【摘要】 目的 了解上海市肉品和水产品中分离致泻大肠埃希菌（DEC）的生物学特征及耐药性，为防控由该菌引起的食源性疾病提供科学依据。方法对食品分离DEC菌株进行全基因组测序及药物敏感性试验，利用BioNumerics软件对全基因组测序数据进行拼接，利用拼接序列开展多位点序列分型、毒力基因和耐药基因分析。结果本研究中56株DEC菌株中肠道聚集性大肠埃希菌（EAEC）占比最高，达73.2%，且以astA基因为主（90.2%）。56株DEC分为37个ST型，显示高度多样性。DEC菌株对喹诺酮类抗生素耐药性较高（64.3%），其次是对氨基糖苷类、β-内酰胺类抗生素和四环素类抗生素耐药，且多重耐药性菌株占48.2%，耐药基因相应的以喹诺酮类、氨基糖苷类、β-内酰胺类抗生素耐药基因为主，且大多数对抗生素耐药的菌株均携带其相应的耐药基因。结论 EAEC是上海市食品中分离DEC菌株的主要型别，对喹诺酮类、β-内酰胺类、氨基糖苷类抗生素的耐药率较高，且携带相应的耐药基因，全基因组测序技术可应用于DEC的分子生物学监测中，为疾病预防控制提供科学依据。更多还原

【Abstract】 Objective This study aimed to analyze the molecular characteristics and antibiotic resistance of diarrheagenic Escherichia coli(DEC) from meat and aquatic products in Shanghai City.Methods The DEC isolates were characterized by applying antibiotic tests and whole genome sequencing(WGS). The BioNumerics software was used to analyze and assemble WGS data. Then, multilocus sequence typing sequencing, virulence profiles, and antibiotic-resistant genes were analyzed adopting assembled genome sequences. The antimicrobial susceptibility was investigated.Results In this study, most DEC isolates were EAEC(73. 2%), and most of the EAEC isolates carried only the astA gene(90. 2%). All 56 DEC isolates have been typed as 37 STs. The resistance rate to NAL was higher(64. 3%),followed by aminoglycoside, beta-lactam, and tetracycline. The multi-drug resistant DEC isolates were 48. 2% resistant; furthermore, the resistance genes were detected in these DEC isolates.Conclusion EAEC isolates are dominant DEC isolates from foods in Shanghai City. Furthermore, these DEC isolates exhibited a higher resistance rate, compared with the corresponding resistance genes. These results suggest that molecular surveillance should be enhanced. Moreover, fundamental data can be obtained by employing the WGS for tracing DEC isolates and analyzing pathogenicity.更多还原