mBio. 2024 Jun 4:e0119824. doi: 10.1128/mbio.01198-24. Online ahead of print.

ABSTRACT

Stenotrophomonas maltophilia expresses a type IV protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria and does so partly by secreting the effector TfcB. Here, we report the structure of TfcB, comprising an N-terminal domain similar to the catalytic domain of glycosyl hydrolase (GH-19) chitinases and a C-terminal domain for recognition and translocation by the T4SS. Utilizing a two-hybrid assay to measure effector interactions with the T4SS coupling protein VirD4, we documented the existence of five more T4SS substrates. One of these was protein 20845, an annotated nuclease. A S. maltophilia mutant lacking the gene for 20845 was impaired for killing Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Moreover, the cloned 20845 gene conferred robust toxicity, with the recombinant E. coli being rescued when 20845 was co-expressed with its cognate immunity protein. The 20845 effector was an 899 amino-acid protein, comprised of a GHH-nuclease domain in its N-terminus, a large central region of indeterminant function, and a C-terminus for secretion. Engineered variants of the 20845 gene that had mutations in the predicted catalytic site did not impede E. coli, indicating that the antibacterial effect of 20845 involves its nuclease activity. Using flow cytometry with DNA staining, we determined that 20845, but not its mutant variants, confers a loss in DNA content of target bacteria. Database searches revealed that uncharacterized homologs of 20845 occur within a range of bacteria. These data indicate that the S. maltophilia T4SS promotes interbacterial competition through the action of multiple toxic effectors, including a potent, novel DNase.IMPORTANCEStenotrophomonas maltophilia is a multi-drug-resistant, Gram-negative bacterium that is an emerging pathogen of humans. Patients with cystic fibrosis are particularly susceptible to S. maltophilia infection. In hospital water systems and various types of infections, S. maltophilia co-exists with other bacteria, including other pathogens such as Pseudomonas aeruginosa. We previously demonstrated that S. maltophilia has a functional VirB/D4 type VI protein secretion system (T4SS) that promotes contact-dependent killing of other bacteria. Since most work on antibacterial systems involves the type VI secretion system, this observation remains noteworthy. Moreover, S. maltophilia currently stands alone as a model for a human pathogen expressing an antibacterial T4SS. Using biochemical, genetic, and cell biological approaches, we now report both the discovery of a novel antibacterial nuclease (TfdA) and the first structural determination of a bactericidal T4SS effector (TfcB).

PMID:38832773 | DOI:10.1128/mbio.01198-24

J Clin Pharmacol. 2024 Jun 3. doi: 10.1002/jcph.2478. Online ahead of print.

ABSTRACT

The lack of data on drug-drug interactions in pediatrics represents a relevant problem in making appropriate therapeutic decisions. Our study aimed to investigate the incidence and risk factors for potential drug-drug interactions (pDDIs) in pediatric pneumonology units, including cystic fibrosis patients. We performed a 6-month prospective observational study during which clinical pharmacists, using the Lexicomp Drug Interactions checker, screened medical records to identify pDDIs. Spearman's rank coefficient, logistic regression, and the Mann-Whitney U test were used to identify correlations, analyze risk factors for pDDIs, and compare cystic fibrosis patients with the rest, respectively. Recommendations were provided for the D and X pDDIs categories. Within the 218 patients, 428 pDDIs were identified, out of which 237 were classified as clinically significant. Almost 60% of patients were exposed to at least one relevant interaction. The number of pDDIs correlated with the number of; drugs (rs = 0.53, P < .001), hospitalization length (rs = 0.20, P < .01), and off-label medicines (rs = 0.25, P < .001). According to the multivariate analysis, at least 6 administered medications (OR = 4.15; 95% CI = 2.21-7.78), 4 days of hospitalization (OR = 6.41; 95% CI = 2.29-17.97), and off-label therapy (OR = 3.37; 95% CI = 1.69-6.70) were the risk factor for pDDIs. Despite significant differences in the number of medications taken, comorbidities, and off-label drugs, cystic fibrosis patients were not more exposed to pDDI. Given the lack of data on pDDIs in the pediatric population, the need for close cooperation between clinicians and clinical pharmacists to improve the safety and efficacy of pharmacotherapy is highlighted.

