Citations

ABSTRACT We compared the performance of two commercial antimicrobial susceptibility testing (AST) systems for contemporary Enterobacterales strains using broth microdilution (BMD) as the reference standard with 2022 Clinical and Laboratory Standards Institute or current FDA breakpoints applied. Enterobacterales clinical isolates with BMD results were tested in parallel using VITEK 2 AST test cards (N802, XN15, bioMérieux, Hazelwood, MO, USA) and MicroScan NM56 AST panels (Beckman Coulter, Sacramento, CA, USA). The 200 isolates (57 Escherichia coli , 55 Klebsiella pneumoniae , 21 Enterobacter cloacae complex, 18 Serratia marcescens , 12 Proteus mirabilis , 10 Citrobacter koseri , 9 Citrobacter freundii , 8 Klebsiella oxytoca , 5 Klebsiella aerogenes , 3 Providencia stuartii , and 2 Morganella morganii ) included 25% extended-spectrum beta-lactamase (ESBL), 23% carbapenem-resistant Enterobacterales (CRE), and 4.5% AmpC resistance phenotypes. For the 28 antimicrobial agents tested, essential agreement (EA, MIC within ±1 doubling dilution), categorical agreement (CA, same categorical interpretation: susceptible, intermediate, susceptible dose dependent, and resistant), and error rates were calculated using BMD as the reference standard. Time to results (TTR) was determined for each instrument for all 200 isolates. Hands-on time was assessed by timing two technologists each setting up six batches of five isolates on each system. Accuracy was similar between systems with an overall CA > 94% and EA ≥ 96%. The CA was ≥90% for most agents tested on both systems (exceptions were ampicillin-sulbactam, cefoxitin, minocycline, and nitrofurantoin). The MicroScan with Prompt inoculum preparation required less hands-on setup time than VITEK (1.29 vs 1.83 min/isolate). The median instrument TTR was less for VITEK (11.7 vs 18 hours, P < 0.001), yielding an overall faster turnaround time. IMPORTANCE There are limited data directly comparing the performance of commercial antimicrobial susceptibility testing systems for contemporary bacterial strains using the Clinical and Laboratory Standards Institute broth microdilution method as the reference standard and applying updated breakpoints. These data will hopefully encourage labs to perform the necessary verification or validation studies needed to implement current breakpoints and ensure antimicrobial resistance is detected.

ABSTRACT Achromobacter species can cause opportunistic infections which are difficult to treat due to a variety of antimicrobial resistance (AMR) mechanisms. As such, antimicrobial susceptibility testing (AST) is a cornerstone to successful treatment for these organisms. Currently, there are no specific Clinical and Laboratory Standards Institute (CLSI) AST guidelines for Achromobacter species. The purpose of this study was to (i) establish tentative CLSI M45 MIC and disk diffusion (DD) breakpoints (BPs), (ii) evaluate the modified carbapenem inactivation method (mCIM), and (iii) understand the mechanisms mediating AMR among Achromobacter species. Contemporary MIC data from multiple sources were collated to define the tentative epidemiological cutoff values (tECVs), and the MIC distributions were used to inform the establishment of MIC BPs for various agents. A disk-to-MIC correlate study with 91 isolates from across the United States was completed by testing reference broth microdilution and DD from the same inoculum and applying the dBETS software to establish DD BPs. Lastly, the mCIM and whole-genome sequencing (WGS) were pursued. The tECVs for piperacillin-tazobactam, imipenem, and meropenem were 1, 2, and 0.5 µg/mL, respectively. Disk correlates met CLSI M23 acceptance criteria with a few exceptions related to a small number of isolates, resulting in high minor errors. WGS revealed that 82 (90.1%) isolates harbored a bla OXA variant with bla OXA-114 predominating (90.2%). Nineteen isolates harbored acquired beta-lactamase genes, including 16 bla AXC , 2 bla VIM-4 , and 1 bla AZM-1. The mCIM had a sensitivity of 100% and specificity of 87%. Upon review, the CLSI M45 committee set tentative MIC and DD BPs for piperacillin-tazobactam, imipenem, meropenem, and trimethoprim-sulfamethoxazole. IMPORTANCE Achromobacter species can cause opportunistic infections which may be difficult to treat due to a variety of antimicrobial resistance mechanisms. Antimicrobial susceptibility testing is a critical component of patient treatment for these infections. Currently, the Clinical and Laboratory Standards Institute M100 non-Enterobacterales susceptibility test interpretive criteria and methodology are utilized for Achromobacter by clinical laboratories and likely do not accurately predict susceptibility results for Achromobacter species. This study was designed to establish tentative MIC and disk diffusion breakpoints specific to Achromobacter species.

