Landscape of plasmids encoding β-lactamases in disinfection residual Enterobacteriaceae from wastewater treatment plants

Conventional disinfection processes, such as chlorination and UV radiation, are ineffective in controling antibiotic-resistant bacteria, especially disinfection residual Enterobacteriaceae (DRE) encoding β-lactamases, some of which have been classified as "critical priority pathogens" by the World Health Organization. However, few studies have focused on the transferability, phenotype, and genetic characteristics of DRE-derived plasmids encoding β-lactamases, especially extended-spectrum β-lactamases and carbapenemases. In this study, we isolated 10 typical DRE harboring plasmid-mediated blaNDM, blaCTX-M, or blaTEM in post-disinfection effluent from two wastewater treatment plants (WWTPs), with transfer frequency ranging from 1.69 × 10-6 to 3.02 × 10-5. According to genomic maps of plasmids, all blaNDM and blaTEM were cascaded with IS26, and blaCTX-M was adjacent to ISEcp1 or IS26, indicating the important role of these elements in the movement of β-lactamase-encoding genes. The presence of intact class 1 integrons on pWTPN-01 and pWTPC-03 suggested the ability of these DRE-derived plasmids to integrate other exogenous antibiotic resistance genes (ARGs). The coexistence of antibiotic, disinfectant, and heavy metal resistance genes on the same plasmid (e.g., pWTPT-03) implied the facilitating role of disinfectants and heavy metals in the transmission of DRE-derived ARGs. Notably, two plasmid transconjugants exhibited no discernible competitive fitness cost, suggesting a heightened environmental persistence. Furthermore, enhanced virulence induced by β-lactamase-encoding plasmids in their hosts was confirmed using Galleria mellonella infection models, which might be attributed to plasmid-mediated virulence genes. Overall, this study describes the landscape of β-lactamase-encoding plasmids in DRE, and highlights the urgent need for advanced control of DRE to keep environmental and ecological security.

Ranking the risk of antibiotic resistance genes by metagenomic and multifactorial analysis in hospital wastewater systems

Antimicrobial resistance poses a serious threat to human health. Hospital wastewater system (HWS) is an important source of antibiotic resistance genes (ARGs). The risk of ARGs in HWS is still an under-researched area. In this study, we collected publicly metagenomic datasets of 71 hospital wastewater samples from 18 hospitals in 13 cities. A total of 9838 contigs were identified to carry 383 unique ARGs across all samples, of which 2946 contigs were plasmid-like sequences. Concurrently, the primary hosts of ARGs within HWS were found to be Escherichia coli and Klebsiella pneumoniae. To further evaluate the risk of each ARG subtype, we proposed a risk assessment framework based on the importance of corresponding antibiotics as defined by the WHO and three other indicators - ARG abundance (A), mobility (M), and host pathogenicity (P). Ninety ARGs were identified as R1 ARGs having high-risk scores, which meant having a high abundance, high mobility, and carried by pathogens in HWS. Furthermore, 25% to 49% of genomes from critically important pathogens accessed from NCBI carried R1 ARGs. A significantly higher number of R1 ARGs was carried by pathogens in the effluents of municipal wastewater treatment plants from NCBI, highlighting the role of R1 ARGS in accelerating health and environmental risks.

Antibiotic resistance genes alterations in murine guts microbiome are associated with different types of drinking water

Antibiotic resistance genes (ARGs) are emerging contaminants threatening public health and commonly found in drinking water. However, the effect of different types of drinking water on ARG alterations in the gut microbiome is unclear. This study examines this issue in murine models in three phases (phase I: acclimation using ddH2O; phase II: treatment using different types of water, i.e. river water (RW), tap water (TW) and commercial bottled water (CBW); and phase III: recovery using ddH2O) using high-throughput qPCR and 16S rRNA amplicon sequencing. Results reveal that exposure to different types of drinking water could lead to significant changes in the gut microbiome, mobile genetic elements (MGEs), and ARGs. In phase II, treatment of RW and TW significantly increased the abundance of aminoglycoside and tetracycline resistance genes in mice guts (P < 0.01). In the recovery phase, consuming distilled water was found to restore ARG profiles to a certain extent in mice guts. Procrustes, network, redundancy and variation partitioning analysis indicated that ARG alterations in mice guts might relate to MGEs and bacterial communities. Our work suggests that the type of drinking water consumed may play a crucial role in shaping ARGs in gut microbiomes, emphasizing the urgent need for access to clean drinking water to mitigate the growing threat of antimicrobial resistance.

Bacteriophages: Vectors of or weapons against the transmission of antibiotic resistance genes in hospital wastewater systems?

