[Laboratory investigation for one gastroenteritis outbreak caused by ].

To understand the etiological characteristics of an acute gastroenteritis outbreak. Real-time polymerase chain reaction (PCR) and bacteria cultures were performed for the samples, including stool samples from patients and cooks, environmental swabs, raw food material (chicken meat), collected during the outbreak. Pulsed-field gel electrophoresis, antibiotics susceptibility test and whole-genome sequencing were performed for the isolates. Four stool samples from patients were positive for by real-time PCR, in which 1 strain was isolated from a case who had no antibiotic treatment. Twelve and 7 isolates were obtained from 4 raw chicken meat samples. The strain isolated from the case was resistant to nalidixic acid, ciprofloxacin, chloramphenicol, florfenicol and tetracycline. The MLST analysis with the whole-genome sequences confirmed that the isolate from the case belonged to ST10075. Antimicrobial resistance genes and were found in the genome of the isolate from the patient by the whole-genome sequencing. No mutation in 23S rRNA was found and the C257T mutation in was identified in this isolate. Laboratory analysis indicated that infection might be the major cause of this gastroenteritis outbreak.