Enterotoxin gene profiles of Staphylococcus aureus isolated from environment and patients in a hospital in Shanghai from 2018 to 2021

Objective To 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.

Methods Specimens 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.

Results A 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.

Conclusion Prevalence 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.