PMID:38831707 | DOI:10.1002/jcph.2478

BMJ Open. 2024 Jun 3;14(6):e081560. doi: 10.1136/bmjopen-2023-081560.

ABSTRACT

INTRODUCTION: Families with children who have cystic fibrosis (CF) face a multitude of challenges. They require complex and time-consuming daily care, various forms of knowledge and intricate care responsibilities. One of the most critical challenges that Iranian families of children with CF face is the lack of adequate support from health teams in the early stages of diagnosis, frequent hospitalisation and the postdischarge process. Unfortunately, limited studies have been conducted in this field, and the Iranian society lacks a comprehensive support programme for these families after leaving treatment centres or home care teams. Therefore, it is necessary to identify and redefine the needs of these families for better care and support in Iran.

METHODS AND ANALYSIS: A mixed-method research design with an exploratory sequential approach will be used in this study. The study consists of three stages: stage (1) the qualitative phase (conventional content analysis and scoping review); stage (2) the programme design phase (development of a support programme) and stage (3) the quantitative phase (validation of the programme through the Delphi method). In the first stage, data will be collected through interviews. Key concepts, evidence and gaps in research will also be identified, collected and analysed through a scoping review. In the second stage, a support programme will be designed based on the results of the content analysis of interviews and the findings from the scoping review. In the final phase, the study will aim to validate the designed programme through a Delphi study.

ETHICS AND DISSEMINATION: This study formed part of a Ph.D. degree and was approved by the ethics committee of Tabriz University of Medical Sciences (IR.TBZMED.REC.1402.395). Informed consent will be obtained from all study participants. Findings will be published in a peer-reviewed journal.

PMID:38830739 | DOI:10.1136/bmjopen-2023-081560

Pflugers Arch. 2024 Jun 3. doi: 10.1007/s00424-024-02975-4. Online ahead of print.

ABSTRACT

The intestinal epithelium is covered by mucus that protects the tissue from the luminal content. Studies have shown that anion secretion via the cystic fibrosis conductance regulator (Cftr) regulates mucus formation in the small intestine. However, mechanisms regulating mucus formation in the colon are less understood. The aim of this study was to explore the role of anion transport in the regulation of mucus formation during steady state and in response to carbamylcholine (CCh) and prostaglandin E2 (PGE2). The broad-spectrum anion transport inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS), CftrdF508 (CF) mice, and the slc26a3 inhibitor SLC26A3-IN-2 were used to inhibit anion transport. In the distal colon, steady-state mucus expansion was reduced by SLC26A3-IN-2 and normal in CF mice. PGE2 stimulated mucus expansion without de novo mucus release in wild type (WT) and CF colon via slc26a3 sensitive mechanisms, while CCh induced de novo mucus secretion in WT but not in CF colon. However, when added simultaneously, CCh and PGE2 stimulated de novo mucus secretion in the CF colon via DIDS-sensitive pathways. A similar response was observed in CF ileum that responded to CCh and PGE2 with DIDS-sensitive de novo mucus secretion. In conclusion, this study suggests that slc26a3 regulates colonic mucus expansion, while Cftr regulates CCh-induced de novo mucus secretion from ileal and distal colon crypts. Furthermore, these findings demonstrate that in the absence of a functional Cftr channel, parallel stimulation with CCh and PGE2 activates additional anion transport processes that help release mucus from intestinal goblet cells.

PMID:38829391 | DOI:10.1007/s00424-024-02975-4

Mol Pharm. 2024 Jun 3. doi: 10.1021/acs.molpharmaceut.4c00128. Online ahead of print.

ABSTRACT

Biopharmaceuticals such as nucleic acids, proteins, and peptides constitute a new array of treatment modalities for chronic ailments. Invasive routes remain the mainstay of administering biopharmaceuticals due to their labile nature in the biological environment. However, it is not preferred for long-term therapy due to the lack of patient adherence and clinical suitability. Therefore, alternative routes of administration are sought to utilize novel biopharmaceutical therapies to their utmost potential. Nanoparticle-mediated pulmonary delivery of biologics can facilitate both local and systemic disorders. Solid lipid nanoparticles (SLNs) afford many opportunities as pulmonary carriers due to their physicochemical stability and ability to incorporate both hydrophilic and hydrophobic moieties, thus allowing novel combinatorial drug/gene therapies. These applications include pulmonary infections, lung cancer, and cystic fibrosis, while systemic delivery of biomolecules, like insulin, is also attractive for the treatment of chronic ailments. This Review explores physiological and particle-associated factors affecting pulmonary delivery of biopharmaceuticals. It compares the advantages and limitations of SLNs as pulmonary nanocarriers along with design improvements underway to overcome these limitations. Current research illustrating various SLN designs to deliver proteins, peptides, plasmids, oligonucleotides, siRNA, and mRNA is also summarized.