Antimicrobial resistance poses a serious threat to human health and is responsible for the death of millions of people annually. Hospital wastewater is an important hotspot for antibiotic-resistance genes (ARGs) and antibiotic-resistant bacteria (ARB). However, little is known about the relationship between phages and ARGs in hospital wastewater systems (HWS). In the present study, the viral diversity of 12 HWSs using data from public metagenomic databases was investigated. Viruses were widely found in both the influent and effluent of each HWS. A total of 45 unique ARGs were carried by 85 viral contigs, which accounted for only 0.14% of the total viral populations, implying that ARGs were not commonly present in phages. Three efflux pump genes were identified as shared between phages and bacterial genomes. However, the predominant types of ARGs in HWS such as aminoglycoside- and beta-lactam-resistance genes were rarely found in phages. Based on CRISPR spacer and tRNA matches, interactions between 171 viral contigs and 60 antibiotic-resistant genomes were predicted, including interactions involving phages and vancomycin-resistant Enterococcus_B faecium or beta-lactam-resistant Klebsiella pneumoniae. More than half (56.1%) of these viral contigs indicated lytic and none of them carried ARGs. As the vOTUs in this study had few ARGs and were primarily lytic, HWS may be a valuable source for phage discovery. Future studies will be able to experimentally validate these sequence-based results to confirm the suitability of HWS phages for pathogen control measures in wastewater.

[Clinical characteristics and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia arising from malignant tumors]

Objective: To investigate the clinical characteristics, cytogenetics, molecular biology, treatment, and prognosis of patients with therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) secondary to malignancies. Methods: The clinical data of 86 patients with t-MDS/AML in West China Hospital of Sichuan University between January 2010 and April 2023 were retrospectively analyzed. The clinical characteristics, primary tumor types, and tumor-related therapies were analyzed. Results: The study enrolled a total of 86 patients with t-MDS/AML, including 67 patients with t-AML, including 1 patient with M(0), 6 with M(1), 27 with M(2), 9 with M(3), 12 with M(4), 10 with M(5), 1 with M(6), and 1 with M(7). Sixty-two patients could be genetically stratified, with a median overall survival (OS) of 36 (95% CI 22-52) months for 20 (29.9%) patients in the low-risk group and 6 (95% CI 3-9) months for 10 (14.9%) in the intermediate-risk group. The median OS time was 8 (95% CI 1-15) months in 32 (47.8%) patients in the high-risk group. For patients with non-acute promyelocytic leukemia (APL) and AML, the median OS of the low-risk group was 27 (95% CI 18-36) months, which was significantly longer than that of the non-low-risk group (χ(2)=5.534, P=0.019). All 9 APL cases were treated according to the initial treatment, and the median OS was not reached, and the 1-, 2-, and 3-year OS rates were 100.0%, (75.0±6.2) %, and (75.0±6.2) % respectively. Of the 58 patients with non-APL t-AML (89.7%), 52 received chemotherapy, and 16 achieved complete remission (30.8%) after the first induction chemotherapy. The 1-, 2-, and 3-year OS rates of the non-APL t-AML group were (42.0 ± 6.6) %, (22.9±5.7) %, and (13.4±4.7) %, respectively. The median OS of patients who achieved remission was 24 (95% CI 18-30) months, and the median OS of those who did not achieve remission was 6 (95% CI 3-9) months (χ(2)=10.170, P=0.001). Bone marrow CR was achieved in 7 (53.8%) of 13 patients treated with vineclar-containing chemotherapy, with a median OS of 12 (95% CI 9-15) months, which was not significantly different from that of vineclar-containing chemotherapy (χ(2)=0.600, P=0.437). In 19 patients with t-MDS, the 1-, 2-, and 3-year OS rates were (46.8±11.6) %, (17.5±9.1) %, and (11.7±9.1) % with a median OS of 12 (95% CI 7-17) months, which was not significantly different from that in t-AML (χ(2)=0.232, P=0.630) . Conclusions: Breast cancer, bowel cancer, and other primary tumors are common in patients with t-MDS/AML, which have a higher risk of adverse genetics. Patients with APL had a high induction remission rate and a good long-term prognosis, whereas patients without APL had a low remission rate and a poor long-term prognosis.

Association between particulate matter (PM)2·5 air pollution and clinical antibiotic resistance: a global analysis

BACKGROUND

Antibiotic resistance is an increasing global issue, causing millions of deaths worldwide every year. Particulate matter (PM)2·5 has diverse elements of antibiotic resistance that increase its spread after inhalation. However, understanding of the contribution of PM2·5 to global antibiotic resistance is poor. Through univariate and multivariable analysis, we aimed to present the first global estimates of antibiotic resistance and burden of premature deaths attributable to antibiotic resistance resulting from PM2·5 pollution.

METHODS

For this global analysis, data on multiple potential predictors (ie, air pollution, antibiotic use, sanitation services, economics, health expenditure, population, education, climate, year, and region) were collected in 116 countries from 2000 to 2018 to estimate the effect of PM2·5 on antibiotic resistance via univariate and multivariable analysis. Data were obtained from ResistanceMap, European Centre for Disease Prevention and Control Surveillance Atlas (antimicrobial-resistance sources), and PLISA Health Information Platform for the Americas. Future global aggregate antibiotic resistance and premature mortality trends derived from PM2·5 in different scenarios (eg, 50% reduced antibiotic use or PM2·5 controlled to 5 μg/m3) were projected until 2050.

