Infection with Yersinia enterocolitica leads to a self-limiting disease, but in a small number of cases a protracted course can develop. The host genetic factors contributing to the advancement of the disease to the chronic phase are not known. We describe a patient suffering from an abdominal inflammatory mass due to chronic yersiniosis. Functional assays revealed defects in the recognition of flagellin by Toll-like receptor 5
(TLR5) and of muramyl dipeptide by NOD2, leading to a defective inflammatory response to Yersinia enterocolitica. Genetic sequencing showed that the patient was compound heterozygous for five different
mutations in TLR5, while being homozygous for the
3020insC NOD2 mutation. In conclusion, we describe a
patient in whom specific defects in the TLR5 and NOD2
recognition pathways led to chronic yersiniosis.