The main objectives of this study were to:<BR> <ul>
<li>Examine bacterial cell surface components which have been implicated as adherence factors:<BR>
a) Ultrastructural studies to characterise cell surface antigens by electron microscopy and immunoprobing<BR>
b) Use competitive inhibitors of bacterial adherence, such as purified adhesins, or antibodies to specific cell surface components
<li>Examine bacterial adherence to the host epithelial cells under various in vitro conditions, which are as close as possible to those in vivo
<li>Examine the expression of adhesins in response to variable physiological conditions e.g. pH; anaerobiosis; low iron; bacterial growth phase
<li>Examine the host cell membrane and characterise possible receptors</li></ul>
Verocytotoxin producing Escherichia coli (VTEC) is recognised as an important human pathogen.
<p>Strains belonging to serotype O157:H7 have been predominantly associated with outbreaks of haemorrhagic colitis and haemolytic uremic syndrome, two potentially life-threatening conditions.
<p>VTEC produces one or more cytotoxins, known as verocytotoxins (VTs).
<p>In addition to toxin production, adherence of these organisms to intestinal mucosal cells is thought to be an important primary event in pathogenesis of VTEC infection.
<p>Since the laboratory culture conditions are not the normal environment that pathogenic organisms find during infection, where growth rate is often restricted by nutrient limitation and host defences, this project was designed to investigate bacterial adherence under conditions which are as close as possible to the in vitro situation in the human colon.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.