ABSTRACTUniparental Disomy (UPD) occurs when both copies of a chromosome or chromosomal segment originate from only one parent. Mosaic genome‐wide UPD (mos gwUPD) is typically identified in cases of fetal demise and placental dysplasia or in prenatal cases, where imprinting effects are associated with abnormal ultrasound findings. Children with mos gwUPD and clinical features due to UPD‐associated imprinting effects (especially Beckwith‐Wiedemann syndrome) have been reported; however, reports of adults with mos gwUPD are rare. Here we describe mos gwUPD in two apparently healthy pregnant adult women. Carrier testing noted variants with skewed allelic ratios outside of the normal heterozygous range, prompting further testing. Single nucleotide polymorphism (SNP) microarray identified mosaicism for gwUPD in both individuals, present at 85% and 90%, respectively, in blood, with varying percentages in other tissues. Neither woman displayed clinical features that would be expected with gwUPD at the time of testing, although retrospective careful personal history was consistent. Both women had uneventful pregnancies and delivered full‐term healthy infants. These two cases demonstrate that mos gwUPD can be an incidental finding identified in apparently healthy adult women. Clinical follow‐up is important for tumor monitoring, genetic counseling, and monitoring of future pregnancies due to mos gwUPD in the maternal endometrial tissue.

Abstract Objective In utero fetal spina bifida repair decreases the risk for cerebrospinal fluid (CSF) diversion including ventriculoperitoneal (VP) shunt placement, reverses hindbrain herniation, and improves motor function with a higher likelihood of independent ambulation. Unfortunately, in utero surgery can be complicated by preterm delivery. The goal of this study was to compare pregnancy and neonatal outcomes between individuals who delivered very preterm, and those who delivered later in gestation following in utero spina bifida repair. Methods Data from the North American Fetal Therapy Network Fetal Myelomeningocele Consortium Registry collected from 2011 to 2024 were analyzed. Three cohorts of patients were categorized by gestational age at delivery and compared: <30 weeks, 30–34 weeks, and >34 weeks. Comparisons between groups for maternal and delivery outcomes were completed for the entire cohort and then analyzed for those with available CSF diversion data up to 1 year of life. Chi‐square or Fisher's exact tests were used to compare categorical variables, and Kruskal–Wallis tests were used to determine if there are significant differences between the distributions of the three groups. A p ‐value <0.05 was considered significant. Results A total of 1213 patients were analyzed (<30 weeks, n = 111 [9.2%]; 30–34 weeks, n = 323 [26.6%]; >34 weeks, n = 779 [64.2%]). Overall fetal and neonatal mortality was 2.2%, 85% of which occurred in the <30‐week cohort, where perinatal mortality was 21%. Latency from fetal surgery to delivery averaged 2.1 weeks for the <30‐week group. Rates of abruption, chorioamnionitis, and spontaneous labor were higher in the <30‐week group compared to later gestational age cohorts. Neonatal morbidity was also significantly higher in the <30‐week cohort for sepsis, apnea, respiratory distress, patent ductus arteriosus, intraventricular hemorrhage, and periventricular leukomalacia in the <30‐week cohort. CSF diversion data were available for 677 neonates (<30 weeks, n = 53; 30–34 weeks, n = 186; >34 weeks, n = 438). There was no significant difference in VP shunt placement between the different gestational age groups. Conclusion Very preterm birth following in utero spina bifida repair results in significant perinatal mortality and neonatal morbidity. Delivery prior to 30 weeks of gestation occurs in 9% of patients after in utero spina bifida repair, resulting in a 21% perinatal mortality rate. However, even among those who delivered very preterm, a reduction in VP shunt rates, a benefit of in utero repair, appears to be preserved. Further data are warranted to assess the impact of prematurity following in utero surgery on ambulation and developmental outcomes.

