Hackensack Meridian Health

EUS-guided gastroenterostomy (EUS-GE) is rapidly emerging as a pivotal procedure in the management of gastric outlet obstruction due to its advantages over historical comparators such as surgical gastroenterostomy and endoscopic placement of gastroduodenal stents. The ability to create a stable surgical-range connection between 2 lumens, distant from the tumor, with the minimally invasive nature of an endoscopic procedure, offers high clinical efficacy, acceptable safety, and low recurrence rates. However, widespread adoption is impeded by the steep learning curve and lack of standardized methodologies. Like other interventional EUS procedures, EUS-GE utilizes lumen apposing metal stents. Unlike drainage procedures, the target in EUS-GE is a mobile structure with a virtual resting caliber that needs to be distended to create the connection, making misdeployment a significant drawback. This comprehensive illustrated technical review dissects the general and specific technical principles of EUS-GE covering the equipment, scene, settings, and endoscopic signs of correct and incorrect placement. It provides a deeper insight into the wireless simplified EUS-GE technique, the EUS-guided double-balloon-occluded gastrojejunostomy bypass, and the direct technique. Through pragmatic tips, expert advice, and elucidative step-by-step videos, a systematic roadmap for mastering this intricate procedure is presented. By addressing common challenges and providing troubleshooting strategies, this review aims to demystify EUS-GE, equipping practitioners with the tools to achieve reproducible and optimal outcomes.

Alveolar macrophages are the first immune cells to encounter Mycobacterium tuberculosis (Mtb) in the lungs, but they frequently fail to eliminate this pathogen, allowing Mtb to persist and replicate. Interstitial macrophages (IMs) are enlisted to restrict bacterial growth and limit immune evasion. While IMs have been implicated in controlling acute Mtb infection, their role during latent tuberculosis infection (LTBI) remains unexplored. To address this, we utilized a previously established mouse model of paucibacillary Mtb infection that recapitulates key aspects of human LTBI to deplete IMs during the latent phase. Depletion of IMs and recruited macrophages (RMs) led to TB relapse in 26% of mice compared to 2% in controls. Mice that relapsed exhibited an increased proportion of pro-inflammatory IMs and elevated concentrations of G-CSF, GM-CSF, IL-3, IL-12, IL-13, IL-17A, and KC in the lung. These findings demonstrate that IMs and RMs play a critical role in controlling latent Mtb and preventing TB relapse.

Cefiderocol (CFDC) is a siderophore-conjugated cephalosporin that hijacks bacterial iron uptake pathways to traverse the outer membrane, offering potent activity against carbapenem-resistant Acinetobacter baumannii (CRAB). Although mutations in pirA, a TonB-dependent siderophore receptor, have been linked to CFDC resistance, the broader genetic basis remains poorly defined. Using Himar1 transposon mutagenesis in a CFDC-susceptible sequence type 2 (ST2) CRAB strain, we identified ten genes whose disruption reduced CFDC susceptibility, spanning siderophore-mediated uptake (pirA and puiA), oxidative and redox stress responses (oxyR, nfuA, aarF, cyoA, and bfmRS), and cell envelope morphogenesis (mreB). Most mutants retained wild-type susceptibility to other β-lactams, indicating that reduced CFDC susceptibility can arise independently of target modification. Quantification of cellular iron revealed modest reductions in several mutants, with the largest decreases observed in strains with disruptions in TonB-dependent receptors. Inactivation of pirA or puiA altered the expression of several alternative TonB-dependent siderophore receptors. Whole-genome sequencing of ST2 clinical isolates with reduced CFDC susceptibility uncovered mutations in TonB-dependent receptors, porins, and PBP3, along with increased β-lactamase expression. Importantly, the β-lactamase inhibitor avibactam restored CFDC susceptibility in isolates with β-lactamase upregulation and intact uptake pathways, whereas strains with concurrent uptake defects remained resistant, underscoring the interplay between permeability and enzymatic drug inactivation. These findings define a multifactorial resistance landscape integrating impaired uptake, redox and envelope stress adaptation, and β-lactamase-mediated drug inactivation.IMPORTANCECefiderocol (CFDC) is one of the few remaining antibiotics with activity against carbapenem-resistant Acinetobacter baumannii (CRAB), an urgent global health threat. Yet, resistance to CFDC is increasingly reported, and the underlying mechanisms remain incompletely defined. Most prior studies have examined single pathways, such as loss of TonB-dependent receptors. Here, we used genome-wide transposon mutagenesis together with genomic and phenotypic analysis of CFDC-resistant clinical isolates to generate a more comprehensive view of how resistance emerges. Our findings show that CFDC resistance is multifactorial, involving disrupted siderophore uptake, alterations in oxidative and envelope-stress responses, porin and cell-wall changes, and β-lactamase activity. By defining how these pathways converge, this work provides a broader mechanistic framework for interpreting emerging resistance in clinical settings. These insights underscore the need for integrated surveillance strategies and highlight the biological complexity that must be considered to preserve the effectiveness of this last-line antibiotic.

