Aerosol infection of animals with strains of Legionella pneumophila of different virulence: comparison with intraperitoneal and intranasal routes of infection.
Infection of guinea-pigs by intranasal (i.n.) instillation of 10(9) viable organisms of two newly isolated strains of Legionella pneumophila (74/81, serogroup 1; 166/81, serogroup 3) did not induce disease, but 10(4) organisms administered as a small particle aerosol (less than 5 microns diameter) produced a fatal widespread broncho-pneumonia within 3 days. Milder illness and less extensive bronchopneumonia were also produced in rhesus monkeys and marmosets by one of these two strains (74/81). Mice were resistant to induction of disease by aerosols of both these two strains, though organisms did persist in the lungs for at least 4 days. Both of these L. pneumophila strains were pathogenic for guinea-pigs by aerosol infection over a wide range of doses but the serogroup 1 type strain (NCTC 11192) was not. There was no mortality after infection of guinea-pigs by intranasal instillation of any of these strains but all proved to be fatal after intraperitoneal (i.p.) injection of large doses. Guinea-pigs, rhesus monkeys and marmosets exposed to aerosol infection with L. pneumophila provide relevant models for studying the pathogenesis of Legionnaires' disease.
D000336:Aerosols; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D002143:Callitrichinae; D004195:Disease Models, Animal; D005260:Female; D006168:Guinea Pigs; D007875:Legionella / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology*; D007877:Legionnaires' Disease / Q000382:microbiology* / Q000473:pathology; D008168:Lung / Q000382:microbiology / Q000473:pathology; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008297:Male; D051379:Mice; D009666:Nose; D010537:Peritoneum
D000336:Aerosols; D000907:Antibodies, Bacterial