Fructose 1,6-Bisphosphate aldolase, a novel immunogenic surface protein on Listeria species

Authors: MENDONÇA, MARCELO - Brazil University; MOREIRA, GUSTAVO - Braunschweig University; CONCEIÇÃO, FABRICIO - Brazil University; HUST, MICHAEL - Braunschweig University; MENDONÇA, KARLA - Brazil University; MOREIRA, ÂNGELA - Brazil University; FRANÇA, RODRIGO - Brazil University; PADILHA DA SILVA, WLADIMIR - Brazil University; BHUNIA, ARUN - Purdue University; ALEIXO, JOSÉ - Brazil University

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2016
Publication Date: 8/4/2016
Citation: Mendonça, M., Moreira, G., Conceição, F., Hust, M., Mendonça, K., Moreira, Â., França, R., Padilha Da Silva, W., Bhunia, A.K., Aleixo, J. 2016. Fructose 1,6-Bisphosphate aldolase, a novel immunogenic surface protein on Listeria species. PLoS One. doi: 10.1371/journal.pone.0160544.

Interpretive Summary: Immunoassays are a commonly used method for detection of harmful foodborne bacteria. The sensitivity and specificity of these assays rely on high affinity and highly specific antibodies. There is a need for antibodies that can be used to detect the foodborne pathogen Listeria monocytogenes and other species of Listeria. This study reports the development and characterization of an antibody against a protein that is expressed on the surface of Listeria cells. The protein is called fructose-bisphosphate aldolase and is present on both pathogenic and nonpathogenic Listeria species and its expression is abundant on bacterial cell surface during enrichment in a standard Listeria enrichment broth. Experiments performed with this antibody show great promise in detecting Listeria species from ready-to-eat soft cheese samples.

Technical Abstract: Listeria monocytogenes is a ubiquitous food-borne pathogen, and its presence in food or production facilities highlights the importance of surveillance. Increased understanding of the surface exposed antigens on Listeria would provide potential diagnostic and therapeutic targets. In the present work, using mass spectrometry and genetic cloning, we show that fructose-1,6-bisphosphate aldolase (FBA) class II in Listeria species is the antigen target of the previously described mAb-3F8. Western and dot blot assays confirmed that the mAb-3F8 could distinguish all tested Listeria species from close-related bacteria. Localization studies indicated that FBA is present in every fraction of Listeria cells, including supernatant and the cell wall, setting Listeria spp. as one of the few bacteria described to have this protein on their cell surface. Epitope mapping using ORFeome display and a peptide membrane revealed a 14-amino acid peptide as the potential mAb-3F8 epitope. The target epitope in FBA allowed distinguishing Listeria spp. from closely-related bacteria, and was identified as part of the active site in the dimeric enzyme. However, its function in cell surface seems not to be host cell adhesion-related. Western and dot blot assays further demonstrated that mAb-3F8 together with anti-InlA mAb-2D12 could differentiate pathogenic from non-pathogenic Listeria isolated from artificially contaminated cheese. In summary, we report FBA as a novel immunogenic surface target useful for the detection of Listeria genus.