Class 1 integrons are vital mobile genetic elements involved in the environmental transmission of antibiotic resistance genes(ARGs).However,knowledge about the diversity and abundance of class 1 integrons and gene cas...Class 1 integrons are vital mobile genetic elements involved in the environmental transmission of antibiotic resistance genes(ARGs).However,knowledge about the diversity and abundance of class 1 integrons and gene cassettes during drinking water treatment and distribution is still limited.In this study,we aimed to uncover the prevalence of class 1 integrons in the drinking water treatment and distribution systems with the combination of culture-dependent and culture-independent methods.Further,we applied the nanopore sequencing method to characterize the diversity and arrangement of ARGs carried by class 1 integron-associated gene cassettes.A total of 42 isolates were inti-positive among the 208 strains isolated from drinking water,which tended to confer multi-drug resistance compared with intll-negative isolates.The absolute abundance of the intl1 average i.15×10^(9) copies/L in the source water and underwent the most significant reduction of over 99.9% after liquid chiorine disinfection.Furthermore,nanopore sequencing revealed that the class 1 integron-associated gene cassettes carried 51 subtypes of ARGs in drinking water,mainly conferring resistance to aminoglycosides and trimethoprim.The treatment processes,especially liquid chlorine disinfection,reduced most of the ARGs carried by gene cassettes,though some of the ARG subtypes persisted along the treatment and distribution ike aac(6)-Il,aadA,and dfrB2.The antibiotic resistance gene cassette array laac(6')-Ⅱ arr was most frequently detected,especially in the chlorinated water.This study underlined that drinking water was potential reservoir for integron-mediated ARGs transfer,indicating that the health risks of resistance gene cassettes in class 1 integrons deserved urgent attention.展开更多
Biotoxicity assessment results of environmental waters largely depend on the sample extraction protocols that enrich pollutants to meet the effect-trigger thresholds of bioassays.However,more chemical mixture does not...Biotoxicity assessment results of environmental waters largely depend on the sample extraction protocols that enrich pollutants to meet the effect-trigger thresholds of bioassays.However,more chemical mixture does not necessarily translate to higher combined biotoxicity.Thus,there is a need to establish the link between chemical extracting efficiency and biotoxicity outcome to standardize extraction methods for biotoxicity assessment of environmental waters.This study compares the performance of five different extraction phases in solid phase extraction(SPE),namely HLB,HLB+Coconut,C18 cartridge,C18 disk and Strata-X,and evaluated their chemical extracting efficiencies and biotoxicity outcomes.We quantitatively assessed cytotoxicity,acute toxicity,genotoxicity,estrogenic activity,and neurotoxicity of the extracts using in vitro bioassays and characterized the chemical extracting efficiencies of the SPE methods through chemical recoveries of 23 model compounds with different polarities and total organic carbon.Using Pareto ranking,we identified HLB+Coconut as the optimal SPE method,which exhibited the highest level of water sample biotoxicity and recovered the most chemicals in water samples.We found that the biotoxicity outcomes of the extracted water samples significantly and positively correlated with the chemical extracting efficiencies of the SPE methods.Moreover,we observed synchronous changing patterns in biotoxicity outcome and chemical extracting efficiencies in response to increasing sample volumes per cartridge(SVPC)during SPE.Our findings underscore that higher chemical extracting efficiency of SPE corresponds to higher biotoxicity outcome of environmental water samples,providing a scientific basis for standardization of SPE methods for adequate assessment of biotoxicities of environmental waters.展开更多