Mycobacterium abscessus (Mab) is a highly drug-resistant non-tuberculous mycobacterium that presents major treatment challenges, particularly in individuals with structural lung disease. Although historically considered ineffective, β-lactam antibiotics have gained renewed attention due to advances in β-lactamase inhibition and cell wall biology. This review synthesizes more than a decade of work, including in vitro susceptibility studies, biochemical characterization of Mab's β-lactamase (BlaMab) and peptidoglycans synthesis, and published clinical cases supporting the potential role of β-lactam-based regimens. We detail the enzymatic pathways involved in peptidoglycan cross-linking and the dual inhibition of D,D- and L,D-transpeptidases by select β-lactams, as well as the functional impact of inhibiting BlaMab. Novel β-lactamase inhibitors such as durlobactam may further enhance β-lactam efficacy. By integrating laboratory insights with clinical experience, this review provides a comprehensive perspective and informs ongoing efforts to design clinical trials repurposing β-lactam/β-lactamase inhibitor combinations.

Candida tropicalis is a leading cause of invasive candidiasis in the Asia-Pacific region with reported crude mortality rates exceeding 50%. The rising prevalence of azole-resistant strains presents a significant clinical challenge. We analyzed 1,016 C. tropicalis clinical isolates collected over nine years from 27 hospitals across North India. Fluconazole resistance was detected in 5.1% (n = 52) of isolates, with cross-resistance observed to voriconazole in 55.7% and itraconazole in 44.2% of isolates. Multilocus sequence typing (MLST) analysis of global 1,630 isolates including 208 Indian and whole-genome sequencing of 716 global isolates (139 Indian) confirmed the clonal emergence and persistence of azole-resistant MLST clade 4 strains in Indian hospitals. Phylogenomic analyses identified that Indian azole-resistant lineage was closely related to azole-resistant isolates from mainland China and Taiwan. The underlying mechanism of resistance involved hotspot mutations (Y132F) in the ERG11 gene along with its duplication, overexpression, and twofold high ergosterol content. Comparative transcriptomics of two clinical isolates exhibiting >512 fold difference in fluconazole susceptibility identified upregulation of virulence-associated genes, ALS7 gene (eightfold), SAP7 and SAP9 (1.6- and 2-fold, respectively) in azole-resistant isolate. Furthermore, azole-resistant isolates showed robust biofilm-associated metabolic activity (twofold), reduced β-glucan exposure, and greater survival in both neutrophil and macrophage killing assays. Notably, azole-resistant lineage exhibits several traits associated with adhesion and immune evasion that could possibly enable its spread in healthcare settings and signals the beginning of a greater spread of this clone. The urgent need for continuous genomic surveillance and antifungal stewardship is warranted to mitigate the spread of multidrug-resistant C. tropicalis.IMPORTANCEInvasive fungal infections affect 6.5 million people annually and are associated with high mortality rates. Despite being the leading cause of invasive yeast infections in the Asia-Pacific, this is the first comprehensive study of Candida tropicalis from India documenting the emergence of azole-resistant clonal lineage (clade 4) in several hospitals in India. Azole resistance is driven by mutations, gene duplication, and overexpression of its target gene ERG11. The Indian azole-resistant isolates showed high genetic relatedness with those from China. Also, resistant isolate showed overexpression of virulence-related genes and robust biofilm formation. Notably, reduced β-glucan exposure in fluconazole-resistant isolates may contribute to their decreased susceptibility to the innate immune system. Importantly, this study provides evidence for the emergence of azole-resistant C. tropicalis lineage in India, which exhibits several traits associated with adhesion and immune evasion that could possibly enable its spread in healthcare settings leading to a public health concern.