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ObjectiveTo investigate the contamination status of Staphylococcus aureus in food and the presence of enterotoxin genes in Jiading District, Shanghai, and to provide a basis for the prevention and treatment of foodborne Staphylococcus aureus disease.MethodsFrom 2021 to 2023, 15 types of food were sampled for S. aureus testing, and the presence of five enterotoxin genes, including sea⁃see, was tested in the strains.ResultsOut of 705 food samples, 88 (12.48%) were positive for S. aureus. S. aureus was detected in 12 of the 15 food types, with the three food types with the highest positive rates being cold noodles (45.00%), raw poultry (26.25%), and vegetable salads (20.00%). The enterotoxin gene carriage rate was 32.95% in food strains. The carriage rates for sea, seb, and sec were 7.95%, 12.50%, and 14.77%, respectively. Neither sed nor see was detected. The detection rate of strains carrying two types of enterotoxin genes was 2.27%. The enterotoxin carriage rates in strains from vegetables, beverages, and raw meat were 57.14%, 40.00%, and 30.00%, respectively.ConclusionThe S. aureus detection rate in food in Jiading District is much higher than the national average. The enterotoxin gene carriage rates are high, with food strains carrying sea, seb, and sec, with sec being the most prevalent. There is a need to enhance monitoring of S. aureus and enterotoxins, especially in high-risk foods such as noodles, vegetables, and non-packaged beverages.

ObjectiveTo investigate the contamination status， serotype distribution and drug resistance of Salmonella in retail poultry in Jiading District， Shanghai.MethodsFour types of poultry （chicken， duck， goose and pigeon） have been sampled from commercial markets. Salmonella contamination has been isolated and identified using serotype analysis. Furthermore， resistance of isolated Salmonella strains towards 16 commonly used antibiotics has been determined.ResultsA total of 60 Salmonella strains were isolated from 80 poultry samples. The detection rates of Salmonella in pigeon， goose， duck and chicken were 86.67%， 81.82%， 72.73% and 59.38%， respectively. Contamination status has been categorized by storage conditions. Lowest detection rate （65.63%） has been noted in poultry samples under refrigeration storage. The majority serotypes of Salmonella have been revealed as Salmonella typhimurium， Salmonella enteritidis and Salmonella corvallis. Relatively higher drug resistance was discovered with tetracycline， nalidixic acid， ampicillin and chloramphenicol， with drug resistance rate of 60.00%， 58.33%， 50.00% and 48.33%， respectively. Low drug resistance was revealed with cefotaxime. In addition， these Salmonella strains were completely sensitive to imipenem. Significant difference in drug resistance was identified across the types of poultry or Salmonella serotypes. The 11.67% of Salmonella strains were non-resistant to any tested drugs. Multi-drug resistant strains accounted for 46.67% of isolated strains， which were resistant to 13 different antibiotics. Ampicillin-tetracycline or chloramphenirol-cefazolin drug resistance pattern suggested that the Salmonella strain was multi-drug resistant.ConclusionSalmonella contamination remains high in retail poultry in Jiading District， Shanghai. Drug resistance to antibiotics is increasing. Therefore， monitoring and control of Salmonella should be strengthened.

ObjectiveTo investigate the prevalence of Staphylococcus aureus in a hospital in Jiading District， Shanghai， and to determine the enterotoxin gene profiles of Staphylococcus aureus isolated from patients and environment.MethodsSpecimens were collected from environment and patients from a hospital for Staphylococcus aureus isolation and identification. Furthermore， enterotoxin genes （SEA‒SEE） of Staphylococcus aureus were detected.ResultsA total of 54 Staphylococcus aureus strains were isolated from 780 hospital environmental specimens from 2018 to 2021， with a prevalence of 6.92%. In the armrests in the wards， patient’s pillows/quilts， and bedside cupboards， the prevalence was determined to be 20.00%， 20.00% and 16.67%， respectively. In contrast， in the computer’s mouse and keyboard and work clothes of physicians and nurses， the prevalence was 17.42% and 16.67%， respectively. Meanwhile， from 2018 to 2021， a total of 75 strains were collected from patients， of which 36.00%， 14.67% and 14.67% were from the departments of intensive care medicine （ICU）， neurosurgery and orthopedics， respectively. The prevalence of Staphylococcus aureus enterotoxin genes were 48.15% and 61.33% in the environment and patients， respectively. Furthermore， the prevalence of SEA， SEB， SEC， SED， and SEE genes were 14.67%， 41.33%， 9.33%， 1.33%， 1.33% in patients， respectively ， whereas 20.37%， 25.93%， 1.85 %， 1.85% and 0% in environmental specimens， respectively. In the environmental specimens isolated from comprehensive ICU， the prevalence of enterotoxin genes was 77.27%. In the patient's specimens， Staphylococcus aureus was mostly isolated in sputum. Additionally， the prevalence of enterotoxin genes was high in the patients of departments of respiratory medicine， ICU， and orthopedics.ConclusionPrevalence of Staphylococcus aureus remains moderate in the hospital environment. Enterotoxin genes of Staphylococcus aureus are common， with seb gene as the most common gene， followed by SEA gene. It warrants strengthening the disinfection and control of Staphylococcus aureus in the hospital， especially in the ICU.

