scholarly journals Novel Therapeutic Strategies Applied to Pseudomonas aeruginosa Infections in Cystic Fibrosis

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4093 ◽  
Author(s):  
Michael E. Chirgwin ◽  
Margaret R. Dedloff ◽  
Alina Maria Holban ◽  
Monica C. Gestal
Keyword(s):  
Drug Delivery ◽  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Genetic Diseases ◽  
Antibiotic Use ◽  
High Rate ◽  
Genetic Mutations ◽  
Novel Therapeutic Strategies ◽  
High Level

Cystic fibrosis (CF) is one of the most prevalent genetic diseases and a total of 1700 different genetic mutations can cause this condition. Patients that suffer this disease have a thickening of the mucus, creating an environment that promotes bacterial infections. Pseudomonas aeruginosa is a ubiquitous bacterium, which is frequently found in the lungs of CF patients. P. aeruginosa is known for its high level of antibiotic resistance as well as its high rate of mutation that allows it to rapidly evolve and adapt to a multitude of conditions. When a CF lung is infected with P. aeruginosa, the decay of the patient is accelerated, but there is little that can be done apart from controlling the infection with antibiotics. Novel strategies to control P. aeruginosa infection are imperative, and nanotechnology provides novel approaches to drug delivery that are more efficient than classic antibiotic treatments. These drug delivery systems are offering new prospects, especially for these patients with special mucus conditions and bacterial characteristics that limit antibiotic use.

scholarly journals Repeated isolation of an antibiotic-dependent and temperature-sensitive mutant of Pseudomonas aeruginosa from a cystic fibrosis patient

2020 ◽  
Author(s):  
Daniel J Wolter ◽  
Alison Scott ◽  
Catherine R Armbruster ◽  
Dale Whittington ◽  
John S Edgar ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Lipid A ◽  
Clinical Laboratory ◽  
Membrane Phospholipid ◽  
Growth Defect ◽  
Genetic Mutations ◽  
Temperature Sensitive ◽  
Isolation And Characterization

Abstract Background Bacteria adapt to survive and grow in different environments. Genetic mutations that promote bacterial survival under harsh conditions can also restrict growth. The causes and consequences of these adaptations have important implications for diagnosis, pathogenesis, and therapy. Objectives We describe the isolation and characterization of an antibiotic-dependent, temperature-sensitive Pseudomonas aeruginosa mutant chronically infecting the respiratory tract of a cystic fibrosis (CF) patient, underscoring the clinical challenges bacterial adaptations can present. Methods Respiratory samples collected from a CF patient during routine care were cultured for standard pathogens. P. aeruginosa isolates recovered from samples were analysed for in vitro growth characteristics, antibiotic susceptibility, clonality, and membrane phospholipid and lipid A composition. Genetic mutations were identified by whole genome sequencing. Results P. aeruginosa isolates collected over 5 years from respiratory samples of a CF patient frequently harboured a mutation in phosphatidylserine decarboxylase (psd), encoding an enzyme responsible for phospholipid synthesis. This mutant could only grow at 37°C when in the presence of supplemented magnesium, glycerol, or, surprisingly, the antibiotic sulfamethoxazole, which the source patient had repeatedly received. Of concern, this mutant was not detectable on standard selective medium at 37°C. This growth defect correlated with alterations in membrane phospholipid and lipid A content. Conclusions A P. aeruginosa mutant chronically infecting a CF patient exhibited dependence on sulphonamides and would likely evade detection using standard clinical laboratory methods. The diagnostic and therapeutic challenges presented by this mutant highlight the complex interplay between bacterial adaptation, antibiotics, and laboratory practices, during chronic bacterial infections.

scholarly journals PmrB Mutations Promote Polymyxin Resistance of Pseudomonas aeruginosa Isolated from Colistin-Treated Cystic Fibrosis Patients

2011 ◽  
Vol 56 (2) ◽  
pp. 1019-1030 ◽  
Author(s):  
Samuel M. Moskowitz ◽  
Mark K. Brannon ◽  
Nandini Dasgupta ◽  
Miyuki Pier ◽  
Nicole Sgambati ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lipid A ◽  
Clinical Isolates ◽  
Gain Of Function ◽  
Content Type ◽  
Regulatory Systems ◽  
Repeated Passage ◽  
High Level

