Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection
Chronic lung infection by Pseudomonas aeruginosa is the major severe complication in cystic fibrosis (CF) patients, where P. aeruginosa persists and grows in biofilms in the endobronchial mucus under hypoxic conditions. Numerous polymorphonuclear leukocytes (PMNs) surround the biofilms and create lo...
| Main Authors: | , , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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2014
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| Online Access: | https://hdl.handle.net/10356/104137 http://hdl.handle.net/10220/19555 |
| _version_ | 1811687302736379904 |
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| author | Hansen, Christine Rønne Liengaard, Lars Kolpen, Mette Kühl, Michael Bjarnsholt, Thomas Moser, Claus Kharazmi, Arsalan Pressler, Tanja Høiby, Niels Jensen, Peter Østrup |
| author2 | Gulbins, Erich |
| author_facet | Gulbins, Erich Hansen, Christine Rønne Liengaard, Lars Kolpen, Mette Kühl, Michael Bjarnsholt, Thomas Moser, Claus Kharazmi, Arsalan Pressler, Tanja Høiby, Niels Jensen, Peter Østrup |
| author_sort | Hansen, Christine Rønne |
| collection | NTU |
| description | Chronic lung infection by Pseudomonas aeruginosa is the major severe complication in cystic fibrosis (CF) patients, where P. aeruginosa persists and grows in biofilms in the endobronchial mucus under hypoxic conditions. Numerous polymorphonuclear leukocytes (PMNs) surround the biofilms and create local anoxia by consuming the majority of O2 for production of reactive oxygen species (ROS). We hypothesized that P. aeruginosa acquires energy for growth in anaerobic endobronchial mucus by denitrification, which can be demonstrated by production of nitrous oxide (N2O), an intermediate in the denitrification pathway. We measured N2O and O2 with electrochemical microsensors in 8 freshly expectorated sputum samples from 7 CF patients with chronic P. aeruginosa infection. The concentrations of NO3− and NO2− in sputum were estimated by the Griess reagent. We found a maximum median concentration of 41.8 µM N2O (range 1.4–157.9 µM N2O). The concentration of N2O in the sputum was higher below the oxygenated layers. In 4 samples the N2O concentration increased during the initial 6 h of measurements before decreasing for approximately 6 h. Concomitantly, the concentration of NO3− decreased in sputum during 24 hours of incubation. We demonstrate for the first time production of N2O in clinical material from infected human airways indicating pathogenic metabolism based on denitrification. Therefore, P. aeruginosa may acquire energy for growth by denitrification in anoxic endobronchial mucus in CF patients. Such ability for anaerobic growth may be a hitherto ignored key aspect of chronic P. aeruginosa infections that can inform new strategies for treatment and prevention. |
| first_indexed | 2024-10-01T05:14:09Z |
| format | Journal Article |
| id | ntu-10356/104137 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:14:09Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | ntu-10356/1041372022-02-16T16:30:30Z Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection Hansen, Christine Rønne Liengaard, Lars Kolpen, Mette Kühl, Michael Bjarnsholt, Thomas Moser, Claus Kharazmi, Arsalan Pressler, Tanja Høiby, Niels Jensen, Peter Østrup Gulbins, Erich Singapore Centre for Environmental Life Sciences Engineering DRNTU::Science::Medicine Chronic lung infection by Pseudomonas aeruginosa is the major severe complication in cystic fibrosis (CF) patients, where P. aeruginosa persists and grows in biofilms in the endobronchial mucus under hypoxic conditions. Numerous polymorphonuclear leukocytes (PMNs) surround the biofilms and create local anoxia by consuming the majority of O2 for production of reactive oxygen species (ROS). We hypothesized that P. aeruginosa acquires energy for growth in anaerobic endobronchial mucus by denitrification, which can be demonstrated by production of nitrous oxide (N2O), an intermediate in the denitrification pathway. We measured N2O and O2 with electrochemical microsensors in 8 freshly expectorated sputum samples from 7 CF patients with chronic P. aeruginosa infection. The concentrations of NO3− and NO2− in sputum were estimated by the Griess reagent. We found a maximum median concentration of 41.8 µM N2O (range 1.4–157.9 µM N2O). The concentration of N2O in the sputum was higher below the oxygenated layers. In 4 samples the N2O concentration increased during the initial 6 h of measurements before decreasing for approximately 6 h. Concomitantly, the concentration of NO3− decreased in sputum during 24 hours of incubation. We demonstrate for the first time production of N2O in clinical material from infected human airways indicating pathogenic metabolism based on denitrification. Therefore, P. aeruginosa may acquire energy for growth by denitrification in anoxic endobronchial mucus in CF patients. Such ability for anaerobic growth may be a hitherto ignored key aspect of chronic P. aeruginosa infections that can inform new strategies for treatment and prevention. Published version 2014-06-04T04:12:27Z 2019-12-06T21:27:16Z 2014-06-04T04:12:27Z 2019-12-06T21:27:16Z 2014 2014 Journal Article Kolpen, M., Kühl, M., Bjarnsholt, T., Moser, C., Hansen, C. R., Liengaard, L., et al. (2014). Nitrous Oxide Production in Sputum from Cystic Fibrosis Patients with Chronic Pseudomonas aeruginosa Lung Infection. PLoS ONE, 9(1), e84353-. 1932-6203 https://hdl.handle.net/10356/104137 http://hdl.handle.net/10220/19555 10.1371/journal.pone.0084353 24465406 en PLoS ONE © 2014 Kolpen et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. application/pdf |
| spellingShingle | DRNTU::Science::Medicine Hansen, Christine Rønne Liengaard, Lars Kolpen, Mette Kühl, Michael Bjarnsholt, Thomas Moser, Claus Kharazmi, Arsalan Pressler, Tanja Høiby, Niels Jensen, Peter Østrup Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection |
| title | Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection |
| title_full | Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection |
| title_fullStr | Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection |
| title_full_unstemmed | Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection |
| title_short | Nitrous oxide production in sputum from cystic fibrosis patients with chronic Pseudomonas aeruginosa lung infection |
| title_sort | nitrous oxide production in sputum from cystic fibrosis patients with chronic pseudomonas aeruginosa lung infection |
| topic | DRNTU::Science::Medicine |
| url | https://hdl.handle.net/10356/104137 http://hdl.handle.net/10220/19555 |
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