Proteomic comparison of epidemic Australian Bordetella pertussis biofilm cells

ABSTRACT: Bordetella pertussis causes whooping cough, a severe respiratory disease. B. pertussis is a highly genetically homogenous species with only minor levels of genetic variation. It has been shown that single nucleotide polymorphism (SNP) cluster I containing the dominant pertussis toxin promoter allele, ptxP3 has overtaken the previously dominant SNP cluster II (ptxP1) strains. Studies comparing cluster I and cluster II strains have identified changes that may relate to the increased dominance of the cluster I strains however these studies were performed on planktonic cells. Recent studies have demonstrated the ability of B. pertussis to form biofilms. Bacteria within biofilms have been shown to be phenotypically distinct from their planktonic counterparts. Therefore, this study compared the biofilm formation capabilities of representative strains of cluster I and cluster II using confocal laser scanning microscopy. It was found that the cluster I strain has a more densely packed biofilm structure. Differences in protein expression of the biofilm cells were then compared using Tandem Mass Tagging (TMT) mass spectrometry. In total, there were 1453 proteins identified of which 40 proteins had significant differential expression between the two strains in biofilm conditions. Of particular interest was a large increase in expression of cytochrome proteins PetABC and BP3650 and a decrease in the alcaligin synthesis protein, AlcC in the cluster I strain. These changes were not identified when a previous study compared these strains in planktonic conditions suggesting they are under the control of a biofilm specific regulator. To identify whether these differences are cluster specific, high resolution multiple reaction monitoring (MRM-hr) mass spectrometry was performed on a subset of 9 of the differentially regulated proteins on an additional 6 strains from each SNP cluster. The major changes in protein expression identified between the two representative strains were not reflected by the additional strains. However, there was a large variation in the expression of the proteins between the different strains from each cluster. These findings suggest that there are large levels of individual proteomic diversity between B. pertussis strains in biofilm conditions despite the highly conserved genome of the species.

INSTRUMENT(S):

ORGANISM(S): Bordetella Pertussis

DISEASE(S): Pertussis

SUBMITTER: Ruiting Lan  

LAB HEAD: Ruiting Lan

PROVIDER: PXD046513 | Pride | 2025-09-22

REPOSITORIES: Pride