To investigate the genetic relatedness between carbapenem-resistant Klebsiella pneumoniae(CRKP) strains isolated from intestinal colonization and subsequent bloodstream infections.

As important biocatalysts, nitrilases can efficiently convert nitrile groups into acids and ammonia in a mild and eco-friendly manner, being widely used in the synthesis of important pharmaceutical intermediates. Early studies reported that nitrilases only had the hydrolysis activity of catalyzing the formation of corresponding carboxylic acid products from nitriles, showing catalytic specificity. However, recent studies have shown that some nitrilases exhibit the hydration activity for catalyzing the formation of amides from nitriles, showing catalytic promiscuity. The catalytic promiscuity of nitrilases has dual effects. On the one hand, the presence of amide by-products increases the difficulties and costs of subsequent separation and purification of carboxylic acid products. On the other hand, however, if the catalytic reaction pathways of nitrilases can be precisely regulated to reshape enzyme functions, the reactions catalyzed by nitrilases can be broadened to provide new ideas for the biosynthesis of high-value amides, which is crucial for the development of artificial enzymes and biocatalysis. This review summarized the research progress in the catalytic promiscuity of nitrilases and discussed the key regulatory factors that may affect the catalytic promiscuity of nitrilases from the evolutionary origin, catalytic domains, and catalytic mechanisms, hoping to provide reference and inspiration for the application of nitrilases in biocatalysis.
Aminohydrolases/chemistry* ; Biocatalysis ; Nitriles/chemistry* ; Substrate Specificity ; Catalytic Domain ; Catalysis

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the effectiveness of applying the CIPP(Context,Input,Process,and Product)model in the training of general workers in a disinfection supply center.Methods From January to March 2023,a total of 24 general workers in our hospital's disinfection supply center underwent traditional training as the pre-management phase.Subse-quently,from July to September 2023,a training system centered on the CIPP model was implemented as the post-management phase.After the training,the examination results and training evaluations were analyzed using SPSS 13.0 statistical software.Results The technical training of the general workers resulted in improved learning outcomes compared to before the training.Conclusion By applying the CIPP model in the training of general workers in a disinfection supply center,their grasp of basic knowledge and professional skills can be enhanced.This can reduce technical errors during operations,improve the quality of sterile items,and reduce the risk of nosocomial infections,thereby ensuring patient safety.

A colon-specific drug delivery system has great potential for the oral administration of colorectal cancer. However, the uncontrollable in vivo fate of liposomes makes their effectiveness for colonic location, and intratumoral accumulation remains unsatisfactory. Here, an oral colon-specific drug delivery system (CBS-CS@Lipo/Oxp/MTZ) was constructed by covalently conjugating Clostridium butyricum spores (CBS) with drugs loaded chitosan (CS)-coated liposomes, where the model chemotherapy drug oxaliplatin (Oxp) and anti-anaerobic bacteria agent metronidazole (MTZ) were loaded. Following oral administration, CBS germinated into Clostridium butyricum (CB) and colonized in the colon. Combined with colonic specifically β-glucosidase responsive degrading of CS, dual colon-specific release of liposomes was achieved. And the accumulation of liposomes at the CRC site furtherly increased by 2.68-fold. Simultaneously, the released liposomes penetrated deep tumor tissue via the permeation enhancement effect of CS to kill localized intratumoral bacteria. Collaborating with blocking the translocation of intestinal pathogenic bacteria from lumen to tumor with the gut microbiota modulation of CB, the intratumoral pathogenic bacteria were eliminated fundamentally, blocking their recruitment to immunosuppressive cells. Furtherly, synchronized with lipopolysaccharide (LPS) released from MTZ-induced dead Fusobacterium nucleatum and the tumor-associated antigens produced by Oxp-caused immunogenic dead cells, they jointly enhanced tumor infiltration of CD8⁺ T cells and reactivated robust antitumor immunity.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in healthcare facilities in major regions of China in 2023.Methods Clinical isolates collected from 73 hospitals across China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2023 Clinical & Laboratory Standards Institute (CLSI) breakpoints.Results A total of 445199 clinical isolates were collected in 2023,of which 29.0％ were gram-positive and 71.0％ were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species (excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi) (MRSA,MRSE and MRCNS) was 29.6％,81.9％ and 78.5％,respectively.Methicillin-resistant strains showed significantly higher resistance rates to most antimicrobial agents than methicillin-susceptible strains (MSSA,MSSE and MSCNS).Overall,92.9％ of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 91.4％ of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis had significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 93.1％ in the isolates from children and and 95.9％ in the isolates from adults.The resistance rate to carbapenems was lower than 15.0％ for most Enterobacterales species except for Klebsiella,22.5％ and 23.6％ of which were resistant to imipenem and meropenem,respectively .Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.6％ to 10.0％.The resistance rate to imipenem and meropenem was 21.9％ and 17.4％ for Pseudomonas aeruginosa,respectively,and 67.5％ and 68.1％ for Acinetobacter baumannii,respectively.Conclusions Increasing resistance to the commonly used antimicrobial agents is still observed in clinical bacterial isolates.However,the prevalence of important crabapenem-resistant organisms such as crabapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a slightly decreasing trend.This finding suggests that strengthening bacterial resistance surveillance and multidisciplinary linkage are important for preventing the occurrence and development of bacterial resistance.

