Inactivation of Bordetella pertussis by Rat Lung Lavage Fluids (LLF)

[摘要] Soluble antibacterial substance(s) in lung lavage fluid (LLF) from healthy normal rats killed phase I Bordetella pertussis in vitro. Phase IV B. pertussis was insusceptible. LLF that was active towards phase I organisms was obtained from rats of the Sprague Dawley, Lewis, Brown Norway, and Hooded Lister strains. Two strains of B. pertussis were mainly used: B. pertussis 18-323 for viable count experiments and B. pertussis lux for tests with the luminometer. The former experiments were more time consuming but more reliable; luminometry, although rapid, was complicated by substances that affected the luciferase reaction. Electron microscopy showed that LLF caused severe damage to the B. pertussis cells, with loss of internal contents Of the several mammalian species tested, the rat yielded LLF of the highest bactericidal activity (BA) towards B. pertussis. The other species LLF were: human, mouse, horse, dog, chicken, rabbit, sheep and calf. Typically rat LLF could be diluted 24 times and still exhibit BA. For assessment of the BA of LLF, both positive and negative control fluids were used. Normal rat serum, which killed the bacteria rapidly, was used for the former, and phosphate buffered saline (PBS), cyclodextrin liquid (CL) medium and casamino acids (CAA) for the latter. The half-life of B. pertussis at 37

[发布机构] University:University of Glasgow

[关键词] Microbiology