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The National Center for the Study of Postsecondary Education Supports (NCSPES) at the University of Hawai'i at Manoa-Center on Disability Studies (CDS) conducted a study that consisted of one survey distributed twice (the second distribution was two years after the first) to a national sample of approximately 1,600 Disability Support Coordinators working in postsecondary educational institutions. The survey focused on the types and frequency of educational supports, accommodations, and services offered to students with disabilities attending two- and four-year postsecondary institutions. This article reports on the findings from two sections of the survey: one, that asked the respondents to address their institutions capacity to offer assistive technology (AT) supports, accommodations, and services as needed by students with disabilities; and another that addressed the availability of distance learning access opportunities. A comparison of findings, over the two-year period, is presented and includes a significant increase in all types of AT supports, accommodations, and services other than AT evaluations; and an increase in the provision of distance learning access opportunities. [ABSTRACT FROM AUTHOR]

Research on the use of voice recognition software (VRS) as a compensatory strategy for written language difficulties, often experienced by postsecondary education students receiving services under the category of learning disabled, is minimal, with one study [13] reporting findings. Higgins and Raskind [13] found writing samples of their subjects, completed with VRS, had higher holistic scores than samples completed with assistance from a transcriber, and without assistance. The research presented in this article builds on this finding through investigation of research questions that address ongoing use of VRS, influence of VRS on writing performance, and variables that influence both of these areas.Key findings include ongoing use of the software being dependent upon need and personal issues; written performance improvements contingent upon need; and key variables influencing ongoing use, including: time, ease of use/acquisition of skills, personal issues, use of Standard English, disability (area affected), and the use of other effective compensatory strategies. This article outlines characteristics of individuals who may benefit from using the software, implications for specific populations, and direction for future research. [ABSTRACT FROM AUTHOR]

The ability of probiotics, comprising live microbiota, to modulate the composition of intestinal microbiomes has been connected to modulation of the central nervous system (Gut-Brain axis), neuroendocrine system (Gut-Skin axis), and immune response (Gut-Immune axis). Less information is known regarding the ability of postbiotics (cell wall components and secreted metabolites derived from live organisms) to regulate host immunity. In the present study, we tested postbiotics comprising single strains of bacteria and yeast ( Lactobacillus acidophilus 16axg, Lacticaseibacillus rhamnosus 18fx, Saccharomyces cerevisiae var. boulardii 16mxg) as well as combinations of multiple strains for their ability to stimulate cytokine production by human CD14 + monocytes. We quantified cytokine gene and protein expression levels in monocytes following stimulation with postbiotics. Both heat-killed L. acidophilus and L. rhamnosus stimulated naïve monocytes without significant differences between them. Heat-killed S. boulardii stimulated less cytokine production compared to postbiotic bacteria at the same concentration. Interestingly, the addition of heat-killed yeast to heat-killed L. acidophilus and L. rhamnosus resulted in an enhancement of immune stimulation. Thus, heat-killed postbiotics have immune-modulating potential, particularly when bacteria and yeast are combined. This approach may hold promise for developing targeted interventions that can be fine-tuned to modulate host immune response with beneficial health impact.

Nitrile-aminothiol conjugation (NATC) stands out as a promising biocompatible ligation technique due to its high chemo-selectivity. Herein we investigated the reactivity and substrate scope of NAT conjugation chemistry, thus developing a novel pH dependent orthogonal NATC as a valuable tool for chemical biology. The study of reaction kinetics elucidated that the combination of heteroaromatic nitrile and aminothiol groups led to the formation of an optimal bioorthogonal pairing, which is pH dependent. This pairing system was effectively utilized for sequential and dual conjugation. Subsequently, these rapid (≈1 h) and high yield (>90 %) conjugation strategies were successfully applied to a broad range of complex biomolecules, including oligonucleotides, chelates, small molecules and peptides. The effectiveness of this conjugation chemistry was demonstrated by synthesizing a fluorescently labelled antimicrobial peptide-oligonucleotide complex as a dual conjugate to imaging in live cells. This first-of-its-kind sequential NATC approach unveils unprecedented opportunities in modern chemical biology, showcasing exceptional adaptability in rapidly creating structurally complex bioconjugates. Furthermore, the results highlight its potential for versatile applications across fundamental and translational biomedical research., (© 2024 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

