Pathogens. 2024 Jan 27;13(2):115. doi: 10.3390/pathogens13020115.

ABSTRACT

Achromobacter spp. are intrinsically resistant to multiple antibiotics and can also acquire resistance to those commonly used for the treatment of respiratory infections, especially in patients with cystic fibrosis. The aim of this study was to perform the genetic and biochemical characterization of AXC-2 from A. ruhlandii and to analyze all available AXC variants. Steady-state kinetic parameters were determined on a purified AXC-2 enzyme. It exhibited higher catalytic efficiencies towards amino-penicillins and older cephalosporins, while carbapenems behaved as poor substrates. Phylogenetic analysis of all blaAXC variants available in the NCBI was conducted. AXC was encoded in almost all A. ruhlandii genomes, whereas it was only found in 30% of A. xylosoxidans. AXC-1 was prevalent among A. xylosoxidans. AXC variants were clustered in two main groups, correlating with the Achromobacter species. No association could be established between the presence of blaAXC variants and a specific lineage of A. xylosoxidans; however, a proportion of AXC-1-producing isolates corresponded to ST 182 and ST 447. In conclusion, this study provides valuable insights into the genetic context and kinetic properties of AXC-2, identified in A. ruhlandii. It also provides a thorough description of all AXC variants and their association with Achromobacter species and various lineages.

PMID:38392853 | DOI:10.3390/pathogens13020115

J Fungi (Basel). 2024 Jan 24;10(2):95. doi: 10.3390/jof10020095.

ABSTRACT

Aspergillus fumigatus can cause different clinical manifestations/phenotypes in lung transplant (LTx) recipients and patients with chronic respiratory diseases. It can also precipitate chronic lung allograft dysfunction (CLAD) in LTx recipients. Many host factors have been linked with the severity of A. fumigatus infection, but little is known about the contribution of different A. fumigatus strains to the development of different phenotypes and CLAD. We used multi-locus microsatellite typing (MLMT) to determine if there is a relationship between strain (i.e., genotype) and phenotype in 60 patients post LTx or with chronic respiratory disease across two time periods (1 November 2006-31 March 2009 and 1 November 2015-30 June 2017). The MLMT (STRAf) assay was highly discriminatory (Simpson's diversity index of 0.9819-0.9942) with no dominant strain detected. No specific genotype-phenotype link was detected, but several clusters and related strains were associated with invasive aspergillosis (IA) and colonisation in the absence of CLAD. Host factors were linked to clinical phenotypes, with prior lymphopenia significantly more common in IA cases as compared with A. fumigatus-colonised patients (12/16 [75%] vs. 13/36 [36.1%]; p = 0.01), and prior Staphylococcus aureus infection was a significant risk factor for the development of IA (odds ratio 13.8; 95% confidence interval [2.01-279.23]). A trend toward a greater incidence of CMV reactivation post-A. fumigatus isolation was observed (0 vs. 5; p = 0.06) in LTx recipients. Further research is required to determine the pathogenicity and immunogenicity of specific A. fumigatus strains.

PMID:38392766 | DOI:10.3390/jof10020095

J Pers Med. 2024 Jan 23;14(2):129. doi: 10.3390/jpm14020129.

ABSTRACT

Complex alleles (CAs) arise when two or more nucleotide variants are present on a single allele. CAs of the CFTR gene complicate the cystic fibrosis diagnosis process, classification of pathogenic variants, and determination of the clinical picture of the disease and increase the need for additional studies to determine their pathogenicity and modulatory effect in response to targeted therapy. For several different populations around the world, characteristic CAs of the CFTR gene have been discovered, although in general the prevalence and pathogenicity of CAs have not been sufficiently studied. This review presents examples of using intestinal organoid models for assessments of the two most common and two rare CFTR CAs in individuals with cystic fibrosis in Russia.

PMID:38392563 | DOI:10.3390/jpm14020129

Antibiotics (Basel). 2024 Jan 25;13(2):119. doi: 10.3390/antibiotics13020119.