ABSTRACTPseudomonas aeruginosacan develop resistance to polymyxin and other cationic antimicrobial peptides. Previous work has shown that mutations in the PmrAB and PhoPQ regulatory systems can confer low to moderate levels of colistin (polymyxin E) resistance in laboratory strains and clinical isolates of this organism (MICs of 8 to 64 mg/liter). To explore the role of PmrAB in high-level clinical polymyxin resistance,P. aeruginosaisolates from chronically colistin-treated cystic fibrosis patients, most with colistin MICs of >512 mg/liter, were analyzed. These cystic fibrosis isolates contained probable gain-of-functionpmrBalleles that conferred polymyxin resistance to strains with a wild-type orpmrABdeletion background. Double mutantpmrBalleles that contained mutations in both the periplasmic and dimerization-phosphotransferase domains markedly augmented polymyxin resistance. Expression of mutantpmrBalleles induced transcription from the promoter of thearnBoperon and stimulated addition of 4-amino-l-arabinose to lipid A, consistent with the known role of this lipid A modification in polymyxin resistance. For some highly polymyxin-resistant clinical isolates, repeated passage without antibiotic selection pressure resulted in loss of resistance, suggesting that secondary suppressors occur at a relatively high frequency and account for the instability of this phenotype. These results indicate thatpmrBgain-of-function mutations can contribute to high-level polymyxin resistance in clinical strains ofP. aeruginosa.

scholarly journals Management of chronic Pseudomonas aeruginosa infection with inhaled levofloxacin in people with cystic fibrosis

2021 ◽  
Author(s):  
J Stuart Elborn ◽  
Patrick A Flume ◽  
Donald R Van Devanter ◽  
Claudio Procaccianti
Keyword(s):  
Quality Of Life ◽  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Function ◽  
Standard Care ◽  
Bacterial Infections ◽  
Pulmonary Infections ◽  
Pseudomonas Aeruginosa Infection

People with cystic fibrosis (CF) are highly susceptible to bacterial infections of the airways. By adulthood, chronic Pseudomonas aeruginosa ( Pa) is the most prevalent infective organism and is difficult to eradicate owing to its adaptation to the CF lung microenvironment. Long-term suppressive treatment with inhaled antimicrobials is the standard care for reducing exacerbation frequency, improving quality of life and increasing measures of lung function. Levofloxacin (a fluoroquinolone antimicrobial) has been approved as an inhaled solution in Europe and Canada, for the treatment of adults with CF with chronic P. aeruginosa pulmonary infections. Here, we review the clinical principles relating to the use of inhaled antimicrobials and inhaled levofloxacin for the management of P. aeruginosa infections in patients with CF.

scholarly journals Intrinsic Abnormalities of Cystic Fibrosis Airway Connective Tissue Revealed by an In Vitro 3D Stromal Model

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1371
Author(s):  
Claudia Mazio ◽  
Laura S. Scognamiglio ◽  
Rossella De Cegli ◽  
Luis J. V. Galietta ◽  
Diego Di Bernardo ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Inflammatory Response ◽  
Bacterial Infections ◽  
Inflammatory Cells ◽  
Lung Model ◽  
Lung Dysfunction ◽  
Novel Therapeutic Strategies ◽  
And Function

Cystic fibrosis is characterized by lung dysfunction involving mucus hypersecretion, bacterial infections, and inflammatory response. Inflammation triggers pro-fibrotic signals that compromise lung structure and function. At present, several in vitro cystic fibrosis models have been developed to study epithelial dysfunction but none of these focuses on stromal alterations. Here we show a new cystic fibrosis 3D stromal lung model made up of primary fibroblasts embedded in their own extracellular matrix and investigate its morphological and transcriptomic features. Cystic fibrosis fibroblasts showed a high proliferation rate and produced an abundant and chaotic matrix with increased protein content and elastic modulus. More interesting, they had enhanced pro-fibrotic markers and genes involved in epithelial function and inflammatory response. In conclusion, our study reveals that cystic fibrosis fibroblasts maintain in vitro an activated pro-fibrotic state. This abnormality may play in vivo a role in the modulation of epithelial and inflammatory cell behavior and lung remodeling. We argue that the proposed bioengineered model may provide new insights on epithelial/stromal/inflammatory cells crosstalk in cystic fibrosis, paving the way for novel therapeutic strategies.

