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 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.

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.

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 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.

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 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.

The continuing challenges that limit effectiveness of tumor therapeutic vaccines were high heterogeneity of tumor immunogenicity, low bioactivity of antigens, as well as insufficient lymph nodes (LNs) drainage of antigens and adjuvants. Transportation of in situ neoantigens and adjuvants to LNs may be an effective approach to solve the abovementioned problems. Therefore, an FA-TSL/AuNCs/SV nanoplatform was constructed by integrating simvastatin (SV) adjuvant loaded Au nanocages (AuNCs) as cores (AuNCs/SV) and folic acid modified thermal-sensitive liposomes (FA-TSL) as shells to enhance de novo antitumor immunity. After accumulation in tumor guided by FA, AuNCs mediated photothermal therapy (PTT) induced the release of tumor-derived protein antigens (TDPAs) and the shedding of FA-TSL. Exposed AuNCs/SV soon captured TDPAs to form in situ recombinant vaccine (AuNCs/SV/TDPAs). Subsequently, AuNCs/SV/TDPAs could efficiently transport to draining LNs owing to the hyperthermia induced vasodilation effect and small particle size, achieving co-delivery of antigens and adjuvant for initiation of specific T cell response. In melanoma bearing mice, FA-TSL/AuNCs/SV and laser irradiation effectively ablated primary tumor, against metastatic tumors and induced immunological memory. This approach served a hyperthermia enhanced platform drainage to enable robust personalized cancer vaccination.

ObjectiveTo explore the relationship between occupational stress， psychological capital and insomnia among nurses， and to test the mediating effect of psychological capital on the relationship between nurses' occupational stress and insomnia. MethodsStratified random sampling method was utilized in selecting 810 nurses from a tertiary A-level hospital from March to May 2021. The Effort-Reward Imbalance questionnaire （ERI）， Psychological Capital Questionnaire （PCQ） and Athens Insomnia Scale （AIS） were used to evaluate the occupational stress， psychological capital and insomnia of nurses， respectively. Then the mediation effect of psychological capital on the relationship between occupational stress and insomnia in nurses was tested by PROCESS macro program. ResultsA total of 658 （81.23%） questionnaires were effectively collected. Analysis found that nurses' effort-reward ratio was positively correlated with AIS score （r=0.379， P<0.01）， and negatively correlated with PCQ score （r=-0.275， P<0.01）. Nurses' PCQ score was negatively correlated with AIS score （r=-0.402， P<0.01）. Nurses' occupational stress could negatively predict psychological capital （β=-11.024， t=-7.324， P<0.01）， and positively predict insomnia （β=4.117， t=10.478， P<0.01）. Psychological capital could negatively predict insomnia （β=-0.087， t=-9.083， P<0.01）. The predictive effect of occupational stress on insomnia was statistically significant with psychological capital introduced as a mediating variable （β=3.158， t=8.185， P<0.01）. ConclusionPsychological capital plays a partial mediating role in the relationship between occupational stress and insomnia in nurses.