ABSTRACT

Pseudomonas aeruginosa (P. aeruginosa) with multi-drug resistance (MDR) is a major cause of serious healthcare-associated infections, leading to high morbidity and mortality. This opportunistic pathogen is responsible for various infectious diseases, such as those seen in cystic fibrosis, ventilator-associated pneumonia, urinary tract infection, otitis externa, and burn and wound injuries. Due to its relatively large genome, P. aeruginosa has great diversity and can use various molecular mechanisms for antimicrobial resistance. For example, outer membrane permeability can contribute to antimicrobial resistance and is determined by lipopolysaccharide (LPS) and porin proteins. Recent findings on the regulatory interaction between peptidoglycan and LPS synthesis provide additional clues against pathogenic P. aeruginosa. This review focuses on recent advances in antimicrobial agents and inhibitors targeting LPS and porin proteins. In addition, we explore current and emerging treatment strategies for MDR P. aeruginosa, including phages, vaccines, nanoparticles, and their combinatorial therapies. Novel strategies and their corresponding therapeutic agents are urgently needed for combating MDR pathogens.

PMID:38391505 | DOI:10.3390/antibiotics13020119

Infect Immun. 2024 Feb 23:e0040723. doi: 10.1128/iai.00407-23. Online ahead of print.

ABSTRACT

Pseudomonas aeruginosa is an opportunistic human pathogen that has developed multi- or even pan-drug resistance toward most frontline and last resort antibiotics, leading to increasing frequency of infections and deaths among hospitalized patients, especially those with compromised immune systems. Further complicating treatment, P. aeruginosa produces numerous virulence factors that contribute to host tissue damage and immune evasion, promoting bacterial colonization and pathogenesis. In this study, we demonstrate the importance of rhamnolipid production in host-pathogen interactions. Secreted rhamnolipids form micelles that exhibited highly acute toxicity toward murine macrophages, rupturing the plasma membrane and causing organellar membrane damage within minutes of exposure. While rhamnolipid micelles (RMs) were particularly toxic to macrophages, they also caused membrane damage in human lung epithelial cells, red blood cells, Gram-positive bacteria, and even noncellular models like giant plasma membrane vesicles. Most importantly, rhamnolipid production strongly correlated with P. aeruginosa virulence against murine macrophages in various panels of clinical isolates. Altogether, our findings suggest that rhamnolipid micelles are highly cytotoxic virulence factors that drive acute cellular damage and immune evasion during P. aeruginosa infections.

PMID:38391248 | DOI:10.1128/iai.00407-23

J Clin Microbiol. 2024 Feb 23:e0167823. doi: 10.1128/jcm.01678-23. Online ahead of print.

NO ABSTRACT

PMID:38391224 | DOI:10.1128/jcm.01678-23

Int J Neonatal Screen. 2024 Feb 14;10(1):13. doi: 10.3390/ijns10010013.

ABSTRACT

The project aimed to gather, analyse, and compare the views of stakeholders about the proposed UK cystic fibrosis (CF) screening protocol incorporating next generation sequencing (NGS). The study design was based on principles of Q-methodology with a willingness-to-pay exercise. Participants were recruited from 12 CF centres in the UK. The study contained twenty-eight adults who have experience with CF (parents of children with CF (n = 21), including parents of children with CF transmembrane conductance regulator (CFTR)-related metabolic syndrome (CRMS)/CF screen positive-inconclusive diagnosis (CFSPID), an uncertain outcome (n = 3), and adults with CF (n = 4)), and nine health professionals involved in caring for children with CF. Parents and health professionals expressed a preference for a sensitive approach to NGS. This was influenced by the importance participants placed on not missing any children with CF via screening and the balance of harm between missing a case of CF compared to picking up more children with an uncertain outcome (CRMS/CFSPID). Given the preference for a sensitive approach, the need for adequate explanations about potential outcomes including uncertainty (CFSPID) at the time of screening was emphasized. More research is needed to inform definitive guidelines for managing children with an uncertain outcome following CF screening.

PMID:38390977 | DOI:10.3390/ijns10010013

Open Forum Infect Dis. 2024 Jan 17;11(2):ofae024. doi: 10.1093/ofid/ofae024. eCollection 2024 Feb.

