• acute lower respiratory infection
• biofilm
• bronchiectasis
• chronic suppurative lung disease
• endotyping
• microbial interactions
• microbiome
• paediatric
• protracted bacterial bronchitis
• treatments

• BAL
• Romanowsky-stained
• bronchiectasis
• bronchoalveolar lavage
• extracellular traps
• light microscopy
• paediatric

• Child
• Humans
• Bronchoalveolar Lavage Fluid
• Extracellular Traps
• Cross-Sectional Studies
• Bronchoalveolar Lavage
• Bronchiectasis/diagnosis
• Fibrosis

• GNT1040830 National Health and Medical Research Council
• APP1154302 National Health and Medical Research Council
• Rebecca L Cooper Foundation
• Charles Darwin University
• Menzies School of Health Research
• National Health and Medical Research Council
• Charles Darwin University
• Menzies School of Health Research

• Pseudomonas aeruginosa
• bronchiectasis
• children
• chronic suppurative lung disease

• adolescents
• bronchiectasis
• children
• chronic cough
• suppurative lung disease

• antibiotic resistance
• biofilm
• polymicrobial
• pulmonary
• respiratory tract

• Anti-Bacterial Agents
• Bacteria
• Biofilms
• Haemophilus influenzae
• Humans
• Pseudomonas aeruginosa
• Respiratory Tract Infections
• Staphylococcal Infections
• Staphylococcus aureus

• R01 HL123771 NHLBI NIH HHS
• R01 HL142587 NHLBI NIH HHS
• R33 HL137077 NHLBI NIH HHS

The aim of this study was to assess the clinical efficacy and safety of mechanical ventilation combined with fiberoptic bronchoalveolar lavage in patients with severe pulmonary infection.

We randomly divided 81 patients with severe pulmonary infection into a control group (n=40) and an observation group (n=41). Both groups were treated using mechanical ventilation, and observation group additionally received assistive fiberoptic bronchoalveolar lavage.

The cure rate and effectiveness rate in the observation group were higher than in the control group (P<0.05, χ²=3.2), and the incidence of ventilator-associated pneumonia in the observation group was significantly lower than that in the control group (P<0.05, χ²=9.4). The partial pressure of oxygen (PaO₂) and oxygen saturation (SaO₂) were higher in the observation group than in the control group (P<0.05, t=3.862, t=33.595), whereas the partial pressure of carbon dioxide (PaCO₂) and respiratory rate were lower in the observation group than in the control group (P<0.05, t=3.307, t=5.043). The levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8) in the 2 groups were lower after treatment than before treatment (all P<0.05), and the levels in the observation group were lower than those in the control group (all P<0.05). Hospital stay, infection control window appearance time, invasive mechanical ventilation time, and total mechanical ventilation time in the observation group were shorter than those in the control group (P<0.05, t=13.990, t=8.643, t=9.717, t=8.980).

Mechanical ventilation combined with fiberoptic bronchoalveolar lavage can effectively improve the curative effects and the blood gas and inflammation indicators in patients.

• antibiotic therapy
• bacterial bronchitis
• bronchiectasis
• nasopharyngeal colonization
• pneumococcal vaccines

Microorganisms are able to form biofilms within respiratory secretions. Methods to disaggregate such biofilms before utilizing standard, rapid, or high throughput diagnostic technologies may aid in pathogen detection during ventilator associated pneumonia (VAP) diagnosis. Our aim was to determine if sonication of endotracheal aspirates (ETA) would increase the sensitivity of qualitative, semi-quantitative, and quantitative bacterial cultures in an animal model of pneumonia caused by Pseudomonas aeruginosa or by methicillin resistant Staphylococcus aureus (MRSA). Material and methods: P. aeruginosa or MRSA was instilled into the lungs or the oropharynx of pigs in order to induce severe VAP. Time point assessments for qualitative and quantitative bacterial cultures of ETA and bronchoalveolar lavage (BAL) samples were performed at 24, 48, and 72 h after bacterial instillation. In addition, at 72 h (autopsy), lung tissue was harvested to perform quantitative bacterial cultures. Each ETA sample was microbiologically processed with and without applying sonication for 5 min at 40 KHz before bacterial cultures. Sensitivity and specificity were determined using BAL as a gold-standard. Correlation with BAL and lung bacterial burden was also determined before and after sonication. Assessment of biofilm clusters and planktonic bacteria was performed through both optical microscopy utilizing Gram staining and Confocal Laser Scanning Microscopy utilizing the LIVE/DEAD^®BacLight kit. Results: 33 pigs were included, 27 and 6 from P. aeruginosa and MRSA pneumonia models, respectively. Overall, we obtained 85 ETA, 69 (81.2%) from P. aeruginosa and 16 (18.8%) from MRSA challenged pigs. Qualitative cultures did not significantly change after sonication, whereas quantitative ETA cultures did significantly increase bacterial counting. Indeed, sonication consistently increased bacterial burden in ETAs at 24, 48, and 72 h after bacterial challenge. Sonication also improved sensitivity of ETA quantitative cultures and maintained specificity at levels previously reported and accepted for VAP diagnosis. Conclusion: The use of sonication in ETA respiratory samples needs to be clinically validated since sonication could potentially improve pathogen detection before standard, rapid, or high throughput diagnostic methods used in routine microbial diagnostics.

