Antibiotic Efficacy Testing in an Ex vivo Model of &lt;em&gt;Pseudomonas aeruginosa&lt;/em&gt; and &lt;em&gt;Staphylococcus aureus&lt;/em&gt; Biofilms in the Cystic Fibrosis Lung

Harrington, Niamh E.; Sweeney, Esther; Alav, Ilyas; Allen, Freya; Moat, John; Harrison, Freya

doi:10.3791/62187

Cited by 16 publications

(19 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All pig lungs used were supplied by a commercial butcher (Steve Quigley & Sons, Cubbington, United Kingdom) and dissected on the day of arrival from the abattoir. Ex vivo pig lung (EVPL) tissue was dissected to extract the bronchioles as previously described ( 14 , 15 , 42 ). Following UV light sterilization, the square bronchiolar tissue pieces were placed into each well of a 24-well plate(s) with a 400 μL, UV-sterilized, 0.8% (wt/vol) agarose pad.…”

Section: Methodsmentioning

confidence: 99%

Transcriptome Analysis of Pseudomonas aeruginosa Biofilm Infection in an Ex Vivo Pig Model of the Cystic Fibrosis Lung

Harrington

Littler

Harrison

2022

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Pseudomonas aeruginosa is the predominant cause of chronic biofilm infections that form in the lungs of people with cystic fibrosis (CF). These infections are highly resistant to antibiotics and persist for years in the respiratory tract. One of the main research challenges is that current laboratory models do not accurately replicate key aspects of a P. aeruginosa biofilm infection, highlighted by previous RNA-sequencing studies. We compared the P. aeruginosa PA14 transcriptome in an ex vivo pig lung (EVPL) model of CF and a well-studied synthetic cystic fibrosis sputum medium (SCFM). P. aeruginosa was grown in the EVPL model for 1, 2 and 7 days, and in vitro in SCFM for 1 and 2 days. The RNA was extracted and sequenced at each time point. Our findings demonstrate that expression of antimicrobial resistance genes was cued by growth in the EVPL model, highlighting the importance of growth environment in determining accurate resistance profiles. The EVPL model created two distinct growth environments: tissue-associated biofilm and the SCFM surrounding tissue, each cued a transcriptome distinct from that seen in SCFM in vitro . The expression of quorum sensing associated genes in the EVPL tissue-associated biofilm at 48 h relative to in vitro SCFM was similar to CF sputum versus in vitro conditions. Hence, the EVPL model can replicate key aspects of in vivo biofilm infection that are missing from other current models. It provides a more accurate P. aeruginosa growth environment for determining antimicrobial resistance that quickly drives P. aeruginosa into a chronic-like infection phenotype. Importance Pseudomonas aeruginosa lung infections that affect people with cystic fibrosis are resistant to most available antimicrobial treatments. The lack of a laboratory model that captures all key aspects of these infections hinders not only research progression but also clinical diagnostics. We used transcriptome analysis to demonstrate how a model using pig lungs can more accurately replicate key characteristics of P. aeruginosa lung infection, including mechanisms of antibiotic resistance and infection establishment. Therefore, this model may be used in the future to further understand infection dynamics to develop novel treatments and more accurate treatment plans. This could improve clinical outcomes as well as quality of life for individuals affected by these infections.

show abstract

Section: Methodsmentioning

confidence: 99%

Transcriptome Analysis of Pseudomonas aeruginosa Biofilm Infection in an Ex Vivo Pig Model of the Cystic Fibrosis Lung

Harrington

Littler

Harrison

2022

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…The antibiofilm activity of antibiotics on S. aureus isolated from CF patients has been scarcely investigated. Considering the 5 antibiotics included in this work, a PubMed search conducted on July 19, 2021, with « ceftaroline » or « ceftobiprole » or « linezolid » or « rifampicin » or « trimethoprim » and « Staphylococcus aureus » and « cystic fibrosis » and « biofilm » found five non-redundant publications supporting the need for data acquisition on the subject of antibiotics' antibiofilm activity against CF S. aureus isolates (Molina et al, 2008;Aktas et al, 2013;Iglesias et al, 2019;Gilpin et al, 2021;Harrington et al, 2021). This is reinforced by the observations that most of these antimicrobial agents have been found to display an antibiofilm activity on S. aureus isolated in other settings.…”

Section: Discussionmentioning

confidence: 92%

Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics

et al. 2021

View full text Add to dashboard Cite

Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.

show abstract

“…The strips were washed in DMEM/RPMI and cut into 5 mm × 5 mm squares. EVPL sections were washed again in DMEM/RPMI, then transferred to a petri dish containing 40 mL ASM and irradiated in UV lightbox for 5 min before being aseptically transferred to the biofilm container [Full dissection methods for the production of EVPL tissue sections are also demonstrated in an open access video protocol ( Harrington et al ., 2021 )].…”

Section: Methodsmentioning

confidence: 99%

An in vitro model for the cultivation of polymicrobial biofilms under continuous-flow conditions

et al. 2021

Self Cite

View full text Add to dashboard Cite

The airways of people with cystic fibrosis (CF) are often chronically colonised with a diverse array of bacterial and fungal species. However, little is known about the relative partitioning of species between the planktonic and biofilm modes of growth in the airways. Existing in vivo and in vitro models of CF airway infection are ill-suited for the long-term recapitulation of mixed microbial communities. Here we describe a simple, in vitro continuous-flow model for the cultivation of polymicrobial biofilms and planktonic cultures on different substrata. Our data provide evidence for inter-species antagonism and synergism in biofilm ecology. We further show that the type of substratum on which the biofilms grow has a profound influence on their species composition. This happens without any major alteration in the composition of the surrounding steady-state planktonic community. Our experimentally-tractable model enables the systematic study of planktonic and biofilm communities under conditions that are nutritionally reminiscent of the CF airway microenvironment, something not possible using any existing in vivo models of CF airway infection.

show abstract

Antibiotic Efficacy Testing in an Ex vivo Model of <em>Pseudomonas aeruginosa</em> and <em>Staphylococcus aureus</em> Biofilms in the Cystic Fibrosis Lung

Cited by 16 publications

References 24 publications

Transcriptome Analysis of Pseudomonas aeruginosa Biofilm Infection in an Ex Vivo Pig Model of the Cystic Fibrosis Lung

Transcriptome Analysis of Pseudomonas aeruginosa Biofilm Infection in an Ex Vivo Pig Model of the Cystic Fibrosis Lung

Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics

An in vitro model for the cultivation of polymicrobial biofilms under continuous-flow conditions

Contact Info

Product

Resources

About