A significant increase in life-threatening infections caused by Gram-negative "superbugs" is a serious threat to global health. With a dearth of new antibiotics in the developmental pipeline, antibiotics with novel mechanisms of action are urgently required to prevent a return to the preantibiotic era. A key strategy to develop novel anti-infective treatments is to discover new natural scaffolds with distinct mechanisms of action. Laterocidine is a unique cyclic lipodepsipeptide with activity against multiple problematic multidrug-resistant Gram-negative pathogens, including Pseudomonas aeruginosa , Acinetobacter baumannii , and Enterobacterales . Here, we developed a total chemical synthesis methodology for laterocidine and undertook systematic structure-activity relationship studies with chemical biology and NMR. We discovered important structural features that drive the antimicrobial activity of laterocidine, leading to the discovery of an engineered peptide surpassing the efficacy of the original peptide. This engineered peptide demonstrated complete inhibition of the growth of a polymyxin-resistant strain of Pseudomonas aeruginosa in static time-kill experiments., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Surfactant administration via an endotracheal tube (ETT) has been the standard of care for infants with respiratory distress syndrome for decades. As non-invasive ventilation has become commonplace in the NICU, methods for administering surfactant without use of an ETT have been developed. These methods include thin catheter techniques (LISA, MIST), aerosolization/ nebulization, and surfactant administration through laryngeal (LMA) or supraglottic airways (SALSA). This review will describe these methods and discuss considerations and implementation into clinical practice., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Objective: We hypothesize that the time, number of attempts, and physiologic stability of placement of an LMA would be superior compared to ETT., Study Design: Videotape and physiologic parameters of LMA (n = 36) and ETT (n = 31) placement procedures for infants 28-36 weeks gestation were reviewed., Results: Duration of attempts (32 vs 66 s, p < 0.001) and mean total airway insertion time (88 vs 153 s, p = 0.06) was shorter for LMA compared to ETT. Mean number of attempts for successful placement was fewer for LMA (1.5 vs 1.9, p = 0.11). Physiologic parameters remained near baseline in both groups despite very different degrees of premedication., Conclusion: Placement of an LMA required less time and fewer number of attempts compared to ETT. Physiologic stability of an LMA was maintained without the use of an analgesic and muscle relaxant. Use of an LMA is a favorable alternative to ETT placement for surfactant delivery in neonates., Trial Registration: NCT01116921., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Comensal Bacteroidota ( Bacteroidota ) and Enterobacteriacea are often linked to gut inflammation. However, the causes for variability of pro-inflammatory surface antigens that affect gut commensal/opportunistic dualism in Bacteroidota remain unclear. By using the classical lipopolysaccharide/O-antigen ' rfb operon' in Enterobacteriaceae as a surface antigen model (5- rfb- gene-cluster rfbABCDX ), and a recent rfbA- typing strategy for strain classification, we characterized the integrity and conservancy of the entire rfb operon in Bacteroidota . Through exploratory analysis of complete genomes and metagenomes, we discovered that most Bacteroidota have the rfb operon fragmented into nonrandom patterns of gene-singlets and doublets/triplets, termed ' rfb- gene-clusters', or rfb-'minioperons' if predicted as transcriptional. To reflect global operon integrity, contiguity, duplication, and fragmentation principles, we propose a six-category (infra/supra-numerary) cataloging system and a Global Operon Profiling System for bacteria. Mechanistically, genomic sequence analyses revealed that operon fragmentation is driven by intra-operon insertions of predominantly Bacteroides -DNA ( thetaiotaomicron/fragilis ) and likely natural selection in gut-wall specific micro-niches or micropathologies. Bacteroides -insertions, also detected in other antigenic operons (fimbriae), but not in operons deemed essential (ribosomal), could explain why Bacteroidota have fewer KEGG-pathways despite large genomes. DNA insertions, overrepresenting DNA-exchange-avid ( Bacteroides ) species, impact our interpretation of functional metagenomics data by inflating by inflating gene-based pathway inference and by overestimating 'extra-species' abundance. Of disease relevance, Bacteroidota species isolated from cavitating/cavernous fistulous tract (CavFT) microlesions in Crohn's Disease have supra-numerary fragmented operons, stimulate TNF-alpha from macrophages with low potency, and do not induce hyperacute peritonitis in mice compared to CavFT Enterobacteriaceae . The impact of 'foreign-DNA' insertions on pro-inflammatory operons, metagenomics, and commensalism/opportunism requires further studies to elucidate their potential for novel diagnostics and therapeutics, and to elucidate the role of co-existing pathobionts in Crohn's disease microlesions.

Multidrug-resistant Gram-negative bacteria present an urgent and formidable threat to the global public health. Polymyxins have emerged as a last-resort therapy against these 'superbugs'; however, their efficacy against pulmonary infection is poor. In this study, we integrated chemical biology and molecular dynamics simulations to examine how the alveolar lung surfactant significantly reduces polymyxin antibacterial activity. We discovered that lung surfactant is a phospholipid-based permeability barrier against polymyxins, compromising their efficacy against target bacteria. Next, we unraveled the structure-interaction relationship between polymyxins and lung surfactant, elucidating the thermodynamics that govern the penetration of polymyxins through this critical surfactant layer. Moreover, we developed a novel analog, FADDI-235, which exhibited potent activity against Gram-negative bacteria, both in the presence and absence of lung surfactant. These findings shed new light on the sequestration mechanism of lung surfactant on polymyxins and importantly pave the way for the rational design of new-generation lipopeptide antibiotics to effectively treat Gram-negative bacterial pneumonia.

Non-invasive modes of respiratory support have been shown to be the preferable way of primary respiratory support of preterm infants with respiratory distress syndrome (RDS). The avoidance of invasive mechanical ventilation can be beneficial for preterm infants in reduction of morbidity and even mortality. However, it is well-established that some infants managed with non-invasive respiratory support from the outset have symptomatic RDS to a degree that warrants surfactant administration. Infants for whom non-invasive respiratory support ultimately fails are prone to adverse outcomes, occurring at a frequency on par with the group intubated primarily. This raises the question how to combine non-invasive respiratory support with surfactant therapy. Several methods of less or minimally invasive surfactant therapy have been developed to address the dilemma between avoidance of mechanical ventilation and administration of surfactant. This paper describes the different methods of less invasive surfactant application, reports the existing evidence from clinical studies, discusses the limitations of each of the methods and the open and future research questions., Competing Interests: Conflict of interest statements AK received support for attending meetings from Chiesi Farmaceutici and served as a consultant on advisory boards established by Chiesi. KR is paid consultant for ONY Biotech for device development. DT has no conflict. COD has no conflict of interest to declare. Chiesi Farmaceutici, Parma, Italia, manufacturers of poractant alfa (Curosurf), the investigational medicinal product studied in the POPART trial, provided the oropharyngeal surfactant free of charge for the study. They had no role in study design, data collection, analysis, interpretation or the decisions to present or publish the results. PD received support for attending meetings from Chiesi Farmaceutici; served as a consultant on advisory boards established by Chiesi and AbbVie; holds (without royalty claims) a design patent for a catheter for surfactant instillation. Received support for the OPTIMIST-A trial from Chiesi (provision of surfactant at reduced cost). The OPTIMIST-A trial funders had no role in the design and conduct of the study., (Copyright © 2023. Published by Elsevier Ltd.)

