scholarly journals The Response of Pseudomonas aeruginosa PAO1 to UV-activated Titanium Dioxide/Silica Nanotubes

2020 ◽  
Vol 21 (20) ◽  
pp. 7748
Author(s):  
Adrian Augustyniak ◽  
Krzysztof Cendrowski ◽  
Bartłomiej Grygorcewicz ◽  
Joanna Jabłońska ◽  
Paweł Nawrotek ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Titanium Dioxide ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Uv Light ◽  
Alternative Methods ◽  
Silica Nanotubes ◽  
Antibiotic Resistant ◽  
Metabolic Functions ◽  
Resistant Strains

Pseudomonas aeruginosa is a bacterium of high clinical and biotechnological importance thanks to its high adaptability to environmental conditions. The increasing incidence of antibiotic-resistant strains has created a need for alternative methods to increase the chance of recovery in infected patients. Various nanomaterials have the potential to be used for this purpose. Therefore, we aimed to study the physiological response of P. aeruginosa PAO1 to titanium dioxide/silica nanotubes. The results suggest that UV light-irradiated nanomaterial triggers strong agglomeration in the studied bacteria that was confirmed by microscopy, spectrophotometry, and flow cytometry. The effect was diminished when the nanomaterial was applied without initial irradiation, with UV light indicating that the creation of reactive oxygen species could play a role in this phenomenon. The nanocomposite also affected biofilm formation ability. Even though the biomass of biofilms was comparable, the viability of cells in biofilms was upregulated in 48-hour biofilms. Furthermore, from six selected genes, the mexA coding efflux pump was upregulated, which could be associated with an interaction with TiO2. The results show that titanium dioxide/silica nanotubes may alter the physiological and metabolic functions of P. aeruginosa PAO1.

scholarly journals Coexistence of Virulence Factors and Efflux Pump Genes in Clinical Isolates of Pseudomonas aeruginosa: Analysis of Biofilm-Forming Strains from Iran

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Shahram Shahraki Zahedani ◽  
Hamed Tahmasebi ◽  
Mojdeh Jahantigh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Critical Role ◽  
Clinical Isolates ◽  
Biochemical Tests ◽  
Clinical Specimens ◽  
Crystal Violet Assay ◽  
Pcr Method ◽  
Resistant Strains

Background. Biofilm formation and efflux pumps (EPs) correlation play a critical role in the pathogenicity and antibiotic resistance of Pseudomonas aeruginosa. In this study, biofilm formation and EP’s collaborative role in clinical isolates of P. aeruginosa infection were investigated. Methods. Eighty-six (86) P. aeruginosa isolates were collected from different clinical specimens and were confirmed using different biochemical tests. The formation of biofilm was investigated by using a crystal violet assay. Also, EP genes were identified by the PCR method. Results. Based on the results, gentamicin-resistant (n = 50, 66.29%) and ciprofloxacin-resistant (n = 61, 69.66%) strains were the most frequent and colistin (n = 1, 1.12%) and ceftazidime (n = 12, 7.86%) resistant strains were the least prevalent. Furthermore, 22 isolates (31.42%) were MDR, and 11 isolates (12.35%) were XDR strains. Also, 19 isolates (22.47%) were classified as strong biofilm, 29 isolates (21.34%) as moderate biofilm, and 3 (11.23%) isolates as weak biofilm producers. The distribution of the EP genes was as follows: mexA (n = 44, 34.83%), mexB (n = 33, 32.58%), oprM (n = 59, 29.21%), oprD (n = 61, 30.33%), tetA (n = 22, 25.58%), tetR (n = 19, 22.09%), and emrE (n = 21, 24.41%). However, there was a strong significant association between biofilm formation and EPs in P. aeruginosa. Conclusions. In this study, we suggested that the presence of a multidrug resistance efflux pump, MexEF-OprN, significantly reduced P. aeruginosa pathogenicity. In contrast, the presence of the MexAB-OprM and MexCD-OprJ pumps did not affect virulence.

scholarly journals Effect of Titanium Dioxide Nanoparticles on the Expression of Efflux Pump and Quorum-Sensing Genes in MDR Pseudomonas aeruginosa Isolates

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 625
Author(s):  
Fatma Y. Ahmed ◽  
Usama Farghaly Aly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Nancy G. F. M. Waly
Keyword(s):  
Titanium Dioxide ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Efflux Pumps ◽  
Antibiofilm Activity ◽  
The Impact

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.

scholarly journals Synergistic Activities of an Efflux Pump Inhibitor and Iron Chelators against Pseudomonas aeruginosa Growth and Biofilm Formation

2010 ◽  
Vol 54 (9) ◽  
pp. 3960-3963 ◽  
Author(s):  
Yang Liu ◽  
Liang Yang ◽  
Søren Molin
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Iron Chelators ◽  
Acetohydroxamic Acid ◽  
Efflux Pump Inhibitor

