Objective To investigate the contamination status of five foodborne pathogens (Salmonella, Listeria monocytogenes, Campylobacter jejuni, Yersinia enterocolitica, and Escherichia coli) in four categories of poultry and meat products sold in Jinan City, and to grasp the serotype, molecular typing features, and antibiotics resistance of isolated Salmonella, providing a reference for preventing foodborne disease outbreaks. Methods According to the "National Food Contaminants and Harmful Factors Risk Monitoring Work Manual", five types of foodborne pathogens were isolated from 132 samples of four categories of poultry and meat products sold in Jinan City from 2021 to 2022, and serotyping was performed using hemagglutination, and molecular typing was performed using pulse field gel electrophoresis (PFGE), while the drug sensitivity of isolates was tested by broth microdilution method. Results Pathogenic bacteria were detected in all four categories of poultry and meat products, with a positive sample detection rate of 53%. A total of 96 strains of pathogenic bacteria were detected from 132 samples, with a total detection rate of 72.7%. The highest detection rate of pathogenic bacteria was in raw poultry meat (93.3%). Among the isolates from raw poultry meat, Salmonella enteritidis was the predominant serotype, and Salmonella rissen was the predominant serotype in isolates from raw livestock meat. The similarity of 46 Salmonella strains ranged from 49.0% to 100.0%, with a total of 35 serotypes. Among them, the similarity of 36 strains was above 85.0%, accounting for 78.3% of the total. The strains isolated from raw poultry meat and livestock meat did not show clustering distribution in the dendrogram, and the isolates were resistant to a variety of antibiotics. Conclusions There is a serious pathogen contamination and food safety risk in raw poultry meat, raw livestock meat, and processed meat products in Jinan. The Salmonella isolates exhibit severe drug resistance, highlighting the need for relevant authorities to conduct risk assessment and implement reasonable risk control measures and drug resistance control measures.

Objective:To construct dual-targeting(CD38 and CD138)chimeric antigen receptor(CAR)gene-modified T cells(CD38/CD138 CAR-T cells)and explore their in vitro cytotoxicity against multiple myeloma(MM)cells.Methods:Based on the high expression of CD38 and CD138 antigens in MM cells,CD38 CAR-T cells and CD138 CAR-T cells targeting CD38 and CD138 respectively,and CD38/CD138 dual-targeted CAR-T cells targeting both CD38 and CD138 were constructed using CAR-T cell technology.The experimental groups included untreated T cells,CD38 CAR-T,CD138 CAR-T,and CD38/CD138 CAR-T cells.The phenotype of CAR-T cells was detected by flow cytometry.The cytotoxicity of various CAR-T cells against MM cells(RPMI8226 and U266)was assessed using the LDH release assay.Results:Three types of CAR-T cells,CD38 CAR-T,CD138 CAR-T,and CD38/CD138 CAR-T cells,were successfully constructed.The CD38/CD138 CAR-T cells tended to differentiate into a memory phenotype,expressing higher levels of proliferation marker(CD25),activation marker(CD27),and lower levels of exhaustion markers(PD-1,CTLA-4,TIM-3)(all P<0.001).Moreover,CD38/CD138 CAR-T cells were less prone to exhaustion and senescence,and expressed lower levels of r-H2AX,p-p53,p21,and p16 proteins(all P<0.01).Under different effector-to-target cell ratios,CD38/CD138 CAR-T cells exhibited stronger cytotoxic effects against RPMI8226 and U266 cells compared to CD38 CAR-T and CD138 CAR-T cells(all P<0.001).Conclusion:CD38/CD138 CAR-T cells targeting both CD38 and CD138 demonstrate an optimal phenotype and enhanced anti-tumor activity in vitro,offering promising potential for immunotherapy in multiple myeloma.