AbstractEndoscopic eradication therapy (EET) is recommended for the management of dysplastic Barrett’s esophagus (BE) and intramucosal adenocarcinoma. Both radiofrequency (RFA) and cryoballoon ablation (CBA) can induce complete remission of intestinal metaplasia (CRIM). We aimed to compare long-term durability following CRIM in patients treated with RFA vs. CBA.We conducted a retrospective cohort study to analyze patient outcomes following EET with RFA or CBA at two referral centers. We measured and compared the recurrence rate of BE, with or without dysplasia, after CRIM, using Cox proportional hazard models and propensity score-matched analyses. Our secondary aim was to identify predictors of recurrence.681 patients who achieved CRIM were included (RFA 610; CBA 71), with median follow-up of 4.1 years and 4.4 years following RFA and CBA, respectively. A multivariable model revealed a higher risk of any recurrence with RFA (hazard ratio [HR] 2.19, 95%CI 1.18–4.06; P = 0.01), but not dysplastic recurrence (HR 0.88, 95%CI 0.39–1.97; P = 0.75). However, a comparable risk of “any recurrence” was observed after excluding intestinal metaplasia of the gastroesophageal junction (HR 1.18, 95%CI 0.61–2.30; P = 0.62). Propensity score-matched analysis (54 cases in each group) showed that the two groups had comparable recurrence risk. Baseline maximum BE length was associated with a higher risk of any recurrence (HR 1.07; P<0.001) and dysplastic recurrence (HR 1.11; P = 0.001).The rates of any BE recurrence and dysplastic recurrence were comparable with the two modalities in this nonrandomized study.

ABSTRACT Complement protein 3 (C3) glomerulopathy (C3G) is a rare and progressive kidney disease primarily affecting young individuals and frequently advancing to end-stage kidney disease (ESKD). For ESKD, kidney transplantation remains the optimal treatment option; however, C3G has a high recurrence rate post-transplantation, affecting over two-thirds of transplanted patients. Despite advances in our understanding of C3G, significant gaps persist regarding the optimal timing for transplantation and the best strategies for peri-transplant management. Currently, no clear evidence links functional complement levels to the risk of post-transplant recurrence. Genetic counseling is also complex, due to variable gene penetrance and weak genotype–phenotype correlations, which limit predictive accuracy. Transplant-related factors are believed to significantly influence C3G recurrence, yet there are no established methods for preventing recurrence after transplantation. Eculizumab has shown inconsistent efficacy in managing recurrent C3G. However, new proximal complement inhibitors, such as factor B and C3 inhibitors, are under investigation in clinical trials and show promise. Some of these trials include kidney transplant patients with C3G, and their outcomes could potentially shape future treatment protocols.

Abstract O.A. Shariq: None. K.E. Lines: None. K.A. English: None. I. Rioja: Employee; Self; GlaxoSmithKline. A. Selberherr: None. H. Ferry: None. A.L. Oberg: None. R. Prinjha: Employee; Self; GlaxoSmithKline. D. Richards: None. R.V. Thakker: None. Background: Effective treatments for metastatic pancreatic neuroendocrine tumors (PNETs) are scarce. We previously showed that inhibiting bromodomain and extra-terminal (BET) epigenetic reader proteins via non-selective targeting of their two bromodomains (BD1 and BD2) reduces proliferation in preclinical PNET models. However, the clinical relevance of BET proteins in PNETs and functional differences between BD1/BD2 are unclear. Here, we characterised BET expression in human PNETs and performed efficacy and mechanistic studies using next-generation BD1- (BD1i) and BD2-selective (BD2i) BET inhibitors. Methods: BET expression was evaluated by immunohistochemistry in functioning and non-functioning human PNETs (n=52) vs normal adjacent islets (n=18). RNA sequencing (RNA-seq) and gene set enrichment analyses (GSEA) were performed in an independent PNET cohort (n=46) to identify biological pathways upregulated in metastatic vs non-metastatic tumors. Effects of BD1i and BD2i on viability, apoptosis, and cell cycle progression were assessed in three PNET cell lines (BON1, QGP1, MIN6). Early (6h) and late (48h) transcriptional responses to BET inhibition were examined in vitro using nascent RNA-seq (SLAM-seq) and standard RNA-seq, respectively. Epigenomic responses were explored using chromatin immunoprecipitation sequencing (ChIP-seq) for the histone mark H3K27ac. Effects of BD1i and BD2i on viability were evaluated in ex vivo neoplastic pancreatic islets derived from Men1L/L/RIP2-Cre mice. Results: BET proteins (BRD2, BRD3 and BRD4) were overexpressed by 1.5-2.5-fold in human PNETs vs islets (p&lt;0.01). GSEA showed enrichment of BET-regulated gene sets in metastatic tumors (normalized enrichment score 1.31, adjusted p=0.04). BD2i marginally affected cell viability (IC50 55-90 µM), apoptosis, and cell cycle profile, while BD1i had a moderate impact on all phenotypes (IC50 1-1.5 µM). Synergistic effects were observed when BD1i+BD2i were combined (IC50 0.2-0.5 µM). RNA-seq and SLAM-seq revealed transcriptional changes that were minimal with BD2i (n=73 and n=10 differentially expressed genes, respectively), modest with BD1i (n=354 and n=60 genes), and greatest with BD1i+BD2i combined (n=1739 and n=375 genes). ChIP-seq showed a reduction in H3K27ac enrichment at promoters and super-enhancers of genes involved in BET protein-regulated pathways (e.g. cell cycle progression), with the greatest decrease observed with BD1i+BD2i combined. In ex vivo cultured neoplastic islets, viability was reduced by &lt;30% with BD2i (p&lt;0.005), ∼40% with BD1i (p&lt;0.0001), and ∼60% with BD1i+BD2i (p&lt;0.0001). Conclusions: Our studies confirm BET proteins as clinically-relevant targets in human PNETs and show that dual (BD1+BD2) inhibition has synergistic efficacy. These findings have important implications for the clinical application of next-generation epigenetic modulators. Sunday, June 2, 2024