FINDINGS

The final dataset included more than 11·5 million tested isolates. Raw antibiotic-resistance data included nine pathogens and 43 types of antibiotic agents. Significant correlations between PM2·5 and antibiotic resistance were consistent globally in most antibiotic-resistant bacteria (R2=0·42-0·76, p<0·0001), and correlations have strengthened over time. Antibiotic resistance derived from PM2·5 caused an estimated 0·48 (95% CI 0·34-0·60) million premature deaths and 18·2 (13·4-23·0) million years of life lost in 2018 worldwide, corresponding to an annual welfare loss of US$395 (290-500) billion due to premature deaths. The 5 μg/m3 target of concentration of PM2·5 in the air quality guidelines set by WHO, if reached in 2050, was estimated to reduce antibiotic resistance by 16·8% (95% CI 15·3-18·3) and avoid 23·4% (21·2-25·6) of premature deaths attributable to antibiotic resistance, equivalent to a saving of $640 (580-671) billion.

INTERPRETATION

This analysis is the first to describe the association between PM2·5 and clinical antibiotic resistance globally. Results provide new pathways for antibiotic-resistance control from an environmental perspective.

FUNDING

National Natural Science Foundation of China, Fundamental Research Funds for the Central Universities, Zhejiang University Global Partnership Fund, and China Postdoctoral Science Foundation.

3D ZnO/Activated Carbon Alginate Beads for the Removal of Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes

The worldwide prevalence of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have become one of the most urgent issues for public health. Thus, it is critical to explore more sustainable methods with less toxicity for the long-term removal of both ARB and ARGs. In this study, we fabricated a novel material by encapsulating zinc oxide (ZnO) nanoflowers and activated carbon (AC) in an alginate biopolymer. When the dosage of ZnO was 1.0 g (≈2 g/L), the composite beads exhibited higher removal efficiency and a slight release of Zn²⁺ in water treatment. Fixed bed column experiments demonstrated that ZnO/AC alginate beads had excellent removal capacities. When the flow rate was 1 mL/min, and the initial concentration was 10⁷ CFU/mL, the removal efficiency of ARB was 5.69-log, and the absolute abundance of ARGs was decreased by 2.44-2.74-log. Moreover, the mechanism demonstrated that ZnO significantly caused cell lysis, cytoplasmic leakage, and the increase of reactive oxygen species induced subsequent oxidative stress state. These findings suggested that ZnO/AC alginate beads can be a promising material for removing ARB and ARGs from wastewater with eco-friendly and sustainable properties.

Modified transcrestal sinus floor elevation with concomitant implant placement in edentulous posterior maxillae with residual bone height of 5 mm or less: a non-controlled prospective study

The aim of this study was to describe a modified transcrestal sinus floor elevation (mTSFE) technique and to evaluate its clinical effectiveness and reliability when residual bone height is severely reduced. Forty-three maxillary edentulous patients who met the inclusion criteria were enrolled. All patients underwent the mTSFE technique; 66 dental implants were inserted simultaneously. Patient-reported outcomes were assessed 2 weeks after surgery. Prosthetic crowns were placed 6 months after surgery. Radiographic analyses and clinical analyses were conducted to assess the clinical effectiveness and feasibility of mTSFE during a follow-up period of 2-8 years. The mean vertical bone increase after surgery was 8.09 mm, and it decreased to 6.56 mm at 6 months after surgery. Two cases of membrane perforation occurred during surgery and one implant was lost in the third year after surgery; the survival rate at the implant level was 98.48%. No severe postoperative complication was reported and the subjective feeling of patients was acceptable. This mTSFE technique could simplify the operative procedure and might be helpful to reduce intraoperative trauma, as well as to alleviate postoperative discomfort.

Epidemiological Characteristics and Influencing Factors of Myopia Among Primary School Students in Southern China: A Longitudinal Study

Objectives: To study the epidemiological characteristics and influencing factors of myopia to provide a scientific basis for the prevention and control of myopia. Methods: 7,597 students studying in grades 1-3 were followed up. Eye examinations and questionnaire surveys were conducted annually from 2019 to 2021. The influencing factors of myopia were analyzed by logistic regression model. Results: The prevalence of myopia among students in grades 1-3 in 2019 was 23.4%, which increased to 41.9% and 51.9% after the 1-and 2-year follow-up, respectively. The incidence of myopia and change in the spherical equivalent refraction (SER) were higher in 2020 than in 2021. The 2-year cumulative incidences of myopia were 2.5%, 10.1%, 15.5%, 36.3%, and 54.1% in students with a baseline SER >+1.50D, +1.00D to +1.50D, +0.50D to +1.00D, 0.00D to +0.50D, and -0.50D to 0.00D, respectively. Outdoor activities, sex, age, baseline SER, parental myopia, sleep time, and digital device exposure were associated with myopia. Conclusion: The prevalence of myopia demonstrated a rapid increase; thus, healthy habits and outdoor activities should be promoted for the prevention and control of myopia.