ObjectiveTo investigate the contamination status and drug resistance of Campylobacter spp. in poultry sold in Jiading District， Shanghai.MethodsFour types of poultry meats （chickens， ducks， geese and pigeons） were sampled from commercial markets， and potential Campylobacter spp. contamination was isolated and identified. Furthermore， resistance of isolated Campylobacter spp. to 15 commonly used antibiotics was tested.ResultsTotally 29 Campylobacter jejuni strains and 34 Campylobacter. coli were isolated from 236 commercial poultry samples. The most severe contamination of Campylobacter spp. was found in chicken samples， with a detection rate of 34.04%， while the lowest detection rate of Campylobacter spp. was found in duck （19.67%）. Contamination status was categorized with different storage conditions. The lowest detection rate of 6.67% was noted under frozen condition， while highest detection rate of 41.27% was noted under cold storage. Campylobacter jejuni was completely resistant to cefazolin， ciprofloxacin， nalidixic acid and tetracycline， and Campylobacter coli was completely resistant to cefazolin， cefoxitin and nalidixic acid； Campylobacter spp. showed the lowest resistance to imipenem. Multi-drug resistant strains accounted for 100.00% of the isolated strains. 96.83% of the strains were resistant to more than 5 drugs， with the highest number reaching 14 kinds of antibiotics.ConclusionThere is a significant difference in the contamination status and drug resistance of Campylobacter spp. isolated from four types of poultry meats sold in Jiading District， Shanghai， and the drug resistance is serious. It is strongly recommended that the use of antibiotics should be strictly controlled. Freezing can effectively reduce Campylobacter spp. pollution.

ObjectiveTo investigate the contamination situation， serotype distribution and drug resistance of salmonella in poultry sold in Jiading District， Shanghai.MethodsBetween 2019 and 2020， four types of poultry meat （chicken， duck， goose and pigeon） were sampled from markets， and potential salmonella contamination was isolated and identified via serotyping. Furthermore， resistance detection of isolated salmonella to 13 commonly-used antibiotics was conducted.ResultsA total of 32 salmonella strains were isolated from 156 commercial poultry samples. No salmonella was identified in pigeon samples， while the most severe contamination was detected in goose samples， with a detection rate of 28.00%. Contamination situation was categorized with different storage conditions. The lowest detection rate of 12.90% was noted under cold storage， while the highest rate of 26.67% was detected under frozen condition. The major serotypes of salmonella were Salmonella typhimurium， Salmonella enteritidis and Salmonella Argonne. Relatively higher drug resistance was detected with nalidixic acid and tetracycline， with drug resistance rate of 59.38% and 40.63%， respectively. Low drug resistance was detected with cephalosporins， and no drug resistance was detected with imipenem. Significant difference in drug resistance was noted in the serotype of Salmonella isolated from meat of chicken， duck and goose. Three major salmonella strains had different drug resistance. 21.88% （7/32） of salmonella strains were non-resistant to any tested drugs. Multi-drug resistant strains accounted for 31.25% （10/32） of the isolated strains. At most， salmonella was resistant to 11 kinds of different antibiotics.ConclusionThere is a significant difference in the contamination situation and drug resistance of Salmonella isolated from four types of poultry meat sold in Jiading District， Shanghai. It is strongly recommended that different supervision strategies and management upon classification be implemented.

In this study, five drying methods (hot air drying [HD], light wave drying [LD], far infrared drying [FID], freeze drying [FD], and heat pump drying [HPD]) were applied to dry Sargassum fusiforme. The color, rehydration rate (RR), and volatile flavor substances of dried S. fusiforme were compared and analyzed, and the content, molecular weight (Mw), monosaccharide composition, and antioxidant activity of dried S. fusiforme crude polysaccharides (SFCPs) were analyzed. The results showed that S. fusiforme dried by different drying methods showed different colors. FD produced S. fusiforme with better RR (p < 0.05). The Mw of the SFCPs were 624.06, 534.86, 683.00, 1077.13, and 981.91 kDa, respectively, for HD, LD, FID, FD, and HPD. The Mw and DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) radical scavenging rates of SFCP‐FD were greater than those of the remaining four drying methods; however, the ABTS (2,2 ′‐azobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid) and OH (hydroxyl) radical scavenging rates were highest in the SFCP‐HPD. GC‐IMS analysis showed that the drying method affected the content and composition of volatile flavor compounds. Principal component analysis (PCA) analysis indicated that the flavors of dried S. fusiforme were quite different from that of fresh S. fusiforme, and the flavors of HD, LD, and FID were similar, while the flavors of FD and HPD were similar. [ABSTRACT FROM AUTHOR]