Biofilm production by clinical isolates of Pseudomonas aeruginosa and structural changes in LasR protein of isolates non biofilm-producing

Lima, Jailton Lobo da Costa; Alves, Lílian Rodrigues; Jácome, Paula Regina Luna de Araújo; Neto, João Pacífico Bezerra; Maciel, Maria Amélia Vieira; Morais, Márcia Maria Camargo de

doi:10.1016/j.bjid.2018.03.003

Cited by 64 publications

(51 citation statements)

References 33 publications

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“…These residues can bind concurrently to cause protein folding, leading to the dimerization of LasR, thus allowing for DNA binding to the promoter and consequent transcriptional activation of QS-controlled genes. Furthermore, Bjarnsholt et al reported that mutations in Tyrosine-56 and Threonine-75 in the lasR protein would impair autoinducer binding since they strongly interact with the autoinducer (33). In contrast, we did not find any mutation in this region, but we found that missense mutations in region Arginine 180 (R180Q) had a damaging effect on protein function; this also reduced the stability of the protein when compared to strain PAO1.…”

Section: Discussioncontrasting

confidence: 62%

The Study of Mutation in LasR and PqsR Genes in Extremely Drug Resistant and Multidrug Resistant Strains of Pseudomonas aeruginosa from Burn Wound Infection

Nodoushan

Moghim

Mirzaei

et al. 2019

Jundishapur J Microbiol

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Background: Pseudomonas aeruginosa is among the top 10 resistant bacteria worldwide. Its extraordinary resistance is principally due to the function of quorum sensing genes, such as lasR and pqsR, which are mainly involved in antibiotic resistance. Objectives: This study aimed to examine possible mutations in lasR and pqsR in resistant clinical isolates of P. aeruginosa. Methods: We obtained 120 suspected isolates of P. aeruginosa from burn patients. The isolates were identified by biochemical tests and toxA gene analysis. The PCR products of LasR and PqsR genes were analyzed in seven resistant isolates. Then, the sequences were compared with a reference strain. Results: We verified Ninety-six isolates as absolute P. aeruginosa. According to antibiograms, 95.8% of the isolates were considered as multidrug-resistant, of which 87.5% were extensively drug-resistant. Based on DNA and protein sequences, only one missense mutation was observed, including R180Q in lasR and A314V in pqsR. While R180Q decreased the stability of LasR and had a deleterious impact on protein function, A314V had a neutral impact on the protein and increased PqsR protein stability. Also, two nonsense mutations in position E259 were observed in the PqsR protein. Conclusions: The lasR and pqsR genes possibly can play a key role in antibiotic resistance, but they are not the only factors. Hence, studying mutations helps design a promising antibiotic to overcome antibiotic resistance as much as possible.

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Section: Discussioncontrasting

confidence: 62%

The Study of Mutation in LasR and PqsR Genes in Extremely Drug Resistant and Multidrug Resistant Strains of Pseudomonas aeruginosa from Burn Wound Infection

Nodoushan

Moghim

Mirzaei

et al. 2019

Jundishapur J Microbiol

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“…In this study, all S. pseudintermedius clinical OE isolates produced biofilm, but 80% of these isolates ( biofilms (Lima et al, 2018). In a study of P. aeruginosa isolates from cases of cystic fibrosis, 68% (n = 74) formed biofilms with the majority (64.9%) being weak biofilm producers (Perez, Costa, Freitas, & Barth, 2011).…”

Section: Discussionmentioning

confidence: 57%

“…This contrasts with a similar study by Pye et al () in which only 40% (33/83) of P. aeruginosa canine otic isolates produced biofilms (8.4% (7/83) weak, 18.1% (15/83) moderate and 13.3% (11/83) strong). In humans, the majority (77.5%) of P. aeruginosa isolates formed weak (42.5%), moderate (27.5%) or strong (5%) biofilms (Lima et al, ). In a study of P. aeruginosa isolates from cases of cystic fibrosis, 68% ( n = 74) formed biofilms with the majority (64.9%) being weak biofilm producers (Perez, Costa, Freitas, & Barth, ).…”

