Abstract: Objective To understand the bacterial isolation situation,serotype,virulence genes,and drug sensitivity test results in the monitoring of bacterial infectious diseases based on the pathogenic bacteria identification network in Dalian City in 2023. Methods In 2023,relevant bacterial isolation and identification were carried out in Dalian City according to the methods in the Laboratory monitoring technical manual of the national pathogenic bacteria identification network（2022 trial edition）. According to GB 4789.4-2016 National food safety standard for microbiological examination of food-Salmonella test,the serum typing of Salmonella was carried out using the slide agglutination method. According to the instructions of the Triple real-time fluorescence PCR detection kit for Vibrio parahaemolyticus tlh/tdh/trh,fluorescence quantitative PCR method was used to detect the virulence genes of Vibrio parahaemolyticus. According to the user manual of Sensititre^TM Gram negative bacteria MIC drug sensitivity board,the drug sensitivity of Vibrio parahaemolyticus,Salmonella,and Escherichia coli causing diarrhea was detected using the broth microdilution method. Results In 2023,a total of 765 samples from five kinds of three categories were monitored in Dalian City. Among 445 samples related to diarrhea,the highest detection rate was Vibrio parahaemolyticus（22.25%）. There were 258 respiratory infection related samples,including 38 pertussis related samples,two strains of Bordetella pertussis were detected（5.26%）. Among 98 respiratory related-pneumonia samples,the highest detection rate was Klebsiella pneumoniae（27.55%）. Among 122 respiratory related- other samples,one strain of Staphylococcus aureus and one strain of Citrobacter were detected. Out of 62 samples related to natural epidemics,four strains of Brucella were detected（6.45%）. 13 strains of Salmonella were identified,with a total of 10 serotypes,without any dominant serotypes. Salmonella bredan and Salmonella enteritis were slightly more common. The detection rate of tlh,tdh and trh for 99 strains of Vibrio parahaemolyticus was 100.00%,77.78% and 0,respectively. Vibrio parahaemolyticus, Salmonella,and Escherichia coli causing diarrhea all had varying degrees of resistance,with Salmonella showing the most severe resistance.10 strains of bacteria were resistant to three or more antibiotics,and four strains of Vibrio parahaemolyticus were resistant to carbapenems. Conclusion The composition of infectious disease pathogens in different regions is different,and the characteristics of strains are also different,and it is of great significance to isolate and identify bacteria from infectious diseases,and to detect the serotype,virulence gene and drug sensitivity of the isolated bacteria.

Key words: Pathogenic bacteria identification network, Bacterial infectious diseases, Serotypes, Toxicity genes, Drug sensitivity