Temperature-sensitive mutants of Pseudomonas aeruginosa: isolation and preliminary immunological evaluation

Abstract

The immunogenicity of two temperature-sensitive (ts) mutants of Pseudomonas aeruginosa immunotype 1, isolated and characterized for the development of a safe, live vaccine strain, was evaluated in a mouse protection model. One mutant, A/10/25, had a limited "coasting" property (i.e., continued replication for two divisions) at the nonpermissive temperature (36°C), whereas the other mutant, E/ 9/9, continued replication for five generations after transfer to 36°C. Groups of 3to 5-week-old ICR mice were immunized intraperitoneally with various doses of the two ts mutants; at various times thereafter, the mice were challenged intraperitoneally with lethal doses of the parental wild type. The more extensive coaster, El919, induced 100% protection at immunizing doses lower than those required for A/10/25 to induce the same protection (1 x 108 to 2 x 108 and 6 x 108 colony-forming units, respectively). Both ts strains induced significant protection for up to 5 weeks after immunization. The results of these studies suggest that the use of P. aeruginosa ts mutants might provide a novel approach to the prevention of P. aeruginosa colonization of patients with cystic fibrosis.

Biological evaluation of Mycoplasma pulmonis temperature-sensitive mutants for use as possible rodent vaccines

“…Temperature-sensitive mutants (TSMs) of M. pulmonis were developed as a vaccine. The use of TSM vaccines has been investigated and tested for controlling viral (21) and bacterial (14,28) diseases and mycoplasmosis in humans (12) and animals (19,20,27), with promising results. The rationale for the effective use of TSM vaccines is based on the decreased nasal cavity temperature compared with the higher temperature of the lungs and other internal organs.…”