Complete Nucleotide Sequences of 93-kb and 3.3-kb Plasmids of an Enterohemorrhagic Escherichia coli O157:H7 Derived from Sakai Outbreak

Abstract

Enterohemorrhagic Escherichia coli (EHEC) O157:H7, derived from an outbreak in Sakai city, Japan in 1996, possesses two kinds of plasmids: a 93-kb plasmid termed pO157, found in clinical EHEC isolates world-wide and a 3.3-kb plasmid termed pOSAK1, prevalent in EHEC strains isolated in Japan. Complete nucleotide sequences of both plasmids have been determined, and the putative functions of the encoded proteins and the cis-acting DNA sequences have been analyzed. pO157 shares strikingly similar genes and DNA sequences with F-factor and the transmissible drug-resistant plasmid R100 for DNA replication, copy number control, plasmid segregation, conjugative functions and stable maintenance in the host, although it is defective in DNA transfer by conjugation due to the truncation and deletion of the required genes and DNA sequences. In addition, it encodes several proteins implicated in EHEC pathogenicity such as an EHEC hemolysin (HlyA), a catalase-peroxidase (KatP), a serine protease (EspP) and type II secretion system. pOSAK1 possesses a ColE1-like replication system, and the DNA sequence is extremely similar to that of a drug-resistant plasmid, NTP16, derived from Salmonella typhimurium except that it lacks drug resistance transposons.

Molecular epidemiology of a household outbreak of Shiga-toxin-producing Escherichia coli in Poland due to secondary transmission of STEC O104 : H4 from Germany

“…1c). The estimated size of the large plasmids was~80 and 90 kb when compared to 93 kb plasmid extracted from reference EDL933 E. coli O157 : H7 strain (Makino et al, 1998). It is noteworthy that the same plasmid profile was found in the wild STEC O104 : H4 strain 155/11 (Fig.…”

Two msbB Genes Encoding Maximal Acylation of Lipid A Are Required for Invasive Shigella flexneri to Mediate Inflammatory Rupture and Destruction of the Intestinal Epithelium

“…This is also observed in enterohemorrhagic E. coli (EHEC), where a second msbB gene is present on the virulence plasmid of serotype O-157 (61,62). No function has been attributed so far to this extra copy of the msbB gene, which is not present on the enteropathogenic E. coli virulence plasmid (63).…”

Pathogenesis and evolution of virulence in enteropathogenic and enterohemorrhagic Escherichia coli

“…Although EHEC O157:H7 strains contain large plasmids similar to those of EPEC, they lack the genes required for synthesis of BFP. Instead, EHEC plasmids carry a homologue of the lifA gene encoding lymphostatin, genes encoding a type II secretion system, catalase-peroxidase (katP), a secreted serine protease (espP), and a hemolysin operon (37,38). It is not clear what, if any, proteins are secreted by the type II system.…”