PMID:38828798 | DOI:10.1021/acs.molpharmaceut.4c00128

bioRxiv [Preprint]. 2024 May 25:2024.05.22.595427. doi: 10.1101/2024.05.22.595427.

ABSTRACT

RATIONALE: Cystic fibrosis is a genetic disorder characterized by recurrent airway infections, inflammation, and progressive decline in lung function. Autopsy and spirometry data suggest that cystic fibrosis may start in the small airways which, due to the fractal nature of the airways, account for most of the airway tree surface area. However, they are not easily accessible for testing.

OBJECTIVES: Here, we tested the hypothesis that mucociliary clearance is abnormal in the small airways of newborn cystic fibrosis pigs.

METHODS: Current mucociliary clearance assays are limited therefore we developed a dynamic positron emission tomography scan assay with high spatial and temporal resolution. Each study was accompanied by a high-resolution computed tomography scan that helped identify the thin outer region of the lung that contained small airways.

MEASUREMENTS AND MAIN RESULTS: Clearance of aerosolized [ 68 Ga]macro aggregated albumin from distal airways occurred within minutes after delivery and followed a two-phase process. In cystic fibrosis pigs, both early and late clearance rates were slower. Stimulation of the cystic fibrosis airways with the purinergic agonist UTP further impaired late clearance. Only 1 cystic fibrosis pig treated with UTP out of 6 cleared more than 20% of the delivered dose.

CONCLUSIONS: These data indicate that mucociliary transport in the small airways is fast and can easily be missed if the acquisition is not fast enough. The data also indicate that mucociliary transport is impaired in small airways of cystic fibrosis pigs. This defect is exacerbated by stimulation of mucus secretions with purinergic agonists.

PMID:38826411 | PMC:PMC11142153 | DOI:10.1101/2024.05.22.595427

bioRxiv [Preprint]. 2024 May 20:2023.09.28.559184. doi: 10.1101/2023.09.28.559184.

ABSTRACT

The Burkholderia cepacia complex contains opportunistic pathogens that cause chronic infections and inflammation in lungs of people with cystic fibrosis. Two closely related species within this complex are Burkholderia cenocepacia and the recently classified Burkholderia orbicola. B. cenocepacia and B. orbicola encode a type VI secretion system and the effector TecA, which is detected by the pyrin/caspase-1 inflammasome, and triggers macrophage inflammatory death. In our earlier study the pyrin inflammasome was dispensable for lung inflammation in mice infected with B. orbicola AU1054, indicating this species activates an alternative pathway of macrophage inflammatory death. Notably, B. cenocepacia J2315 and K56-2 can damage macrophage phagosomes and K56-2 triggers activation of the caspase-11 inflammasome, which detects cytosolic LPS. Here we investigated inflammatory cell death in pyrin-deficient ( Mefv -/- ) mouse macrophages infected with B. cenocepacia J2315 or K56-2 or B. orbicola AU1054 or PC184. Macrophage inflammatory death was measured by cleavage of gasdermin D protein, release of cytokines IL-1α and IL-1β and plasma membrane rupture. Findings suggest that J2315 and K56-2 are detected by the caspase-11 inflammasome in Mefv -/- macrophages, resulting in IL-1β release. In contrast, inflammasome activation is not detected in Mefv -/- macrophages infected with AU1054 or PC184. Instead, AU1054 triggers an alternative macrophage inflammatory death pathway that requires TecA and results in plasma membrane rupture and IL-1α release. Amino acid variation between TecA isoforms in B. cenocepacia and B. orbicola may explain how the latter species triggers a non-inflammasome macrophage death pathway.

PMID:38826213 | PMC:PMC11142134 | DOI:10.1101/2023.09.28.559184

J Sex Med. 2024 May 28;21(6):505-506. doi: 10.1093/jsxmed/qdae011.