Short-term inhalation exposure evaluations of airborne antibiotic resistance genes in environments

Antibiotic resistance is a sword of Damocles that hangs over humans. In regards to airborne antibiotic resistance genes (AARGs), critical knowledge gaps still exist in the identification of hotspots and quantification of exposure levels in different environments. Here, we have studied the profiles of AARGs, mobile genetic elements (MGEs) and bacterial communities in various atmospheric environments by high throughput qPCR and 16S rRNA gene sequencing. We propose a new AARGs exposure dose calculation that uses short-term inhalation (STI). Swine farms and hospitals were high-risk areas where AARGs standardised abundance was more abundant than suburbs and urban areas. Additionally, resistance gene abundance in swine farm worker sputum was higher than that in healthy individuals in other environments. The correlation between AARGs with MGEs and bacteria was strong in suburbs but weak in livestock farms and hospitals. STI exposure analysis revealed that occupational intake of AARGs (via PM₁₀) in swine farms and hospitals were 110 and 29 times higher than in suburbs, were 1.5 × 10⁴, 5.6 × 10⁴ and 5.1 × 10² copies, i.e., 61.9%, 75.1% and 10.7% of the overall daily inhalation intake, respectively. Our study comprehensively compares environmental differences in AARGs to identify high-risk areas, and forwardly proposes the STI exposure dose of AARGs to guide risk assessment.

Research trends and hotspots in the relationship between outdoor activities and myopia: A bibliometric analysis based on the web of science database from 2006 to 2021

Objectives

This study aimed to explore the current status, hotspots, and emerging research trends regarding the relationship between outdoor activities and myopia.

Methods

Publications on the relationship between outdoor activities and myopia from 2006 to 2021 were collected from the Web of Science Core Collection database. CiteSpace (version 6.1.R2) was used to performed a bibliometric analysis, and R software (version 4.1.0) was used to visualize the trends and hot map of publications.

Results

A total of 640 publications were collected and analyzed in the present study. China was the major contributor (n = 204), followed by the United States of America (n = 181) and Australia (n = 137). The United States of America had the most extensive foreign cooperation (centrality = 0.25), followed by Australia (centrality = 0.20). The National University of Singapore contributed the largest number of publications (n = 48), followed by Sun Yat-Sen University (n = 41) and the Australian National University (n = 41). Among institutions, Cardiff University in the United Kingdom had the most extensive foreign cooperation (centrality = 0.12), followed by the National University of Singapore (centrality = 0.11). Saw S from Singapore had the largest number of publications (n = 39), followed by Morgan I from Australia (n = 27) and Jonas J from Germany (n = 23). Investigative ophthalmology & visual science is the most important journal to study the relationship between outdoor activities and myopia. "Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050" published by Holden BA was the most cited paper in this field with 177 citations. Co-occurrence and burst analyses of keywords showed that research trends and hotspots in this field focused mainly on "risk," "prevention" and "school".

Conclusions

The influence of outdoor activities on myopia remains a concern. In the future, deeper cooperation between countries or institutions is required to explore the effects of outdoor activities on myopia. Outdoor activities for the prevention of myopia and reduction of the risk of myopia among school students may be the focus of future research.

Trends in Myopia Development Among Primary and Secondary School Students During the COVID-19 Pandemic: A Large-Scale Cross-Sectional Study

Objectives

To evaluate myopia development among primary and secondary school students during the coronavirus 2019 (COVID-19) pandemic.

Methods

A cross-sectional study was conducted to evaluate the development of myopia among students in Shenzhen, China during the COVID-19 outbreak.

Results

The study included 1,472,957 and 1,573,824 students in 2019 and 2020, respectively. The prevalence of myopia was 46.9 and 50.5% in 2019 and 2020, respectively. The prevalence of myopia among students in the former Shenzhen Special Economic Zone (SEZ) was higher than that in areas outside the former Shenzhen SEZ (2019: 47.0 vs. 43.7%; 2020: 50.5 vs. 47.3%). The prevalence of myopia among girls was higher than that among boys (2019: 50.4 vs. 44.0%; 2020: 54.0 vs. 47.6%). The 50th percentile (P50) of spherical equivalent refraction (SER) in the right eye among girls was lower than that in boys. The prevalence of myopia continued to increase as the grade increased, with the greatest annual increase observed in Grades 2–5 (3.4–3.9%). The P50 of SER in the right eye of students decreased as the grade increased.

Conclusions

The prevalence of myopia among students increased during the COVID-19 pandemic, especially in primary school Grades 2–5.