Background： Neuromyelitis optica spectrum disorder （NMOSD） was long believed to be an aggressive form of multiple sclerosis （MS）. This study aimed to describe the clinical features of patients with MS and NMOSD t...Background： Neuromyelitis optica spectrum disorder （NMOSD） was long believed to be an aggressive form of multiple sclerosis （MS）. This study aimed to describe the clinical features of patients with MS and NMOSD to assist in differential diagnoses in clinical practice. Methods： Data including the patients＇ serum and cerebrospinal fluid （CSF） tests, image findings, and clinical information from 175 patients with MS or NMOSD at Xuanwu Hospital, Capital Medical University from November 2012 to May 2014 were collected and analyzed retrospectively. An enzyme-linked immunosorbent assay was performed to detect the myelin oligodendrocyte glycoprotein （MOG） autoantibodies in CSF and serum. Cell-based assays were used to detect aquaporin-4-antibody （AQP4-Ab）. The Chi-square test was used to compare the categorical variables. Wilcoxon rank sum test was peribrmed to analyze the continuous variables. Results： Totally 85 MS patients （49%） and 90 NMOSD patients （51%） were enrolled, including 124 （71%） women and 51 （29%） men. Fewer MS patients （6%） had autoinamune diseases compared to NMOSD （19%） （x2= 6.9, P 〈 0.01 ）. Patients with NMOSD had higher Expanded Disability Status Scale scores （3.5 [3]） than MS group （2 [2]） （x2= -3.69, P 〈 0.01）. The CSF levels of white cell count and protein in both two groups were slightly elevated titan the normal range, without significant difference between each other. Positivity of serum AQP4-Ab in NMOSD patients was higher than that in MS patients （MS： 0, NMOSD： 67%; x2= 63.9, P 〈 0.01 ）. Oligoclonal bands in CSF among NMOSD patients were remarkably lower than that among MS （MS： 59%, NMOSD： 20%; x2= 25.7, P 〈 0.01）. No significant difference of MOG autoantibodies was found between the two groups. Conclusion： The different CSF features combined with clinical, magnetic resonance imaging, and serum characteristics between Chinese patients with MS and NMOSD could assist in the differential diagnosis.展开更多
High-throughput sequencing of 16S rRNA gene amplicons was conducted to characterize the changing patterns of bacterial community and potential pathogens in full-scale drinking water treatment and distribution systems....High-throughput sequencing of 16S rRNA gene amplicons was conducted to characterize the changing patterns of bacterial community and potential pathogens in full-scale drinking water treatment and distribution systems.Results showed that Actinobacteria was the predominant phylum in source water,while Proteobacteria dominated after chlorine disinfection and its relative abundance increased from 40.88%±9.45%to 67.86%±27.10%.The genera Pseudarthrobacter,Arenimonas,and Limnohabitans were effectively removed by chlorination,while Phreatobacter,Undibacterium,Pseudomonas,and Sphingomonas within the Proteobacteria phylum were greatly enriched after chlorination.Metagenomic analyses revealed the occurrence of 56 species of potential pathogenic bacteria within 17 genera in drinking water,mainly including Pseudomonas fluorescens and five mycobacteria species,which were also persistent in tap water samples.The bacteria were found to be involved in various pathways,among which considerable groups were related to human diseases,including infectious diseases and even cancers.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52025102,52192682,and 52200057)the Jiangsu Funding Program for Excellent Postdoctoral Talent(China)(No.2022ZB35).
文摘Class 1 integrons are vital mobile genetic elements involved in the environmental transmission of antibiotic resistance genes(ARGs).However,knowledge about the diversity and abundance of class 1 integrons and gene cassettes during drinking water treatment and distribution is still limited.In this study,we aimed to uncover the prevalence of class 1 integrons in the drinking water treatment and distribution systems with the combination of culture-dependent and culture-independent methods.Further,we applied the nanopore sequencing method to characterize the diversity and arrangement of ARGs carried by class 1 integron-associated gene cassettes.A total of 42 isolates were inti-positive among the 208 strains isolated from drinking water,which tended to confer multi-drug resistance compared with intll-negative isolates.The absolute abundance of the intl1 average i.15×10^(9) copies/L in the source water and underwent the most significant reduction of over 99.9% after liquid chiorine disinfection.Furthermore,nanopore sequencing revealed that the class 1 integron-associated gene cassettes carried 51 subtypes of ARGs in drinking water,mainly conferring resistance to aminoglycosides and trimethoprim.The treatment processes,especially liquid chlorine disinfection,reduced most of the ARGs carried by gene cassettes,though some of the ARG subtypes persisted along the treatment and distribution ike aac(6)-Il,aadA,and dfrB2.The antibiotic resistance gene cassette array laac(6')-Ⅱ arr was most frequently detected,especially in the chlorinated water.This study underlined that drinking water was potential reservoir for integron-mediated ARGs transfer,indicating that the health risks of resistance gene cassettes in class 1 integrons deserved urgent attention.