Bronchopulmonary dysplasia (BPD) is one of the most devastating morbidities of preterm infants. Antenatal factors like growth restriction and inflammation are risk factors for its development. Use of oxygen and positive pressure ventilation, which are often necessary to treat respiratory distress syndrome (RDS), increase the risk for development of BPD. Continuous positive airway pressure (CPAP) as primary respiratory support allows for avoidance of positive pressure ventilation in many cases but may lead to a delay of surfactant administration which is a proven therapy for RDS. Several alternative surfactant delivery strategies, including nebulization of surfactant, pharyngeal instillation of surfactant, delivery of surfactant via supraglottic airway device or surfactant delivery via a thin endotracheal catheter have been described which allow for the benefit of surfactant therapy while on CPAP. This review reports available data and discusses the existing evidence of their value in preventing BPD as well as further research directions., (Copyright © 2023. Published by Elsevier Inc.)

Objective: To provide the best clinical practice guidance for surfactant use in preterm neonates with respiratory distress syndrome (RDS). The RDS-Neonatal Expert Taskforce (RDS-NExT) initiative was intended to add to existing evidence and clinical guidelines, where evidence is lacking, with input from an expert panel., Study Design: An expert panel of healthcare providers specializing in neonatal intensive care was convened and administered a survey questionnaire, followed by 3 virtual workshops. A modified Delphi method was used to obtain consensus around topics in surfactant use in neonatal RDS., Result: Statements focused on establishing RDS diagnosis and indicators for surfactant administration, surfactant administration methods and techniques, and other considerations. After discussion and voting, consensus was achieved on 20 statements., Conclusion: These consensus statements provide practical guidance for surfactant administration in preterm neonates with RDS, with a goal to contribute to improving the care of neonates and providing a stimulus for further investigation to bridge existing knowledge gaps., (© 2023. The Author(s).)

Background: Informal learning experiences in science, technology, engineering, and math (STEM) can enhance STEM learning that occurs in formal educational settings and curricula as well as generate enthusiasm for considering STEM careers. The aim of this systematic review is to focus on the experiences of neurodiverse students in informal STEM learning. Neurodiversity is a subgroup of neurodevelopmental conditions, such as autism, attention deficit disorder, dyslexia, dyspraxia, and other neurological conditions. The neurodiversity movement regards these conditions as natural forms of human variation, as opposed to dysfunction, and recognizes that neurodiverse individuals possess many strengths relevant to STEM fields., Methods: The authors will systematically search electronic databases for relevant research and evaluation articles addressing informal STEM learning for K-12 children and youth with neurodiverse conditions. Seven databases and content-relevant websites (e.g., informalscience.org) will be searched using a predetermined search strategy and retrieved articles will be screened by two members of the research team. Data synthesis will include meta-synthesis techniques, depending on the designs of the studies., Discussion: The synthesis of the findings resulting from various research and evaluation designs, across the K-12 age span, and across various informal STEM learning contexts, will lead to depth and breadth of understanding of ways to improve informal STEM learning programs for neurodiverse children and youth. The identification of informal STEM learning program components and contexts shown to yield positive results will provide specific recommendations for improving inclusiveness, accessibility, and STEM learning for neurodiverse children and youth., Trial Registration: The current study has been registered in PROSPERO., Registration Number: CRD42021278618., (© 2023. The Author(s).)

The causes for variability of pro-inflammatory surface antigens that affect gut commensal/opportunistic dualism within the phylum Bacteroidota remain unclear (1, 2). Using the classical lipopolysaccharide/O-antigen ' rfb operon' in Enterobacteriaceae as a surface antigen model (5-gene-cluster rfbABCDX ), and a recent rfbA- typing strategy for strain classification (3), we characterized the architecture/conservancy of the entire rfb operon in Bacteroidota . Analyzing complete genomes, we discovered that most Bacteroidota have the rfb operon fragmented into non-random gene-singlets and/or doublets/triplets, termed 'minioperons'. To reflect global operon integrity, duplication, and fragmentation principles, we propose a five-category (infra/supernumerary) cataloguing system and a Global Operon Profiling System for bacteria. Mechanistically, genomic sequence analyses revealed that operon fragmentation is driven by intra-operon insertions of predominantly Bacteroides -DNA ( thetaiotaomicron/fragilis ) and likely natural selection in specific micro-niches. Bacteroides -insertions, also detected in other antigenic operons (fimbriae), but not in operons deemed essential (ribosomal), could explain why Bacteroidota have fewer KEGG-pathways despite large genomes (4). DNA insertions overrepresenting DNA-exchange-avid species, impact functional metagenomics by inflating gene-based pathway inference and overestimating 'extra-species' abundance. Using bacteria from inflammatory gut-wall cavernous micro-tracts (CavFT) in Crohn's Disease (5), we illustrate that bacteria with supernumerary-fragmented operons cannot produce O-antigen, and that commensal/CavFT Bacteroidota stimulate macrophages with lower potency than Enterobacteriaceae , and do not induce peritonitis in mice. The impact of 'foreign-DNA' insertions on pro-inflammatory operons, metagenomics, and commensalism offers potential for novel diagnostics and therapeutics., Competing Interests: Conflict of Interest: The authors declare they have no conflicts of interest.

