In vitro adhesion and invasion of Salmonella enterica serovar Havana.

A total of 132 isolates of the Havana serovar of Salmonela enterica were studied for their adhesion to and invasion of Hela cells in the presence of D-mannose. A total of 124 (93.9%) isolates were adherent, and 51% of these were invasive. Of these 124 strains 82 (66%) adhered to HeLa cells with a pattern typical for enteroaggregative (EAgg) Escherichia coli whereas the remaining 34% adhered in a non-aggregative (non-EAgg) pattern. Of the 82 strains showing the EAgg pattern 60% were invasive whereas only 33% of the 49 non-EAgg isolates invaded HeLa cells (P < 0.01). The action of mannose-sensitive type 1 pili was inhibited by the addition of D-mannose. Therefore we conclude that type 1 pili are not important in adhesion and invasion of Havana.