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In response to the escalating antibiotic resistance in multidrug-resistant pathogens, we propose an innovative phagemid-based capsid system to generate CRISPR-Cas13a-loaded antibacterial capsids (AB-capsids) for targeted therapy against multidrug-resistant Staphylococcus aureus. Our optimized phagemid system maximizes AB-capsid yield and purity, showing a positive correlation with phagemid copy number. Notably, an 8.65-fold increase in copy number results in a 2.54-fold rise in AB-capsid generation. Phagemids carrying terL-terS-rinA-rinB (prophage-encoded packaging site genes) consistently exhibit high packaging efficiency, and the generation of AB-capsids using lysogenized hosts with terL-terS deletion resulted in comparatively lower level of wild-type phage contamination, with minimal compromise on AB-capsid yield. These generated AB-capsids selectively eliminate S. aureus strains carrying the target gene while sparing non-target strains. In conclusion, our phagemid-based capsid system stands as a promising avenue for developing sequence-specific bactericidal agents, offering a streamlined approach to combat antibiotic-resistant pathogens within the constraints of efficient production and targeted efficacy. Phagemid-based capsid system delivers CRISPR-Cas13a to target MRSA, showing efficient packaging, minimal wild-type phage contamination, and specific bactericidal activity, providing a promising alternative to antibiotics. [ABSTRACT FROM AUTHOR]

In response to the escalating global threat of antimicrobial resistance, our laboratory has established a phagemid packaging system for the generation of CRISPR-Cas13a-antimicrobial capsids targeting methicillin-resistant Staphylococcus aureus (MRSA). However, a significant challenge arose during the packaging process: the unintentional production of wild-type phages alongside the antimicrobial capsids. To address this issue, the phagemid packaging system was optimized by strategically incorporated silent mutations. This approach effectively minimized contamination risks without compromising packaging efficiency. The study identified the indispensable role of phage packaging genes, particularly terL-terS, in efficient phagemid packaging. Additionally, the elimination of homologous sequences between the phagemid and wild-type phage genome was crucial in preventing wild-type phage contamination. The optimized phagemid-LSAB(mosaic) demonstrated sequence-specific killing, efficiently eliminating MRSA strains carrying target antibiotic-resistant genes. While acknowledging the need for further exploration across bacterial species and in vivo validation, this refined phagemid packaging system offers a valuable advancement in the development of CRISPR-Cas13a-based antimicrobials, shedding light on potential solutions in the ongoing battle against bacterial infections. [ABSTRACT FROM AUTHOR]

Purpose: New therapies are needed for relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma. This phase 1b, open-label trial evaluated two anti-CD20-based triplet combinations. Methods: Patients with R/R follicular lymphoma (FL; n = 13) were treated with obinutuzumab, atezolizumab, and polatuzumab vedotin (G-atezo-pola; 1.4 mg/kg/1.8 mg/kg) and patients with R/R diffuse large B-cell lymphoma (DLBCL; n = 23) received rituximab (R)-atezo-pola. The primary efficacy endpoint was complete response (CR) at end of induction (EOI) by PET-CT (investigator assessed; modified Lugano 2014 criteria). Safety endpoints were also assessed. Results: 13 FL patients were treated and evaluable for safety; 2/23 DLBCL patients did not receive treatment and were not included in the safety population. Median observation time was 23.3 and 5.7 months in the FL and DLBCL cohorts, respectively. At EOI, CR rates in FL patients treated with G-atezo-pola at pola doses of 1.4 mg/kg (N = 3) and 1.8 mg/kg (N = 7) were 33% and 14%, respectively. In DLBCL patients receiving R-atezo-pola, the CR rate at EOI was 13%. In the FL cohort, 62% of patients experienced a grade 3–5 adverse event (AE; including two deaths) and 31% developed a serious AE (SAE). In DLBCL patients, R-atezo-pola was associated with a lower incidence of grade 3–5 AEs (24%; one death) and SAEs (10%). In both cohorts, the most common grade 3–5 AEs were hematologic toxicities. Conclusion: Based on these safety issues, considered as related specifically to G-atezo-pola, and limited efficacy, no further development of either combination is planned. Trial registration: NCT02729896; Date of registration: April 6, 2016. [ABSTRACT FROM AUTHOR]