基金supported by the National Natural Science Foundation of China(Nos.52025102,52192682,51908276)the Excellent Research Program of Nanjing University(No.ZYJH005)the Fundamental Research Funds for the Central Universities(No.0211/14380200)。
文摘Biotoxicity assessment results of environmental waters largely depend on the sample extraction protocols that enrich pollutants to meet the effect-trigger thresholds of bioassays.However,more chemical mixture does not necessarily translate to higher combined biotoxicity.Thus,there is a need to establish the link between chemical extracting efficiency and biotoxicity outcome to standardize extraction methods for biotoxicity assessment of environmental waters.This study compares the performance of five different extraction phases in solid phase extraction(SPE),namely HLB,HLB+Coconut,C18 cartridge,C18 disk and Strata-X,and evaluated their chemical extracting efficiencies and biotoxicity outcomes.We quantitatively assessed cytotoxicity,acute toxicity,genotoxicity,estrogenic activity,and neurotoxicity of the extracts using in vitro bioassays and characterized the chemical extracting efficiencies of the SPE methods through chemical recoveries of 23 model compounds with different polarities and total organic carbon.Using Pareto ranking,we identified HLB+Coconut as the optimal SPE method,which exhibited the highest level of water sample biotoxicity and recovered the most chemicals in water samples.We found that the biotoxicity outcomes of the extracted water samples significantly and positively correlated with the chemical extracting efficiencies of the SPE methods.Moreover,we observed synchronous changing patterns in biotoxicity outcome and chemical extracting efficiencies in response to increasing sample volumes per cartridge(SVPC)during SPE.Our findings underscore that higher chemical extracting efficiency of SPE corresponds to higher biotoxicity outcome of environmental water samples,providing a scientific basis for standardization of SPE methods for adequate assessment of biotoxicities of environmental waters.
文摘Background： Neuromyelitis optica spectrum disorder （NMOSD） was long believed to be an aggressive form of multiple sclerosis （MS）. This study aimed to describe the clinical features of patients with MS and NMOSD to assist in differential diagnoses in clinical practice. Methods： Data including the patients＇ serum and cerebrospinal fluid （CSF） tests, image findings, and clinical information from 175 patients with MS or NMOSD at Xuanwu Hospital, Capital Medical University from November 2012 to May 2014 were collected and analyzed retrospectively. An enzyme-linked immunosorbent assay was performed to detect the myelin oligodendrocyte glycoprotein （MOG） autoantibodies in CSF and serum. Cell-based assays were used to detect aquaporin-4-antibody （AQP4-Ab）. The Chi-square test was used to compare the categorical variables. Wilcoxon rank sum test was peribrmed to analyze the continuous variables. Results： Totally 85 MS patients （49%） and 90 NMOSD patients （51%） were enrolled, including 124 （71%） women and 51 （29%） men. Fewer MS patients （6%） had autoinamune diseases compared to NMOSD （19%） （x2= 6.9, P 〈 0.01 ）. Patients with NMOSD had higher Expanded Disability Status Scale scores （3.5 [3]） than MS group （2 [2]） （x2= -3.69, P 〈 0.01）. The CSF levels of white cell count and protein in both two groups were slightly elevated titan the normal range, without significant difference between each other. Positivity of serum AQP4-Ab in NMOSD patients was higher than that in MS patients （MS： 0, NMOSD： 67%; x2= 63.9, P 〈 0.01 ）. Oligoclonal bands in CSF among NMOSD patients were remarkably lower than that among MS （MS： 59%, NMOSD： 20%; x2= 25.7, P 〈 0.01）. No significant difference of MOG autoantibodies was found between the two groups. Conclusion： The different CSF features combined with clinical, magnetic resonance imaging, and serum characteristics between Chinese patients with MS and NMOSD could assist in the differential diagnosis.
基金supported by the National Natural Science Foundation of China(52025102 and 51908274)Nanjing University Excellent Research Program(ZYJH005)State Key Laboratory of Pollution Control and Resource Reuse Foundation(PCRRF20004).
文摘High-throughput sequencing of 16S rRNA gene amplicons was conducted to characterize the changing patterns of bacterial community and potential pathogens in full-scale drinking water treatment and distribution systems.Results showed that Actinobacteria was the predominant phylum in source water,while Proteobacteria dominated after chlorine disinfection and its relative abundance increased from 40.88%±9.45%to 67.86%±27.10%.The genera Pseudarthrobacter,Arenimonas,and Limnohabitans were effectively removed by chlorination,while Phreatobacter,Undibacterium,Pseudomonas,and Sphingomonas within the Proteobacteria phylum were greatly enriched after chlorination.Metagenomic analyses revealed the occurrence of 56 species of potential pathogenic bacteria within 17 genera in drinking water,mainly including Pseudomonas fluorescens and five mycobacteria species,which were also persistent in tap water samples.The bacteria were found to be involved in various pathways,among which considerable groups were related to human diseases,including infectious diseases and even cancers.