scholarly journals Pseudomonas aeruginosa Cystic Fibrosis Isolates from Individual Patients Demonstrate a Range of Levels of Lethality in Two Drosophila melanogaster Infection Models

2008 ◽  
Vol 76 (5) ◽  
pp. 1877-1888 ◽  
Author(s):  
Erika I. Lutter ◽  
Monica M. P. Faria ◽  
Harvey R. Rabin ◽  
Douglas G. Storey
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Drosophila Melanogaster ◽  
Burn Wound ◽  
Pathogenic Potential ◽  
Patient Level ◽  
Infection Models ◽  
High Level ◽  
Significant Mortality

ABSTRACT Recently, two Drosophila melanogaster models of infection, fly feeding and fly nicking, have been developed that allow a determination of pathogenic potential of Pseudomonas aeruginosa isolates. In this study, control strains, isolates from burn wounds, and isolates from the sputa of cystic fibrosis (CF) patients were used to compare the two infection models to determine whether any of the isolates might be better adapted to either of the models. In addition, our goal was to determine the variability of isolates from individual CF patients. Three of four control strains (PAO1, PAK, and PA14) caused significant mortality in the flies in both models of infection. The remaining control strain, PA103, was lethal to flies in the nicking model but lacked significant lethality in the feeding model. The burn wound isolates had a high level of lethality in both models. Interestingly, the CF isolates had the largest diversity of lethality in both models of infection. The range of pathogenic potentials of the CF isolates occurred across a cohort of patients, both at the patient level and down to the level of individual sputum samples. The majority of all isolates had similar levels of lethality in both fly infection models. However, two CF isolates were significantly more lethal in the nicking model, and three CF isolates were significantly more lethal in the feeding model. In conclusion, the two Drosophila infection models were useful for the analysis of the diversity of pathogenic potentials of P. aeruginosa isolates.

scholarly journals Multidrug-resistant Pseudomonas aeruginosa from sputum of patients with cystic fibrosis demonstrates a high rate of susceptibility to ceftazidime–avibactam

2018 ◽  
Vol Volume 11 ◽  
pp. 1499-1510 ◽  
Author(s):  
Stan Atkin ◽  
Shadaan Abid ◽  
Michael Foster ◽  
Moumita Bose ◽  
Ashley Keller ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
High Rate

scholarly journals Mechanisms of Pyocyanin Toxicity and Genetic Determinants of Resistance in Staphylococcus aureus

2017 ◽  
Vol 199 (17) ◽  
Author(s):  
Michael J. Noto ◽  
William J. Burns ◽  
William N. Beavers ◽  
Eric P. Skaar
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Respiratory Infections ◽  
Severe Disease ◽  
Ros Generation ◽  
Content Type ◽  
Small Colony Variant ◽  
High Concentrations

