APEC leads to severe economic losses due to decreased egg production and increased mortality in broiler breeders resulting in high first-week mortality and horizontal transmission in hatcheries. Vertical transmission from breeders to chicks, including transmission of antibiotic resistance genes, exacerbates the issue, with infected chicks and contaminated eggshells spreading the infection in hatcheries.

APEC's zoonotic potential is highlighted by its genetic similarities with human pathogenic E. coli strains, suggesting a possible transmission route from poultry to humans.

Traditional control methods focus on strict biosecurity, hygiene, and antibiotic treatments. However, the rise of antibiotic-resistant APEC strains necessitates alternative approaches like vaccines and other alternatives to antibiotics. Current vaccines offer limited cross-protection due to the bacterial strains' continuous evolution. Thus, developing more potent vaccines targeting diverse APEC strains is critical.

The diversity of APEC serotypes however complicates vaccine development and thus combination with other treatment strategies may be required to control infection of young chicks.

Led by Professor Daisy Vanrompay and Professor Jan Gettemans, in the CHLAPECONTROL project a combination of a next generation vaccine with another targeted treatment against APEC will be developed and evaluated in an in vivo APEC-challenge model with SPF chickens.

Professor Daisy Vanrompay is Director of the Laboratory for Immunology and Animal Biotechnology at Ghent University and Director of the National Diagnostic Reference Laboratory for C. psittaci infections in humans. She is a member of PROVAXS. Here research involves: i) the development of molecular diagnostics for bacterial pathogens, ii) unravelling the molecular pathogenesis of bacterial infections, and iii) gaining insight in protective mucosal immunity. She focuses on Chlamydia infections in humans and animals, Escherichia coli O157:H7 infections in ruminants, APEC infections in poultry and Vibrio spp infections in aquatic animals. In vitro and in vivo models are used for developing virulence blockers e.g. TFs and genetic vaccines. D. Vanrompay has over 100 A1 publications and 13 book chapters, and she was awarded with the “Geneviève Spike Award” for the best oral presentation during the XIII th International Conference on Lactoferrin. D. Vanrompay has patents granted on a Chlamydia vaccine (US9308248),

Jan Gettemans is a nanobody expert. The Nanobody Lab in the department of Biomolecular Medicine has been working on nanobodies and nanobody technology for over 2 decades. The lab specialized in the development and characterization of nanobodies against a variety of proteins considered potential drug targets. The lab generated nanobodies against targets from start to finish, including antigen cDNA cloning, expression and purification, immunization, VHH library generation, phage panning, affinity determination, biological experimentation. Nanobody technology has been the common denominator in all projects of the lab for the past ~20 years. Camelid nanobodies can offer advantages over conventional antibodies in particular circumstances: a) they are much smaller but have similar specificity and binding affinities as conventional antibodies, b) they are coded by a single exon (~360 nucleotides) and can be easily amplified by PCR and expressed in large amounts in bacteria, c) due to their smaller size (~15 kDa), they can be combined into dimers, trimers, or larger multimers, thus targeting several antigens. Like conventional antibodies, nanobodies constitute excellent tools in the structural and functional characterization as well as perturbation of their target antigens. The lab has developed expertise in knocking out specific functions of proteins in cells using nanobodies. Basically, they can serve two main purposes: use as research tools or further development into diagnostic or therapeutic instruments.

The CHLAPECONTROL project is backed by around €400,000 funding from the university’s Industrial Research Fund and is also supported by provaxs.

If you want more information on the project you can contact Sven Arnouts (sven.arnouts@ugent.be), business development manager at UGent  provaxs (www.provaxs.com).