ABSTRACT

BACKGROUND: People with cystic fibrosis (CF) are at increased risk for bronchiectasis, and several reports suggest that CF carriers may also be at higher risk for developing bronchiectasis. The purpose of this study was to determine if CF carriers are at risk for more severe courses or complications of bronchiectasis.

METHODS: Using MarketScan data (2001-2021), we built a cohort consisting of 105 CF carriers with bronchiectasis and 300 083 controls with bronchiectasis but without a CF carrier diagnosis. We evaluated if CF carriers were more likely to be hospitalized for bronchiectasis. In addition, we examined if CF carriers were more likely to be infected with Pseudomonas aeruginosa or nontuberculous mycobacteria (NTM) or to have filled more antibiotic prescriptions. We considered regression models for incident and rate outcomes that controlled for age, sex, smoking status, and comorbidities.

RESULTS: The odds of hospitalization were almost 2.4 times higher (95% CI, 1.116-5.255) for CF carriers with bronchiectasis when compared with non-CF carriers with bronchiectasis. The estimated odds of being diagnosed with a Pseudomonas infection for CF carriers vs noncarriers was about 4.2 times higher (95% CI, 2.417-7.551) and 5.4 times higher (95% CI, 3.398-8.804) for being diagnosed with NTM. The rate of distinct antibiotic fill dates was estimated to be 2 times higher for carriers as compared with controls (95% CI, 1.735-2.333), and the rate ratio for the total number of days of antibiotics supplied was estimated as 2.8 (95% CI, 2.290-3.442).

CONCLUSIONS: CF carriers with bronchiectasis required more hospitalizations and more frequent administration of antibiotics as compared with noncarriers. Given that CF carriers were also more likely to be diagnosed with Pseudomonas and NTM infections, CF carriers with bronchiectasis may have a phenotype more resembling CF-related bronchiectasis than non-CF bronchiectasis.

PMID:38390464 | PMC:PMC10883289 | DOI:10.1093/ofid/ofae024

Curr Med Imaging. 2024;20:1-8. doi: 10.2174/0115734056255925231108052743.

ABSTRACT

BACKGROUND: Only a small number of the investigations that were carried out in the Middle East attempted to characterize patients with NCFB. In order to characterize patients with NCFB, as well as their etiologies, microbiological profiles, and outcomes, we therefore carried out this investigation.

METHODS: This retrospective cohort study was carried out at the Jordan University Hospital (JUH), a tertiary facility located in Amman, Jordan. Non-cystic Fibrosis Bronchiectasis (NCFB) was defined as an HRCT scan typical for bronchiectasis along with a negative sweat chloride test to rule out cystic fibrosis. Patients' data were collected by the use of Electronic Medical Records (EMR) at our institution. Frequent exacerbation was defined as more than 2 exacerbations in 1 year of the onset of the diagnosis.

RESULTS: A total of 79 patients were included, and 54.4% of them were female. The mean and standard deviation of the patient's age was 48.61 ± 19.62. The etiologies of bronchiectasis were evident in 79.7% of the sample. Asthma, Chronic Obstructive Pulmonary Diseases (COPD), and Kartagener syndrome were the most prevalent etiologies, accounting for related illnesses in 21.8%, 21.5%, and 13.9% of the patients, respectively. The most frequent bacteria cultured in our cohort were Pseudomonas and Candida Species. Moreover, 43 patients of the study cohort were frequent exacerbators, and 5 patients died.

CONCLUSION: Our study supports the need to identify several bronchiectasis phenotypes linked to various causes. These findings provide information to clinicians for the early detection and treatment of bronchiectasis in Jordan.

PMID:38389348 | DOI:10.2174/0115734056255925231108052743

J Physiol. 2024 Feb 22. doi: 10.1113/JP285702. Online ahead of print.

