ObjectiveTo explore the microbiological characteristics of Staphylococcus epidermidis with hemolytic phenotype （SEHP）. MethodsHemolytic phenotype was detected using the three-point inoculation method， involving a total of 5 strains of SEHP and 5 strains of Staphylococcus epidermidis with non-hemolytic phenotype （SENHP） . Bacterial species were identified using the Microflex LT MALDI-TOF mass spectrometer， and a phylogenetic tree was constructed through 16S rRNA sequence alignment. Growth curves were monitored through the microcultivation assay. Biofilm formation ability was assessed by microplate crystal violet staining. Red blood cell toxicity was detected using the microplate method. Antimicrobial susceptibility testing of SEHP and SENHP against commonly used antibiotics was performed using a VITEK 2 GP639 test kit. Antagonistic effects of SEHP and SENHP against Staphylococcus aureus and Corynebacterium striatum were evaluated by the Oxford cup inhibition assay. ResultsCompared with SENHP， SEHP exhibited a marked decrease in growth rate during the late logarithmic phase， accompanied by significant hemolytic toxicity. Additionally， it showed lower resistance rates to levofloxacin and moxifloxacin， and could antagonize Staphylococcus aureus and Corynebacterium striatum. ConclusionThe microbiological characteristics of SEHP differ from those of SENHP in that SEHP demonstrates antagonistic effects against S. aureus and C. striatum.

Objective : To investigate the causes of false negative results in the detection of Streptococcus agalactiae using fluorescent quantitative PCR(qPCR) targeting the CAMP factor gene(cfb),and to perform a comprehensive analysis of the associated molecular mechanisms. Methods: A total of 76 vaginal secretion samples were evaluated using both qPCR based on cfb gene and bacterial culture methods. Four suspicious strains exhibiting negative qPCR results but positive culture findings were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS),latex agglutination antigen detection,and the CAMP test. Whole genome analysis was conducted utilizing the MGI DNBSEQ-T7 and Nanopore-PromethION 48 sequencing platforms. Phylogenetic and circular evolutionary trees were constructed using the 16S rRNA gene for strain verification. Multilocus sequence typing(MLST) was conducted,and cfb sequences were aligned and analyzed based on spliced sequences and original data. Specific primers targeting the cfb gene were designed for full-length amplification,followed by verification through agarose gel electrophoresis. Results: The four strains identified as suspicious were classified as S. agalactiae through MALDI-TOF MS,antigen detection,and 16S rRNA gene analysis,with MLST typing indicating ST-862. Phenotypic analysis revealed a negative CAMP test. Whole genome sequence alignment failed to detect the cfb gene or any homologous sequences,and molecular testing confirmed the absence of cfb gene PCR amplification products,thereby confirming its complete deletion. Conclusion This deletion is identified as the molecular mechanism responsible for the false negative qPCR detection of S. agalactiae when targeting this specific gene.It is recommended that the qPCR detection targeting a single cfb gene has limitation,and this may impact clinical diagnosis and treatment decisions. This limitation warrants carefulconsideration.

Objective: To investigate the hemolytic phenotypes of Staphylococcus aureus clinical isolates． Methods: The hemolytic phenotypes of 105 Staphylococcus aureus isolates were analyzed and summarized using the three-point inoculation method．Real-time fluorescence quantitative PCR was used to measure the mRNA expression levels of four hemolysin genes (hla，hlb，hlc，and hld) ; The VITEK 2 GP639 antimicrobial susceptibility card was used to detect resistance to commonly used antibiotics ; DNA gel electrophoresis was performed to determine the prevalence of the mecA，sea，tst，and pvl genes ; The microtiter plate crystal violet staining method was used to assess biofilm formation ability ; The CCK-8 assay was used to evaluate cytotoxicity against macrophages． Results: Seven hemo- lytic phenotypes were identified among the Staphylococcus aureus clinical isolates． Differences were found among Staphylococcus aureus clinical isolates with different hemolytic phenotypes in terms of mRNA expression levels of he- molysin genes，antibiotic resistance，virulence gene prevalence，biofilm formation ability，and cytotoxicity to mouse macrophages (P ＜0. 05 ) ． Conclusion Staphylococcus aureus clinical isolates exhibit diverse hemolytic pheno- types，which should be a focus across multiple dimensions，including microbiological testing，clinical treatment， and nosocomial infection prevention and control．