Intravenous administration of the last-line polymyxins results in poor drug exposure in the lungs and potential nephrotoxicity; while inhalation therapy offers better pharmacokinetics/pharmacodynamics for pulmonary infections by delivering the antibiotic to the infection site directly. However, polymyxin inhalation therapy has not been optimized and adverse effects can occur. This study aimed to quantitatively determine the intracellular accumulation and distribution of polymyxins in single human alveolar epithelial A549 cells. Cells were treated with an iodine-labeled polymyxin probe FADDI-096 (5.0 and 10.0 μM) for 1, 4, and 24 h. Concentrations of FADDI-096 in single A549 cells were determined by synchrotron-based X-ray fluorescence microscopy. Concentration- and time-dependent accumulation of FADDI-096 within A549 cells was observed. The intracellular concentrations (mean ± SEM, n ≥ 189) of FADDI-096 were 1.58 ± 0.11, 2.25 ± 0.10, and 2.46 ± 0.07 mM following 1, 4 and 24 h of treatment at 10 μM, respectively. The corresponding intracellular concentrations following the treatment at 5 μM were 0.05 ± 0.01, 0.24 ± 0.04, and 0.25 ± 0.02 mM (n ≥ 189). FADDI-096 was mainly localized throughout the cytoplasm and nuclear region over 24 h. The intracellular zinc concentration increased in a concentration- and time-dependent manner. This is the first study to quantitatively map the accumulation of polymyxins in human alveolar epithelial cells and provides crucial insights for deciphering the mechanisms of their pulmonary toxicity. Importantly, our results may shed light on the optimization of inhaled polymyxins in patients and the development of new-generation safer polymyxins., (Copyright © 2021 American Society for Microbiology.)

Polymyxins (polymyxin B and colistin) are lipopeptide antibiotics used as a last-line treatment for life-threatening multidrug-resistant (MDR) Gram-negative bacterial infections. Unfortunately, their clinical use has been affected by dose-limiting toxicity and increasing resistance. Structure-activity (SAR) and structure-toxicity (STR) relationships are paramount for the development of safer polymyxins, albeit very little is known about the role of the conserved position 10 threonine (Thr) residue in the polymyxin core scaffold. Here, we synthesized 30 novel analogues of polymyxin B 1 modified explicitly at position 10 and examined the antimicrobial activity against Gram-negative bacteria and in vivo toxicity and performed molecular dynamics simulations with bacterial outer membranes. For the first time, this study revealed the stereochemical requirements and role of the β-hydroxy side chain in promoting the correctly folded conformation of the polymyxin that drives outer membrane penetration and antibacterial activity. These findings provide essential information for developing safer and more efficacious new-generation polymyxin antibiotics.

Polymyxins are last-line antibiotics for the treatment of Gram-negative 'superbugs'. However, nephrotoxicity can occur in up to 60% of patients administered intravenous polymyxins. The mechanisms underpinning nephrotoxicity remain unclear. To understand polymyxin-induced nephrotoxicity, human renal proximal tubule cells were treated for 24 h with 0.1 mM polymyxin B or two new analogues, FADDI-251 or FADDI-287. Transcriptomic analysis was performed, and differentially expressed genes (DEGs) were identified using ANOVA (FDR < 0.2). Cell viability following treatment with polymyxin B, FADDI-251 or FADDI-287 was 66.0 ± 5.33%, 89.3 ± 3.96% and 90.4 ± 1.18%, respectively. Transcriptomics identified 430, 193 and 150 DEGs with polymyxin B, FADDI-251 and FADDI-287, respectively. Genes involved with metallothioneins and Toll-like receptor pathways were significantly perturbed by all polymyxins. Only polymyxin B induced perturbations in signal transduction, including FGFR2 and MAPK signaling. SIGNOR network analysis showed all treatments affected essential regulators in the immune system, autophagy, cell cycle, oxidative stress and apoptosis. All polymyxins caused significant perturbations of metal homeostasis and TLR signaling, while polymyxin B caused the most dramatic perturbations of the transcriptome. This study reveals the impact of polymyxin structure modifications on transcriptomic responses in human renal tubular cells and provides important information for designing safer new-generation polymyxins.

Weissella is a genus earlier considered a member of the family Leuconostocaceae, which was reclassified into the family Lactobacillaceae in 1993. Recently, there have been studies emphasizing the probiotic and anti-inflammatory potential of various species of Weissella, of which W. confusa and W. cibaria are the most representative. Other species within this genus include: W. paramesenteroides, W. viridescens, W. halotolerans, W. minor, W. kandleri, W. soli, W. ghanensis, W. hellenica, W. thailandensis, W. fabalis, W. cryptocerci, W. koreensis, W. beninensis, W. fabaria, W. oryzae, W. ceti, W. uvarum, W. bombi, W. sagaensis, W. kimchi, W. muntiaci, W. jogaejeotgali, W. coleopterorum, W. hanii, W. salipiscis, and W. diestrammenae. Weissella confusa, W. paramesenteroides, W. koreensis, and W. cibaria are among the few species that have been isolated from human samples, although the identification of these and other species is possible using metagenomics, as we have shown for inflammatory bowel disease (IBD) and healthy controls. We were able to isolate Weissella in gut-associated bacteria (post 24 h food deprivation and laxatives). Other sources of isolation include fermented food, soil, and skin/gut/saliva of insects/animals. With the potential for hospital and industrial applications, there is a concern about possible infections. Herein, we present the current applications of Weissella on its antimicrobial and anti-inflammatory mechanistic effects, the predisposing factors (e.g., vancomycin) for pathogenicity in humans, and the antimicrobials used in patients. To address the medical concerns, we examined 28 case reports focused on W. confusa and found that 78.5% of infections were bacteremia (of which 7 were fatal; 1 for lack of treatment), 8 were associated with underlying malignancies, and 8 with gastrointestinal procedures/diseases of which 2 were Crohn’s disease patients. In cases of a successful resolution, commonly administered antibiotics included: cephalosporin, ampicillin, piperacillin-tazobactam, and daptomycin. Despite reports of Weissella-related infections, the evolving mechanistic findings suggest that Weissella are clinically treatable bacteria with emerging antimicrobial and probiotic benefits ranging from oral health, skin care, obesity, and inflammatory diseases to cancer.

