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Cysteamine (Lynovex®), a novel mucoactive antimicrobial & antibiofilm agent for the treatment of cystic fibrosis.

Charrier C, Rodger C, Robertson J, Kowalczuk A, Shand N, Fraser-Pitt D, Mercer D, O'Neil D - Orphanet J Rare Dis (2014)

Bottom Line: Any successful therapeutic strategy designed to combat the respiratory pathology of this condition must address the altered lung physiology and recurrent, complex, polymicrobial infections and biofilms that affect the CF pulmonary tract.In all cases, the 'gold standard' therapeutic agents were employed as control/comparator compounds against which the efficacy of cysteamine was compared.The data we present here provides a platform for cysteamine's continued investigation as a novel treatment for this poorly served orphan disease.

View Article: PubMed Central - PubMed

Affiliation: NovaBiotics Ltd, Cruickshank Building, Craibstone, Aberdeen, AB21 9TR, UK. cedric.charrier@gmail.com.

ABSTRACT

Background: There remains a critical need for more effective, safe, long-term treatments for cystic fibrosis (CF). Any successful therapeutic strategy designed to combat the respiratory pathology of this condition must address the altered lung physiology and recurrent, complex, polymicrobial infections and biofilms that affect the CF pulmonary tract. Cysteamine is a potential solution to these unmet medical needs and is described here for the first time as (Lynovex®) a single therapy with the potential to deliver mucoactive, antibiofilm and antibacterial properties; both in oral and inhaled delivery modes. Cysteamine is already established in clinical practice for an unrelated orphan condition, cystinosis, and is therefore being repurposed (in oral form) for cystic fibrosis from a platform of over twenty years of safety data and clinical experience.

Methods: The antibacterial and antibiofilm attributes of cysteamine were determined against type strain and clinical isolates of CF relevant pathogens using CLSI standard and adapted microbiological methods and a BioFlux microfluidic system. Assays were performed in standard nutrient media conditions, minimal media, to mimic the low metabolic activity of microbes/persister cells in the CF respiratory tract and in artificial sputum medium. In vivo antibacterial activity was determined in acute murine lung infection/cysteamine nebulisation models. The mucolytic potential of cysteamine was assessed against DNA and mucin in vitro by semi-quantitative macro-rheology. In all cases, the 'gold standard' therapeutic agents were employed as control/comparator compounds against which the efficacy of cysteamine was compared.

Results: Cysteamine demonstrated at least comparable mucolytic activity to currently available mucoactive agents. Cysteamine was rapidly bactericidal against both metabolically active and persister cells of Pseudomonas aeruginosa and also emerging CF pathogens; its activity was not sensitive to high ionic concentrations characteristic of the CF lung. Cysteamine prevented the formation of, and disrupted established P. aeruginosa biofilms. Cysteamine was synergistic with conventional CF antibiotics; reversing antibiotic resistance/insensitivity in CF bacterial pathogens.

Conclusions: The novel mucolytic-antimicrobial activity of cysteamine (Lynovex®) provides potential for a much needed new therapeutic strategy in cystic fibrosis. The data we present here provides a platform for cysteamine's continued investigation as a novel treatment for this poorly served orphan disease.

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Related in: MedlinePlus

Post-Antimicrobial effect (PAE) of cysteamine, tobramycin and combinations thereof. The impact of cysteamine or tobramycin (A) and combinations thereof (B) on the recovery of growth of P. aeruginosa PAO1 cells that had been exposed to either/both of these antimicrobial agents for 16 h was monitored for 24 h post termination of cysteamine or/and tobramycin treatment at 37°C in a BioTek Synergy HT microplate reader.
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Fig7: Post-Antimicrobial effect (PAE) of cysteamine, tobramycin and combinations thereof. The impact of cysteamine or tobramycin (A) and combinations thereof (B) on the recovery of growth of P. aeruginosa PAO1 cells that had been exposed to either/both of these antimicrobial agents for 16 h was monitored for 24 h post termination of cysteamine or/and tobramycin treatment at 37°C in a BioTek Synergy HT microplate reader.

Mentions: Following biofilm prevention experiments, samples were analysed to determine whether cysteamine elicited a post-antimicrobial effect (PAE) on bacteria. Kinetic growth assays on these samples did reveal a post-antimicrobial effect; namely in that delayed growth of bacteria from cysteamine-treated (non-biofilm forming) cells was observed, but interestingly, no delayed growth/PAE was observed in samples from tobramycin-treated cells/biofilms (Figure 7A). Combinations of tobramycin and cysteamine however exerted a greater PAE than cysteamine administered as a mono-treatment (Figure 7B). It is likely that the PAE seen after treatment with combinations of these antimicrobial agents is a result of continued/sustained interactions with their bacterial targets. For example, the PAE of rifampicin, which targets bacterial RNA polymerase, correlates with the time taken for recovery of RNA and protein synthesis [29]. The PAE observed for cysteamine potentially has significant implications for clinical dosing regimens; a combination of cysteamine and tobramycin may have the potential for longer dosing intervals and lower doses therein than treatment with tobramycin alone.Figure 7


Cysteamine (Lynovex®), a novel mucoactive antimicrobial & antibiofilm agent for the treatment of cystic fibrosis.