NO ABSTRACT

PMID:38825573 | DOI:10.1093/jsxmed/qdae011

Curr Probl Pediatr Adolesc Health Care. 2024 Jun 1:101636. doi: 10.1016/j.cppeds.2024.101636. Online ahead of print.

NO ABSTRACT

PMID:38825429 | DOI:10.1016/j.cppeds.2024.101636

J Infect Public Health. 2024 May 14;17(7):102450. doi: 10.1016/j.jiph.2024.05.007. Online ahead of print.

ABSTRACT

BACKGROUND: In spite of major effectiveness, a residual risk after COVID-19 primary vaccination was identified, in particular, for vulnerable individuals of advanced age or with comorbidities. Less is known about the Omicron period in people protected by a booster dose. We aimed to identify the characteristics associated with severe COVID-19 during the Omicron period in a population that had received a booster dose in France and to compare differences with the previous periods of the pandemic.

METHODS: This study was carried out using the French national COVID-19 vaccination database (VAC-SI) coupled with the National Health Data System (SNDS). Individuals aged 12 years or over who received at least one booster dose were identified. Associations between socio-demographic and clinical characteristics and the risk of COVID-19 hospitalisation occurring at least 14 days after receiving a third dose of vaccine during the period of Omicron predominance, i.e., from 1 January 2022 to 10 November 2022, were assessed using Cox proportional hazard models adjusted for age, sex, time since booster dose and vaccination schedule. Analyses were performed overall and by sub-period of circulation of the strains BA.1, BA.2, and BA.4/BA.5, defined as periods where the main sub-variant accounted for more than 80 % of genotyped samples.

FINDINGS: In total, 35,640,387 individuals received a booster dose (mean follow-up of 291 days) and 73,989 were hospitalised for COVID-19 during the total period. Older age (aHR 20.5 95 % CI [19.6-21.5] for 90 years of age or older versus 45-54 years of age), being male (aHR 1.52 [1.50-1.55]), and social deprivation (aHR 1.33 [1.30-1.37] for the most deprived areas versus the least deprived) were associated with an increased risk of hospitalisation for COVID-19. Most of the chronic diseases considered were also positively associated with a residual risk, in particular, cystic fibrosis (aHR 9.83 [7.68-12.56]), active lung cancer (aHR 3.26 [3.06-3.47]), chronic dialysis (aHR 3.79 [3.49-4.11]), psychological and neurodegenerative diseases (more markedly than during the periods of circulation of the alpha and delta variants), and organ transplantation. The use of immunosuppressants was also associated with an increased risk (aHR 2.24 [2.14-2.35], including oral corticosteroids aHR (2.58 [2.50-2.67]).

CONCLUSION: Despite an effective booster and a generally less virulent circulating variant, a residual risk of severe COVID-19 still exists in vulnerable populations, especially those with neurological disorders.

PMID:38823086 | DOI:10.1016/j.jiph.2024.05.007

Gut. 2024 May 31:gutjnl-2024-332577. doi: 10.1136/gutjnl-2024-332577. Online ahead of print.

NO ABSTRACT

PMID:38821859 | DOI:10.1136/gutjnl-2024-332577

PLoS Pathog. 2024 May 31;20(5):e1011453. doi: 10.1371/journal.ppat.1011453. Online ahead of print.

