Yersinia-associated arthritis in the rat: experimental model for human reactive arthritis?

Bacteria-Triggered reactive arthritis: implications for antibacterial treatment

Reactive arthritis (ReA) is definitely caused by an infection. Several observations suggest that the triggering microbe may persist in the tissues of the patient for a prolonged time. The obvious conclusion is to consider antibacterial treatment. In two instances antibacterial agents are of definite value: in the primary and secondary prevention of rheumatic fever and for early eradication of Borrelia burgdorferi in order to prevent development of the arthritis associated with Lyme disease. Altogether, clinical and experimental data exist to indicate that if antibacterial treatment of ReA can be started very early during the pathogenetic process, the disease can be prevented or the prognosis improved. In fully developed ReA, the value of antibacterial agents is less certain. All available evidence indicates that short term antibacterial treatment has no effect on the prognosis and final outcome of ReA, and the results with long term administration of antibacterials are also overall poor. In some instances sulfasalazine appears useful, rather as a result of its antirheumatic effect or influence on an underlying inflammatory bowel disease than its action as an antibacterial agent. Tetracyclines have also been found to have an effect on ReA, but again, this is probably due to their anti-inflammatory action rather than any antibacterial effect.

Construction of urease-negative mutants of Yersinia enterocolitica serotypes O:3 and o:8: role of urease in virulence and arthritogenicity

Yersinia enterocolitica serotype O:3 and O:8 urease-negative mutants unable to express the 19-kDa beta subunit of urease were constructed and tested for virulence and arthritogenicity. Our results indicate that urease is needed for full virulence in oral infections and that it is not an arthritogenic factor in the rat model.

Decomplementation by cobra venom factor suppresses Yersinia-induced arthritis in rats

Lewis rats experimentally infected with Yersinia enterocolitica O8 develop Yersinia-induced arthritis (YIA), which resembles very much reactive arthritis in humans. To investigate the involvement of serum complement in induction and maintenance of YIA, we decomplementated Yersinia-infected Lewis rats by treatment with cobra venom factor starting on day 7 after infection (prearthritic state). Reduction of serum complement activity in vivo by cobra venom factor treatment coincided with suppression of YIA clinically and histomorphologically.

Role of YadA-mediated collagen binding in arthritogenicity of Yersinia enterocolitica serotype O:8: experimental studies with rats

Outer membrane protein YadA, Yersinia adhesin, is one of the plasmid-encoded virulence factors of yersiniae. YadA protects bacteria against host defense through several different mechanisms. One important role of YadA is to mediate binding to several collagen types. Our recent study revealed that a yadA null mutant of Yersinia enterocolitica serotype O:8 has a drastically reduced arthritogenic capacity when injected intravenously into Lewis rats. To further characterize the arthritogenic role of YadA, we repeated the rat experiments with strain Y. enterocolitica O:8/pYV082; this strain expresses a YadA deletion derivative lacking 22 amino acids from the amino-terminal hydrophobic region and does not bind to collagen. Y. enterocolitica O:8/pYV082 induced arthritis in 5 to 14% of rats inoculated with arthritogenic doses, whereas the arthritis incidence with the wild-type parent strain was 65%. The parent strain was slightly more virulent than Y. enterocolitica O:8/pYV082, as determined by rat mortality. It also frequently induced skin abscesses, whereas Y. enterocolitica O:8/pYV082 did not. Infection kinetics in spleen and mesenteric lymph nodes were about the same with both of the bacterial strains used, and the same was true of the Yersinia-specific antibody response. Altogether, these results suggest that YadA-mediated collagen binding contributes to the arthritogenicity of Y. enterocolitica O:8.

