Urbanization strongly affects biodiversity, altering natural communities and often leading to a reduced species richness. Yet, despite its increasingly recognized importance, how urbanization impacts on the health of individual animals, wildlife populations and on disease ecology remains poorly understood. To test whether, and how, urbanization-driven ecosystem alterations influence pathogen dy...

OBJECTIVES To further evaluate the role of bacterial antigens in triggering inflammation in the joint in patients with reactive arthritis by studying local antibody synthesis in the joint. METHODS Yersinia-specific antibodies in paired serum and synovial fluid samples from 29 patients with yersinia triggered reactive arthritis were studied using an enzyme linked immunosorbent assay (ELISA), a...

As scored by several specified plating procedures, clinical and environmental strains of Yersinia enterocolitica, Yersinia pseudotuberculosis, and Klebsiella pneumoniae "Oxytocum" showed detectable, albeit generally weak, ability to digest polygalacturonic (pectic) acid. None of these bacterial strains had the vigorous and rapid pectolytic activity on these polygalacturonic acid-containing medi...

A characteristic of the three human-pathogenic Yersinia spp. (the plague agent Yersinia pestis and the enteropathogenic Yersinia pseudotuberculosis and Yersinia enterocolitica) is the expression of the virulence (V)-antigen (LcrV). LcrV is a released protein which is involved in contact-induced secretion of yersinia antihost proteins and in evasion of the host's innate immune response. Here we ...

We developed a multilocus sequence typing (MLST) scheme and used it to study the population structure and evolutionary relationships of three pathogenic Yersinia species. MLST of these three Yersinia species showed a complex of two clusters, one composed of Yersinia pseudotuberculosis and Yersinia pestis and the other composed of Yersinia enterocolitica. Within the first cluster, the predominan...

The occurrence of immune complexes (ICs) containing Yersinia enterocolitica antigen and immunoglobulin was studied in 216 serum samples from 51 patients with recent yersiniosis at an early stage of the disease and during a follow up of two to 12 months. Twenty eight of the patients developed reactive arthritis, 23 recovered from the infection without any complications. An enzyme linked immunoso...

Yersinia pseudotuberculosis mutants that overproduce the DNA adenine methylase (DamOP Yersinia) are attenuated, confer robust protective immune responses, and synthesize or secrete several Yersinia outer proteins (Yops) under conditions that are nonpermissive for synthesis and secretion in wild-type strains. To understand the molecular basis of immunity elicited by DamOP Yersinia, we investigat...

Pathogenic Yersinia spp. translocate the effectors YopT, YopE, and YopO/YpkA into target cells to inactivate Rho family GTP-binding proteins and block immune responses. Some Yersinia spp. also secrete the Rho protein activator cytotoxic necrotizing factor-Y (CNF-Y), but it has been unclear how the bacteria may benefit from Rho protein activation. We show here that CNF-Y increases Yop translocat...

The acquired immune responses are crucial to the survival of Yersinia-infected animals. Mice lacking T cells are sensitive to Yersinia infection, and a humoral response to Yersinia can be protective. Diverse mechanisms for Yersinia to impair and evade the host innate immune defense have been suggested, but the effects of Yersinia on lymphocytes are not known. Here, we demonstrate that after a t...

OmpF is one of the major general porins of Enterobacteriaceae that belongs to the first line of bacterial defense and interactions with the biotic as well as abiotic environments. Porins are surface exposed and their structures strongly reflect the history of multiple interactions with the environmental challenges. Unfortunately, little is known on diversity of porin genes of Enterobacteriaceae...