Section: Discussionmentioning

confidence: 99%

Biofilm production by pathogens associated with canine otitis externa, and the antibiofilm activity of ionophores and antimicrobial adjuvants

Chan

Hickey

Page³

et al. 2019

Vet Pharm & Therapeutics

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Otitis externa (OE) is a frequently reported disorder in dogs associated with secondary infections by Staphylococcus, Pseudomonas and yeast pathogens. The presence of biofilms may play an important role in the resistance of otic pathogens to antimicrobial agents. Biofilm production of twenty Staphylococcus pseudintermedius and twenty Pseudomonas aeruginosa canine otic isolates was determined quantitatively using a microtiter plate assay, and each isolate was classified as a strong, moderate, weak or nonbiofilm producer. Minimum biofilm eradication concentration (MBEC) of two ionophores (narasin and monensin) and three adjuvants (N‐acetylcysteine (NAC), Tris‐EDTA and disodium EDTA) were investigated spectrophotometrically (OD570nm) and quantitatively (CFU/ml) against selected Staphylococcus and Pseudomonas biofilm cultures. Concurrently, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of planktonic cultures were assessed. 16/20 of the S. pseudintermedius clinical isolates were weak biofilm producers. 19/20 P. aeruginosa clinical isolates produced biofilms and were distributed almost equally as weak, moderate and strong biofilm producers. While significant antibiofilm activity was observed, no MBEC was achieved with narasin or monensin. The MBEC for NAC ranged from 5,000–10,000 µg/ml and from 20,000–80,000 µg/ml against S. pseudintermedius and P. aeruginosa, respectively. Tris‐EDTA eradicated P. aeruginosa biofilms at concentrations ranging from 6,000/1,900 to 12,000/3,800 µg/ml. The MBEC was up to 16‐fold and eightfold higher than the MIC/MBC of NAC and Tris‐EDTA, respectively. Disodium EDTA reduced biofilm growth of both strains at concentrations of 470 µg/ml and higher. It can be concluded that biofilm production is common in pathogens associated with canine OE. NAC and Tris‐EDTA are effective antibiofilm agents in vitro that could be considered for the treatment of biofilm‐associated OE in dogs.

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“…Numerous external factors affect biofilm formation by Pseudomonas aeruginosa. In addition, the type of tissue has strong impact on biofilm formation, and researchers commonly test biofilm formation of Pseudomonas aeruginosa from a variety of clinical sources [41]. In our study, various clinical strains showed differences in sensitivity to tested compounds, but those variations were not connected to specific bacterial source (urine, ear swab, sputum).…”

Section: Discussionmentioning

confidence: 76%

Inhibitory effect of propafenone derivatives on pseudomonas aeruginosa biofilm and pyocyanin production

et al. 2020

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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 µg/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 μg/ml), treated with chloroform, and chloroform layer mixed with HCl. Results A total of 500 µg/ml of 5OF and 5CF3 completely inhibited biofilm formation in 10/10 and 4/10 strains, respectively. A total of 250 µg/ml of 5OF and 5CF3 strongly inhibited biofilm formation in 7/10 strains, while inhibition with 125 µg/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 μg/ml of 5OF and 5CF3, respectively. At 250 µg/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.

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Biofilm production by clinical isolates of Pseudomonas aeruginosa and structural changes in LasR protein of isolates non biofilm-producing

Abstract: The modeling of the resulting LasR protein showed a conformational change in its structure, suggesting that this might be the reason why these isolates are unable to produce biofilm.

Cited by 64 publications

References 33 publications

The Study of Mutation in LasR and PqsR Genes in Extremely Drug Resistant and Multidrug Resistant Strains of Pseudomonas aeruginosa from Burn Wound Infection

The Study of Mutation in LasR and PqsR Genes in Extremely Drug Resistant and Multidrug Resistant Strains of Pseudomonas aeruginosa from Burn Wound Infection

Biofilm production by pathogens associated with canine otitis externa, and the antibiofilm activity of ionophores and antimicrobial adjuvants

Inhibitory effect of propafenone derivatives on pseudomonas aeruginosa biofilm and pyocyanin production

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