ABSTRACT

Type 1 diabetes is a disease of the endocrine pancreas; however, it also affects exocrine function. Although most studies have examined the effects of diabetes on acinar cells, much less is known regarding ductal cells, despite their important protective function in the pancreas. Therefore, we investigated the effect of diabetes on ductal function. Diabetes was induced in wild-type and cystic fibrosis transmembrane conductance regulator (CFTR) knockout mice following an i.p. administration of streptozotocin. Pancreatic ductal fluid and HCO3 - secretion were determined using fluid secretion measurements and fluorescence microscopy, respectively. The expression of ion transporters was measured by real-time PCR and immunohistochemistry. Transmission electron microscopy was used for the morphological characterization of the pancreas. Serum secretin and cholecystokinin levels were measured by an enzyme-linked immunosorbent assay. Ductal fluid and HCO3 - secretion, CFTR activity, and the expression of CFTR, Na+ /H+ exchanger-1, anoctamine-1 and aquaporin-1 were significantly elevated in diabetic mice. Acute or chronic glucose treatment did not affect HCO3 - secretion, but increased alkalizing transporter activity. Inhibition of CFTR significantly reduced HCO3 - secretion in both normal and diabetic mice. Serum levels of secretin and cholecystokinin were unchanged, but the expression of secretin receptors significantly increased in diabetic mice. Diabetes increases fluid and HCO3 - secretion in pancreatic ductal cells, which is associated with the increased function of ion and water transporters, particularly CFTR. KEY POINTS: There is a lively interaction between the exocrine and endocrine pancreas not only under physiological conditions, but also under pathophysiological conditions The most common disease affecting the endocrine part is type-1 diabetes mellitus (T1DM), which is often associated with pancreatic exocrine insufficiency Compared with acinar cells, there is considerably less information regarding the effect of diabetes on pancreatic ductal epithelial cells, despite the fact that the large amount of fluid and HCO3 - produced by ductal cells is essential for maintaining normal pancreatic functions Ductal fluid and HCO3 - secretion increase in T1DM, in which increased cystic fibrosis transmembrane conductance regulator activation plays a central role. We have identified a novel interaction between T1DM and ductal cells. Presumably, the increased ductal secretion represents a defence mechanism in the prevention of diabetes, but further studies are needed to clarify this issue.

PMID:38389307 | DOI:10.1113/JP285702

Br Dent J. 2024 Feb;236(4):309. doi: 10.1038/s41415-024-7154-9.

NO ABSTRACT

PMID:38388608 | DOI:10.1038/s41415-024-7154-9

Cell Biosci. 2024 Feb 22;14(1):27. doi: 10.1186/s13578-024-01203-x.

ABSTRACT

BACKGROUND: Sodium-Glucose cotransporter 1 and 2 (SGLT1/2) belong to the family of glucose transporters, encoded by SLC5A1 and SLC5A2, respectively. SGLT2 is almost exclusively expressed in the renal proximal convoluted tubule cells. SGLT1 is expressed in the kidneys but also in other organs throughout the body. Many SGLT inhibitor drugs have been developed based on the mechanism of blocking glucose (re)absorption mediated by SGLT1/2, and several have gained major regulatory agencies' approval for treating diabetes. Intriguingly these drugs are also effective in treating diseases beyond diabetes, for example heart failure and chronic kidney disease. We recently discovered that SGLT1 is upregulated in the airway epithelial cells derived from patients of cystic fibrosis (CF), a devastating genetic disease affecting greater than 70,000 worldwide.

RESULTS: In the present work, we show that the SGLT1 upregulation is coupled with elevated endoplasmic reticulum (ER) stress response, indicated by activation of the primary ER stress senor inositol-requiring protein 1α (IRE1α) and the ER stress-induced transcription factor X-box binding protein 1 (XBP1), in CF epithelial cells, and in epithelial cells of other stress conditions. Through biochemistry experiments, we demonstrated that the spliced form of XBP1 (XBP1s) acts as a transcription factor for SLC5A1 by directly binding to its promoter region. Targeting this ER stress → SLC5A1 axis by either the ER stress inhibitor Rapamycin or the SGLT1 inhibitor Sotagliflozin was effective in attenuating the ER stress response and reducing the SGLT1 level in these cellular model systems.

CONCLUSIONS: The present work establishes a causal relationship between ER stress and SGLT1 upregulation and provides a mechanistic explanation why SGLT inhibitor drugs benefit diseases beyond diabetes.

PMID:38388523 | DOI:10.1186/s13578-024-01203-x

J Cyst Fibros. 2024 Feb 21:S1569-1993(24)00021-3. doi: 10.1016/j.jcf.2024.02.006. Online ahead of print.

