大肠杆菌J2_5的全基因组测序及比较基因组分析.

Objective: A novel multidrug resistant (MDR) Escherichia coli (E.coli) strain J2_5 was isolated from a patient’s mid stream urine sample. According to the genome sequence of J2_5, we analyzed its evolutionary classification, drug resistance genes and virulence genes, providing theoretical basis for clinical diagnosis and drug selection for drug resistant bacterial infection. Methods: Genome DNA of J2_5 was isolated and sequenced by high throughput sequencing technology, after analyzed the high throughput sequencing data and compared it with known databases by a variety of bioinformatics tools, a high integrity genome of J2_5 was obtained. Results: The total length of the whole genome of J2_5 was 4.7Mb and GC content was 50.78%. Phylogenetic tree analysis showed that J2_ 5’genome was closely related to that of wild type E. coli strain MG1655. But Multilocus sequence typing (MLST) analysis revealed ST type of J2_5 was ST2491, which was different from that of MG1655 (ST10) . Furthermore, CARD database analysis showed that the genome of J2_5 encodes 65 drug resistance genes, which make the strain obtain drugresistant ability through four different mechanisms (antibiotic efflux pump, antibiotic inactivation, antibiotic target change, reduced permeability to antibiotics) . VFDB database analysis showed that there were 40 virulence genes in 7 categories, encoding adhesive proteins, invasion proteins, autonomic transporters and other toxin proteins. After analyzing the whole genome of J2_5 through the Prophage Hunter online tool, we found that there were three prophages in the genome of J2_5, and a virulence gene was carried by one of the prophages. Conclusion: The whole genome sequencing results showed that J2_5 carries some virulence genes and drug resistance genes, which makes the strain obtain strong pathogenicity and resistance ability to a variety of antibiotics. [ABSTRACT FROM AUTHOR]