• Pseudomonas aeruginosa
• Staphylococcus aureus
• animal model
• biofilm
• endotracheal aspirate
• sonication
• ventilator associated pneumonia

Bronchiectasis is usually classified as cystic fibrosis (CF) related or CF unrelated (non-CF); the latter is not considered an orphan disease any more, even in developed countries. Irrespective of the underlying etiology, bronchiectasis is the result of interaction between host, pathogens, and environment. Vitamin D is known to be involved in a wide spectrum of significant immunomodulatory effects such as down-regulation of pro-inflammatory cytokines and chemokines. Respiratory epithelial cells constitutively express 1α-hydroxylase leading to the local transformation of the inactive 25(OH)-vitamin D to the active 1,25(OH)₂-vitamin D. The latter through its autocrine and paracrine functions up-regulates vitamin D dependent genes with important consequences in the local immunity of lungs. Despite the scarcity of direct evidence on the involvement of vitamin D deficiency states in the development of bronchiectasis in either CF or non-CF patients, it is reasonable to postulate that vitamin D may play some role in the pathogenesis of lung diseases and especially bronchiectasis. The potential contribution of vitamin D deficiency in the process of bronchiectasis is of particular clinical importance, taking into consideration the increasing prevalence of vitamin D deficiency worldwide and the significant morbidity of bronchiectasis. Given the well-established association of vitamin D deficiency with increased inflammation, and the indicative evidence for harmful consequences in lungs, it is intriguing to speculate that the administration of vitamin D supplementation could be a reasonable and cost effective supplementary therapeutic approach for children with non-CF bronchiectasis. Regarding CF patients, maybe in the future as more data become available, we have to re-evaluate our policy on the most appropriate dosage scheme for vitamin D.

• Vitamin D
• Bronchiectasis
• Cystic fibrosis
• Vitamin D supplementation

• Bronchiectasis
• children
• cough
• treatment

• bronchiectasis
• chronic cough
• endobronchial infection
• protracted bacterial bronchitis
• recurrent bronchitis

Most, if not all, bacteria form a biofilm, a multicellular structure that protects them from antimicrobial actions of the host immune system and affords resistance to antibiotics. The latter is especially disturbing with the increase in multiresistant bacterial clones worldwide. Bacterial biofilm formation is a multistep process that starts with surface adhesion, after which attached bacteria divide and give rise to biomass. The actual steps required for Haemophilus influenzae biofilm formation are largely not known. We show that interference with peptidoglycan biosynthesis increases biofilm formation because of the release of bacterial genomic DNA. Subinhibitory concentrations of β-lactam antibiotics, which are often prescribed to treat H. influenzae infections, increase biofilm formation through a similar mechanism. Therefore, when β-lactam antibiotics do not reach their MIC in vivo, they might not only drive selection for β-lactam-resistant clones but also increase biofilm formation and resistance to other antimicrobial compounds.

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.

IMPORTANCE Most, if not all, bacteria form a biofilm, a multicellular structure that protects them from antimicrobial actions of the host immune system and affords resistance to antibiotics. The latter is especially disturbing with the increase in multiresistant bacterial clones worldwide. Bacterial biofilm formation is a multistep process that starts with surface adhesion, after which attached bacteria divide and give rise to biomass. The actual steps required for Haemophilus influenzae biofilm formation are largely not known. We show that interference with peptidoglycan biosynthesis increases biofilm formation because of the release of bacterial genomic DNA. Subinhibitory concentrations of β-lactam antibiotics, which are often prescribed to treat H. influenzae infections, increase biofilm formation through a similar mechanism. Therefore, when β-lactam antibiotics do not reach their MIC in vivo, they might not only drive selection for β-lactam-resistant clones but also increase biofilm formation and resistance to other antimicrobial compounds.

• DNA
• Haemophilus influenzae
• biofilms
• otitis media
• peptidoglycan
• postantibiotic effect

• bronchiectasis
• children
• chronic suppurative lung disease
• immunology
• microbiology

• Airway clearance therapy
• Antibiotics
• Children
• Chronic suppurative lung disease

• Haemophilus influenzae
• airways
• bacterial bronchitis
• infection
• inflammation
• mechanism

• Adolescent
• Bacterial Infections/complications
• Bacterial Infections/diagnosis
• Bronchiectasis/complications
• Bronchiectasis/diagnosis
• Bronchitis/complications
• Bronchitis/diagnosis
• Bronchoalveolar Lavage
• Bronchoscopy
• Child
• Child, Preschool
• Cough/etiology
• Haemophilus influenzae/isolation & purification
• Humans
• Quality of Life
• Recurrence

• Indigenous
• acute respiratory infections
• bronchiectasis
• children
• lung health
• outcomes