Experimental infection characteristics of Bordetella pertussis via aerosol challenge on rhesus macaques

Abstract

The effect of aerosol challenge of rhesus macaques with Bordetella pertussis and the feasibility of using rhesus monkeys as an animal model for pertussis infection were evaluated in this study. Four 1-year old rhesus macaques were aerosol challenged with B. pertussis at the concentration of 105 CFU/mL for 30 min (group 1) or 60 min (group 2). Rectal temperature was found slightly increased at days 3 and 5 and returned to baseline levels at day 21 after challenge. White blood cell counts peaked at day 7, with a 4.7~6.1-fold increase and returned to baseline levels at day 45. Bacteria colonization of nasopharyngeal swabs was observed, and the number of colonies was gradually increased and peaked at day 14, reaching 5.4-8.1 x 106/mL. The seroconversion rate of anti-pertussis toxin (PT), pertactin (PRN), and filamentous hemagglutinin(FHA) antibodies was 100%, with an increase in geometric mean titers after challenge. Analysis of cytokines revealed that the levels of cytokines including IL-2, IL-6, IL-8, IL-10, IL-17A, IL-13, IL-12, and IL-18 were significantly increased at days 5 to 14 in group 2. These results demonstrate that the characteristic of pertussis infection in infant rhesus macaque was similar as in human beings, which provide a clue to using infant rhesus macaque as a candidate model for pertussis infection in the future studies