Arthritogenicity of genetically manipulated Yersinia enterocolitica serotype O8 for Lewis rats

Yersinia enterocolitica strains of serotype O8 but not strains of other human pathogenic serotypes (e.g., O3 or O9) are able to induce a reactive arthritis-like disease in Lewis rats after intravenous inoculation (J. L. Hill and D. T. Yu, Infect. Immun. 55:721-726, 1987). To assess which bacterial components or pathogenic factors are crucial for arthritis induction, six genetically manipulated Y. enterocolitica O8 derivatives have been compared with the parental strain in Lewis rats. Neither differences in the length of the lipopolysaccharide side chain (smooth to semirough) of Y. enterocolitica O8 nor replacement of the virulence plasmid (pYVO8) of Y. enterocolitica O8 with that of the nonarthritogenic Y. enterocolitica O9 (pYVO9) had a significant influence on arthritogenic potential or virulence in rats. Transposon insertional inactivation of the plasmid gene yadA encoding the Yersinia adhesin and the collagen-binding protein or of the secretion of YopH resulted in decreased arthritogenicity (increase of the arthritogenic infectious dose) and pathogenicity (decreased persistence of the pathogen in spleens and livers of rats and increase of the 50% lethal dose for mice). However, mutants impaired in yersiniabactin production or uptake proved to be nonarthritogenic for rats, probably because of pronounced attenuation in virulence. From these results, we conclude that the arthritogenic potential of Y. enterocolitica serotype O8 is closely related to the virulence potential determined as the 50% lethal dose in mice and the ability to persist in lymphatic tissue of Lewis rats. A specific arthritogenic determinant of Y. enterocolitica could not be identified.

Yersinia associated arthritis in SHR rats: effect of the microbial status of the host

Following the intravenous injection of live Yersinia enterocolitica O:8, 50-69% of SHR rats developed arthritis; these rats were antibody free against all rat pathogens tested. In contrast, only 20-25% of SHR rats which had serum antibodies against Bacillus piliformis, Kilham rat virus, and Toolan H-1 virus developed arthritis. The results indicate that the microbial load of the host has a profound effect on the susceptibility to experimental arthritis.

Experimental Yersinia enterocolitica infection in rats: analysis of the immune response to plasmid-encoded antigens of arthritis-susceptible Lewis rats and arthritis-resistant Fischer rats

Recently, experimentally Yersinia-induced arthritis in Lewis and SHR rats has been described as a potential animal model for analyzing the pathomechanism of reactive arthritis (Toivanen et al. 1986; Hill and Yu 1987). We could confirm that Lewis but not Fischer rats develop aseptic arthritis about 2 weeks after an intravenous inoculation of Yersinia enterocolitica, serotype 0:8 (Hill and Yu 1987). Moreover, we compared the antibody response to virulence-associated Yersinia antigens (Yops) of experimentally infected Lewis rats with that of Fischer rats using an enzyme-linked immunosorbent assay (ELISA) and immunoblotting. The ELISA results revealed a more rapid and vigorous specific IgG, IgA and IgM response for Lewis rats than for Fischer rats in the early state of infection. As demonstrated by immunoblotting, the IgG response was directed predominantly against the plasmid-encoded YopM, YopH, YopD and the V-antigen during the acute phase followed by antibodies against YopE and YadA. Although both rat strains seroconverted against this set of antigens, IgG antibodies to YadA were more prevalent and of higher titer in arthritis-susceptible rats compared to arthritis-resistant rats.

Long term follow up of SHR rats with experimental yersinia associated arthritis

One hundred and one SHR rats were injected intravenously with live Yersinia enterocolitica O:8. The rats were randomly divided into two groups consisting of 48 and 53 rats. The group of 48 rats was monitored for 245 days to establish the incidence and the clinical features of the arthritis. The remaining 53 rats were killed in groups of three to five rats at intervals from four to 245 days after inoculation to examine the clearance of bacteria and the development of histological changes in the synovial membrane. Arthritis developed in 23/48 (48%) rats at seven to 27 days after inoculation. The arthritis subsided in most rats within four weeks, without leading to ankylosis of the affected joints. The arthritis was prolonged in three rats and recurrent in two. In the group of 53 rats Yersinia enterocolitica O:8 was cleared from most of the internal organs by day 77, but persisted in the inguinal lymph nodes in many of the rats up to day 245. All macroscopically arthritic joints showed clear histological signs of non-suppurative synovitis. No histological synovitis was detected in those joints observed macroscopically to be non-arthritic. Yersinia associated arthritis in SHR rats provides a potential model for reactive arthritis. There are strong similarities in the course of the arthritis and histopathological changes in the synovium between this animal model and reactive arthritis in humans. This study supports the association between poor elimination of the causative agent and the development of arthritis.