Serotyping of Serratia marcescens: confirmation of five recently described new O-antigens and characterization of an additional O-antigen.

Five new Serratia marcescens O-antigens (O16--O20) of Le Minor and Pigache were confirmed. An additional O-antigens (O21) was found and characterized. All six O-antigens cross-reacted with previously established O-antigens of S. marcescens, necessitating the employment of cross-absorbed rabbit anti-O immune sera for definitive O-antigen analyses.