ABSTRACT

Mucosa-associated biofilms are associated with many human disease states, but the host mechanisms promoting biofilm remain unclear. In chronic respiratory diseases like cystic fibrosis (CF), Pseudomonas aeruginosa establishes chronic infection through biofilm formation. P. aeruginosa can be attracted to interspecies biofilms through potassium currents emanating from the biofilms. We hypothesized that P. aeruginosa could, similarly, sense and respond to the potassium efflux from human airway epithelial cells (AECs) to promote biofilm. Using respiratory epithelial co-culture biofilm imaging assays of P. aeruginosa grown in association with CF bronchial epithelial cells (CFBE41o-), we found that P. aeruginosa biofilm was increased by potassium efflux from AECs, as examined by potentiating large conductance potassium channel, BKCa (NS19504) potassium efflux. This phenotype is driven by increased bacterial attachment and increased coalescence of bacteria into aggregates. Conversely, biofilm formation was reduced when AECs were treated with a BKCa blocker (paxilline). Using an agar-based macroscopic chemotaxis assay, we determined that P. aeruginosa chemotaxes toward potassium and screened transposon mutants to discover that disruption of the high-sensitivity potassium transporter, KdpFABC, and the two-component potassium sensing system, KdpDE, reduces P. aeruginosa potassium chemotaxis. In respiratory epithelial co-culture biofilm imaging assays, a KdpFABCDE deficient P. aeruginosa strain demonstrated reduced biofilm growth in association with AECs while maintaining biofilm formation on abiotic surfaces. Furthermore, we determined that the Kdp operon is expressed in vivo in people with CF and the genes are conserved in CF isolates. Collectively, these data suggest that P. aeruginosa biofilm formation can be increased by attracting bacteria to the mucosal surface and enhancing coalescence into microcolonies through aberrant AEC potassium efflux sensed by the KdpFABCDE system. These findings suggest host electrochemical signaling can enhance biofilm, a novel host-pathogen interaction, and potassium flux could be a therapeutic target to prevent chronic infections in diseases with mucosa-associated biofilms, like CF.

PMID:38820569 | DOI:10.1371/journal.ppat.1011453

PLoS One. 2024 May 31;19(5):e0304555. doi: 10.1371/journal.pone.0304555. eCollection 2024.

ABSTRACT

Inflammation is a key driver in the pathogenesis of cystic fibrosis (CF). We assessed the effectiveness of elexacaftor/tezacaftor/ivacaftor (ETI) therapy on downregulating systemic and immune cell-derived inflammatory cytokines. We also monitored the impact of ETI therapy on clinical outcome. Adults with CF, heterozygous for F508del (n = 19), were assessed at baseline, one month and three months following ETI therapy, and clinical outcomes were measured, including sweat chloride, lung function, weight, neutrophil count and C-reactive protein (CRP). Cytokine quantifications were measured in serum and following stimulation of peripheral blood mononuclear cells (PBMCs) with lipopolysaccharide (LPS) and adenosine triphosphate and analysed using LEGEND plex™ Human Inflammation Panel 1 by flow cytometry (n = 19). ASC specks were measured in serum and caspase-1 activity and mRNA levels determined from stimulated PBMCs were determined. Patients remained stable over the study period. ETI therapy resulted in decreased sweat chloride concentrations (p < 0.0001), CRP (p = 0.0112) and neutrophil count (p = 0.0216) and increased percent predicted forced expiratory volume (ppFEV1) (p = 0.0399) from baseline to three months, alongside a trend increase in weight. Three months of ETI significantly decreased IL-18 (p< 0.0011, p < 0.0001), IL-1β (p<0.0013, p = 0.0476), IL-6 (p = 0.0109, p = 0.0216) and TNF (p = 0.0028, p = 0.0033) levels in CF serum and following PBMCs stimulation respectively. The corresponding mRNA levels were also found to be reduced in stimulated PBMCs, as well as reduced ASC specks and caspase-1 levels, indicative of NLRP3-mediated production of pro-inflammatory cytokines, IL-1β and IL-18. While ETI therapy is highly effective at reducing sweat chloride and improving lung function, it also displays potent anti-inflammatory properties, which are likely to contribute to improved long-term clinical outcomes.

PMID:38820269 | DOI:10.1371/journal.pone.0304555

Sci Adv. 2024 May 31;10(22):eadl5576. doi: 10.1126/sciadv.adl5576. Epub 2024 May 31.

ABSTRACT

Despite great progress in the field, chronic Pseudomonas aeruginosa (Pa) infections remain a major cause of mortality in patients with cystic fibrosis (pwCF), necessitating treatment with antibiotics. Pf is a filamentous bacteriophage produced by Pa and acts as a structural element in Pa biofilms. Pf presence has been associated with antibiotic resistance and poor outcomes in pwCF, although the underlying mechanisms are unclear. We have investigated how Pf and sputum biopolymers impede antibiotic diffusion using pwCF sputum and fluorescent recovery after photobleaching. We demonstrate that tobramycin interacts with Pf and sputum polymers through electrostatic interactions. We also developed a set of mathematical models to analyze the complex observations. Our analysis suggests that Pf in sputum reduces the diffusion of charged antibiotics due to a greater binding constant associated with organized liquid crystalline structures formed between Pf and sputum polymers. This study provides insights into antibiotic tolerance mechanisms in chronic Pa infections and may offer potential strategies for novel therapeutic approaches.