Activating humoral and cellular immunity in lymph nodes (LNs) of nanoparticle-based vaccines is critical to controlling tumors. However, how the physical properties of nanovaccine carriers orchestrate antigen capture, lymphatic delivery, antigen presentation and immune response in LNs is largely unclear. Here, we manufactured gold nanoparticles (AuNPs) with the same size but different shapes (cages, rods, and stars), and loaded tumor antigen as nanovaccines to explore their disparate characters on above four areas. Results revealed that star-shaped AuNPs captured and retained more repetitive antigen epitopes. On lymphatic delivery, both rods and star-shaped nanovaccines mainly drain into the LN follicles region while cage-shaped showed stronger paracortex retention. A surprising finding is that the star-shaped nanovaccines elicited potent humoral immunity, which is mediated by CD4⁺ T helper cell and follicle B cell cooperation significantly preventing tumor growth in the prophylactic study. Interestingly, cage-shaped nanovaccines preferentially presented peptide-MHC I complexes to evoke robust CD8⁺ T cell immunity and showed the strongest therapeutic efficacy when combined with the PD-1 checkpoint inhibitor in established tumor study. These results highlight the importance of nanoparticle shape on antigen delivery and presentation for immune response in LNs, and our findings support the notion that different design strategies are required for prophylactic and therapeutic vaccines.

Objective:To conduct meta analysis to compare the effect of complete resection with or without postoperative radiotherapy (PORT) on survival in stage Ⅲ(N 2) non-small cell lung cancer (NSCLC). Methods:Relevant studies of the efficacy of PORT for stage Ⅲ(N 2) NSCLC were searched from Wanfang Data, PubMed, and Cochrane Library from January 2006 to January 2022. Literature screening, extraction of information and assessment of the risk of bias of the included literature was carried out by two independent researchers. Meta analysis was performed using R4.0.3 software. Results:A total of 12 publications consisting of 2992 patients were included, 1479 cases in the PORT group and 1513 cases in the control group. PORT improved the overall survival (OS) and disease free survival (DFS) compared to the control group. Fixed-effects model meta analysis of 6 randomized controlled trials showed that PORT did not significantly reduce the risk of death ( HR=0.98, 95% CI: 0.80-1.20). Fixed-effects model meta analysis of 6 retrospective studies showed that PORT improved prognosis ( HR=0.68, 95% CI: 0.59-0.79). PORT could improve OS of patients with multiple (station) metastasis of ipsilateral mediastinum and / or submandibular lymph nodes ( HR=0.89, 95% CI: 0.80-0.99). Conclusions:PORT could improve OS and DFS in stage Ⅲ(N 2) NSCLC. A trend towards benefit can be observed in the subgroup with multiple/multi-station N2 metastasis.

Objective To investigate the effect of sirtuin 3(SIRT3)on the oxidative stress response and hypoxia inducible factor-1α(HIF-1α)expression in lung cancer cells through reactive oxygen species(ROS)under hypoxic conditions and its mechanism.Methods Human non-small cell lung cancer A549 cells were exposed to hypoxia for 0 h,12 h,24 h and 48 h.The mRNA and protein expressions of HIF-1α and SIRT3 were detected by RT-PCR and Western blot to determine the optimal time of hypoxia induction.A549 cells were divided into 5 groups:control group,hypoxia group,hypoxia+ROS inhibitor n-acetylcysteine(NAC)group,hypoxia+(SIRT3 overexpression)SIRT3-OE group and hypoxia+SIRT3-OE+NAC group.Cell proliferation was detected by MTT assay.Cell apop-tosis was detected by flow cytometry.The mRNA and protein expressions of HIF-1 α and SIRT3 in each group were detected by RT-PCR and Western blot.ROS content in each group was detected by flow cytometry.The contents of malondialdehyde(MDA),superoxide dismutase(SOD)and glutathione(GSH)in the cells of each group were detected by biochemical kits.Results The optimal induction time of hypoxia was 24 h.Compared with the control group,the apoptosis rate,SIRT3 mRNA and protein levels,SOD and GSH contents in the hypoxia group signifi-cantly decreased(P＜0.01),the cell proliferation ability,HIF-1 α mRNA and protein levels,ROS and MDA con-tent in cells significantly increased(P＜0.01).Compared with the hypoxia group,the apoptosis rate,SIRT3 mR-NA and protein levels,SOD and GSH contents in the hypoxia+NAC and hypoxia+SIRT3-OE groups increased(P＜0.05),the cell proliferation ability,HIF-1 α mRNA and protein levels,ROS and MDA content in cells de-creased(P＜0.05).Compared with the hypoxia+NAC group,the apoptosis rate,SIRT3 mRNA and protein lev-els,SOD and GSH contents in the hypoxia+SIRT3-OE+NAC group significantly increased(P＜0.01),the cell proliferation ability,HIF-1 α mRNA and protein levels,ROS and MDA content in cells significantly decreased(P＜0.01).Conclusion Under hypoxic conditions,SIRT3 can promote cell apoptosis and inhibit lung cancer pro-gression by mediating ROS to inhibit oxidative stress response and HIF-1 α expression in lung cancer cells.