Mechanisms underlying the effect of chlorination and UV disinfection on VBNC state Escherichia coli isolated from hospital wastewater

The occurrence of viable but non-culturable (VBNC) bacteria in the wastewater system poses a huge threat to environmental and public health, in particular in hospital wastewater treatment system (HWTS). HWTS-oriented studies have been conducted to assess the effectiveness of chlorination and UV disinfection using indigenous bacteria. Results revealed that the VBNC Escherichia coli and ARGs remained persistent even at high chlorination (12 mg/L for 2.5 h) and UV doses (1000 mJ/cm²). The molecular mechanisms underlying chlorination-/UV-induced VBNC state in E. coli were explored through the transcriptomics and results suggested that most energy-dependent physiological activities (e.g., metabolism) have been suppressed in VBNC E. coli, while the pathogenicity-related genes varied insignificantly compared to the culturable cells, indicating that the VBNC E. coli could potentially display pathogenicity. Further Galleria mellonella model experiment has confirmed that although the disinfection-induced VBNC state made cells less infectious, these cells could regain their pathogenicity after resuscitation. This in vitro study can be used as a reference for studies on infections from VBNC bacteria and highlights the health risk due to VBNC pathogens in hospital effluents. There is a need to develop effluent standards specifically for healthcare facilities, and a stricter downstream disinfection strategy should be considered for the removal of VBNC cells and ARGs in the effluent.

The accuracy of the axial length and axial length/corneal radius ratio for myopia assessment among Chinese children

OBJECTIVES

The aim of this study was to assess the association between axial length/corneal radius ratio (AL/CR ratio), AL, and refractive status and evaluate the accuracy of AL and AL/CR ratio for myopia assessment among Chinese children.

METHODS

A diagnostic trial was conducted in Shenzhen Eye Hospital from June 2020 to December 2020. Cycloplegic refraction and demographic characteristic survey were carried out, and AL and CR were measured. The Pearson correlation analysis between AL, AL/CR ratio, and spherical equivalent (SE) was carried out. The sensitivity, specificity, Youden index, positive predictive value, and negative predictive value of the AL/CR ratio and AL for myopia assessment were analyzed using cycloplegic refraction as the gold standard by drawing receiver operating characteristic (ROC) curves.

RESULTS

A total of 300 children aged 8-18 years participated in this study. The Pearson correlation coefficient between AL and SE was -0.667 (P < 0.05) and -0.754 (P < 0.05) between AL/CR ratio and SE. There were significant differences in SE, AL, and AL/CR ratio among different age groups (p < 0.05). SE decreased by 1.185 diopter (D) for every 1 mm increase in AL and decreased by 0.667 D for every 0.1 increase in the AL/CR ratio. Taking cycloplegic refraction SE ≤ -0.50 D as the gold standard for the diagnosis of myopia, the area under the ROC curve of AL for myopia assessment was 0.836 (95% confidence interval [CI]: 0.767-0.906), with specificity, sensitivity, and Youden index of 0.833, 0.767, and 0.600, respectively. The area under the ROC curve of AL/CR ratio for myopia assessment was 0.937 (95% CI: 0.878-0.996), with specificity, sensitivity, Youden index, positive predictive value, and negative predictive value of 0.703, 0.913, 0.622, 0.956, and 0.771, respectively. The area under the ROC curve of the combination of AL/CR ratio and parental myopia for myopia assessment was 0.976 (95% CI: 0.957-0.996).

CONCLUSION

The correlation between SE and AL/CR ratio was stronger than that between SE and AL in children. The AL/CR ratio may be an alternative indicator for myopia assessment in children, and the combination of demographic factors and AL/CR ratio can improve the accuracy of myopia assessment.

Dissemination of antibiotic resistance genes in swimming pools and implication for human skin

Swimming pools are crowd-gathering places that are associated with numerous outbreaks of water-borne diseases. Herein, we investigated the distribution of antibiotic resistance genes (ARGs) and bacterial communities in swimming pools and determined the influencing factors and potential human exposure. Sixteen swimming pools with different bather loads (0.01-0.16 person/m²·h) were investigated. Water samples were collected, before opening and after closing of the facilities, from six swimming pools, and skin samples were collected from volunteers. Comprehensive approaches, high-throughput qPCR and 16S rRNA gene sequencing, were used. The results showed that swimming pools contained a higher relative abundance (0.62 gene copies/16S rRNA) and absolute abundance (6.57×10⁸ gene copies/L) of ARGs on average. Bather loads contributed to the increase of core ARGs, and the absolute abundance of ARGs significantly increased by 1.47-1.94 orders of magnitude when the bather load was more than 0.1 person/m²·h. Dermal contact was estimated as the main exposure route of ARGs. Eighteen ARGs that were not detected before swimming were found on human skin and remained after showering. Furthermore, the event intake burden of ARGs via dermal contact was higher than that via ingestion when swimming. This study provides an assessment of ARGs and antibiotic-resistant bacteria (ARB) in swimming pools and helps to define the health risks to swimmers.