ABSTRACT

BACKGROUND: In 2017, the US Food and Drug Administration initiated expansion of drug labels for the treatment of cystic fibrosis (CF) to include CF transmembrane conductance regulator (CFTR) gene variants based on in vitro functional studies. This study aims to identify CFTR variants that result in increased chloride (Cl-) transport function by the CFTR protein after treatment with the CFTR modulator combination elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA). These data may benefit people with CF (pwCF) who are not currently eligible for modulator therapies.

METHODS: Plasmid DNA encoding 655 CFTR variants and wild-type (WT) CFTR were transfected into Fisher Rat Thyroid cells that do not natively express CFTR. After 24 h of incubation with control or TEZ and ELX, and acute addition of IVA, CFTR function was assessed using the transepithelial current clamp conductance assay. Each variant's forskolin/cAMP-induced baseline Cl- transport activity, responsiveness to IVA alone, and responsiveness to the TEZ/ELX/IVA combination were measured in three different laboratories. Western blots were conducted to evaluate CFTR protein maturation and complement the functional data.

RESULTS AND CONCLUSIONS: 253 variants not currently approved for CFTR modulator therapy showed low baseline activity (<10 % of normal CFTR Cl- transport activity). For 152 of these variants, treatment with ELX/TEZ/IVA improved the Cl- transport activity by ≥10 % of normal CFTR function, which is suggestive of clinical benefit. ELX/TEZ/IVA increased CFTR function by ≥10 percentage points for an additional 140 unapproved variants with ≥10 % but <50 % of normal CFTR function at baseline. These findings significantly expand the number of rare CFTR variants for which ELX/TEZ/IVA treatment should result in clinical benefit.

PMID:38388235 | DOI:10.1016/j.jcf.2024.02.006

J Cyst Fibros. 2024 Feb 21:S1569-1993(24)00011-0. doi: 10.1016/j.jcf.2024.01.012. Online ahead of print.

ABSTRACT

After three publications defining an updated guidance on the diagnostic criteria for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (pwCFTR-RDs), establishing its relationship to CFTR-dysfunction and describing the individual disorders, this fourth and last paper in the series addresses some critical challenges facing health care providers and pwCFTR-RD. Topics included are: 1) benefits and obstacles to collect data from pwCFTR-RD are discussed, together with the opportunity to integrate them into established CF-registries; 2) the potential of infants designated CRMS/CFSPID to develop a CFTR-RD and how to communicate this information; 3) a description of the challenges in genetic counseling, with particular regard to phenotypic variability, unknown long-term evolution, CFTR testing and pregnancy termination 4) a proposal for the assessment of potential barriers to the implementation and dissemination of the produced documents to health care professionals involved in the care of pwCFTR-RD and a process to monitor the implementation of the CFTR-RD recommendations; 5) clinical trials investigating the efficacy of CFTR modulators in CFTR-RD and how endpoints and outcomes might be adapted to the heterogeneity of these disorders.

PMID:38388234 | DOI:10.1016/j.jcf.2024.01.012

Eur Respir J. 2024 Feb 22;63(2):2400068. doi: 10.1183/13993003.00068-2024. Print 2024 Feb.

NO ABSTRACT

PMID:38388000 | DOI:10.1183/13993003.00068-2024

Eur Respir J. 2024 Feb 22:2301512. doi: 10.1183/13993003.01512-2023. Online ahead of print.

NO ABSTRACT

PMID:38387968 | DOI:10.1183/13993003.01512-2023

Diagn Microbiol Infect Dis. 2024 Feb 11;109(1):116212. doi: 10.1016/j.diagmicrobio.2024.116212. Online ahead of print.

ABSTRACT

Pseudomonas aeruginosa, one of the most notorious organisms, causes fatal diseases like-, meningitis, pneumonia as well as worsens the prognosis of cystic fibrosis patients. It is also multi-drug resistant and resists a wide range of antibiotics. Attempts have been made to reduce its virulence/pathogenic potential using a number of organic compounds. For this purpose, the Quorum sensing (QS) system of P. aeruginosa was targeted, which regulates its virulence. Pseudomonas Quinolone System (PQS), one of the four quorum sensing systems, producing pyocyanin pigment was chosen. 2-heptyl-3-hydroxy-4-quinolone (HHQ) is a ligand which binds to PQS protein is responsible for pyocyanin pigment production. Attempts were made to find a compound analogous to HHQ which could bind to PQS active site and inhibit the pigment formation. In-silico analysis was performed to estimate possible interactions and to find/predict the possible PQS inhibitors.

