Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, Bursa Uludag University, Gorukle Bursa, 16059, Türkiye.
Department of Aquatic Animal Disease, Faculty of Veterinary Medicine, Bursa Uludag University, Gorukle Bursa, 16059, Türkiye.
BMC Genomics. 2024 Nov 1;25(1):1027. doi: 10.1186/s12864-024-10945-4.
This study aimed to assess the prevalence and genomic characteristics of Shiga-toxigenic (STEC) and Enteroaggregative E. coli (EAEC) strains in raw mussels and ready-to-eat (RTE)-stuffed mussels, focusing on potential public health implications for identifying virulence and antimicrobial resistance genes.
The genome sequence analysis identified the E. coli strain named 23EM as serotype O111:H12, with adhesion (fimH-54) and fumarate hydratase (fumC-11) genes. The draft genome (4.9 Mb, 50.6% GC content, 111 contigs, 4,688 genes) is available in NCBI GenBank (accession JAWXVJ000000000). The strain, classified as ST292 and CC ST10, showed high similarity to nonpathogenic E. coli MG1655 but was distinct from pathogenic strains such as EAEC and ExPEC. In silico serotyping revealed the presence of O111-antigen flippase (wzx) and H12-antigen flagellin (fliC) genes. The strain harbors an IncFII (pCoo) plasmid with 96.95% identity. PathogenFinder predicted a 92% probability of being a human pathogen, supported by 720 pathogenic protein families. CRISPR analysis identified one high-evidence sequence with nine spacers and six low-evidence sequences. Phylogenetic analysis using RAxML positioned 23EM close to nonpathogenic E. coli but distant from other pathogenic strains. Antimicrobial resistance genes across multiple classes, including macrolides, fluoroquinolones, and aminoglycosides, were identified. The strain also contains several virulence factors, such as adhesins (e.g., ECP, ELF, TIF, type IV pili), and autotransporter genes (espP, pic), highlighting its significant pathogenic potential and public health risk.
This study highlights the ability of the detection of E. coli strains harboring virulence and antimicrobial resistance genes in mussels, thus emphasizing the importance of ongoing surveillance and careful consideration of the potential risks associated with the consumption of these shellfish.
本研究旨在评估贝类和即食贻贝类中肠产毒性（STEC）和肠聚集性大肠杆菌（EAEC）菌株的流行率和基因组特征，重点关注鉴定毒力和抗微生物药物耐药基因的潜在公共卫生意义。
基因组序列分析鉴定出一株名为 23EM 的大肠杆菌血清型为 O111:H12，具有粘附（fimH-54）和延胡索酸水合酶（fumC-11）基因。该草案基因组（4.9 Mb，GC 含量为 50.6%，111 个连续序列，4688 个基因）可在 NCBI GenBank 中获得（访问号 JAWXVJ000000000）。该菌株被归类为 ST292 和 CC ST10，与非致病性大肠杆菌 MG1655 高度相似，但与 EAEC 和 ExPEC 等致病性菌株不同。计算机血清型预测存在 O111-抗原翻转酶（wzx）和 H12-抗原鞭毛（fliC）基因。该菌株携带一个 IncFII（pCoo）质粒，具有 96.95%的同一性。PathogenFinder 预测其为人病原体的概率为 92%，有 720 种致病性蛋白家族支持。CRISPR 分析鉴定出一个高证据序列，带有 9 个间隔序列和 6 个低证据序列。使用 RAxML 进行的系统发育分析将 23EM 定位在非致病性大肠杆菌附近，但与其他致病性菌株相距较远。鉴定出多种抗微生物药物耐药基因，包括大环内酯类、氟喹诺酮类和氨基糖苷类。该菌株还含有多种毒力因子，如粘附素（如 ECP、ELF、TIF、IV 型菌毛）和自转运基因（espP、pic），突出了其显著的致病性潜力和公共卫生风险。
本研究强调了在贝类中检测携带毒力和抗微生物药物耐药基因的大肠杆菌菌株的能力，因此强调了对这些贝类进行持续监测和谨慎考虑与食用这些贝类相关的潜在风险的重要性。
