Investigation of the potential role of 6-hydroxynicotinate-3-monooxygenase in the modulation of virulence in Bordetella pertussis

Samantha Justice, The College of Wooster

Abstract

Bordetella pertussis, the causative agent of whooping cough, claims the lives of an estimated 300,000 each year. Previous studies exploring modulation of B. pertussis have shown that high levels of nicotinic acid (NA) modulate the expression of virulence-associated genes. Here we provide evidence supporting the hypothesis that 6-hydroxynicotinate-3-monooxygenase (NicC), an enzyme involved in NA catabolism in Bordetella, plays a role in a mechanism of modulation. Several NA derivatives, including 2,5-pyridinedicarboxylate (2,5-PDC) and 6-chloronicotinate (6-ClNA), are known modulators of B. pertussis and have shown to bind to NicC by fluorescence titration experiments. Kinetic inhibition studies further suggest that 6-ClNA and 2,5-PDC inhibit NicC. The first steps toward isolating a characterizing a B. pertussis strain in which the nicC gene is knocked out (ΔnicC) have been made. Once isolated, experiments will be conducted to quantify the levels of filamentous hemagglutinin expression in the ΔnicC knockout strain compared to those of wild-type B. pertussis in varying growth conditions to determine whether or not NicC is essential for maintaining pathogenicity in B. pertussis.