ABSTRACT
@#Abstract: Objective To investigate the prevalence and pathogenic characteristics of Yersinia enterocolitica infection in children with diarrhea under 5 years of age in western Yunnan, and to provide a basis for the prevention and treatment of infectious diarrhea in children. Methods Feces were collected from under five-year-old children with diarrhea in the First Affiliated Hospital of Dali University from 2020 to 2021. Clinical information of the cases was also collected. Yersinia enterocolitica was isolated from the samples after cold enrichment on selective culture plates, and the pathogenic characteristics of Yersinia enterocolitica were analyzed by biological type and serotype and virulence gene detection. Results A total of 397 feces were collected. Seven strains of Yersinia enterocolitica were isolated in three samples, and the prevalence of Yersinia enterocolitica infection was 0.76% (3/397). Among the three positive samples, two Yersinia frederiksenii or Yersinia intermedia were isolated in specimen No. 212 , and five Yersinia enterocolitica were detected in specimens No. 24 and 226. Two Yersinia enterocolitica isolated from one sample were biological type 1A, and the virulence gene test results were ail-/ystA-/ ystB+ /yadA-/virF-, which were non-pathogenic Yersinia enterocolitica. Three Yersinia enterocolitica isolated from the other sample were biological type 3, serotype O∶3 (rfbc+), and virulence gene detection results were ail+/ystA+/ystB-/yadA+ /virF+, which were pathogenic Yersinia enterocolitica. While pathogenic Yersinia enterocolitica was detected from feces of children with diarrhea at 11 months of age with a infection rate of 0.50%(2/397). Conclusion Sporadic infection of pathogenic Yersinia enterocolitica was found in under five-year-old children in western Yunnan Province. It is necessary to strengthen the monitoring and research of Yersinia enterocolitica.