Bacterial lysis through interference with peptidoglycan synthesis increases biofilm formation by nontypeable haemophilus influenzae

Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that mainly causes otitis media in children and community-acquired pneumonia or exacerbations of chronic obstructive pulmonary disease in adults. A large variety of studies suggest that biofilm formation by NTHi may be an importa...

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Bibliographic Details
Authors: Martí Martí, Sara, Puig Pitarch, Carmen, Merlos, Alexandra, Viñas, Miquel, Jonge, Marien I. de, Liñares Louzao, Josefina, Ardanuy Tisaire, María Carmen, Langereis, Jeroen D.
Format: article
Status:Published version
Publication Date:2017
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/127778
Online Access:https://hdl.handle.net/2445/127778
Access Level:Open access
Keyword:Otitis mitjana
Malalties infeccioses en els infants
Pneumònia
Antibiòtics
Síntesi de pèptids
Biofilms
ADN
Otitis media
Communicable diseases in children
Pneumonia
Antibiotics
Peptide synthesis
DNA
Description
Summary:Nontypeable Haemophilus influenzae (NTHi) is an opportunistic pathogen that mainly causes otitis media in children and community-acquired pneumonia or exacerbations of chronic obstructive pulmonary disease in adults. A large variety of studies suggest that biofilm formation by NTHi may be an important step in the pathogenesis of this bacterium. However, the underlying mechanisms involved in this process are poorly elucidated. In this study, we used a transposon mutant library to identify bacterial genes involved in biofilm formation. The growth and biofilm formation of 4,172 transposon mutants were determined, and the involvement of the identified genes in biofilm formation was validated in in vitro experiments. Here, we present experimental data showing that increased bacterial lysis, through interference with peptidoglycan synthesis, results in elevated levels of extracellular DNA, which increased biofilm formation. Interestingly, similar results were obtained with subinhibitory concentrations of β-lactam antibiotics, known to interfere with peptidoglycan synthesis, but such an effect does not appear with other classes of antibiotics. These results indicate that treatment with β-lactam antibiotics, especially for β-lactam-resistant NTHi isolates, might increase resistance to antibiotics by increasing biofilm formation.