Objective: To validate the analytical performance, operational performance, and process control measures of a domestic fully automatic nucleic acid testing (NAT) system, thereby ensuring an efficient and orderly blood screening workflow. Methods: The concordance rate and sensitivity of WanTag-Vortex Plus system were verified using WHO standard reference panels of HIV-1, HCV and HBV, while precision was assessed using weak positive samples of HIV-1, HCV and HBV. As for its operational performance evaluation, cross-contamination resistance was assessed using strong positive samples, and throughput and stress testing were conducted using negative samples. Reagent stability was verified using weak positive samples, and inter-system performance consistency was assessed using verification panels. In addition, the process control measures were verified using the laboratory quality control demand scale. Results: 1) Verification of concordance rate: The detection results of negative and positive samples of HIV-1, HCV and HBV by WanTag-Vortex Plus system were all consistent with expectations, and the concordance rate was 100%. 2) Precision verification: the repeatability and intermediate precision were extremely high, and the coefficient of variation was less than 5%. 3) Verification of analytical sensitivity: The detection limit of 95% for standard strains of HIV-1, HCV and HBV by WanTag-Vortex Plus system in our laboratory was consistent with the analytical sensitivity provided by reagent manufacturers. 4) Verification of cross-contamination resistance: Five strong positive samples and 87 negative samples were placed according to the actual working conditions and equipment operation design, and the test results were consistent with expectations, with no cross-contamination in the testing system. 5) Throughput and stress testing: Each system completed the individual donor-nucleic acid amplification testing (ID-NAT) of 276 samples in three batches within 12 hours, and successfully completed the ID-NAT test of 828 samples in three consecutive days. 6) Verification of reagent stability: After extreme storage (unsealed storage for 1 week with 4 freeze-thaw cycles), the reagents maintained 100% detection rate in the weak positive samples of HIV-1, HCV, and HBV, showing no significant differences from the control group (Kappa=1). 7) Verification of inter-system performance consistency: The system has stable operation performance, and the performance comparison results across the four devices were consistent (Kappa=1). 8) Process control measures: WanTag-Vortex Plus system software accurately controlled the equipment operation process with strict quality control measures, and correctly interpreted and safely reported the test results. Conclusion: The analytical and operational performance of the WanTag-Vortex Plus system complies with manufacturer design standards and essential laboratory workflow requirements. Integrated with laboratory information system (LIS), the system's control software meets standard process control requirements, yet requires further improvement.

Objective : To investigate the antagonistic activity of Lactococcus garvieae SHAMU-LG6 against Staphy- lococcus . Methods : VITEK 2 GP identification card , Microflex LT MALDI-TOF mass spectrometer and 16S rDNA amplification sequencing were used to identify the strain species . The antagonistic activity of L. garvieae SHAMU- LG6 against different Staphylococcus was detected by Oxford cup method for bacterial inhibition ; the antimicrobial active components were preliminarily isolated and purified by adsorption on XAD16 nonionic macroporous resin , gradient ethanol elution and rotary evaporation drying. Results : L. garvieae SHAMU-LG6 exhibited potent antago- nistic effect against methicillin-resistant Staphylococcus aureus , methicillin-susceptible S. aureus , S. epidermidis , S. saprophyticus , S. lugdunensis , S. hominis , S. capitis and S. warneri , with inhibitory indices of 3 . 3 , 3 . 0 , 4. 3 , 2. 0 , 4. 0 , 3 . 5 , 3 . 8 , and 3 . 5 , respectively. The antimicrobial active components produced by L. garvieae SHAMU-LG6 were mainly present in 70% and 80% ethanol eluates . Conclusion L. garvieae SHAMU-LG6 ex- hibits a potent antagonistic effect on Staphylococcus , and the antimicrobial active components produced by it are ex- pected to be a lead compound for the development of novel antimicrobial agents .

