Serotype distribution, molecular type, and antimicrobial resistance of Salmonella isolated in Haidian district of Beijing, 2016–2019

  Objective  To analyze the serotype distribution, PFGE pattern and the antimicrobial resistance of Salmonella isolated from Haidian district of Beijing, and understand the circulating characteristics and antimicrobial resistance of Salmonella in Haidian.

  Methods  Serotyping, PFGE and antimicrobial resistance testing of 76 strains of Salmonella isolated in Haidian between 2016 and 2019 were conducted.

  Results  The proportion of Salmonella enteritidis was highest (59.2%, 45/76). In the 76 Salmonella strains, 35 PFGE patterns were detected. The similarity between these patterns was 48.7%–100.0%, and 51 strains of Salmonella formed 4 clusters (type similarity ≥85%). The 76 strains of Salmonella were all sensitive to imipenem (100.0%, 76/76). The intermediary rate to levofloxacin was highest (80.3%, 61/76). The resistance rate to nalidixic was highest (68.4%, 52/76). The overall multi-drug resistance rate was 52.6% (40/76), showing 27 multi-drug resistance spectrums.

  Conclusion  In the Salmonella strains isolated in Haidian from 2016 to 2019, the serotype and PFGE pattern showed high consistency, the strains with same serotype shared same or highly similar PFGE pattern and a strong association of antimicrobial resistance spectrums exited among the strains with same serotype and same PFGE pattern or in same cluster.