Administration of liquid surfactant through an endotracheal tube for the treatment of respiratory distress syndrome has been the standard of care for decades. Surfactant administration through laryngeal or supraglottic airways (SALSA) is a simplified procedure for delivery of surfactant that is less invasive and better tolerated. The Al Bashir Maternity and Children’s Hospital NICU in Amman, Jordan, implemented SALSA as a potentially better practice in 2019 with the objective to effectively and efficiently deliver surfactant in a minimally invasive way and to decrease the adverse events associated with intubation−surfactant−extubation (InSurE) and laryngoscopy. The quality improvement initiative was conducted from March 2019 to December 2019. All infants who weighed 750 g or more who required surfactant were eligible. As physicians were trained in the technique and use expanded, we were able to use plan−do−study−act cycles to observe differences between SALSA and InSurE. The primary aim was the optimization of non-invasive ventilation by the effective and efficient delivery of surfactant. Balancing measures included episodes of bradycardia while receiving surfactant or the need for a second dose of surfactant. We evaluated 220 infants who received surfactant by SALSA or InSurE with a mean gestational age of 32 weeks and a mean birth weight of 1.8 kg. The Respiratory Severity Score (RSS) prior to surfactant administration was 2.7 in the SALSA group compared to 2.9 in the InSurE group (p = 0.024). Those in the InSurE group had a lower mean heart rate during the procedure (p =< 0.0001) and were more likely to need a second dose of surfactant (p = 0.026) or require intubation for mechanical ventilation (p = 0.022). Both groups were effectively delivered surfactant as evidenced by improvement in their RSS over an 8 h period. SALSA was a more time efficient surfactant delivery method (93 vs. 111 secs, p =< 0.0001). Implementation of SALSA into the Al Bashir NICU was successful. We found that it was equally effective to InSurE, but was a more efficient method of delivery. Infants who received surfactant by this method tolerated it well.

Multidrug-resistant Gram-negative bacteria seriously threaten modern medicine due to the lack of efficacious therapeutic options. Their outer membrane (OM) is an essential protective fortress to exclude many antibiotics. Unfortunately, current structural biology methods are not able to resolve the membrane structure and it is difficult to examine the specific interaction between the OM and small molecules. These limitations hinder mechanistic understanding of antibiotic penetration through the OM and antibiotic discovery. Here, we developed biologically relevant OM models by quantitatively determining membrane lipidomics of Pseudomonas aeruginosa and elucidated how lipopolysaccharide modifications and OM vesicles mediated resistance to polymyxins. Supported by chemical biology and pharmacological assays, our multiscale molecular dynamics simulations provide an intelligent platform to quantify the membrane-penetrating thermodynamics of peptides and predict their antimicrobial activity. Through experimental validations with our in-house polymyxin analogue library, our computational strategy may have significant potential in accelerating the discovery of lipopeptides against bacterial "superbugs".

The emergence of multidrug-resistant (MDR) Gram-negative pathogens is an urgent global medical challenge. The old polymyxin lipopeptide antibiotics (polymyxin B and colistin) are often the only therapeutic option due to resistance to all other classes of antibiotics and the lean antibiotic drug development pipeline. However, polymyxin B and colistin suffer from major issues in safety (dose-limiting nephrotoxicity, acute toxicity), pharmacokinetics (poor exposure in the lungs) and efficacy (negligible activity against pulmonary infections) that have severely limited their clinical utility. Here we employ chemical biology to systematically optimize multiple non-conserved positions in the polymyxin scaffold, and successfully disconnect the therapeutic efficacy from the toxicity to develop a new synthetic lipopeptide, structurally and pharmacologically distinct from polymyxin B and colistin. This resulted in the clinical candidate F365 (QPX9003) with superior safety and efficacy against lung infections caused by top-priority MDR pathogens Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae., (© 2022. The Author(s).)

Administration of liquid surfactant through an endotracheal tube for the treatment of respiratory distress syndrome has been the standard of care for decades. A skilled health care provider is needed to perform this procedure. In lower-income and middle-income countries (LMICs), healthcare resources are often limited, leading to increased mortality of premature infants, many of whom would benefit from surfactant administration. Therefore, having a simplified procedure for delivery of surfactant without the need for advanced skills could be life-saving, potentially diminish gaps in care, and help ensure more equitable global neonatal survival rates. Modifications to the standard approach of surfactant administration have been put into practice and these include: INtubation-SURfactant-Extubation (INSURE), thin catheter surfactant administration (TCA), aerosolized surfactant, and surfactant administration through laryngeal or supraglottic airways (SALSA). Although there is a need for larger studies to evaluate the comparative effectiveness of these newer methods, these methods are being embraced by the global community and being implemented in various settings throughout the world. Because the SALSA technique does not require laryngoscopy, a provider skilled in laryngoscopy is not required for the procedure. Therefore, because of the ease of use and safety profile, the SALSA technique should be strongly considered as a viable method of delivering surfactant in LMICs., Competing Interests: PF, KR, and SG have worked for and received payments from ONY Biotech in the past. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer AP declared past co-authorships with one of the authors KR and the absence of any ongoing collaboration with any of the authors to the handling editor., (Copyright © 2022 Zapata, Fort, Roberts, Kaluarachchi and Guthrie.)

