Wang Jitao, Zheng Weidong, Li Yuezhen, Xu Jihong, Jia Xiaomei, Miao Lin, Wu Junhong, Zhang Ping, An Teng, Xu Yang, Liang Lirong, Zhang Xiaohua
School of Public Health, Shanxi Medical University, No. 56, Xinjian South Road, Yingze District, Taiyuan, Shanxi Province, 030001, China.
Taiyuan Center for Disease Control and Prevention, No. 22, Huazhang West Street, Xiaodian District, Taiyuan, Shanxi Province, 030032, China.
BMC Infect Dis. 2025 Jul 24;25(1):943. doi: 10.1186/s12879-025-11305-7.
From July 23 to 24, 2022, Qingxu People's Hospital in Taiyuan reported an increase in acute gastroenteritis cases among individuals who had dined together.An investigation was initiated to identify factors associated with acute intestinal infection and to prevent further illness.
To isolate, cultivate, and identify pathogens, we collected samples from patients, food, and the environment. The isolated strains underwent multiple tests, including antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing (WGS). Based on the WGS data, analyses were conducted, including serotype prediction, resistance gene prediction, multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST), single nucleotide polymorphism (SNP) analysis, and phylogenetic analysis.
A total of 11 samples were collected from Patient 1's residence and the supermarket. These included 2 samples of leftover food from a family gathering, 4 samples of the supermarket environment, and 5 stool samples from 5 patients. Among these, two strains of Salmonella were isolated from the food, and three strains were isolated from the patients' stools. All five strains of Salmonella were identified as Salmonella Agona (S. Agona) and were susceptible to the 15 antibiotics tested. The PFGE banding patterns were identical among the strains. Bioinformatics analysis revealed that the isolated strains were all S. Agona of sequence type ST13 and cgMLST type cgST164980. They all carried the resistance genes aac(6')-laa and fosA7. SNP disparities ranged from 0 to 2. In the phylogenetic tree, the five strains of S. Agona isolated clustered closely together.
In this investigation of a food poisoning outbreak caused by S. Agona, we employed two key molecular techniques: Pulsed-Field Gel Electrophoresis (PFGE) and Whole Genome Sequencing (WGS). PFGE provided initial high-resolution DNA fingerprinting to identify bacterial strains and establish their clonal relatedness, offering preliminary but crucial insights into understanding the microbial causes of the epidemic. Subsequently, WGS delivered comprehensive genetic information with unparalleled precision, confirming that the pathogen was S. Agona and revealing its genomic characteristics. The integration of PFGE and WGS results provided strong evidence proving the epidemic was related to S. Agona. This comprehensive approach not only confirmed the etiology of the food poisoning event but also highlighted the power of molecular and genomic tools in modern epidemiological investigations. Our findings emphasize the importance of these techniques in rapidly and accurately identifying pathogens, thereby enabling timely public health interventions and reinforcing food safety measures to prevent similar outbreaks in the future.
2022年7月23日至24日，太原市清徐县人民医院报告称，一起聚餐人员中急性肠胃炎病例有所增加。随即展开调查，以确定与急性肠道感染相关的因素，并预防进一步发病。
为分离、培养和鉴定病原体，我们从患者、食物和环境中采集了样本。对分离出的菌株进行了多项检测，包括药敏试验、脉冲场凝胶电泳（PFGE）和全基因组测序（WGS）。基于WGS数据进行了分析，包括血清型预测、耐药基因预测、多位点序列分型（MLST）、核心基因组多位点序列分型（cgMLST）、单核苷酸多态性（SNP）分析和系统发育分析。
共从患者1的住所和超市采集了11份样本。其中包括2份家庭聚餐剩饭样本、4份超市环境样本和5名患者的5份粪便样本。其中，从食物中分离出2株沙门氏菌，从患者粪便中分离出3株。所有5株沙门氏菌均被鉴定为阿哥纳沙门氏菌（S. Agona），且对所检测的15种抗生素敏感。各菌株的PFGE条带模式相同。生物信息学分析显示，分离出的菌株均为序列型ST13和cgMLST型cgST164980的S. Agona。它们均携带耐药基因aac(6')-laa和fosA7。SNP差异范围为0至2。在系统发育树中，分离出的5株S. Agona紧密聚集在一起。
在本次由S. Agona引起的食物中毒暴发调查中，我们采用了两项关键分子技术：脉冲场凝胶电泳（PFGE）和全基因组测序（WGS）。PFGE提供了初步的高分辨率DNA指纹图谱，用于鉴定细菌菌株并确定其克隆相关性，为了解疫情的微生物病因提供了初步但至关重要的见解。随后，WGS以无与伦比的精度提供了全面的遗传信息，证实病原体为S. Agona并揭示了其基因组特征。PFGE和WGS结果的整合提供了有力证据，证明疫情与S. Agona有关。这种综合方法不仅证实了食物中毒事件的病因，还凸显了分子和基因组工具在现代流行病学调查中的作用。我们的研究结果强调了这些技术在快速准确鉴定病原体方面的重要性，从而能够及时采取公共卫生干预措施并加强食品安全措施，以预防未来类似的暴发。
