Objective To probe into the feasibility and applicability of the foodborne food risk monitoring and sentinel hospital foodborne disease surveillance on the Salmonella serotype identification by liquid phase suspension array. Methods The serotyping of Salmonella isolates was performed by traditional glass agglutination test. Meanwhile, the liquid phase suspension array was operated to analyze the antigen O, H and AT for classification identification. Results From 2012 to 2019, a total of 215 strains of Salmonella were collected divided into 38 serotypes, 96% of them could be analyzed by SSA kit. The results of xMAP were in accordance with the traditional agglutination. 8 of the 11 strains which cannot be checked out by glass agglutination seemed to be easy detected by liquid phase suspension array. Conclusion The liquid phase suspension array has advantages of high throughput, high sensitivity and high specificity. It is able to detect the Salmonella serotype rapidly during a short time. Compared with the traditional serum agglutination method, the liquid phase suspension array has obvious advantages in detection time. It can be useful and important in the break out of foodborne disease caused by Salmonella spp.

Objective To investigate the source of microbial contamination in the clean room of the workshop. Methods Microbiological sampling was carried out from the air, environment and personnel of the workshop. The samples were cultivated, the microorganisms were detected by MALDI-TOF-MS, and homology analysis was performed with the microbial identification system of the instrument. Results A total of 14 species and 41 strains of bacteria were detected. Nine strains of Staphylococcus epidermidis were selected for homology analysis, and the Staphylococcus epidermidis from personnel gloves and headgear had 94% homology. There was 83% homology among the staphylococcus epidermidis derived from the sedimentation bacteria, the ground environment and personnel, which was higher than the 71% of the standard strain. Conclusion The homology analysis demonstrates that the pollution in the clean room of the workshop mainly comes from personnel, and secondly comes from the environment outside the workshop. Enterprises need to strengthen management to prevent the occurrence of microbial contamination. MALDI-TOF-MS can be used for rapid detection of complex environmental bacteria and for homology analysis.

Objective To analyze serotype distribution, drug resistance, quinolone resistance gene carrying status and genetic relationship of foodborne Salmonella and human Salmonella isolates in Changzhou from 2012 to 2018, to provide scientific basis for the prevention and control of Salmonella. Methods The serum type was identified by serum agglutination and liquid chip. The antibiotic sensitivity was determined by micro broth dilution method. The quinolone antibiotic resistance gene was determined by gene sequencing method. The multilocus sequence typing ( MLST ) typing was performed on quinolone-resistant Salmonella, and the genetic relationship was analyzed by BioNumerics 8.0. Results A total of 10 and 36 serotypes were detected in 46 foodborne Salmonella strains and 152 human Salmonella strains, respectively. The dominant serotypes were Indiana Salmonella and Salmonella typhimurium. Erythromycin resistance rate was the highest in both Salmonella strains, and the proportion of multidrug-resistant bacteria was 93.47 % ( 43 / 46 ) and 80.92 % ( 123 / 152 ), respectively. 38 strains of quinolone-resistant foodborne Salmonella GyrA subunit mainly occurred double mutations Asp87Asn, Ser83Phe, ParC subunit mainly occurred single mutation Ser80Arg, 119 strains of quinolone-resistant human Salmonella qnrS gene detection rate was higher, reached 68.1 % ( 81 / 119 ) ; The dominant ST types of quinolone-resistant Salmonella from two sources were ST17 and ST19, respectively. Conclusions The antibiotic sensitivity of the two Salmonella resistant strains from Changzhou was the same ; Synergistic drug resistance, but both quinolone resistance genemutations and carry inconsistent ; The ST type distribution of quinolone resistant strains isalso inconsistent, and the genetic relationship is far. It is suggested that the probability of Salmonella resistant bacteria infection caused by food transmission in our region is small, and the treatment of the two should be differentiated.