[Distribution of Yersinia pseudotuberculosis in Japan and epidemiology of human infection]

Association of Yersinia Infection With Kawasaki Disease: A Prospective Multicenter Cohort Study

BACKGROUND

Yersinia infection is known to present with Kawasaki disease (KD)-like symptoms although differentiating the 2 has been a challenge. The present study aimed to describe the clinical characteristics and prevalence of Yersinia infection presenting with KD-like symptoms.

METHODS

The present, prospective, multicenter study enrolled patients who received a diagnosis of KD between January 2021 and January 2022 at 2 hospitals in Tokyo. Stool samples were collected within 3 days of the start of KD treatment, and cultures were performed for Yersinia . Clinical history and symptoms suggestive of Yersinia infection were also evaluated.

RESULTS

During the study period, 141 KD patients were screened and 117 patients with evaluable stool samples were registered. Only 1 patient was positive for Yersinia pseudotuberculosis , which was detected from both stool and blood cultures. The patient was refractory to KD treatment but improved after initiation of appropriate antibiotic therapy.

CONCLUSIONS

Routine screening for Yersinia is not appropriate for patients with KD and should be limited to certain patients in high-risk areas and those who are refractory to the standard KD treatment.

Far East Scarlet-like Fever Masquerading as Adult-onset Kawasaki Disease

A previously healthy 31-year-old man was referred to us with refractory septic shock accompanied by bilateral conjunctival congestion and erythema of his right lower limb. Nine days after admission, he had bilateral desquamation of the fingertips, and his presentation satisfied the criteria for Kawasaki disease. A serological examination was positive for Yersinia pseudotuberculosis, and he was diagnosed with Far East scarlet-like fever (FESLF). Interestingly, his 11-month-old baby boy had similar symptoms around the same time, indicating the intrafamilial transmission of the pathogen. We should consider FESLF when we encounter a familial occurrence of systemic manifestations of Kawasaki disease.

A study on the efficacy of the recombinant Yersinia adhesin A vaccine against yersiniosis in the early phase

Yersinia pseudotuberculosis (Y. ptb) is a zoonotic pathogenic bacterial species of the family Enterobacteriaceae and causes yersiniosis, an acute intestinal infection in humans and animals. Y. ptb is often implicated in lethal epidemics in zoo animals and reductions in the breeding population, but a valid prevention method has not been established. Therefore, this study aimed to develop a vaccine for yersiniosis control. The immunogenicity of one of the adhesion factors involved in pathogenic mechanisms of Y. ptb, Yersinia adhesin A (YadA), was investigated. BALB/c mice were divided into 3 groups: in group 1, mice received insoluble recombinant YadA (rYadA) produced in genetically engineered Escherichia coli (100 µg/dose); in group 2, mice received inactivated Y. ptb with strong expression of YadA (20 mg/dose);and in group 3, mice received phosphate-buffered saline (0.2 ml/dose). All interventions were administered subcutaneously twice at an interval of 1 week. One week after the second administration, Y. ptb (10⁷ cells/mouse) was inoculated orally. As a result, the survival rate was 100% in group 1, 60% in group 2, and 0% in group 3. The anti-YadA antibody titer increased in a stepwise fashion in groups 1 and 2. The present study results suggest that rYadA shows promise as a protective antigen against yersiniosis. This study concluded that vaccination against Y. ptb may become available as a new method to prevent lethal epidemics in animals.