Peptide-Peptide Nucleic Acid (PNA) conjugates targeting essential bacterial genes have shown significant potential in developing novel antisense antimicrobials. The majority of efforts in this area are focused on identifying different PNA targets and the selection of peptides to deliver the peptide-PNA conjugates to Gram-negative bacteria. Notably, the selection of a linkage strategy to form peptide-PNA conjugate plays an important role in the effective delivery of PNAs. Recently, a unique Cysteine- 2-Cyanoisonicotinamide (Cys-CINA) click chemistry has been employed for the synthesis of cyclic peptides. Considering the high selectivity of this chemistry, we investigated the efficiency of Cys-CINA conjugation to synthesize novel antimicrobial peptide-PNA conjugates. The PNA targeting acyl carrier protein gene ( acpP ), when conjugated to the membrane-active antimicrobial peptides (polymyxin), showed improvement in antimicrobial activity against multidrug-resistant Gram-negative Acinetobacter baumannii . Thus, indicating that the Cys-CINA conjugation is an effective strategy to link the antisense oligonucleotides with antimicrobial peptides. Therefore, the Cys-CINA conjugation opens an exciting prospect for antimicrobial drug development., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Patil, Thombare, Li, He, Lu, Yu, Wickremasinghe, Pamulapati, Azad, Velkov, Roberts and Li.)

Less invasive surfactant administration methods without laryngoscopy and endotracheal catheterization include delivery via laryngeal mask airway, pharyngeal instillation, and aerosolization. These less invasive techniques are promising and have several advantages over INSURE (Intubation-Surfactant-Extubation) and thin catheter techniques. The objective of this review is to discuss the requisites, techniques, short-term outcomes, and adverse events associated with these methods., (© 2021 Wiley Periodicals LLC.)

For preterm infants with respiratory distress syndrome, delivery of surfactant via brief intubation (INtubate, SURfactant, Extubate; InSurE) has been the standard technique of surfactant administration. However, this method requires intubation and positive pressure ventilation. It is thought that even the short exposure to positive pressure inflations may be enough to initiate the cascade of events that lead to lung injury in the smallest neonates. In an effort to avoid tracheal intubation and positive pressure ventilation, several alternative and less invasive techniques of exogenous surfactant administration have been developed over the years. These have been investigated in clinical studies, including randomized clinical trials, and have demonstrated advantages such as a decrease in the need for mechanical ventilation and incidence of bronchopulmonary dysplasia. These newer techniques of surfactant delivery also have the benefit of being easier to perform. Surfactant delivery via pharyngeal instillation, laryngeal mask, aerosolization, and placement of a thin catheter are being actively pursued in research. We present a contemporary review of surfactant administration for respiratory distress syndrome via these alternative methods in the hope of guiding physicians in their choices for surfactant application in the neonatal intensive care unit.

Noninvasive ventilation is frequently used in the treatment of infants with respiratory distress syndrome. This practice is often effective in higher gestational age neonates, but can be difficult in those with lower gestational ages as surfactant deficiency can be severe. While noninvasive ventilation avoids the negative effects of intubation and ventilator-induced lung injury, failure of this mode of support does occur with relative frequency and is primarily caused by the poorly compliant, surfactant-deficient lung. Because of the potential problems associated with laryngoscopy and intubation, neonatologists have developed various methods to deliver surfactant in minimally invasive ways with the aim of improving the success of noninvasive ventilation. Methods of minimally invasive surfactant administration include various thin catheter techniques, aerosolization/nebulization, and the use of a laryngeal mask airway/supraglottic airway device. The clinician should recognize that currently the only US Food and Drug Administration-approved device to deliver surfactant is an endotracheal tube and all methods reviewed here are considered off-label use. This review will focus primarily on surfactant administration through laryngeal or supraglottic airways, providing a review of the history of this technique, animal and human trials, and comparison with other minimally invasive techniques. In addition, this review provides a step-by-step instruction guide on how to perform this procedure, including a multimedia tutorial to facilitate learning., (Copyright © 2021 by the American Academy of Pediatrics.)

Multidrug-resistant Gram-negative bacteria represent a major medical challenge worldwide. New antibiotics are desperately required with 'old' polymyxins often being the only available therapeutic option. Here, we systematically investigated the structure-activity relationship (SAR) of polymyxins using a quantitative lipidomics-informed outer membrane (OM) model of Acinetobacter baumannii and a series of chemically synthesized polymyxin analogs. By integrating chemical biology and all-atom molecular dynamics simulations, we deciphered how each residue of the polymyxin molecule modulated its conformational folding and specific interactions with the bacterial OM. Importantly, a novel designed polymyxin analog FADDI-287 with predicted stronger OM penetration showed improved in vitro antibacterial activity. Collectively, our study provides a novel chemical biology and computational strategy to expedite the discovery of new-generation polymyxins against life-threatening Gram-negative 'superbugs'., Competing Interests: J. L., T. V., K. D. R., P. E. T. are listed as inventors on the patent WO2015149131 ‘Polymyxin Derivatives as Antimicrobial Compounds’ which covers FADDI-287 and has been licenced to Qpex Biopharma., (This journal is © The Royal Society of Chemistry.)

Competing Interests: Competing interests: None declared.

