TY - JOUR
T1 - Bacterial biofilms predominate in both acute and chronic human lung infections
AU - Kolpen, Mette
AU - Kragh, Kasper Norskov
AU - Enciso, Juan Barraza
AU - Faurholt-Jepsen, Daniel
AU - Lindegaard, Birgitte
AU - Egelund, Gertrud Baunbaek
AU - Jensen, Andreas Vestergaard
AU - Ravn, Pernille
AU - Mathiesen, Inger Hee Mabuza
AU - Gheorge, Alexandra Gabriella
AU - Hertz, Frederik Boetius
AU - Qvist, Tavs
AU - Whiteley, Marvin
AU - Jensen, Peter Ostrup
AU - Bjarnsholt, Thomas
PY - 2022
Y1 - 2022
N2 - Background A basic paradigm of human infection is that acute bacterial disease is caused by fast growing planktonic bacteria while chronic infections are caused by slow-growing, aggregated bacteria, a phenomenon known as a biofilm. For lung infections, this paradigm has been thought to be supported by observations of how bacteria proliferate in well-established growth media in the laboratory-the gold standard of microbiology. Objective To investigate the bacterial architecture in sputum from patients with acute and chronic lung infections. Methods Advanced imaging technology was used for quantification and direct comparison of infection types on fresh sputum samples, thereby directly testing the acute versus chronic paradigm. Results In this study, we compared the bacterial lifestyle (planktonic or biofilm), growth rate and inflammatory response of bacteria in freshly collected sputum (n=43) from patient groups presenting with acute or chronic lung infections. We found that both acute and chronic lung infections are dominated by biofilms (aggregates of bacteria within an extracellular matrix), although planktonic cells were observed in both sample types. Bacteria grew faster in sputum from acute infections, but these fast-growing bacteria were enriched in biofilms similar to the architecture thought to be reserved for chronic infections. Cellular inflammation in the lungs was also similar across patient groups, but systemic inflammatory markers were only elevated in acute infections. Conclusions Our findings indicate that the current paradigm of equating planktonic with acute and biofilm with chronic infection needs to be revisited as the difference lies primarily in metabolic rates, not bacterial architecture.
AB - Background A basic paradigm of human infection is that acute bacterial disease is caused by fast growing planktonic bacteria while chronic infections are caused by slow-growing, aggregated bacteria, a phenomenon known as a biofilm. For lung infections, this paradigm has been thought to be supported by observations of how bacteria proliferate in well-established growth media in the laboratory-the gold standard of microbiology. Objective To investigate the bacterial architecture in sputum from patients with acute and chronic lung infections. Methods Advanced imaging technology was used for quantification and direct comparison of infection types on fresh sputum samples, thereby directly testing the acute versus chronic paradigm. Results In this study, we compared the bacterial lifestyle (planktonic or biofilm), growth rate and inflammatory response of bacteria in freshly collected sputum (n=43) from patient groups presenting with acute or chronic lung infections. We found that both acute and chronic lung infections are dominated by biofilms (aggregates of bacteria within an extracellular matrix), although planktonic cells were observed in both sample types. Bacteria grew faster in sputum from acute infections, but these fast-growing bacteria were enriched in biofilms similar to the architecture thought to be reserved for chronic infections. Cellular inflammation in the lungs was also similar across patient groups, but systemic inflammatory markers were only elevated in acute infections. Conclusions Our findings indicate that the current paradigm of equating planktonic with acute and biofilm with chronic infection needs to be revisited as the difference lies primarily in metabolic rates, not bacterial architecture.
KW - pneumonia
KW - cystic fibrosis
KW - respiratory infection
KW - bacterial infection
KW - PSEUDOMONAS-AERUGINOSA
KW - GROWTH-RATES
KW - DORMANT
U2 - 10.1136/thoraxjnl-2021-217576
DO - 10.1136/thoraxjnl-2021-217576
M3 - Journal article
C2 - 35017313
VL - 77
SP - 1015
EP - 1022
JO - Thorax
JF - Thorax
SN - 0040-6376
ER -