Protective effect of vaccination against Mycoplasma pulmonis respiratory disease in rats

Abstract

Intravenous vaccination of rats with either viable or Formalin-inactivated Mycoplasma pulmonis reduced the incidence and severity of lower respiratory tract lesions after intranasal challenge with viable organisms. Intranasal vaccination with killed organisms reduced the severity of rhinitis, but did not affect lesions in any other region of the respiratory tract. The maximum protection against upper tract lesions (rhinitis, otitis, and laryngotracheitis) was provided by intravenous immunization with viable organisms. Dual vaccination (intraperitoneal plus intranasal) with killed organisms provided no significant protection in any segment of the tract. However, these ineffective vaccine regimens did not potentiate the lesions. These results conclusively demonstrate that vaccination of rats against mycoplasma respiratory disease is feasible and also suggest that systemic vaccination may provide greater protection for the lungs than intranasal vaccination, at least when equivalent antigen doses are used.

Murine respiratory mycoplasmosis in F344 and LEW rats: evolution of lesions and lung lymphoid cell populations

“…Pathogen-free LEW rats, reared and maintained in a similar fashion, were obtained from the Trudeau Institute, Inc., Saranac Lake, N.Y. Intracage ammonia levels were monitored twice weekly, and the bedding was changed as necessary to maintain levels between 19 and 38 mg/liter (25 and 50 ppm) (4). At 2 months of age, F344 or LEW rats were sedated with a combination of fentanyl and droperidol (Innovar-Vet; Pittman Moore, Inc., Washington Crossing, N.J.) and intranasally inoculated with either 0.05 ml of sterile Hayflick broth or 9 x 106 colonyforming units of M. pulmonis (UAB 6510) in 0.05 ml of Hayflick broth (7). Control rats (those receiving sterile broth) were killed at 0, 60, or 120 days, and M.…”

Vaccination of Lewis rats with temperature-sensitive mutants of Mycoplasma pulmonis: adoptive transfer of immunity by spleen cells but not by sera

“…Immune sera taken from the very same donor rats showed no significant protection against acute infection, although the IgG and IgM anti-M. pulmonis titers of the sera used were quite high. We chose M. pulmonis UAB 6510 to challenge the animals because this strain was isolated originally from a rat lung and causes severe lung lesions in infected rats (3,7). Lewis rats were chosen because they are genetically susceptible to this disease (7) and therefore provide a good model for protection studies.…”

“…The small number of mycoplasmas present in immune spleen cell suspensions (groups 1 and 2) could theoretically have elicited immune responses to the later challenge dose of wild-type organisms. However, this may not be the case, since the protective cellular immune response takes weeks to develop (3). In these studies, we challenged rats infused with sensitized (immune or vaccinated) cells within 2 h. Therefore, the recipient animals had little time to develop their own immune response.…”

“…Although reinfection of previously infected animals can occur, such animals are generally protected against development of subsequent MRM. Rats, like mice, can be effectively protected by immunization (3,15). The immunopathologic character of the respiratory disease caused by the same M. pulmonis in rats and mice suggests that the immune mechanisms opera-* Corresponding author.…”

Gnotobiotics and the Microbiome

“…Luckey (1968) provided an extensive bibliography on the effects of bacterial species on the monoassociated rat. Cassell and colleagues made effective use of monoassociated mice and rats to study the pathogenesis of Mycoplasma diseases and the host response (Cassell et al, 1974;Cassell and Davis, 1978). No differences were found in the susceptibility of GF rats to Plasmodium berghei primary infections via mosquito-borne sporozoites, nor were there any differences in the resulting pathology (Martin et al, 1966).…”