Charrier C, Rodger C, Robertson J, Kowalczuk A, Shand N, Fraser-Pitt D, Mercer D, O'Neil D - Orphanet J Rare Dis (2014)

Post-Antimicrobial effect (PAE) of cysteamine, tobramycin and combinations thereof. The impact of cysteamine or tobramycin (A) and combinations thereof (B) on the recovery of growth of P. aeruginosa PAO1 cells that had been exposed to either/both of these antimicrobial agents for 16 h was monitored for 24 h post termination of cysteamine or/and tobramycin treatment at 37°C in a BioTek Synergy HT microplate reader.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4260250&req=5

Fig7: Post-Antimicrobial effect (PAE) of cysteamine, tobramycin and combinations thereof. The impact of cysteamine or tobramycin (A) and combinations thereof (B) on the recovery of growth of P. aeruginosa PAO1 cells that had been exposed to either/both of these antimicrobial agents for 16 h was monitored for 24 h post termination of cysteamine or/and tobramycin treatment at 37°C in a BioTek Synergy HT microplate reader.
Mentions: Following biofilm prevention experiments, samples were analysed to determine whether cysteamine elicited a post-antimicrobial effect (PAE) on bacteria. Kinetic growth assays on these samples did reveal a post-antimicrobial effect; namely in that delayed growth of bacteria from cysteamine-treated (non-biofilm forming) cells was observed, but interestingly, no delayed growth/PAE was observed in samples from tobramycin-treated cells/biofilms (Figure 7A). Combinations of tobramycin and cysteamine however exerted a greater PAE than cysteamine administered as a mono-treatment (Figure 7B). It is likely that the PAE seen after treatment with combinations of these antimicrobial agents is a result of continued/sustained interactions with their bacterial targets. For example, the PAE of rifampicin, which targets bacterial RNA polymerase, correlates with the time taken for recovery of RNA and protein synthesis [29]. The PAE observed for cysteamine potentially has significant implications for clinical dosing regimens; a combination of cysteamine and tobramycin may have the potential for longer dosing intervals and lower doses therein than treatment with tobramycin alone.Figure 7

Bottom Line: Any successful therapeutic strategy designed to combat the respiratory pathology of this condition must address the altered lung physiology and recurrent, complex, polymicrobial infections and biofilms that affect the CF pulmonary tract.In all cases, the 'gold standard' therapeutic agents were employed as control/comparator compounds against which the efficacy of cysteamine was compared.The data we present here provides a platform for cysteamine's continued investigation as a novel treatment for this poorly served orphan disease.

View Article: PubMed Central - PubMed

Affiliation: NovaBiotics Ltd, Cruickshank Building, Craibstone, Aberdeen, AB21 9TR, UK. cedric.charrier@gmail.com.

ABSTRACT

Background: There remains a critical need for more effective, safe, long-term treatments for cystic fibrosis (CF). Any successful therapeutic strategy designed to combat the respiratory pathology of this condition must address the altered lung physiology and recurrent, complex, polymicrobial infections and biofilms that affect the CF pulmonary tract. Cysteamine is a potential solution to these unmet medical needs and is described here for the first time as (Lynovex®) a single therapy with the potential to deliver mucoactive, antibiofilm and antibacterial properties; both in oral and inhaled delivery modes. Cysteamine is already established in clinical practice for an unrelated orphan condition, cystinosis, and is therefore being repurposed (in oral form) for cystic fibrosis from a platform of over twenty years of safety data and clinical experience.

Methods: The antibacterial and antibiofilm attributes of cysteamine were determined against type strain and clinical isolates of CF relevant pathogens using CLSI standard and adapted microbiological methods and a BioFlux microfluidic system. Assays were performed in standard nutrient media conditions, minimal media, to mimic the low metabolic activity of microbes/persister cells in the CF respiratory tract and in artificial sputum medium. In vivo antibacterial activity was determined in acute murine lung infection/cysteamine nebulisation models. The mucolytic potential of cysteamine was assessed against DNA and mucin in vitro by semi-quantitative macro-rheology. In all cases, the 'gold standard' therapeutic agents were employed as control/comparator compounds against which the efficacy of cysteamine was compared.

Results: Cysteamine demonstrated at least comparable mucolytic activity to currently available mucoactive agents. Cysteamine was rapidly bactericidal against both metabolically active and persister cells of Pseudomonas aeruginosa and also emerging CF pathogens; its activity was not sensitive to high ionic concentrations characteristic of the CF lung. Cysteamine prevented the formation of, and disrupted established P. aeruginosa biofilms. Cysteamine was synergistic with conventional CF antibiotics; reversing antibiotic resistance/insensitivity in CF bacterial pathogens.

Conclusions: The novel mucolytic-antimicrobial activity of cysteamine (Lynovex®) provides potential for a much needed new therapeutic strategy in cystic fibrosis. The data we present here provides a platform for cysteamine's continued investigation as a novel treatment for this poorly served orphan disease.

Show MeSH
Related in: MedlinePlus