O and H serotyping of Pseudomonas cepacia

Procedures for the preparation, absorption, and titration of Pseudomonas cepacia O and H rabbit antisera are described. Seven O antigens (O1 to O7) for the slide agglutination test and five H antigens (H1, H3, H5, H6, and H7) for the agglutination and H immobilization tests were determined. Nearly 300 strains of P. cepacia isolated from hospitalized patients (a majority from Strasbourg hospitals) were serotyped. The use of P. cepacia serotyping as an epidemiological tool, especially in outbreak situations, was emphasized. Difficulties in obtaining monospecific H antisera are discussed.