Cyanide Measurements in Bacterial Culture and Sputum

Nair, Chandrika Goh; Ryall, Ben; Williams, Huw D.

doi:10.1007/978-1-4939-0473-0_27

Cited by 4 publications

(2 citation statements)

References 15 publications

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“…Hundred microliters of bacterial suspension at 10 8 cells mL −1 were dropped at the center of the HCN induction medium plate (40 g L −1 tryptic soy agar, 4.4 g L −1 glycine) (Wei et al ., ). Then a Whatman paper impregnated with reaction mix (CHCL 3 containing copper (II)‐ethylacetoacetate complex (5 mg L −1 ) and N , N ‐dimethylaniline (5 mg L −1 ) (Nair et al ., ) was fixed to the underside of the petri dish covers. Petri dishes were sealed with parafilm and incubated 24 h at 28°C.…”

Section: Methodsmentioning

confidence: 99%

Phenotype and toxicity of the recently discovered exlA‐positive Pseudomonas aeruginosa strains collected worldwide

Reboud

Elsen

Bouillot

et al. 2016

Environmental Microbiology

126

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We recently identified a hypervirulent strain of Pseudomonas aeruginosa, differing significantly from the classical strains in that it lacks the type 3 secretion system (T3SS), a major determinant of P. aeruginosa virulence. This new strain secretes a novel toxin, called ExlA, which induces plasma membrane rupture in host cells. For this study, we collected 18 other exlA-positive T3SS-negative strains, analyzed their main virulence factors and tested their toxicity in various models. Phylogenetic analysis revealed two groups. The strains were isolated on five continents from patients with various pathologies or in the environment. Their proteolytic activity and their motion abilities were highly different, as well as their capacity to infect epithelial, endothelial, fibroblastic and immune cells, which correlated directly with ExlA secretion levels. In contrast, their toxicity towards human erythrocytes was limited. Some strains were hypervirulent in a mouse pneumonia model and others on chicory leaves. We conclude that (i) exlA-positive strains can colonize different habitats and may induce various infection types, (ii) the strains secreting significant amounts of ExlA are cytotoxic for most cell types but are poorly hemolytic, (iii) toxicity in planta does not correlate with ExlA secretion.

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Section: Methodsmentioning

confidence: 99%

Phenotype and toxicity of the recently discovered exlA‐positive Pseudomonas aeruginosa strains collected worldwide

Reboud

Elsen

Bouillot

et al. 2016

Environmental Microbiology

126

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“…As measured with a cyanide selective electrode [31], the culture supernatants of PA14 and DphzS strains contained 73 mM and 75 mM cyanide in solution, respectively, whereas no detectable cyanide was present in the DhcnA strain. The culture supernatant from PA14 caused a significant decrease in CBF after 60 min (23% fall; p,0.001).…”

Section: Effect Of P Aeruginosa Culture Supernatants On Ciliary Beatmentioning

confidence: 99%

Cyanide levels found in infected cystic fibrosis sputum inhibit airway ciliary function

Nair

Shoemark

Chan³

et al. 2014

Eur Respir J

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We have previously reported cyanide at concentrations of up to 150 mM in the sputum of cystic fibrosis patients infected with Pseudomonas aeruginosa and a negative correlation with lung function. Our aim was to investigate possible mechanisms for this association, focusing on the effect of pathophysiologically relevant cyanide levels on human respiratory cell function.Ciliary beat frequency measurements were performed on nasal brushings and nasal air-liquid interface (ALI) cultures obtained from healthy volunteers and cystic fibrosis patients.Potassium cyanide decreased ciliary beat frequency in healthy nasal brushings (n56) after 60 min (150 mM: 47% fall, p,0.0012; 75 mM: 32% fall, p,0.0001). Samples from cystic fibrosis patients (n53) showed similar results (150 mM: 55% fall, p50.001). Ciliary beat frequency inhibition was not due to loss of cell viability and was reversible. The inhibitory mechanism was independent of ATP levels. KCN also significantly inhibited ciliary beat frequency in ALI cultures, albeit to a lesser extent. Ciliary beat frequency measurements on ALI cultures treated with culture supernatants from P. aeruginosa mutants defective in virulence factor production implicated cyanide as a key component inhibiting the ciliary beat frequency.If cyanide production similarly impairs mucocilliary clearance in vivo, it could explain the link with increased disease severity observed in cystic fibrosis patients with detectable cyanide in their airway. @ERSpublications Cyanide levels detectable in sputum inhibit ciliary function

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Quantitative assessment of cyanide in cystic fibrosis sputum and its oxidative catabolism by hypochlorous acid

Eiserich

Ott

Kadir

et al. 2018

Free Radical Biology and Medicine

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Cyanide Measurements in Bacterial Culture and Sputum

Cited by 4 publications

References 15 publications

Phenotype and toxicity of the recently discovered exlA‐positive Pseudomonas aeruginosa strains collected worldwide

Phenotype and toxicity of the recently discovered exlA‐positive Pseudomonas aeruginosa strains collected worldwide

Cyanide levels found in infected cystic fibrosis sputum inhibit airway ciliary function

Quantitative assessment of cyanide in cystic fibrosis sputum and its oxidative catabolism by hypochlorous acid

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