Metagenomic analysis of microbiota and antibiotic resistome in household activated carbon drinking water purifiers

Existing drinking water treatment systems have limited ability to control emerging contaminants such as antibiotic resistance genes (ARGs). Household activated carbon water purifiers (HWPs) are convenient measures to assure drinking water quality. However, ARGs distribution in HWPs has not been reported. Here, ARGs, mobile genetic elements (MGEs) and bacteria communities were profiled in tap water (TW), filter water (FW) and activated carbon (AC) biofilm from six kinds of HWPs after 80 days operation, using metagenomics. Results showed that the bacteria community diversities in FW and AC were higher than those in TW. A total of 88, 116 and 80 ARG subtypes were detected in TW, AC and FW, respectively. The AC structure was an important factor influencing the bacterial communities and ARG profiles in FW. The network analysis revealed the co-occurrence patterns between ARGs and bacteria. SourceTracker analyses showed AC biofilms were important contributors of microbes (29-79%) and ARGs (17-53%) in FW. Moreover, MGEs e.g. pBBta01, pMKMS02 and pMFLV01 plasmids, and ISMysp3 had significant co-occurrence patterns with ARGs in the AC biofilms. This study helps to understand the actual purification effect of HWPs and provides a theoretical reference for the management and control of ARGs pollution in domestic drinking water.

Antibiotic resistance genes and microcystins in a drinking water treatment plant

Problems with antibiotic resistance genes (ARGs) and secondary pollution from microcystins (MCs), caused by cyanobacterial blooms have become significant global issues. These two pollutants co-occur in drinking water treatment plants (DWTPs), but the exact relationships between them requires further clarification. Here, a high-throughput quantitative real-time PCR and enzyme-linked immunosorbent assay were used to investigate the behavior of ARGs and MCs in a practical DWTP in the first place. After the on-site investigation, the effect of MCs on the horizontal transfer of ARGs was studied under laboratory conditions, and mechanisms explored at both cellular and molecular levels. MCs could promote the spread of ARGs, especially in relatively stationary and stable environments such as biofilms. MC-LR was the most efficient microcystin subtype promoting conjugative transfer, which was 25.13 times higher than for the control group. MCs affected the horizontal transfer of ARGs by regulating a series of gene systems involved in conjugative transfer, stimulating the formation of reactive oxygen species (ROS), and increasing cell membrane permeability. This study can provide a theoretical basis for the control of ARGs and MCs in DWTPs, which is of great significance for the scientific assessment of drinking water safety.

Comprehensive Understanding of the Plasmid-Mediated Colistin Resistance Gene mcr-1 in Aquatic Environments

The emergence of plasmid-mediated colistin resistance gene mcr-1 has attracted global attention and raised serious concerns about its possible cross-environment dissemination. However, the systematic exploration of mcr-1 both by monitoring and genetic dissection in aquatic environments has not been conducted. This study addresses the gap related to the occurrence and distribution of mcr-1 in watersheds, eastern China. The results showed an abundance of mcr-1 gene in four watersheds, and the highest level of mcr-1 reached 1.8 × 10⁹ gene copies per liter of water. Furthermore, the transfer frequencies of the plasmids in isolated Escherichia coli were 2.76 × 10^-6-6.11 × 10^-4 within genera and minimal inhibitory concentrations of polymyxin resistance were 8-16 mg/L for transconjugants. Mass spectrometry data allowed visualization of the function of mcr-1 expression, rendering bacterial resistance to colistin. The genetic details of six mcr-1-harboring plasmids in E. coli isolates of aquatic origin were obtained by single-molecule real-time sequencing. These plasmids were closely associated with E. coli strains of pig and human origin, supporting the concept of mcr-1 dissemination across natural environments, livestock farms, and humans. In conclusion, this study provides the first glimpse of the profile of mcr-1-harboring plasmids and their genetic environment in aquatic ecosystems.

Ultrasound Imaging Based on Molecular Targeting for Quantitative Evaluation of Hepatic Ischemia-Reperfusion Injury

The aim of the present study was to quantitatively diagnose and monitor the therapy response of hepatic ischemia-reperfusion injury (IRI) with the use of targeted ultrasound (US) imaging. Targeted microbubbles (MBs) were fabricated, and the binding of intracellular adhesion molecule 1 (ICAM-1) antibodies to MBs was observed. To establish a quantitative method based on targeted US imaging, contrast-enhanced US was applied for IRI rats. After andrographolide treatment, the IRI rats were subjected to the quantitative targeted US imaging for a therapeutic effect. Effective binding of ICAM-1 antibodies to MBs was observed. According to the quantitative targeted US imaging, the ICAM-1 normalized intensity difference (NID) in the IRI rats (38.74 ± 15.08%) was significantly higher than that in the control rats (10.08 ± 2.52%, p = 0.048). Further, different degrees of IRI (mild IRI, moderate to severe IRI) were distinguished by the use of the NID (37.14 ± 2.14%, 22.34 ± 1.08%, p = 0.002). Analysis of mRNA expression demonstrated the accuracy of analyzing the NID by using quantitative targeted US imaging (R²  = 0.7434, p < 0.001). Andrographolide treatment resulted in an obviously weakened NID of ICAM-1 (17.7 ± 4.8% vs 34.2 ± 6.6%, p < 0.001). The study showed the potential of the quantitative targeted US imaging method for the diagnosis and therapeutic monitoring of IRI.

