Protection against experimental Pseudomonas aeruginosa infection by recombinant P. aeruginosa lipoprotein I expressed in Escherichia coli.

Lipoprotein I (OprI) is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. OprI is a candidate for a vaccine against P. aeruginosa, because it cross-reacts antigenically in all serotype strains of the International Antigenic Typing Scheme. We recently cloned and expressed the gene coding for OprI in Escherichia coli. This heterologously expressed OprI was used successfully to immunize mice against P. aeruginosa. In addition, OprI from serogroup 12 of P. aeruginosa was highly purified by preparative isoelectric focusing and used for immunization of mice. Both vaccines protected the mice against a challenge with a four- to fivefold 50% lethal dose of P. aeruginosa.