PMID:38820163 | DOI:10.1126/sciadv.adl5576

Int J Cardiovasc Imaging. 2022 Jul;38(7):1587-1589. doi: 10.1007/s10554-022-02594-z. Epub 2022 May 26.

NO ABSTRACT

PMID:38819544 | DOI:10.1007/s10554-022-02594-z

Med Sci (Paris). 2024 May;40(5):467-470. doi: 10.1051/medsci/2024047. Epub 2024 May 31.

ABSTRACT

TITLE: Une thérapie génique systémique dans le traitement de la mucoviscidose.

ABSTRACT: Le master I2VB se propose de donner les bases conceptuelles et pratiques des différents aspects de l’infectiologie. Il s’appuie sur une coopération exemplaire entre les équipes de recherche en infectiologie et en immunologie de l’Université de Tours, et celles, entre autres, de l’Unité Infectiologie et Santé Publique (ISP) du Centre INRAE de Tours-Nouzilly, concrétisée par une profonde interaction entre chercheurs et enseignants-chercheurs. Cette formation aborde aussi bien les aspects fondamentaux et appliqués de l’infectiologie et de l’immunologie allant de l’étude moléculaire des interactions entre le pathogène et son hôte, jusqu’à la conception et la mise sur le marché des produits de la vaccinologie, des biothérapies anti-infectieuses et des anticorps immuno-thérapeutiques. Le master I2VB (niveau M1) donne lieu aux parcours ICM, I&B et AcT (niveau M2). L’option Infectiologie Cellulaire et Moléculaire (ICM) (responsables : Françoise Debierre-Grockiego et Martine Braibant) a pour objectifs de : former des scientifiques dotés d’une culture générale et technique spécialisée dans les biotechnologies, l’infectiologie, les interactions hôte-pathogène et les mécanismes de la réponse immunitaire anti-infectieuse, contribuant à l’avancée des connaissances scientifiques et à ses applications industrielles, demandes sociétales en forte progression. former des pharmaciens, médecins, vétérinaires, ingénieurs agronomes aux enjeux actuels de l’infectiologie à la fois dans les domaines fondamentaux et appliqués. L’option Immunité et biomédicaments (I&B) (responsables : Anne di Tommaso et Isabelle Dimier-Poisson) a pour objectifs de : former des scientifiques dotés d’une culture générale et technique spécialisée dans les biotechnologies, l’infectiologie, la vaccinologie, les biomédicaments et les biothérapies anti-infectieuses contribuant à l’avancée des connaissances scientifiques et à ses applications industrielles, demandes sociétales en forte progression. former de jeunes scientifiques, pharmaciens, médecins, vétérinaires, ingénieurs agronomes aux enjeux actuels de l’infectiologie et des biomédicaments à la fois dans les domaines fondamentaux et appliqués. L’option Anticorps thérapeutiques (AcT) (responsables : Laurie Lajoie et Isabelle Dimier-Poisson) a pour objectifs de : former des scientifiques dotés d’une culture générale et technique spécialisée dans les biotechnologies, l’immunologie, la cancérologie et les biomédicaments dont les anticorps thérapeutiques, contribuant à l’avancée des connaissances scientifiques et à ses application industrielles et juridiques, demandes sociétales en forte progression. former de jeunes scientifiques, pharmaciens, médecins, vétérinaires, ingénieurs agronomes aux enjeux actuels de l’infectiologie et des biomédicaments à la fois dans les domaines fondamentaux et appliqués.

PMID:38819285 | DOI:10.1051/medsci/2024047

Am J Respir Cell Mol Biol. 2024 Jun;70(6):527-530. doi: 10.1165/rcmb.2023-0419LE.

NO ABSTRACT

PMID:38819123 | DOI:10.1165/rcmb.2023-0419LE

Pract Lab Med. 2024 May 21;40:e00403. doi: 10.1016/j.plabm.2024.e00403. eCollection 2024 May.

