dimitriou ◽  
Kostas Kostoulas ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Molecular Epidemiology ◽  
Financial Resources ◽  
Drug Resistant ◽  
Hospital Acquired Infections ◽  
Antimicrobial Sensitivity ◽  
Tertiary Hospitals ◽  
Hospital Acquired ◽  
First Time ◽  
Hospital Transmission

Resistant Pseudomonas aeruginosa isolates are one of the major causes of both hospital-acquired infections (HAIs) and community-acquired infections (CAIs). However, management of P. aeruginosa infections is difficult as the bacterium is inherently resistant to many antibiotics. In this study, a collection of 75 P. aeruginosa clinical isolates from two tertiary hospitals from Athens and Alexnadroupolis in Greece was studied to assess antimicrobial sensitivity and molecular epidemiology. All P. aeruginosa isolates were tested for susceptibility to 11 commonly used antibiotics, and the newly introduced Double Locus Sequence Typing (DLST) scheme was implemented to elucidate the predominant clones. The tested P. aeruginosa isolates presented various resistant phenotypes, with Verona Integron-Mediated Metallo-β-lactamase (VIM-2) mechanisms being the majority, and a new phenotype, FEPR-CAZS, being reported for the first time in Greek isolates. DLST revealed two predominant types, 32-39 and 8-37, and provided evidence for intra-hospital transmission of the 32-39 clone in one of the hospitals. The results indicate that DLST can be a valuable tool when local outbreaks demand immediate tracking investigation with limited time and financial resources.

Effective inhibition of PBPs by cefepime and zidebactam in the presence of VIM-1 drives potent bactericidal activity against MBL-expressing Pseudomonas aeruginosa

2020 ◽  
Vol 75 (6) ◽  
pp. 1474-1478 ◽  
Author(s):  
Bartolome Moya ◽  
Sachin Bhagwat ◽  
Gabriel Cabot ◽  
German Bou ◽  
Mahesh Patel ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bactericidal Activity ◽  
Bactericidal Effect ◽  
Mouse Lung ◽  
Binding Affinities ◽  
The Novel ◽  
Effective Inhibition ◽  
Mechanistic Basis ◽  
Time Kill ◽  
First Time

Abstract Objectives The combination of cefepime and the novel β-lactam enhancer zidebactam (WCK 5222) is under development for the treatment of difficult-to-treat Gram-negative infections. Against MBL-producing pathogens, cefepime and zidebactam induce cell elongation and spheroplast formation, indicating PBP3 and PBP2 dysfunction, respectively, having a potent bactericidal effect as a combination. The objective of the present study was to determine the mechanistic basis of the bactericidal effect of cefepime/zidebactam on MBL-expressing pathogens. Methods Pseudomonal PBP-binding affinities of cefepime, zidebactam and imipenem were assessed at different timepoints and also in the presence of purified VIM-1 using a Bocillin FL competition assay. The antibacterial activity of cefepime/zidebactam against three VIM-expressing Pseudomonas aeruginosa isolates was assessed by time–kill and neutropenic mouse lung/thigh infection studies. Results Amidst cefepime-hydrolysing concentrations of VIM-1, substantial cefepime binding to target PBPs was observed. High-affinity binding of zidebactam to PBP2 remained unaltered in the presence of VIM-1; however, MBL addition significantly affected imipenem PBP2 binding. Furthermore, the rate of cefepime binding to the primary target PBP3 was found to be higher compared with the imipenem PBP2 binding rate. Finally, complementary PBP inhibition by cefepime/zidebactam resulted in enhanced bactericidal activity in time–kill and neutropenic mouse lung/thigh infection studies against VIM-6-, VIM-10- and VIM-11-expressing P. aeruginosa, thus revealing the mechanistic basis of β-lactam enhancer action. Conclusions For the first time ever (to the best of our knowledge), this study demonstrates that in the presence of VIM-1 MBL, β-lactamase-labile cefepime and β-lactamase-stable zidebactam produce effective inhibition of respective target PBPs. For cefepime, this seems to be a result of a faster rate of PBP binding, which helps it overcome β-lactamase-mediated hydrolysis.

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