New fimbrial hemagglutinin in Serratia species

Strains of Serratia marcescens, Serratia liquefaciens, Serratia marinorubra, and Serratia plymuthica produced one or more of the following hemagglutinins (HAs): mannose-sensitive HA and mannose-resistant K-HA (MR/K-HA) and P-HA (MR/P-HA) (J. P. Duguid and D. C. Old, in E. H. Beachey (ed.), Bacterial adherence, vol. 6., p. 185-217, 1980). Most strains (82%) were multiply hemagglutinating. The properties of the three HAs are described. Each HA was associated with a distinct type of fimbria: mannose-sensitive HA with type 1 fimbriae. MR/K-HA with type 3 fimbriae, and MR/P-HA with a new type of thin fimbriae provisionally called MR/P fimbriae. This is the first report of the production of MR/P-HA and MR/P fimbriae by Serratia species. The range of Serratia HAs, which may reflect in vivo colonization potential, is more complex than previously reported.