ABSTRACT The efflux pump inhibitor phenyl-arginine-β-naphthylamide (PAβN) was paired with iron chelators 2,2′-dipyridyl, acetohydroxamic acid, and EDTA to assess synergistic activities against Pseudomonas aeruginosa growth and biofilm formation. All of the tested iron chelators synergistically inhibited P. aeruginosa growth and biofilm formation with PAβN. PAβN-EDTA showed the most promising activity against P. aeruginosa growth and biofilm formation.

scholarly journals Role of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033 and PA2070 in Pseudomonas aeruginosa

2018 ◽  
Author(s):  
Prasanth Manohar ◽  
Thamaraiselvan Shanthini ◽  
Reethu Ann Philip ◽  
Subramani Ramkumar ◽  
Manali Kale ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Biofilm Formation ◽  
Tamil Nadu ◽  
Antibiotic Resistance Genes ◽  
Clinical Samples ◽  
Cross Sectional ◽  
Antibiotic Resistant ◽  
Resistant Genes

AbstractTo evaluate the presence of biofilm-specific antibiotic-resistant genes, PA0756-0757, PA5033 and PA2070 in Pseudomonas aeruginosa isolated from clinical samples in Tamil Nadu. For this cross-sectional study, 24 clinical isolates (included pus, urine, wound, and blood) were collected from two diagnostic centers in Chennai from May 2015 to February 2016. Biofilm formation was assessed using microtiter dish biofilm formation assay and minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) were determined for planktonic and biofilm cells (MBC assay). Further, PCR amplification of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033 and PA2070 were performed. Biofilm formation was found to be moderate/strong in 16 strains. MBC for planktonic cells showed that 4, 7, 10 and 14 strains were susceptible to gentamicin, ciprofloxacin, meropenem and colistin respectively. In MBC assay for biofilm cells (MBC-B), all the 16 biofilm producing strains were resistant to ciprofloxacin and gentamicin whereas nine and four were resistant to meropenem, and colistin respectively. The biofilm-specific antibiotic-resistant genes PA0756-0757 was found in 10 strains, 6 strains with PA5033 and 9 strains with PA2070 that were found to be resistant phenotypically. This study highlighted the importance of biofilm-specific antibiotic resistance genes PA0756-0757, PA5033, and PA2070 in biofilm-forming P. aeruginosa.

scholarly journals Trp-Containing Antibacterial Peptides Impair Quorum Sensing and Biofilm Development in Multidrug-Resistant Pseudomonas aeruginosa and Exhibit Synergistic Effects With Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Dejing Shang ◽  
Xue Han ◽  
Wanying Du ◽  
Zhiru Kou ◽  
Fengquan Jiang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Biofilm Development ◽  
Antibiotic Efflux

Pseudomonas aeruginosa uses quorum sensing (QS) to control virulence, biofilm formation and antibiotic efflux pump expression. The development of effective small molecules targeting the QS system and biofilm formation represents a novel attractive strategy. In this present study, the effects of a series of Trp-containing peptides on the QS-regulated virulence and biofilm development of multidrug-resistant P. aeruginosa, as well as their synergistic antibacterial activity with three classes of traditional chemical antibiotics were investigated. The results showed that Trp-containing peptides at low concentrations reduced the production of QS-regulated virulence factors by downregulating the gene expression of both the las and rhl systems in the strain MRPA0108. Biofilm formation was inhibited in a concentration-dependent manner, which was associated with extracellular polysaccharide production inhibition by downregulating pelA, algD, and pslA transcription. These changes correlated with alterations in the extracellular production of pseudomonal virulence factors and swarming motility. In addition, the combination of Trp-containing peptides at low concentration with the antibiotics ceftazidime and piperacillin provided synergistic effects. Notably, L11W and L12W showed the highest synergy with ceftazidime and piperacillin. A mechanistic study demonstrated that the Trp-containing peptides, especially L12W, significantly decreased β-lactamase activity and expression of efflux pump genes OprM, MexX, and MexA, resulting in a reduction in antibiotic efflux from MRPA0108 cells and thus increasing the antibacterial activity of these antibiotics against MRPA0108.

scholarly journals Titanium Dioxide Nanoparticles – Prospects and Applications in Medicine

2020 ◽  
Author(s):  
Daniel Ziental ◽  
Beata Czarczynska-Goslinska ◽  
Dariusz T. Mlynarczyk ◽  
Arleta Glowacka-Sobotta ◽  
Beata Stanisz ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Metallic Nanoparticles ◽  
Malignant Tumors ◽  
Uv Light ◽  
Titanium Dioxide Nanoparticles ◽  
Aqueous Media ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Tio2 Nps ◽  
Wide Range