Abstract J.A. McNeil: None. J. Herndon: None. A.Y. Chang: None. C.J. Davidge-Pitts: None. O. Hamidi: None. Background: Testosterone therapy (TT) in individuals assigned female at birth (AFAB) is linked to an atherogenic lipid profile, including lower HDL cholesterol, elevated triglycerides, and LDL cholesterol. Polycystic ovary syndrome (PCOS), characterized by androgen excess, affects 16-20% of cisgender individuals AFAB. Recent data suggests a greater PCOS prevalence in transmasculine transgender/gender diverse (TGD) individuals at 23.8% to 38.8%. Whether TT in AFAB individuals with history of PCOS triggers more adverse metabolic changes than in TGD individuals without PCOS remains uncertain. While cohort studies haven't indicated increased cardiovascular (CV) risk with TT, it's unclear if specific subgroups, such as those with PCOS, develop more CV risk factors. Objective: To compare the effects of TT on CV risk factors in TGD individuals with a history of PCOS vs. TGD without PCOS. Methods: We retrospectively reviewed 454 records in a multispecialty TGD clinic to identify 62 with PCOS, and 132 controls without PCOS (1:2 case-control ratio) matched on age. Data included longitudinal vital signs, metabolic profiles, and details on psychiatric and medical conditions. PCOS diagnosis was validated using Rotterdam criteria. Exclusions comprised individuals under 14, those on puberty-suppressing gonadotropin-releasing hormone analogues, or already undergoing TT at the initial visit. Results: Among 454 subjects, 62 (13.7%) were diagnosed with PCOS. At baseline, PCOS was associated with significantly higher BMI (p &lt; 0.01), SBP (p = 0.01), prevalence of obesity (p &lt; 0.01), obstructive sleep apnea (OSA, p &lt; 0.01), and type 2 diabetes mellitus (p = 0.01). History of PCOS was associated with greater metformin use (p &lt; 0.001), CV disease history (p = 0.003), and transaminitis (p = 0.03). After weight adjustment, only baseline metformin use differed significantly between PCOS and controls. 140 (72.2%) received TT, 50 (80.6%) with PCOS and 90 (68.2%) controls. After weight adjustment, notable baseline changes in ALT (p = 0.006), HDL (p &lt; 0.001), LDL (p &lt; 0.001), hypertension, and hypertriglyceridemia prevalence (p=0.001) were observed in the full cohort on TT. Compared to controls, PCOS patients on TT exhibited higher hypercholesterolemia prevalence (p = 0.03) and elevated bioavailable testosterone (p = 0.04) after weight correction. Conclusions: TGD Individuals with PCOS had significantly worse CV risk profile compared to controls before starting TT attributed to greater weight. Significant changes in ALT, LDL, HDL, and prevalence of hypertriglyceridemia were seen across the entire TGD cohort treated with TT, but only hypercholesterolemia prevalence remained significantly higher in TGD PCOS cases on TT when corrected for weight. PCOS history was not associated with greater changes in CV risk factors in TGD individuals starting TT. Sunday, June 2, 2024