Differential Expression of the Bhmp39 Major Outer Membrane Proteins of Brachyspira hyodysenteriae

Abstract

The enteric, anaerobic spirochete Brachyspira hyodysenteriae is the causative agent of swine dysentery, a severe mucohemorrhagic diarrheal disease of pigs that has economic significance in every major porkproducing country. Recent investigation into potential vaccine candidates has focused on the outer membrane proteins of B. hyodysenteriae. Bhmp39 (formerly Vsp39) is the most abundant surface-exposed outer membrane protein of B. hyodysenteriae; its predicted gene sequence has previously been shown to share sequence similarity to eight genes divided evenly between two paralogous loci. The peptide sequence suggested that Bhmp39 is encoded by one of these genes, bhmp39h. The biological significance of maintaining eight homologous bhmp39 genes is unclear, though it has been proposed that this may play a role in antigenic variation. In this study, real-time, reverse transcription-PCR was used to demonstrate that bhmp39f and bhmp39h were the transcripts most abundantly expressed by B. hyodysenteriae strain B204 cultured under in vitro growth conditions. Mass spectrometry data of the purified 39-kDa membrane protein showed that both Bhmp39f and Bhmp39h were present. Northern blot analysis across predicted Rho-independent terminators demonstrated that the genes of the bhmp39efgh locus result in monocistronic transcripts.

Phylogenetic diversity, antimicrobial susceptibility and virulence gene profiles of Brachyspira hyodysenteriae isolates from pigs in Germany

“…Of the bhmp39a-h , forming a set of paralogous genes, bhmp39f was present in almost all isolates, while bhmp39h could not be detected at all. This is in contrast to former studies that demonstrated a wide distribution of both genes [ 43 ]. The remaining OMPs encoding genes ( bhlp16 and bhlp17 .…”

“…A reasonable explanation implicates that bhmp39f is not essential for the viability of the pathogen as it has recently been concluded for some plasmid genes possibly associated with virulence [ 41 ]. It should also be emphasized, that any negative finding could be the result of a false negative PCR due to variations in primer binding sites, which may particularly be the case in OMP genes that are involved in antigenic variability [ 43 ]. Whether mismatches result in an altered functionality of the protein cannot be determined at this moment.…”

The multifunctional role of the pallilysin‐associated Treponema pallidum protein, Tp0750, in promoting fibrinolysis and extracellular matrix component degradation

“…RNA was isolated from T. pallidum ssp. pallidum (Nichols strain) as described elsewhere (Witchell et al, 2006). The orientation-specific RT-PCR sense and antisense primers for tp0750 and tp0751 (pallilysin) are indicated in Table 2.…”

Swine Dysentery: Aetiology, Pathogenicity, Determinants of Transmission and the Fight against the Disease

“…An alternative approach may be to generate subunit vaccines that might be delivered by the expression of recombinant B. hyodysenteriae proteins on a bacterial delivery vector [113]. Investigations into potential targets for such recombinant vaccines have focused on outer membrane proteins [114,115,116,117], flagelar proteins [118,119] or iron storage proteins [120], although in most occasions recombinant vaccines tested have failed to provide enough protection in pigs.…”