Verocytotoxin-producing Escherichia coli (VTEC) O157 and other VTEC from human infections in England and Wales: 1995–1998

Abstract

A total of 3429 isolations of verocytotoxin-producing Escherichia coli O157 (VTEC O157) was con®rmed from human sources in England and Wales during the period 1995±1998. The largest annual total was 1087 in 1997. Most infections occurred in the third quarter of each year. The overall rate of infection ranged from 1.28 to 2.10=100 000 population and showed regional variation. The highest incidence was in children aged 1±4 years. Annually, between 5% and 11% of strains were from patients who had travelled abroad. There were 67 general outbreaks of infection represented by 407 (11.9%) VTEC O157 isolates. Outbreaks involved transmission by contaminated food or water, person-toperson spread and direct or indirect animal contact, and ®ve were associated with foreign travel. The majority (76%) of strains carried verocytotoxin (VT) 2 genes and 23.3% were VT1 VT2. Most strains had the¯agellar antigen H7, but c. 14% were non-motile. Approximately 20% of isolates were resistant to antimicrobial agents, predominantly streptomycin, sulphonamides and tetracycline. In addition to VTEC O157, strains of serogroup O157 that did not possess VT genes were identi®ed. These were either derivatives of VTEC O157 that had lost VT genes or were strains with H antigens other than H7 that have never been associated with VT production. Strains of VTEC other than O157 were characterised. Most were associated with diarrhoea, bloody diarrhoea or haemolytic uraemic syndrome and had virulence markers in addition to VT.

Production of serum antibodies that recognise epitopes located on the R3 region of Escherichia coli core lipopolysaccharides by patients infected with strains of enterohaemorrhagic E. coli

“…Verocytotoxin-producing Escherichia coli (VTEC), and particularly strains of serotype O157:H7, are recognised as a major cause of diarrhoea, bloody diarrhoea and haemolytic uraemic syndrome (HUS) in North America [1] and the UK [2]. Certain other VTEC, and in particular those belonging to serogroups O26, O103, O111 and O145 [3], also cause a disease characterised by bloody diarrhoea, which may develop into HUS [4].…”

Intraserotype diversity among Argentinian verocytotoxigenic Escherichia coli detected by random amplified polymorphic DNA analysis

“…Although some rapid PCR-based methods, such as those based on randomly amplified fragments (RAPD), or repetitive element PCR (Rep-PCR), may not give sufficient discrimination as a consequence of the highly clonal nature of VTEC O157 (Willshaw et al, 2001), we were able to find three different RAPD profiles among six strains belonging to serotype O157 : H7.…”

Luminescence based enzyme-labeled phage (Phazyme) assays for rapid detection of Shiga toxin producingEscherichia coliserogroups

“…The rationale for focusing on these serogroups is due to the fact that STEC is associated with a wide spectrum of illness ranging from uncomplicated watery diarrhea to hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS), which may result in death and many studies have confirmed that serogroups O26, O103, O111, O145 and O157 are highly associated with HC and HUS. [26][27][28][29][30][31] In pure culture, the direct detection limits of the Phazyme assays ranged from 6.82 x 10 4 CFU/ml for serogroup O145 to 1.32 x 10 6 CFU/ml for serogroup O111 ( fig. 2).…”