Background: MDR bacteria represent an urgent threat to human health globally. Polymyxins are a last-line therapy against life-threatening Gram-negative 'superbugs', including Acinetobacter baumannii. Polymyxins exert antimicrobial activity primarily via permeabilizing the bacterial outer membrane (OM); however, the mechanism of interaction between polymyxins and the OM remains unclear at the atomic level., Methods: We constructed a lipid A-based OM model of A. baumannii using quantitative membrane lipidomics data and employed all-atom molecular dynamics simulations with umbrella sampling techniques to elucidate the structure-interaction relationship and thermodynamics governing the penetration of polymyxins [B1 and E1 (i.e. colistin A) representing the two clinically used polymyxins] into the OM., Results: Polymyxin B1 and colistin A bound to the A. baumannii OM by the initial electrostatic interactions between the Dab residues of polymyxins and the phosphates of lipid A, competitively displacing the cations from the headgroup region of the OM. Both polymyxin B1 and colistin A formed a unique folded conformation upon approaching the hydrophobic centre of the OM, consistent with previous experimental observations. Polymyxin penetration induced reorientation of the headgroups of the OM lipids near the penetration site and caused local membrane disorganization, thereby significantly increasing membrane permeability and promoting the subsequent penetration of polymyxin molecules into the OM and periplasmic space., Conclusions: The thermodynamics governing the penetration of polymyxins through the outer leaflet of the A. baumannii OM were examined and novel structure-interaction relationship information was obtained at the atomic and membrane level. Our findings will facilitate the discovery of novel polymyxins against MDR Gram-negative pathogens., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The octapeptins are lipopeptide antibiotics that are structurally similar to polymyxins yet retain activity against polymyxin-resistant Gram-negative pathogens, suggesting they might be used to treat recalcitrant infections. However, the basis of their unique activity is unclear because of the difficulty in generating high-resolution experimental data of the interaction of antimicrobial peptides with lipid membranes. To elucidate these structure-activity relationships, we employed all-atom molecular dynamics simulations with umbrella sampling to investigate the conformational and energetic landscape of octapeptins interacting with bacterial outer membrane (OM). Specifically, we examined the interaction of octapeptin C4 and FADDI-115, lacking a single hydroxyl group compared with octapeptin C4, with the lipid A-phosphoethanolamine modified OM of Acinetobacter baumannii Octapeptin C4 and FADDI-115 both penetrated into the OM hydrophobic center but experienced different conformational transitions from an unfolded to a folded state that was highly dependent on the structural flexibility of their respective N-terminal fatty acyl groups. The additional hydroxyl group present in the fatty acyl group of octapeptin C4 resulted in the molecule becoming trapped in a semifolded state, leading to a higher free energy barrier for OM penetration. The free energy barrier for the translocation through the OM hydrophobic layer was ∼72 kcal/mol for octapeptin C4 and 62 kcal/mol for FADDI-115. Our results help to explain the lower antimicrobial activity previously observed for octapeptin C4 compared with FADDI-115 and more broadly improve our understanding of the structure-function relationships of octapeptins. These findings may facilitate the discovery of next-generation octapeptins against polymyxin-resistant Gram-negative 'superbugs.', Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article., (© 2020 Jiang et al.)

Multidrug-resistant Gram-negative bacteria are a serious global threat to human health. Polymyxins are increasingly used in patients as a last-line therapy to treat infections caused by these life-threatening 'superbugs'. Unfortunately, polymyxin-induced nephrotoxicity is the major dose-limiting factor and understanding its mechanism is crucial for the development of novel, safer polymyxins. Here, we undertook the first all-atom molecular dynamics simulations of the interaction between four naturally occurring polymyxins A 1 , B 1 , M 1 and colistin A (representative structural variations of the polymyxin core structure) and the membrane of human kidney proximal tubular cells. All polymyxins inserted spontaneously into the hydrophobic region of the membrane where they were retained, although their insertion abilities varied. Polymyxin A 1 completely penetrated into the hydrophobic region of the membrane with a unique folded conformation, whereas the other three polymyxins only inserted their fatty acyl tails into this region. Furthermore, local membrane defects and increased water penetration were induced by each polymyxin, which may represent the initial stage of cellular membrane damage. Finally, the structure-interaction relationship of polymyxins was investigated based on atomic interactions at the cell membrane level. The hydrophobicity at positions 6/7 and stereochemistry at position 3 regulated the interactions of polymyxins with the cell membrane. Collectively, our results provide new mechanistic insights into polymyxin-induced nephrotoxicity at the atomic level and will facilitate the development of new-generation polymyxins.