A compound chimeric antigen receptor strategy for targeting multiple myeloma

Current clinical outcomes using chimeric-antigen receptors (CARs) against multiple myeloma show promise in the eradication of bulk disease. However, these anti-BCMA (CD269) CARs observe relapse as a common phenomenon after treatment due to the reemergence of either antigen-positive or -negative cells. Hence, the development of improvements in CAR design to target antigen loss and increase effector cell persistency represents a critical need. Here, we report on the anti-tumor activity of a CAR T-cell possessing two complete and independent CAR receptors against the multiple myeloma antigens BCMA and CS1. We determined that the resulting compound CAR (cCAR) T-cell possesses consistent, potent and directed cytotoxicity against each target antigen population. Using multiple mouse models of myeloma and mixed cell populations, we are further able to show superior in vivo survival by directed cytotoxicity against multiple populations compared to a single-expressing CAR T-cell. These findings indicate that compound targeting of BCMA and CS1 on myeloma cells can potentially be an effective strategy for augmenting the response against myeloma bulk disease and for initiation of broader coverage CAR therapy.

Preclinical targeting of aggressive T-cell malignancies using anti-CD5 chimeric antigen receptor

The outlook for T-cell malignancies remain poor due to the lack of effective therapeutic options. Chimeric antigen receptor (CAR) immunotherapy has recently shown promise in clinical trials for B-cell malignancies, however, designing CARs for T-cell based disease remain a challenge due to the shared surface antigen pool between normal and malignant T-cells. Normal T-cells express CD5 but NK (natural killer) cells do not, positioning NK cells as attractive cytotoxicity cells for CD5CAR design. Additionally, CD5 is highly expressed in T-cell acute lymphoblastic leukemia (T-ALL) and peripheral T-cell lymphomas (PTCLs). Here, we report a robust anti-CD5 CAR (CD5CAR) transduced into a human NK cell line NK-92 that can undergo stable expansion ex vivo. We found that CD5CAR NK-92 cells possessed consistent, specific, and potent anti-tumor activity against a variety of T-cell leukemia and lymphoma cell lines as well as primary tumor cells. Furthermore, we were able to demonstrate significant inhibition and control of disease progression in xenograft mouse models of T-ALL. The data suggest that CAR redirected targeting for T-cell malignancies using NK cells may be a viable method for new and complementary therapeutic approaches that could improve the current outcome for patients.

Artesunate protects pancreatic beta cells against cytokine-induced damage via SIRT1 inhibiting NF-κB activation

AIM

Artesunate (ART) has been known as the most effective and safe reagents to treat malaria for many years. In this study, we explored whether ART could protect pancreatic beta-cell against cytokine-induced damage.

MATERIALS AND METHODS

The production of nitrite (NO) was detected with the Griess Assay Kit. SIRT1 and inducible nitric oxide synthase (iNOS) expression were determined with Western blot. The transcriptional activity of NF-κB was evaluated by luciferase reporter assay. The expression of Sirt1 was silenced by RNA interference. Glucose-stimulated insulin secretion (GSIS) and potassium-stimulated insulin secretion (KSIS) assays were performed to measure the effect of ART on pancreatic beta-cells' function. The effect of ART on beta-cells apoptosis was evaluated by using Hochest/PI staining and TUNEL assay.

RESULTS

ART enhanced GSIS (KSIS) and reduced apoptosis of pancreatic beta-cells induced by IL-1β. Further study showed that ART inhibited IL-1β-induced increase of NF-κB activity, iNOS expression, and NO production. Moreover, ART up-regulated SIRT1 expression in INS-1 cells and islets exposed to IL-1β. Inhibition of SIRT1 expression could partially abolished the inhibitory effect of ART on NF-κB activity in IL-1β-treated beta-cells. More importantly, the protective effect of ART on cytokine-induced damage was reversed by silencing SIRT1 expression.

CONCLUSIONS

ART can elicit a protective effect on beta-cells exposed to IL-1β by stimulating SIRT1 expression, which resulted in the decrease of NF-κB activity, iNOS expression, and NO production. Hence, ART might be an effective drug for diabetes.

Inhibition enhancer of zeste homologue 2 promotes senescence and apoptosis induced by doxorubicin in p53 mutant gastric cancer cells

OBJECTIVES

Enhancer of zeste homologue 2 (EZH2) is crucially involved in epigenetic silencing by acting as a histone methyltransferase. Although EZH2 is overexpressed in many cancers and is involved in malignant cell proliferation and invasion, the role of EZH2 in senescence induced by DNA damage has up to now remained largely unknown. In this study, we sought to explore the outcome of EZH2 depletion along with exposure of doxorubicin (DOX), and related mechanisms, in gastric cancer cells.

MATERIALS AND METHODS

Here, senescence induced by DNA damage was achieved in gastric cancer cells by DOX treatment. EZH2 was downregulated by transfection with siRNA or treated with (-)-epigallocatechin-3-gallate, a targeted inhibitor. Senescence-associated β galactosidase (SA-β-gal) and formation of senescence-associated heterochromatin foci were used to identify cell senescence. To investigate effects of EZH2 depletion on the cell cycle, apoptosis and proliferation, flow cytometry and MTT analysis were employed. Changes in p53-p21 axis activation were detected by Western blotting.