In this study, a simple and effective analytical method for the determination of 17 total amino acids in infant formula was established and validated. The procedure was based on microwave-assisted acid hydrolysis and conventional alkaline hydrolysis (only for tryptophan) prior to pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate and quantification using ultra-high-performance liquid chromatography (UHPLC) coupled with photodiode array (PDA) detector. For all amino acids examined, the satisfactory validation results, using certified reference material, were obtained with good linearity (R2 ≥ 0.9997), high precision (HorRat < 2), and acceptable accuracy (%R 98–104). The expanded measurement uncertainty for the analytical method were not exceeding 10%. The developed method was also successfully applied to real samples. In summary, the entire outcome indicated that this UHPLC-PDA method is sufficiently appropriate for its intended purpose and can be effectively used in routine analysis for further commercial products quality monitoring program. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial-resistant bacteria is an increasingly serious threat to global health, necessitating the development of innovative antimicrobials. Here we report the development of a series of CRISPR-Cas13a-based antibacterial nucleocapsids, termed CapsidCas13a(s), capable of sequence-specific killing of carbapenem-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus by recognizing corresponding antimicrobial resistance genes. CapsidCas13a constructs are generated by packaging programmed CRISPR-Cas13a into a bacteriophage capsid to target antimicrobial resistance genes. Contrary to Cas9-based antimicrobials that lack bacterial killing capacity when the target genes are located on a plasmid, the CapsidCas13a(s) exhibit strong bacterial killing activities upon recognizing target genes regardless of their location. Moreover, we also demonstrate that the CapsidCas13a(s) can be applied to detect bacterial genes through gene-specific depletion of bacteria without employing nucleic acid manipulation and optical visualization devices. Our data underscore the potential of CapsidCas13a(s) as both therapeutic agents against antimicrobial-resistant bacteria and nonchemical agents for detection of bacterial genes. CRISPR technology is emerging as a potential antimicrobial against antimicrobial-resistant bacteria. Here the authors develop a bacteriophage delivered Cas13a system for killing target bacteria and detecting bacterial genes. [ABSTRACT FROM AUTHOR]

Purpose: Mucositis is a significant complication of intensive chemotherapy or hematopoietic cell transplantation (HCT), with few treatment options. Ketamine mouthwashes have been used for pain relief, but supporting evidence is limited. The primary objective of this study was to assess the reduction in pain intensity of stomatodynia and odynophagia compared to baseline assessment.Methods: This open-label, prospective, phase II interventional study (NCT01566448) was conducted from February 2012 through July 2015. Patients with grade 3 or 4 oral mucositis according to the World Health Organization (WHO) scale as a result of chemotherapy were treated with ketamine mouthwash 20 mg/5 mL four times daily and every 4 h as needed.Results: Thirty patients were enrolled and a total of 136 assessments were conducted. A statistically significant reduction in pain scores of 2 and 3 points was achieved after 1 h and 3 days, respectively (p < 0.0001, p = 0.0003). Pain scores were significantly improved while swallowing, reduced 1 and 4 points at 1-h and 3-day assessment, respectively (p = 0.0006, p = 0.0001). No patients developed adverse effects related to ketamine administration.Conclusion: Ketamine mouthwashes resulted in clinically meaningful and statistically significant reduction in pain scores, have an acceptable safety profile, and can be a useful adjunctive treatment in the multi-modal management of severe mucositis. [ABSTRACT FROM AUTHOR]

Purpose: For an outpatient cancer center to operate efficiently, optimizing the use of chair time is essential. Allogeneic hematopoietic cell transplant (allo-HCT) recipients are seen frequently in this setting after hospital discharge and regularly for several months thereafter. Aggressive electrolyte replacement is commonly required in these patients, primarily due to renal wasting with calcineurin inhibitor use. Frequent intravenous (IV) magnesium repletion, requiring several hours of infusion time, is often needed in these patients to adequately manage their magnesium deficiencies. The purpose of this study is to explore the impact of extending the infusion rate of intravenous magnesium sulfate on the frequency and degree of IV magnesium replacements required in allo-HCT recipients.Methods: We conducted a retrospective study to compare two cohorts of patients administered IV magnesium sulfate at a rate of 4 g/1 h versus 4 g/2 h.Results: A total of 103 continuous patients were assessed in two groups as cohort 1 at the 4 g/1 h rate and cohort 2 at the 4 g/2 h rate. Cohort 1 required less IV magnesium per outpatient visit (median 2.2 vs. 2.9 g/visit, P = 0.0211) and less total IV magnesium replacement through day +100 (median 68 vs. 85 g, P = 0.0479) than cohort 2.Conclusion: These data suggest that there is no apparent benefit of prolonging magnesium infusion from 1 to 2 h in our outpatient allo-HCT population. [ABSTRACT FROM AUTHOR]

Autologous hematopoietic cell transplantation (AutoHCT) is a potentially curative treatment modality for relapsed/refractory Hodgkin lymphoma (HL). However, no large studies have evaluated pretransplant factors predictive of outcomes of AutoHCT in children, adolescents and young adults (CAYA, age <30 years). In a retrospective study, we analyzed 606 CAYA patients (median age 23 years) with relapsed/refractory HL who underwent AutoHCT between 1995 and 2010. The probabilities of PFS at 1, 5 and 10 years were 66% (95% confidence interval (CI): 62-70), 52% (95% CI: 48-57) and 47% (95% CI: 42-51), respectively. Multivariate analysis for PFS demonstrated that at the time of AutoHCT patients with Karnofsky/Lansky score ⩾90, no extranodal involvement and chemosensitive disease had significantly improved PFS. Patients with time from diagnosis to first relapse of <1 year had a significantly inferior PFS. A prognostic model for PFS was developed that stratified patients into low-, intermediate- and high-risk groups, predicting for 5-year PFS probabilities of 72% (95% CI: 64-80), 53% (95% CI: 47-59) and 23% (95% CI: 9-36), respectively. This large study identifies a group of CAYA patients with relapsed/refractory HL who are at high risk of progression after AutoHCT. Such patients should be targeted for novel therapeutic and/or maintenance approaches post-AutoHCT. [ABSTRACT FROM AUTHOR]

