Electron Microscopic Observations on Tracheal Epithelia of Mice Infected with Bordetella bronchiseptica

Abstract

To clarify the pathogenesis of Bordetella in vivo infection, the tracheal epithelia of mice were examined in detail by electron microscopy at various intervals after intranasal inoculation with graded doses of phase I Bordetella bronchiseptica. In mice infected with a lethal dose (6 to 7 × 107 CFU), a remarkable rupture of the cell membranes of cilia and microvilli of the middle trachea was found on day I postinfection. The rupture of the membrane was observed over the entire tracheal epithelia, on day 2 after infection. The affected cilia were constricted at the transitional region and were broken off. In the ciliated cells the adherence of organisms to ciliary apexes and colonization in the interciliary spaces were also remarkable. In both the ciliated and nonciliated epithelial cells, the cytoplasmic vacuolation and pyknosis or karyorrehexis were also notable. In mice infected with one‐tenth of the lethal dose, similar findings were seen, but appeared more slowly and the bacteria were not seen attaching to ciliary apexes. In mice receiving one‐hundredth of the lethal dose, only mild cilial abnormality such as aggregation of cilia, and slight cytoplasmic vacuolation were found 6 days postinfection. Based on these findings, a possible mechanism of the ciliary damages produced by B. bronchiseptica was postulated.

Hag Mediates Adherence ofMoraxella catarrhalisto Ciliated Human Airway Cells

“…1, 2, and 3A). Tropism for ciliated cells has been reported for other pathogens of the respiratory tract, including Bordetella pertussis (62,80,89,101), Bordetella bronchiseptica (5,33,85), M. hyopneumoniae (44,45), M. pneumoniae (58), P. aeruginosa (6,31,38,46,108), and Klebsiella pneumoniae (36). B. pertussis and M. pneumoniae have been shown to associate primarily with the base of cilia, whereas P. aeruginosa preferentially locates at the tip.…”

“…The ciliated cells of the respiratory tract and other mucosal membranes keep secretions moving out of the body so as to assist in preventing colonization by invading microbial pathogens (10,26,71,91). Given this critical role in host defense, it is interesting to note that a few bacterial pathogens target ciliated cells for adherence, including Actinobacillus pleuropneumoniae (32), Pseudomonas aeruginosa (38, 108), Mycoplasma pneumoniae (58), Mycoplasma hyopneumoniae (44, 45), and Bordetella species (5,62,85,101).In the present study, M. catarrhalis is shown to specifically …”

Bordetella avium causes induction of apoptosis and nitric oxide synthase in turkey tracheal explant cultures

“…A number of disorders and pathogens are known to initiate respiratory epithelial cell apoptosis resulting in aberrant host or pathogenic cell removal [12–13]. Bordetellae attachment to host cilia is extremely specific [5],[7], and [10–11]; thus selective elimination of ciliated cells via apoptosis would be beneficial to the host, resulting in the removal of the bacteria while maintaining epithelium barrier integrity.…”

“…In more serious cases of the disease, the tracheal rings become highly distorted resulting in a collapse of the trachea [2–3]. Similar pathogenic changes occur in vitro with turkey tracheal organ cultures [5–6], and are also seen during infection of B. bronchiseptica [7] and B. pertussis [8–11] in similar organ culture systems.…”

Adherence of Bordetella bronchiseptica 276 to porcine trachea maintained in organ culture

“…Porcine atrophic rhinitis is a multifactorial disease characterized by severe necrosis in the epithelia of the upper respiratory tract (19,22). Bordetella bronchiseptica is considered a primary causative agent of atrophic rhinitis (11,24). Infection by this microorganism is transmitted by aerosol droplets, and the bacteria can be localized on respiratory epithelial cells; the bacteria are noninvasive and remain on the respiratory surfaces.…”