Invasion of ileal mucosa by strains of <i>Salmonella typhimurium</i>: quantitative studies <i>in vitro</i>

In the preceding contribution by Douce et al., a series of TnphoA mutants were described which were generated from &lt;i&gt;Salmonella typhimurium&lt;/i&gt; strain TML and whose invasive phenotype was determined in a HEp-2 cell assay for invasiveness (Douce et al., 1991). To date no quantitative system has been described in which invasiveness has been measured in functional gut &lt;i&gt;in vitro&lt;/i&gt;. This contribution describes such a system