We describe 47 patients with lymphoma and failed prior autologous hematopoietic cell transplantation (HCT) who received TLI-ATG (anti-thymocyte globulin) conditioning followed by allogeneic HCT. Thirty-two patients had non-Hodgkin lymphoma (NHL; diffuse large B-cell lymphoma (n=19), T-cell NHL (n=6), mantle cell lymphoma (n=4) or other B-cell subtypes (n=3)), and 15 had Hodgkin lymphoma. The median follow-up was 4.9 (range, 2.1-11.9) years. The cumulative incidence of grade II-IV acute GvHD at day +100 was 12%, and the cumulative incidence of extensive chronic GvHD at 1 year was 36%. The 3-year cumulative incidences of overall survival (OS), PFS and non-relapse mortality (NRM) were 81%, 44% and 7%, respectively. Fifteen patients died (relapse, n=10; NRM, n=5). Among the 25 patients with relapse after allogeneic HCT, 11 (44%) achieved durable (>1 year) CRs following donor lymphocyte infusion or chemoradiotherapy. The majority of surviving patients (75%; n=24) were able to discontinue all immunosuppression. For patients with relapsed lymphoma after autologous HCT, allogeneic HCT using TLI-ATG conditioning is a well-tolerated, predominantly outpatient therapy with low NRM (7% at 3 years), a low incidence of GvHD, durable disease control and excellent OS (81% at 3 years). [ABSTRACT FROM AUTHOR]

Varicella-zoster virus (VZV) reactivation is a relatively common cause of morbidity following autologous hematopoietic cell transplant (auto-HCT). The Centers for Disease Control in 2009 recommended extending VZV prophylaxis for 1 year post-transplantation. We retrospectively analyzed rates of VZV reactivation following auto-HCT at our transplant center prior to and after the implementation of extended antiviral prophylaxis in June 2008. The study population was divided into three different cohorts according to the length of VZV prophylaxis as following: (1) prophylaxis until neutrophil recovery to ≥500/μL ( n = 77), (2) prophylaxis for 6 months ( n = 12), or (3) 12 months ( n = 40) post-auto-HCT. All patients received acyclovir 400 mg oral or intravenously twice daily or valacyclovir 500 mg oral daily. For patients in whom VZV reactivation occurred, data was collected on severity of infection, time of onset, treatment, and any associated complications. One hundred twenty-nine patients undergoing auto-HCT between January 1, 2004 and January 31, 2010 were included in the study. There was a significant difference in the rates of VZV reactivation between the neutrophil recovery and 12 months prophylaxis cohorts at 14 % ( n = 11) and 2 % ( n = 1) ( P = 0.04), respectively. VZV reactivation rate in the 6-month prophylaxis group was 17 % ( n = 2), but did not reach statistical significance due to small numbers. In the subset of auto-HCT patients treated with bortezomib, 13 % ( n = 2) developed VZV reactivation in the neutrophil recovery group, while no events occurred in the other two cohorts. Complications of VZV reactivation include post-herpetic neuralgia ( n = 5), severe pain ( n = 3), scarring ( n = 1), and motor weakness ( n = 1); two patients required hospitalization and three patients developed disseminated zoster. Our limited retrospective analysis suggests a significant reduction in rates of post-auto-HCT rates of VZV reactivation with extended 12 months antiviral prophylaxis. VZV reactivation is a significant complication post-auto-HCT, and extended prophylaxis appears to be safe and effective in this setting. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus strains that are susceptible to the β-lactam antibiotic oxacillin despite carrying mecA (OS-MRSA) cause serious clinical problems globally because of their ability to easily acquire β-lactam resistance. Understanding the genetic mechanism(s) of acquisition of the resistance is therefore crucial for infection control management. For this purpose, a whole-genome sequencing-based analysis was performed using 43 clinical OS-MRSA strains and 100 mutants with reduced susceptibility to oxacillin (MICs 1.0–256 µg/mL) generated from 26 representative OS-MRSA strains. Genome comparison between the mutants and their respective parent strains identified a total of 141 mutations in 46 genes and 8 intergenic regions. Among them, the mutations are frequently found in genes related to RNA polymerase (rpoBC), purine biosynthesis (guaA, prs, hprT), (p)ppGpp synthesis (relSau), glycolysis (pykA, fbaA, fruB), protein quality control (clpXP, ftsH), and tRNA synthase (lysS, gltX), whereas no mutations existed in mec and bla operons. Whole-genome transcriptional profile of the resistant mutants demonstrated that expression of genes associated with purine biosynthesis, protein quality control, and tRNA synthesis were significantly inhibited similar to the massive transcription downregulation seen in S. aureus during the stringent response, while the levels of mecA expression and PBP2a production were varied. We conclude that a combination effect of mecA upregulation and stringent-like response may play an important role in acquisition of β-lactam resistance in OS-MRSA. [ABSTRACT FROM AUTHOR]