Canying Liu
Foshan University, China
Title: Genome analysis and in vivo virulence of porcine extraintestinal pathogenic Escherichia coli strain PCN033
Biography
Biography: Canying Liu
Abstract
Strains of extraintestinal pathogenic Escherichia coli (ExPEC) can invade and colonize extraintestinal sites and cause a wide range of infections. Porcine ExPEC becomed one of the bacterial pathogens that threat the development of Chinese pig industry. But nowadays, research reports about ExPEC have focused on isolates of human and avain origin, with little attention on porcine ExPEC infection, with no porcine isolates yet to be sequenced. To better understand the genomic attributes underlying the pathogenicity of porcine ExPEC, we performed genomic analysis of one representative porcine ExPEC strain PCN033, assessed its in vivo virulence and compared its genomes with other characteristic E. coli strains. Result of genomic analysis showed that compared with an nonpathogenic E. coli strain PCN061 isolated from pig, PCN033-specific sequences including genes encoding adhesins, unique lipopolysaccharide, unique capsular polysaccharide, iron acquistion and transport systems, and metabolism. A large plasmid PCN033p3 harboring many typical ExPEC virulence factors was identified in PCN033. Additionally, PCN033 was pathogenic to pig and able to cause pathogenic changes in pig brain. Furthermore, the comparative genomic analyses showed that the PCN033 genome shared many similarities with genomic sequences of human ExPEC strains. This suggested that some connections between porcine and human ExPEC strains exist. Additionally, comparison of PCN033 genome with other nine characteristic E. coli genomes revealed 425 PCN033-special coding sequences. Genes of this subset included those encoding type I restriction-modification (R-M) system, type VI secretion system (T6SS) and membrane-associated proteins which possibly provide insights towards the molecular mechanisms of porcine ExPEC infections.