[Pathogenic detection and molecular tracing of a bacillary dysentery outbreak by Shigella sonnei in Huainan city].

To understand the virulence gene and drug resistance profile of outbreak in Huainan city, and conduct pathogenic traceability analysis. Water samples and feces related to an infectious diarrhea outbreak in Huainan city in August 2020 were collected for multiple pathogen detection. Virulence gene, drug sensitivity, pulse-field gel electrophoresis and whole genome sequencing of isolates were analyzed respectively. 38 strains of were detected in 56 samples of mucilage feces with a positive rate 67.86%, and all serotypes were Phase I. Three strains of were detected by fluorescence PCR in the Gram-negative (GN) bacterial enrichment solution of terminal water and well water. Virulence genes were positive (38), (31) and positive (1), respectively. The drug resistance spectrum showed that 9 of 14 antibiotics were 100% resistant, and only imipenem, chloramphenicol, ceftazidime and ciprofloxacin were effective drugs. Ⅰ restriction enzyme map type of 36 isolates was completely consistent, and the ST type analysis of 3 strains was ST152. Whole genome sequencing and analysis verified that the outbreak was caused by a single clonal group of strains, and revealed that the isolates of the outbreak were clustered into a large cluster with 3 Chinese strains and 1 Korean strain in the database, far away from the strains of other countries. The outbreak is caused by a single clone of , which are low virulence strains and have multiple drug resistance.