Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 6, 2002
Publication Date: June 6, 2002
Citation: Register, K.B. 2002. Comparative sequence analysis of bordetella bronchiseptica pertactin gene repeat regions (oral presentation for 2002 IPVS). Pig Veterinary Society International Congress Proceedings. Vol. 2, p. 342.
Bordetella bronchiseptica is an etiologic agent of atrophic rhinitis and primary bronchopneumonia in young pigs. It may also increase the frequency and severity of respiratory disease due to PRRSV and other pathogens. The product of the B. bronchiseptica pertactin gene, prn, has been implicated as an adhesin and a protective immunogen in swine. Recent studies demonstrate prn sequence heterogeneity in swine isolates and vaccine strains within and surrounding the region 1 amino acid repeat GGXXPn and the region 2 amino acid repeat PQPn. However, only a few isolates were evaluated. Allelic variation between vaccine strains and field isolates may affect vaccine efficacy, since region 2 is known to encode an immunodominant protective epitope. In the present study, comparative sequence analysis of prn regions 1 and 2 from 30 recent swine field isolates and 3 vaccine strains was carried out. Four prn types, 3 of which hhave been described in prior studies, were identified from the field isolates based on the combined region 1 and region 2 sequences. Seventy- seven percent of isolates possess type 1-3a / 2-7a. Type 1-4a / 2-6a accounted for 17% of isolates, while types 1-3a / 2-8e and 1-5b / 2-8d each accounted for 3%. Type 1-3a / 2-8e, found in a Scottish isolate, has not been previously reported. Only vaccine strain A possessed the prn type found most frequently in swine field isolates. The types found in vaccine strains B and C were not present in any of the swine isolates examined.