Objective : To explore the molecular characteristics of four CAMP negativeStreptococcus agalactiae(S.agalactiae) in whole genome sequencing. Methods : The identification of suspicious bacterial strains was conducted using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS). For the strains confirmed asS.agalactiaethrough identification, further CAMP experiments were conducted. For CAMP negative strains, whole genome sequencing was performed using MGI DNBSEQ-T7 and MinION Flow Cell sequencing platforms. Subsequently, multi-locus sequence typing(MLST), virulence genes and resistance genes of the strains were compared and analyzed using various databases. Phoenix M50 fully automatic drug sensitivity analyzer was employed to determine the sensitivity of the bacterial strains to commonly used antibiotics. Results: Four CAMP-negativeS.agalactiaestrains were included. Whole-genome sequencing analysis revealed that all four CAMP-negativeS.agalactiaestrains belonged to the ST862 type. These strains harbored 22 virulence genes associated with capsular polysaccharides, β-hemolysin, and hyaluronidase, as well as seven resistance genes linked to macrolides, lincosamides, polypeptides, and aminoglycosides. Antimicrobial susceptibility testing revealed that CAMP-negativeS.agalactiaewas susceptible to penicillin G, cefepime, cefotaxime, and vancomycin. However, three strains exhibited resistance to erythromycin, and one strain demonstrated resistance to clindamycin. Conclusion Four CAMP negativeS.agalactiaeof the ST862 type possess multiple virulence and drug resistance genes, showing high resistance to erythromycin, warranting clinical attention.

Objective:To construct a VP8-mRNA vaccine using human rotavirus spike protein VP8 domain as the immunogen and analyze its immunogenicity in mice.Methods:The VP8-mRNA sequence was designed, optimized, and synthesized. The VP8 gene of rotavirus G1P[8] type was used to construct the plasmid pUC57-VP8-Kan-SapⅠ, which was then sequenced. The plasmid confirmed by sequencing was subjected to large-scale amplification and extraction, followed by linearization, in vitro transcription, and capping. The purified capped products were encapsulated with lipid nanoparticles using a microfluidic control apparatus. The encapsulated VP8-mRNA vaccine was administered intramuscularly to mice at 10, 15, and 20 μg. Serum samples were collected for antibody detection by ELISA. Cellular immune responses were detected by flow cytometry and ELISPOT. Statistical analysis was performed using one-way or two-way analysis of variance and Tukey-Kramer test. Results:The encapsulated VP8-mRNA vaccine was rounded and spherical, with a particle size of about 100 nm, a polymer dispersion index of 0.088, and an encapsulation rate of 92.3%. Two doses of VP8-mRNA vaccine immunization could induce a good immune response in mice. The level of IgG antibody induced after immunization in the 15 μg group was comparable to that of the 20 μg group, and there was no statistical difference ( P>0.05), but the antibody levels in the two groups were significantly higher than that in the 10 μg group ( P<0.000 1). VP8-mRNA vaccine could induce neutralizing antibodies against rotavirus G1 and G9 types. The highest level of neutralizing antibodies against rotavirus type G1 was observed in the 15 μg group, which was significantly higher than that in the 10 μg group ( P<0.05). All immunization groups exhibited good neutralizing ability against rotavirus G9 type. The results of ELISPOT showed that lymphocytes from mice in each vaccine group were able to secrete IFN-γ when stimulated with VP8 peptide. Flow cytometry showed that the proportions of CD8 + T cell subsets in the vaccine groups were higher than that in the control group. Conclusion:The VP8-mRNA vaccine has good immunogenicity in mice and can induce good humoral and T-cell immune responses.

Objective: To validate the analytical performance, operational performance, and process control measures of a domestic fully automatic nucleic acid testing (NAT) system, thereby ensuring an efficient and orderly blood screening workflow. Methods: The concordance rate and sensitivity of WanTag-Vortex Plus system were verified using WHO standard reference panels of HIV-1, HCV and HBV, while precision was assessed using weak positive samples of HIV-1, HCV and HBV. As for its operational performance evaluation, cross-contamination resistance was assessed using strong positive samples, and throughput and stress testing were conducted using negative samples. Reagent stability was verified using weak positive samples, and inter-system performance consistency was assessed using verification panels. In addition, the process control measures were verified using the laboratory quality control demand scale. Results: 1) Verification of concordance rate: The detection results of negative and positive samples of HIV-1, HCV and HBV by WanTag-Vortex Plus system were all consistent with expectations, and the concordance rate was 100%. 2) Precision verification: the repeatability and intermediate precision were extremely high, and the coefficient of variation was less than 5%. 3) Verification of analytical sensitivity: The detection limit of 95% for standard strains of HIV-1, HCV and HBV by WanTag-Vortex Plus system in our laboratory was consistent with the analytical sensitivity provided by reagent manufacturers. 4) Verification of cross-contamination resistance: Five strong positive samples and 87 negative samples were placed according to the actual working conditions and equipment operation design, and the test results were consistent with expectations, with no cross-contamination in the testing system. 5) Throughput and stress testing: Each system completed the individual donor-nucleic acid amplification testing (ID-NAT) of 276 samples in three batches within 12 hours, and successfully completed the ID-NAT test of 828 samples in three consecutive days. 6) Verification of reagent stability: After extreme storage (unsealed storage for 1 week with 4 freeze-thaw cycles), the reagents maintained 100% detection rate in the weak positive samples of HIV-1, HCV, and HBV, showing no significant differences from the control group (Kappa=1). 7) Verification of inter-system performance consistency: The system has stable operation performance, and the performance comparison results across the four devices were consistent (Kappa=1). 8) Process control measures: WanTag-Vortex Plus system software accurately controlled the equipment operation process with strict quality control measures, and correctly interpreted and safely reported the test results. Conclusion: The analytical and operational performance of the WanTag-Vortex Plus system complies with manufacturer design standards and essential laboratory workflow requirements. Integrated with laboratory information system (LIS), the system's control software meets standard process control requirements, yet requires further improvement.

