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Biomedical subjects

Cheng Cheng

Publications and source records attributed to Cheng Cheng.

4 recordsLinked to original sources

Fate of antibiotic resistance genes during rural domestic wastewater treatment: Anaerobic unit as enrichment hotspot versus aerobic unit as attenuation zone.

Rural domestic wastewater treatment systems are important but understudied reservoirs for antibiotic resistance genes (ARGs), whose full-process migration mechanisms remain unclear. Herein, the contribution of each treatment unit of ARGs was investigated using metagenomic methods across two seasons in typical rural domestic wastewater treatment systems. Although a removal efficiency (69 % in winter and 22 % in summer) was observed for ARGs, higher antibiotic residues and temperature dramatically induced ARG occurrence in wastewater and horizontal gene transfer (HGT) risk during wastewater treatment. The ARG abundances in the anaerobic unit increased by 1.6-2.1 fold compared to the regulating pool, primarily driven by elevated mobile genetic element (MGE) activity. In sharp contrast, ARG reduction was achieved through ARG host removal and suppressed HGT potential in the aerobic unit. Notably, mobile ARGs were dominated by tetracycline resistance genes in winter and co-dominated by tetracycline and sulfonamide genes in summer, with most flanked by transposases. Key pathogenic hosts, including Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa carrying ARG-MGE complexes, were primarily concentrated in the regulating pool and the influent, forming high-risk upstream sources of dissemination. Partial least-squares path model highlighted MGEs as the primary drivers, and variance partitioning analysis indicated that MGEs account for 31 % of the explained variation in ARGs during wastewater treatment. In summary, the anaerobic unit was an ARG enrichment hotspot, while the aerobic unit as ARG attenuation zone during wastewater treatment. These findings provide crucial evidence to optimize rural wastewater treatment processes and to target the control of antibiotic resistance.

Wastewater

Hematological diseases-related mucormycosis: A retrospective single center study.

BACKGROUND AND AIM: Mucormycosis is a life-threatening invasive fungal infection. This study aimed to analyze the clinical characteristics of patients with hematologic malignancies complicated with mucormycosis. METHODS: This retrospective study investigated the clinical characteristics, epidemiological features, treatment, and prognosis of 46 patients with hematological diseases and Mucor infection as indicated by mNGS from August 28, 2020 to September 11, 2023. Metagenomic next-generation sequencing (mNGS) refers to the application of high-throughput sequencing technology for the comprehensive analysis of nucleic acid content in patient samples, facilitating the detection and characterization of microbial DNA and/or RNA, and then comparing and analyzing the results with an information database to determine the types of pathogenic microorganisms present in the sample. RESULTS: The median age of admission for the included patients was 49 years (9-78). Multivariate analysis identified age over 60 years (p&#x2009;=&#x2009;0.006&#x2009;<&#x2009;0.05), high-dose corticosteroids (p&#x2009;=&#x2009;0.001&#x2009;<&#x2009;0.05), neutropenia lasting more than 10 days (p&#x2009;=&#x2009;0.041&#x2009;<&#x2009;0.05), and two or more Mucor infections (p&#x2009;=&#x2009;0.004&#x2009;<&#x2009;0.05) were independent risk factors for OS in patients with hematological diseases. Moreover, differences between groups were analyzed using the Fisher exact probability method, and no significant difference was observed in the efficacy of various types of antifungal therapies. CONCLUSION: Patients with hematologic malignancies benefit greatly from early diagnosis and treatment when suspected of Mucor infection. mNGS is an important supplementary method for early diagnosis of Mucor infection. Moderated use of corticosteroids, reducing the duration of neutropenia, and enhancing autologous immune function are important measures to reduce patient mortality rate.

Retrospective Studies

AAV gene therapy for autosomal recessive deafness 9: a single-arm trial.

Gene therapy for congenital deafness has shown promising results in children but lacks data in older populations. We conducted a single-arm trial of adeno-associated virus (AAV)-OTOF gene therapy using the Anc80L65 capsid in ten participants with autosomal recessive deafness&#x2009;9 aged 1.5 to 23.9&#x2009;years at five sites in China. The primary endpoints were safety and tolerability within 5&#x2009;years, and secondary endpoints assessed auditory function. Initial findings from the ten patients with 6-12 months of follow-up, including one patient who received two injections, revealed that the therapy was well tolerated, with 162 grade&#x2009;I/II adverse events. Decreased neutrophil percentage was the most common event (16 of 162). All ten participants had at least 6&#x2009;months of follow-up and improved their pure-tone-average hearing level from baseline 106&#x2009;&#xb1;&#x2009;9 (mean&#x2009;&#xb1;&#x2009;s.d.) to 52&#x2009;&#xb1;&#x2009;30 decibels (dB). Other secondary endpoints showed similar improvements, including the average click auditory brainstem response (ABR) threshold, the tone-burst ABR threshold and the auditory steady-state response (101&#x2009;&#xb1;&#x2009;1 to 48&#x2009;&#xb1;&#x2009;26&#x2009;dB, 91&#x2009;&#xb1;&#x2009;4 to 57&#x2009;&#xb1;&#x2009;19&#x2009;dB and 80&#x2009;&#xb1;&#x2009;14 to 64&#x2009;&#xb1;&#x2009;21&#x2009;dB, respectively). Post hoc analyses were conducted to evaluate the timecourse and factors contributing to the hearing improvement. Therapeutic effect was rapid, taking 1&#x2009;month to achieve most of the overall hearing improvement. On an individual level, click and tone-burst ABR thresholds, but not the auditory steady-state response, reliably predicted the behavioral pure-tone-average thresholds after 4&#x2009;months (R2&#x2009;=&#x2009;0.68, 0.73 and 0.17, respectively). An age-dependent therapeutic effect was observed, with optimal outcomes in 5- to 8-year-olds. These preliminary results show that AAV-OTOF was safe and well tolerated in patients ranging from toddlerhood to adulthood. The trial remains ongoing and requires extended follow-up to confirm the long-term safety and efficacy. ClinicalTrials.gov registration: NCT05901480 .

Humans

Structure-activity relationships study on inhibition of CRISPR-Cas9 by glycosaminoglycans.

The CRISPR-Cas9 system is a revolutionary genome editing system known for its precision, simplicity and efficiency, playing a crucial role in gene-editing. It has enabled applications ranging from biomedicine to agriculture. However, the uncontrollable activity of Cas9 has raised significant safety concerns in clinical settings, limiting its broader application. Consequently, regulating CRISPR-Cas9 activity holds substantial promise for enhancing the safety and efficacy of gene-editing technologies. In this study, we demonstrated that sulfated glycosaminoglycans (GAGs) exhibit inhibitory effects of Cas9. Specifically, both chondroitin sulfate (CS) and heparin (HP) can inhibit CRISPR/Cas9 activity, with heparin showing a stronger inhibitory effect that correlates positively with its concentration. Molecular dynamics simulations indicate that sulfated heparin residues might inhibit Cas9 function by binding to essential DNA-binding sites, which are crucial for functional interactions, potentially impairing activity. Additionally, higher molecular weight GAGs exhibit enhanced inhibitory effects under the same sulphation. Notably, the sulfation site also influenced activity. C6-sulfation of chondroitin sulfate is more favorable for Cas9 inhibition, and N-sulfation of heparin enhances its inhibitory effect on Cas9 activity. These findings provide valuable insights into the development of carbohydrate-based inhibitors for CRISPR-Cas9, offering a foundation for further exploration in this field.

CRISPR-Cas Systems