RESULTS

We found that cell proliferative arrest caused by DOX could be promoted by EZH2 depletion. Mechanistically, EZH2 depletion not only worked in coordination with DNA damage during the progression of cell senescence but also promoted apoptosis in p53 mutant cells. However, it had no cooperative relationship with DOX in p53 wild-type cells.

CONCLUSIONS

These data help unravel a crucial role for EZH2 in senescence and apoptosis in gastric cancer cells and that p53 genomic status was associated with different cell responses to EZH2 silencing.

Different iron-deposition patterns of multiple system atrophy with predominant parkinsonism and idiopathetic Parkinson diseases demonstrated by phase-corrected susceptibility-weighted imaging

BACKGROUND AND PURPOSE

MSA-P and IPD have similar clinical presentations that may complicate accurate clinical diagnosis. Different iron-deposition patterns of those 2 diseases have been demonstrated in histopathology. The aim was to demonstrate the different iron-deposition patterns of MSA-P and IPD by using SWI phase images.

MATERIALS AND METHODS

Sixteen patients with IPD, 8 with MSA-P, and 44 age-matched healthy controls underwent SWI of brain. The different phase shifts as well as the high iron percentage of the area in several gray nuclei were statistically evaluated. The putamen was divided into 4 subregions for further analysis.

RESULTS

Patients with MSA-P had significantly higher iron deposition in the putamen and PT compared with those with IPD (P < .05). Moreover, ROC curves indicated slightly more sensitivity in differentiating MSA-P from IPD, by means of the high-iron-deposition-percentage area than the average phase shift (putamen: AUC = 0.88 versus 0.78; PT: AUC = 0.79 versus 0.62). Moreover, the lower inner region of the putamen was the most valuable subregion in differentiating MSA-P from IPD among the 4 subregions (AUC = 0.92 and 0.91 for high-iron-percentage area and average phase shift, respectively).

CONCLUSIONS

Higher iron deposition in the putamen and PT may differentiate MSA-P from IPD, but the lower inner region of the putamen may be better compared with the PT and other subregions of the putamen. Moreover, the high iron percentage makes it possible to detect smaller increases in iron content more confidently in comparison with average phase shift.

Different effects of electroacupuncture on esophageal motility and serum hormones in cats with esophagitis

We aim to investigate the effects of different electroacupuncture (EA) frequencies at ST-36 on esophageal motility, and to compare the effect of EA on serum gastrin (GAS), motilin (MTL), and vasoactive intestinal peptide (VIP). Thirty-two cats were divided into four equal groups. All animals underwent a Heller myotomy. After esophagitis developed two frequencies (2/15 Hz or 2/100 Hz) of EA were delivered into ST-36 (LEA group [low EA], HEA group [high EA]). Animals submitted to EA on a non-point region (EANP) were used as controls (LEANP group, HEANP group), respectively. Esophageal motility was continuously monitored. The lower esophageal sphincter pressure (LESP) decreased significantly after myotomy. The LESP decreased in both LEA and LEANP cats, and in LEA cats the pressure decrease was greater. The LESP increased in the HEA group, which was higher than that in the HEANP group (P < 0.05). High-frequency EA significantly increased the peak amplitude in esophageal peristalsis. There was a decrease in serum GAS and MTL in LEA cats compared with LEANP cats (both P < 0.01). GAS and MTL were higher in the HEA group than in the HEANP group (both P < 0.01). Serum VIP decreased in the HEA group (P < 0.05), while it increased in the LEA group (P < 0.05), compared with EANP groups, respectively. EA with a high frequency at ST-36 enhances LESP as well as esophageal motility, while EA with a low frequency decreases LESP. The effect of EA is acupoint-specific, and this effect appears to be mediated through GAS, MTL and VIP.

Enzymatic degradation of atactic poly(R,S-3-hydroxybutyrate) induced by amorphous polymers and the enzymatic degradation temperature window of an amorphous polymer system

The phase structure and biodegradability were investigated for amorphous blends of chemosynthetic fully amorphous atactic poly(R,S-3-hydroxybutyrate) (a-PHB) with atactic poly(methyl methacrylate) (PMMA) and atactic poly(R,S-lactide) (a-PLA). The differential scanning calorimetry thermal analysis indicated that a-PHB/PMMA blends were partially miscible while a-PHB/a-PLA blends were miscible in the studied composition range. The biodegradations of the blends were carried out in phosphate buffer solution in the presence of bacterial poly(R-3-hydroxybutyrate) extracellular depolymerases purified from Alcaligenes faecalis T1 and P. stutzeri. Although a-PHB in the pure state was not degraded by these depolymerase, it was degraded by blending with PMMA and a-PLA. The results demonstrated that the enzymatic degradation of a-PHB can be induced by amorphous polymers such as PMMA and a-PLA. Also, the biodegradation rate of a-PHB in the blends decreased drastically when the degradation temperature is too much away from the polymer glass transition temperatures. On the basis of these results, a temperature window of the enzymatic degradation was first proposed for the blend and the essence of induced degradation was discussed.