ABSTRACT Pseudomonas aeruginosa and Staphylococcus aureus are commonly isolated from polymicrobial infections, such as wound infections and chronic respiratory infections of persons with cystic fibrosis. Despite their coisolation, P. aeruginosa produces substances toxic to S. aureus, including pyocyanin, a blue-pigmented molecule that functions in P. aeruginosa virulence. Pyocyanin inhibits S. aureus respiration, forcing it to derive energy from fermentation and adopt a small-colony variant (SCV) phenotype. The mechanisms by which S. aureus sustains infection in the presence of pyocyanin are not clear. We sought to clarify the mechanisms of pyocyanin toxicity in S. aureus as well as identify the staphylococcal factors involved in its resistance to pyocyanin toxicity. Nonrespiring S. aureus SCVs are inhibited by pyocyanin through pyocyanin-dependent reactive oxygen species (ROS) production, indicating that pyocyanin toxicity is mediated through respiratory inhibition and ROS generation. Selection on pyocyanin yielded a menadione auxotrophic SCV capable of growth on high concentrations of pyocyanin. Genome sequencing of this isolate identified mutations in four genes, including saeS, menD, NWMN_0006, and qsrR. QsrR is a quinone-sensing repressor of quinone detoxification genes. Inactivation of qsrR resulted in significant pyocyanin resistance, and additional pyocyanin resistance was achieved through combined inactivation of qsrR and menadione biosynthesis. Pyocyanin-resistant S. aureus has an enhanced capability to inactivate pyocyanin, suggesting QsrR-regulated gene products may degrade pyocyanin to alleviate toxicity. These findings demonstrate pyocyanin-mediated ROS generation as an additional mechanism of pyocyanin toxicity and define QsrR as a key mediator of pyocyanin resistance in S. aureus. IMPORTANCE Many bacterial infections occur in the presence of other microbes, where interactions between different microbes and the host impact disease. In patients with cystic fibrosis, chronic lung infection with multiple microbes results in the most severe disease manifestations. Staphylococcus aureus and Pseudomonas aeruginosa are prevalent cystic fibrosis pathogens, and infection with both is associated with worse outcomes. These organisms have evolved mechanisms of competing with one another. For example, P. aeruginosa produces pyocyanin, which inhibits S. aureus growth. Our research has identified how pyocyanin inhibits S. aureus growth and how S. aureus can adapt to survive in the presence of pyocyanin. Understanding how S. aureus sustains infection in the presence of P. aeruginosa may identify means of disrupting these microbial communities.

scholarly journals Oxidative Modification of Proteins in Pediatric Cystic Fibrosis with Bacterial Infections

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Izabela Sadowska-Bartosz ◽  
Sabina Galiniak ◽  
Grzegorz Bartosz ◽  
Marta Rachel
Keyword(s):  
Oxidative Stress ◽  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Protein Carbonyl ◽  
Oxidative Modification ◽  
Transferase Activity ◽  
Oxidative Modification Of Proteins ◽  
Chronic Oxidative Stress

Pseudomonas aeruginosaandStaphylococcus aureuscause chronic lung infection in cystic fibrosis (CF) patients, inducing chronic oxidative stress. Several markers of plasma protein oxidative damage and glycoxidation and activities of erythrocyte antioxidant enzymes have been compared in stable CF patients chronically infected withPseudomonas aeruginosa(n=12) andStaphylococcus aureus(n=10) in relation to healthy subjects (n=11). Concentration of nitric oxide was also measured in the exhaled air from the lower respiratory tract of patients with CF. Elevated glycophore (4.22 ± 0.91 and 4.19 ± 1.04 versus control 3.18 ± 0.53 fluorescence units (FU)/mg protein;P<0.05) and carbonyl group levels (1.9 ± 0.64, 1.87 ± 0.45 versus control 0.94 ± 0.19 nmol/mg protein;P<0.05) as well as increased glutathioneS-transferase activity (2.51 ± 0.88 and 2.57 ± 0.79 U/g Hb versus 0.77 ± 0.16 U/g Hb;P<0.05) were noted inPseudomonas aeruginosaandStaphylococcus aureusinfected CF. Kynurenine level (4.91 ± 1.22 versus 3.89 ± 0.54 FU/mg protein;P<0.05) was elevated only inStaphylococcus aureusinfected CF. These results confirm oxidative stress in CF and demonstrate the usefulness of the glycophore level and protein carbonyl groups as markers of oxidative modifications of plasma proteins in this disease.

scholarly journals Sodium Nitrite Inhibits Killing of Pseudomonas aeruginosa Biofilms by Ciprofloxacin

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Anna C. Zemke ◽  
Brian R. Kocak ◽  
Jennifer M. Bomberger
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Sodium Nitrite ◽  
Bacterial Infections ◽  
Liquid Culture ◽  
Bacterial Respiration ◽  
Biofilm Model

ABSTRACT Sodium nitrite inhibits bacterial respiration and is in development as an antimicrobial for chronic bacterial infections associated with cystic fibrosis. The goal of the current study was to investigate the interaction between nitrite and ciprofloxacin. Using liquid culture killing assays and a biotic biofilm model, we observed that nitrite induces tolerance of ciprofloxacin.

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