Aortic aneurysm(AA)and aortic dissection(AD)are critical cardiovascular disease emergencies that seriously threaten human life and health.Due to various factors,the progressive reduction of various types of cells,such as smooth muscle cells and endothelial cells in the aortic wall,is an essential mechanism for developing AA and AD.On this basis,AD is induced by mechanical stresses such as hypertension,leading to damaged endothelial rupture or hemor-rhage within the aortic wall.However,AA causes the aortic wall to thin and expand outward in response to stimuli such as prolonged blood flow impingement.At present,increasing evidence shows that various programmed cell death,such as apoptosis,necroptosis,pyroptosis,ferroptosis,copper death,poly ADP-ribose polymerase 1(PARP-1)-dependent cell death,and immunogenic cell death,play essential roles in the pathogenesis of AA and AD.Therefore,understanding the key molecules and pathways in the pathogenesis of AA and AD from the perspective of programmed cell death and searching for inhibitors of various types of programmed death is essential to prevent aortic destruction and disease progression.The review summarizes the roles and research progress of different types of programmed cell death modalities in the development of AA and AD,clarifies the central position of programmed cell death in forming AA and AD,and searches for new thera-peutic methods for the clinic.

Objective:To construct a VP8-mRNA vaccine using human rotavirus spike protein VP8 domain as the immunogen and analyze its immunogenicity in mice.Methods:The VP8-mRNA sequence was designed, optimized, and synthesized. The VP8 gene of rotavirus G1P[8] type was used to construct the plasmid pUC57-VP8-Kan-SapⅠ, which was then sequenced. The plasmid confirmed by sequencing was subjected to large-scale amplification and extraction, followed by linearization, in vitro transcription, and capping. The purified capped products were encapsulated with lipid nanoparticles using a microfluidic control apparatus. The encapsulated VP8-mRNA vaccine was administered intramuscularly to mice at 10, 15, and 20 μg. Serum samples were collected for antibody detection by ELISA. Cellular immune responses were detected by flow cytometry and ELISPOT. Statistical analysis was performed using one-way or two-way analysis of variance and Tukey-Kramer test. Results:The encapsulated VP8-mRNA vaccine was rounded and spherical, with a particle size of about 100 nm, a polymer dispersion index of 0.088, and an encapsulation rate of 92.3%. Two doses of VP8-mRNA vaccine immunization could induce a good immune response in mice. The level of IgG antibody induced after immunization in the 15 μg group was comparable to that of the 20 μg group, and there was no statistical difference ( P>0.05), but the antibody levels in the two groups were significantly higher than that in the 10 μg group ( P<0.000 1). VP8-mRNA vaccine could induce neutralizing antibodies against rotavirus G1 and G9 types. The highest level of neutralizing antibodies against rotavirus type G1 was observed in the 15 μg group, which was significantly higher than that in the 10 μg group ( P<0.05). All immunization groups exhibited good neutralizing ability against rotavirus G9 type. The results of ELISPOT showed that lymphocytes from mice in each vaccine group were able to secrete IFN-γ when stimulated with VP8 peptide. Flow cytometry showed that the proportions of CD8 + T cell subsets in the vaccine groups were higher than that in the control group. Conclusion:The VP8-mRNA vaccine has good immunogenicity in mice and can induce good humoral and T-cell immune responses.