PMID:38387214 | DOI:10.1016/j.diagmicrobio.2024.116212

Clin Med (Lond). 2024 Jan 17;24(1):100017. doi: 10.1016/j.clinme.2024.100017. Online ahead of print.

ABSTRACT

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause significant disease in both immunocompromised and immunocompetent individuals. The incidence of NTM pulmonary disease (NTM-PD) is rising globally. Diagnostic challenges persist and treatment efficacy is variable. This article provides an overview of NTM-PD for clinicians. We discuss how common it is, who is at risk, how it is diagnosed and the multidisciplinary approach to its clinical management.

PMID:38387207 | DOI:10.1016/j.clinme.2024.100017

Lab Med. 2024 Feb 22:lmae009. doi: 10.1093/labmed/lmae009. Online ahead of print.

ABSTRACT

OBJECTIVE: Cystic Fibrosis Foundation guidelines recommend annual diabetes screening by oral glucose tolerance test (OGTT) in pediatric patients with cystic fibrosis (CF) starting at the age of 10 years. Adherence to these guidelines proves to be challenging, and the nationwide screening rates are still considered suboptimal. The aim of this study was to assess and improve the screening rates at our large pediatric center.

METHODS: A 4-year retrospective audit of OGTT completion among pediatric patients with CF of age ≥10 years who are not yet diagnosed with diabetes was conducted. A collaborative working group was formed to identify the barriers to screening and formulate a quality improvement plan, which was monitored and evaluated for a 9-month period.

RESULTS: Diabetes screening rates determined by OGTT completion at our center showed a gradual decline during the COVID-19 pandemic from 2019 to 2022. Following the implementation of the quality improvement plan during the summer of 2023, there was a marked increase in OGTT ordering compliance by providers as well as test completion by patients. Notably, the fractional OGTT completion rate rose from 45% during the preintervention phase (January-April 2023) to 70% during the postintervention phase (May-September 2023).

CONCLUSION: Diabetes screening in pediatric patients with CF can be effectively improved by refining practices related to patient experience, care coordination, and laboratory testing strategies.

PMID:38387038 | DOI:10.1093/labmed/lmae009

J Gastrointestin Liver Dis. 2024 Feb 22. doi: 10.15403/jgld-5005. Online ahead of print.

ABSTRACT

Exocrine pancreatic insufficiency (EPI) is frequently described as underscreened, underdiagnosed, and undertreated. The treatment for EPI is pancreatic enzyme replacement therapy (PERT), which is costly, and provider confidence in prescribing may be one barrier to reducing undertreatment. The lack of interchangeability studies for prescription PERT and/or lack of efficacy studies of over-the-counter enzyme options may be another barrier. This paper reviewed the prevalence of EPI in the general population and in co-conditions. Prevalence of EPI in the general population is commonly estimated around 10-20%, and further research is needed to evaluate EPI across all age groups and to better understand in which age group EPI becomes more prevalent, as an age effect is often seen in EPI prevalence studies. EPI is perceived to be highly correlated with certain co-conditions, and the majority (~65%) of EPI literature is related to a co-condition such as cystic fibrosis, pancreatitis, post-surgery, cancer, or diabetes. It can be estimated that 85% of literature in identified co-conditions, or 56% of total EPI literature, is on rarer co-conditions which only represent <1% of EPI overall. In contrast, there is very little research and literature on EPI in the general population. The highest absolute rates of EPI with co-conditions are likely diabetes and possibly irritable bowel syndrome with diarrhea, yet they are among the least commonly researched in co-condition and EPI studies. A lack of research on EPI in the general population and in the more common co-conditions may be contributing to the rates of underdiagnosis and underscreening, as well as undertreatment for those with low fecal elastase-1 levels.

PMID:38386889 | DOI:10.15403/jgld-5005