ABSTRACT

BACKGROUND: The advent of CFTR modulators highlighted that the sweat test (ST) for CF can be used also as an outcome measure for the basic defect of CFTR. Despite the technological advances, ST still remains operator-dependent and its execution should be strongly paired with guidelines. In 2022, due to the advent of CFTR modulators, the Italian CF Society introduced a specific ST report. The aim of the present paper is to discuss the impact of this new report in the 2022-23 round of the Italian External Quality Assessment program for ST (I-EQA-SCT).

METHODS: The scheme of the I-EQA-SCT is prospective, enrolment is voluntary, the payment of a fee is required and results are shared through a web-facility. Assessment covers analysis, interpretation, and reporting of results. In the 2022-23 round, 2 out of the 3 mock clinical information referred to patients who started modulators.

RESULTS: Fourteen laboratories completed the 2022-23 I-EQA-SCT round. Three of them failed in the interpretation of results from these two mock cases and/or used a wrong report not consistent with the more recent Italian Sweat Test Recommendations.

CONCLUSIONS: The overall results obtained from the laboratories involved in the I-EQA-SCT program clearly showed that the laboratories' qualitative and quantitative performance improved significantly. Results emerged from this round highlighted an issue in the report form used for monitoring patients on CFTR modulator therapy thus stressing the importance of these programs in improving both the performance of lab services and ameliorating the sweat test recommendations.

PMID:38818249 | PMC:PMC11137549 | DOI:10.1016/j.plabm.2024.e00403

PLoS Biol. 2024 May 30;22(5):e3002628. doi: 10.1371/journal.pbio.3002628. eCollection 2024 May.

ABSTRACT

The peptidoglycan (PG) layer is a critical component of the bacterial cell wall and serves as an important target for antibiotics in both gram-negative and gram-positive bacteria. The hydrolysis of septal PG (sPG) is a crucial step of bacterial cell division, facilitated by FtsEX through an amidase activation system. In this study, we present the cryo-EM structures of Escherichia coli FtsEX and FtsEX-EnvC in the ATP-bound state at resolutions of 3.05 Å and 3.11 Å, respectively. Our PG degradation assays in E. coli reveal that the ATP-bound conformation of FtsEX activates sPG hydrolysis of EnvC-AmiB, whereas EnvC-AmiB alone exhibits autoinhibition. Structural analyses indicate that ATP binding induces conformational changes in FtsEX-EnvC, leading to significant differences from the apo state. Furthermore, PG degradation assays of AmiB mutants confirm that the regulation of AmiB by FtsEX-EnvC is achieved through the interaction between EnvC-AmiB. These findings not only provide structural insight into the mechanism of sPG hydrolysis and bacterial cell division, but also have implications for the development of novel therapeutics targeting drug-resistant bacteria.

PMID:38814940 | DOI:10.1371/journal.pbio.3002628

Turk J Pediatr. 2024 May 23;66(2):257-264. doi: 10.24953/turkjpediatr.2024.4588.

ABSTRACT

BACKGROUND: Acute respiratory failure is a prevalent condition in childhood with a high rate of mortality. Invasive mechanical ventilation support may be required for the management of these patients. Extracorporeal membrane oxygenation (ECMO) is a method used when ventilation support is insufficient. However, the less invasive extracorporeal carbon dioxide removal method can be used as an alternative in cases of hypercapnic respiratory failure.

CASE: A 9-year-old patient with cystic fibrosis presented to the hospital with acute respiratory failure due to pneumonia. Bilateral patchy areas of consolidation were evident in the chest x-ray. Invasive mechanical ventilation support was consequently provided to treat severe hypercapnia. Although peak and plateau pressure levels exceeded 32 cmH₂O (49 cmH₂O) and 28 cmH₂O (35 cmH₂O), respectively, the patient continued to have severe respiratory acidosis. Therefore extracorporeal carbon dioxide removal support was initiated to provide lung-protective ventilation. By Day 10, venovenous ECMO support was initiated due to deteriorating oxygenation.

CONCLUSION: In cases where conventional invasive mechanical ventilation support is insufficient due to acute hypercapnic respiratory failure, extracorporeal carbon dioxide removal support, which is less invasive compared to ECMO, should be considered as an effective and reliable alternative method. However, it should be noted that extracorporeal carbon dioxide removal support does not affect oxygenation; it functions solely as a carbon dioxide removal system.

PMID:38814300 | DOI:10.24953/turkjpediatr.2024.4588