Metallic nanoparticles (NPs), among polymeric NPs, liposomes, micelles, quantum dots, dendrimers, or fullerenes, are becoming more and more important due to their potential use in the novel medical therapies. Titanium dioxide (titanium(IV) oxide, titania, TiO2) is an inorganic compound that owes its recent rise in scientific interest to photoactivity. After the illumination in aqueous media with UV light, TiO2 produces an array of reactive oxygen species (ROS). The capability to produce ROS and thus induce cell death has found application in the photodynamic therapy (PDT) for the treatment of a wide range of maladies, from psoriasis to cancer. Titanium dioxide NPs were studied as photosensitizing agents in the treatment of malignant tumors as well as in photodynamic inactivation of antibiotic-resistant bacteria. Both TiO2 NPs themselves, as well as their composites with other molecules, can be successfully used as photosensitizers in PDT. Moreover, various organic compounds can be grafted on TiO2 NPs, leading to hybrid materials. These nanostructures can reveal increased light absorption allowing their further use in targeted therapy in medicine. In order to improve efficient anticancer therapy, many approaches utilizing titanium dioxide were tested. The most significant studies are discussed in this review.

scholarly journals Use of an Efflux Pump Inhibitor To Determine the Prevalence of Efflux Pump-Mediated Fluoroquinolone Resistance and Multidrug Resistance in Pseudomonas aeruginosa

2005 ◽  
Vol 49 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Jane Kriengkauykiat ◽  
Edith Porter ◽  
Olga Lomovskaya ◽  
Annie Wong-Beringer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistance ◽  
Substrate Specificity ◽  
Efflux Pump ◽  
Fluoroquinolone Resistance ◽  
Cross Resistance ◽  
Broth Microdilution ◽  
Efflux Pump Inhibitor ◽  
Broad Substrate Specificity ◽  
Resistant Strains

ABSTRACT Fluoroquinolone-resistance in Pseudomonas aeruginosa may be due to efflux pump overexpression (EPO) and/or target mutations. EPO can result in multidrug resistance (MDR) due to broad substrate specificity of the pumps. MC-04,124, an efflux pump inhibitor (EPI) shown to significantly potentiate activity of levofloxacin in P. aeruginosa, was used to examine the prevalence of EPO in clinical isolates. MICs were determined for ciprofloxacin, levofloxacin, moxifloxacin, and gatifloxacin with or without EPI and for other antipseudomonal agents by using broth microdilution against P. aeruginosa isolates from adults (n = 119) and children (n = 24). The prevalence of the EPO phenotype (≥8-fold MIC decrease when tested with EPI) was compared among subgroups with different resistance profiles. The EPO phenotype was more prevalent among levofloxacin-resistant than levofloxacin-sensitive strains (61%, 48/79 versus 9%, 6/64). EPO was present in 60% of fluoroquinolone-resistant strains without cross-resistance, while it was present at variable frequencies among strains with cross-resistance to other agents: piperacillin-tazobactam (86%), ceftazidime (76%), cefepime (65%), imipenem (56%), gentamicin (55%), tobramycin (48%), and amikacin (27%). The magnitude of MIC decrease with an EPI paralleled the frequency of which the EPO phenotype was observed in different subgroups. EPI reduced the levofloxacin MIC by as much as 16-fold in eight strains for which MICs were 128 μg/ml. Efflux-mediated resistance appears to contribute significantly to fluoroquinolone resistance and MDR in P. aeruginosa. Our data support the fact that increased fluoroquinolone usage can negatively impact susceptibility of P. aeruginosa to multiple classes of antipseudomonal agents.

Adaptation to benzalkonium chloride and ciprofloxacin affects biofilm formation potential, efflux pump and haemolysin activity of Escherichia coli of dairy origin

2012 ◽  
Vol 79 (4) ◽  
pp. 383-389 ◽  
Author(s):  
Ankita Pagedar ◽  
Jitender Singh ◽  
Virender K. Batish
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Benzalkonium Chloride ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Resistant Isolate ◽  
Percentage Increase ◽  
Antibiotic Resistant ◽  
Formation Potential ◽  
Adaptive Resistance

The present study investigates the effect of adaptive resistance to ciprofloxacin (Cip) and benzalkonium chloride (BC) on biofilm formation potential (BFP), efflux pump activity (EPA) and haemolysin activity of Escherichia coli isolates of dairy origin. All the isolates, irrespective of antimicrobial susceptibility, developed significant adaptive resistance (P < 0·05). All the resistant phenotypes (antibiotic resistant: AR; & biocide resistant: BR) were stronger biofilm former and post-adaptation, an insignificant change was observed in their BFP. Whereas, post-adaptation, non-resistant isolates (antibiotic non-resistant: ANR; biocide non-resistant: BNR) transformed from poor or moderate to strong biofilm formers. Post-adaptive percentage increase in EPA was highly significant in non-resistant categories (P < 0·01) and significant at P < 0·05 in BR category. Interestingly, post-adaptive increase in EPA in BR isolates was more than that in AR yet, the latter exhibited greater adaptive resistance than the former. These findings indicated prevalence of some other specific resistance mechanism/s responsible for adaptive resistance against Cip. Strain specific variations were observed for stability of adaptive resistance and haemolysin activity for all the categories. Our findings especially in reference to post-adaptation upgradation of BFP status of non-resistant isolates seems to be providing an insight into the process of conversion of non-resistant isolate into resistant ones with enhanced BFP. These observations emphasize the serious implications of sub-lethal residual levels of antimicrobials in food environments and suggest a role of food chain in emergence of antimicrobial resistances.

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