Challenges and opportunities in elucidating the structures of biofilm exopolysaccharides: A case study of the Pseudomonas aeruginosa exopolysaccharide called Pel

Magnetic Resonance in Chemistry, Journal Year: 2023, Volume and Issue: unknown

Published: Nov. 2, 2023

Abstract Biofilm formation protects bacteria from antibiotic treatment and host immune responses, making biofilm infections difficult to treat. Within biofilms, bacterial cells are entangled in a self‐produced extracellular matrix that typically includes exopolysaccharides. Molecular‐level descriptions of components, especially exopolysaccharides, have been challenging attain due their complex nature lack solubility crystallinity. Solid‐state nuclear magnetic resonance (NMR) has emerged as key tool determine the structure exopolysaccharides without degradative sample preparation. In this review, we discuss challenges studying opportunities develop solid‐state NMR approaches study these generally intractable materials. We specifically highlight investigations exopolysaccharide called Pel made by opportunistic pathogen, Pseudomonas aeruginosa . provide roadmap for determining future such systems using NMR. The strategies discussed elucidating should be broadly applicable structures other glycans.

Language: Английский

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Polymicrobial Biofilms in Cystic Fibrosis Lung Infections: Effects on Antimicrobial Susceptibility

Springer series on biofilms, Journal Year: 2022, Volume and Issue: unknown, P. 231 - 267

Published: Dec. 18, 2022

Language: Английский

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ExoS Effector in Pseudomonas aeruginosa Hyperactive Type III Secretion System Mutant Promotes Enhanced Plasma Membrane Rupture in Neutrophils

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 25, 2024

Pseudomonas aeruginosa is an opportunistic bacterial pathogen responsible for a large percentage of airway infections that cause morbidity and mortality in immunocompromised patients, especially those with cystic fibrosis (CF). One important P. virulence factor type III secretion system (T3SS) translocates effectors into host cells. ExoS T3SS effector ADP ribosyltransferase (ADPRT) activity. The ADPRT activity promotes by inhibiting phagocytosis limiting the oxidative burst neutrophils. also flagellin, which can activate NLRC4 inflammasome, resulting in: 1) gasdermin-D (GSDMD) pores, release IL-1β pyroptosis; 2) histone 3 citrullination (CitH3) decondensation expansion nuclear DNA cytosol. However, recent studies laboratory strain PAO1 indicate inhibits activation inflammasome Here, ExoS+ CF clinical isolate hyperactive was identified. Variants mutant or were used to infect neutrophils from C57BL/6 mice engineered have genotype defect assembly. Responses assembly assayed, results found be similar had enhanced resistance neutrophil killing, like previously identified hypervirulent isolates. regulated responses but promoted CitH3 plasma membrane rupture (PMR). Glycine supplementation inhibited PMR caused mutant, suggesting ninjurin-1 required this process. These identify as pathogenic

Language: Английский

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Evaluating Sinus Microbiology by Transplant Status in Persons With Cystic Fibrosis: A Matched Cohort Study

OTO Open, Journal Year: 2024, Volume and Issue: 8(1)

Published: Jan. 1, 2024

Abstract Objective Sinus disease is prevalent in persons with cystic fibrosis (PwCF) and may be a reservoir of airway infection postlung transplant (pTx) patients. The microbial composition sinuses its associations chronic rhinosinusitis (CRS) relatively unexplored. We aimed to examine the sinus lower microbiome their CRS PwCF pTxPwCF. Study Design Prospective single‐centre study. Setting A total 31 sex age (±2 years) matched Methods Demographic clinical data along swabs sputum were collected. was assessed using Sinonasal Outcome Test‐22 (SNOT‐22) (patient reported outcome) Lund‐McKay (computed tomography sinus) scores. Samples underwent MiSeq Illumina sequencing universal 16S ribosomal RNA gene. Results (15 pTxPwCF) included. Aggregate airways dominated by Pseudomonas (46%), Haemophilus (14%), Staphylococcus (11%), Streptococcus (10%), Fusobacterium (6%). α‐diversity significantly post‐Tx samples across both ( P = .005). β‐diversity different between .004), but not .75) status. While there trend higher associated SNOT‐22 score at time first visit, this did reach significance .05). Conclusion microbiomes differed pTxPwCF, organisms remained consistent. Elucidating relationship status better understand when intervene accordingly needed optimize management PwCF.

Language: Английский

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Definition of sinonasal and otologic exacerbation in patients with primary ciliary dyskinesia - an expert consensus

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 9, 2024

Abstract Background Recurrent infections of the nose, sinuses, and ears are common problems for people with primary ciliary dyskinesia (PCD). While pulmonary exacerbations in PCD defined, there is no definition Ear-Nose-Throat (ENT) exacerbations, a potential outcome research clinical trials. Methods We set up an expert panel 24 ENT specialists, respiratory physicians, other healthcare professionals, patients to develop consensus definitions sinonasal otologic children adults settings. reviewed literature used modified Delphi approach four electronic surveys. Results Both based on combination major minor criteria, requiring three or two at least criteria each. Major exacerbation are: 1) reported acute increase nasal discharge change colour; 2) pain sensitivity sinus regions; 3) mucopurulent examination. Minor include: symptoms; examination signs; doctoŕs decision treat; improvement after 14-days. ear sensitivity, discharge, examination, 4) signs otitis media otoscopy. hearing problems; complication; treat. Conclusion These might offer useful measure different They should be validated future studies trials together outcomes, assess their usability.

Language: Английский

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