A term neonate was admitted to the Neonatal Intensive Care Unit for respiratory distress, hypotonia and atypical genitalia. Significant findings included a small phallic structure, labial folds, no palpable gonads and two perineal openings. Pelvic ultrasound showed uterine didelphys and a gonad in the right inguinal canal. The right gonad was removed during diagnostic laparoscopy with microscopic evaluation showing infantile testicular tissue and fluorescence in-situ hybridisation showed only XY signal suggesting that the removed gonad was a male-developed testis. Infant was 46,XY, SRY probe positive. The parents chose a female sex assignment prior to gonadectomy. The infant had respiratory insufficiency and central hypotonia that persisted on discharge. Whole exome sequencing showed a heterozygous pathogenic variant of the PBX1 gene. This variant encodes the pre-B-cell leukaemia homeobox PBX transcription factor and has been associated with malformations and severe hypoplasia or aplasia of multiple organs including lungs and gonads. Whole exome sequencing was crucial in providing a unifying diagnosis for this patient., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The US Office of Adolescent Health (OAH) funded studies of teen pregnancy and sexually transmitted infection (STI) prevention programs in 2010. The results of a 5-year OAH study conducted in the state of Hawai'i with middle school youth has implications for school leaders in the selection and implementation of comprehensive sex education curricula yielding positive outcomes for youth., Methods: A cluster randomized controlled trial was conducted across 34 middle school in the state of Hawai'i with 1783 student participants in pre-, post-, and 1-year follow-up surveys to determine effectiveness of a culturally responsive teen pregnancy prevention curriculum, called Pono Choices, specifically developed for youth in Hawai'i., Results: Students receiving the Pono Choices curriculum had significantly higher rates of knowledge gains than students in control schools, although there were no statistically significant differences in initiation of sexual activity between the groups at the 1-year follow-up. Teachers implemented the curriculum at high rates of adherence to fidelity making this a model for implementation., Conclusions: Knowledge and retention of medically accurate teen pregnancy and STI prevention information can be attributed to implementation of a comprehensive program with attention to factors such as fidelity, program quality, engagement, and dosage., (© 2019, American School Health Association.)

The antimicrobial lipopeptides polymyxin B and colistin (polymyxin E) are used as a 'last-line' therapy for infections caused by multidrug-resistant (MDR) Gram-negative pathogens. However, their effective use as antibiotic drugs in the clinical setting is still plagued by significant toxicity issues, in particular their potential for nephrotoxicity. Furthermore, resistance to the polymyxins has begun to emerge in the clinic, which implies a total lack of antibiotics for the treatment of life-threatening infections caused by the Gram-negative 'superbugs'. This chapter details our current understanding of polymyxin structure-activity relationships as well as recent pre-clinical and clinical drug development efforts aimed at generating new polymyxin antibiotics with improved safety and efficacy.

Polymyxins are naturally occurring cyclic lipopeptides that were discovered more than 60 years ago. They have a narrow antibacterial spectrum, which is mainly against Gram-negative pathogens. The dry antibiotic pipeline, together with the increasing incidence of bacterial resistance in the clinic, has been dubbed 'the perfect storm'. This has forced a re-evaluation of 'old' antibiotics, in particular the polymyxins, which retain activity against many multidrug-resistant (MDR) Gram-negative organisms. As a consequence, polymyxin B and colistin (polymyxin E) are now used as the last therapeutic option for infections caused by 'superbugs' such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae. This chapter covers the history, chemistry and antibacterial spectrum of these very important last-line lipopeptide antibiotics.

The mucoid biofilm mode of growth of Pseudomonas aeruginosa ( P. aeruginosa) in the lungs of cystic fibrosis patients makes eradication of infections with antibiotic therapy very difficult. The lipopeptide antibiotics polymyxin B and colistin are currently the last-resort therapies for infections caused by multidrug-resistant P. aeruginosa. In the present study, we investigated the antibacterial activity of a series of polymyxin lipopeptides (polymyxin B, colistin, FADDI-003, octapeptin A 3 , and polymyxin A 2 ) against a panel of polymyxin-susceptible and polymyxin-resistant P. aeruginosa cystic fibrosis isolates grown under planktonic or biofilm conditions in artificial sputum and their interactions with sputum component biomolecules. In sputum media under planktonic conditions, the lipopeptides FADDI-003 and octapeptin A 3 displayed very promising activity against the polymyxin-resistant isolate FADDI-PA066 (polymyxin B minimum inhibitory concentration (MIC) = 32 mg/L), while retaining their activity against the polymyxin-sensitive strains FADDI-PA021 (polymyxin B MIC = 1 mg/L) and FADDI-PA020 (polymyxin B MIC = 2 mg/L). Polymyxin A 2 was only effective against the polymyxin-sensitive isolates. However, under biofilm growth conditions, the hydrophobic lipopeptide FADDI-003 was inactive compared to the more hydrophilic lipopeptides, octapeptin A 3 , polymyxin A 2 , polymyxin B, and colistin. Transmission electron micrographs revealed octapeptin A 3 caused reduction in the cell numbers in biofilm as well as biofilm disruption/"antibiofilm" activity. We therefore assessed the interactions of the lipopeptides with the component sputum biomolecules, mucin, deoxyribonucleic acid (DNA), surfactant, F-actin, lipopolysaccharide, and phospholipids. We observed the general trend that sputum biomolecules reduce lipopeptide antibacterial activity. Collectively, our data suggests that, in the airways, lipopeptide binding to component sputum biomolecules may reduce antibacterial efficacy and is dependent on the physicochemical properties of the lipopeptide.

Resistance to the last-resort antibiotic colistin is now widespread and new therapeutics are urgently required. We report the first in toto chemical synthesis and pre-clinical evaluation of octapeptins, a class of lipopeptides structurally related to colistin. The octapeptin biosynthetic cluster consisted of three non-ribosomal peptide synthetases (OctA, OctB, and OctC) that produced an amphiphilic antibiotic, octapeptin C4, which was shown to bind to and depolarize membranes. While active against multi-drug resistant (MDR) strains in vitro, octapeptin C4 displayed poor in vivo efficacy, most likely due to high plasma protein binding. Nuclear magnetic resonance solution structures, empirical structure-activity and structure-toxicity models were used to design synthetic octapeptins active against MDR and extensively drug-resistant (XDR) bacteria. The scaffold was then subtly altered to reduce plasma protein binding, while maintaining activity against MDR and XDR bacteria. In vivo efficacy was demonstrated in a murine bacteremia model with a colistin-resistant P. aeruginosa clinical isolate., (Copyright © 2018 Elsevier Ltd. All rights reserved.)