Far Eastern Scarlet-Like Fever is a Special Clinical and Epidemic Manifestation of Yersinia pseudotuberculosis Infection in Russia

Genome Analysis of Japanese Yersinia pseudotuberculosis Strains Isolated From Kawasaki Disease Patients and Other Sources and Their Phylogenetic Positions in the Global Y. pseudotuberculosis Population

Yersinia pseudotuberculosis (Ypt) is a gram-negative bacterium that infects both humans and animals primarily through fecal‒oral transmission. While Ypt causes acute gastroenteritis in humans, an association with Kawasaki disease (KD), a disease that primarily affects infants and young children and causes multisystemic vasculitis, has also been suspected. Although KD represents a significant health concern worldwide, the highest annual incidence rate is reported in Japan. Previously, a geographical origin-dependent population structure of Ypt comprising the Asian, transitional, and European clades was proposed. However, genomic data on KD-associated Ypt strains is currently unavailable. In this study, to analyze the phylogenetic and genomic features of KD-associated strains, we determined the whole-genome sequences of 35 Japanese Ypt strains, including 11 KD-associated strains, and constructed a genome set (n = 204) representing the global population of Ypt by adding publicly available Ypt genomes. In a phylogenetic analysis, all sequenced Japanese strains, including the KD-associated strains, belonged to the Asian clade, which appeared to be the ancestral clade of Ypt, and the KD-associated strains belonged to multiple lineages in this clade. Strains from patients with Far East scarlet-like fever (FESLF), a KD-related disease, also belonged to the Asian clade. Moreover, no KD strain-specific genes were identified in pan-genome-wide association study analyses. Notably, however, the gene encoding a superantigen called Yersinia pseudotuberculosis-derived mitogen (YPM) showed a distribution pattern highly biased to the Asian clade. Although further studies are needed, our results suggest that Asian clade strains may have a greater potential to trigger KD.

Repeated plague infections across six generations of Neolithic Farmers

In the period between 5,300 and 4,900 calibrated years before present (cal. BP), populations across large parts of Europe underwent a period of demographic decline1,2. However, the cause of this so-called Neolithic decline is still debated. Some argue for an agricultural crisis resulting in the decline3, others for the spread of an early form of plague4. Here we use population-scale ancient genomics to infer ancestry, social structure and pathogen infection in 108 Scandinavian Neolithic individuals from eight megalithic graves and a stone cist. We find that the Neolithic plague was widespread, detected in at least 17% of the sampled population and across large geographical distances. We demonstrate that the disease spread within the Neolithic community in three distinct infection events within a period of around 120 years. Variant graph-based pan-genomics shows that the Neolithic plague genomes retained ancestral genomic variation present in Yersinia pseudotuberculosis, including virulence factors associated with disease outcomes. In addition, we reconstruct four multigeneration pedigrees, the largest of which consists of 38 individuals spanning six generations, showing a patrilineal social organization. Lastly, we document direct genomic evidence for Neolithic female exogamy in a woman buried in a different megalithic tomb than her brothers. Taken together, our findings provide a detailed reconstruction of plague spread within a large patrilineal kinship group and identify multiple plague infections in a population dated to the beginning of the Neolithic decline.

Past Endemic Izumi Fever or Yersinia pseudotuberculosis Infection Reappears Sporadically

Izumi fever (IF), also known as Far East scarlet-like fever (FESLF), is caused by Yersinia pseudotuberculosis and it has clinical features resembling those of Kawasaki disease (KD). As both diseases are rare in adolescents and young adults, it is challenging to recognize them, thus often leading to a delayed diagnosis. We herein present two cases of IF or FESLF (IF/FESLF). The first case was misdiagnosed as KD, which led to a diagnostic delay. The second case was recognized earlier owing to our experience with the first case. Although cultures were negative in both cases, presumably due to the prior use of antimicrobial agents, our clinical suspicion and a paired serological assay for anti-Y. pseudotuberculosis antibodies finally led to a successful diagnosis.

Effect of Non-Specific Porins from the Outer Membrane of Yersinia pseudotuberculosis on Mice Brain Cortex Tissues

It was found that a single-dose immunization of mice with Yersinia pseudotuberculosis porins OmpF and OmpC causes development of pathological changes in the deep layers of cerebral cortex characterized by dystrophic changes in the cells against the background of the increasing titer of specific antibodies. At the same time, the increased level of caspase-3 expression is observed in the neurons, which indicates induction of proapoptotic signaling pathways. The obtained results indicate potential ability of nonspecific pore-forming proteins of the outer membrane of Gram-negative bacteria to initiate development of degenerative changes in brain cells.

First Description of a Yersinia pseudotuberculosis Clonal Outbreak in France, Confirmed Using a New Core Genome Multilocus Sequence Typing Method

Yersinia pseudotuberculosis is an enteric pathogen causing mild enteritis that can lead to mesenteric adenitis in children and septicemia in elderly patients. Most cases are sporadic, but outbreaks have already been described in different countries. We report for the first time a Y. pseudotuberculosis clonal outbreak in France, that occurred in 2020. An epidemiological investigation based on food queries pointed toward the consumption of tomatoes as the suspected source of infection. The Yersinia National Reference Laboratory (YNRL) developed a new cgMLST scheme with 1,921 genes specific to Y. pseudotuberculosis that identified the clustering of isolates associated with the outbreak and allowed to perform molecular typing in real time. In addition, this method allowed to retrospectively identify isolates belonging to this cluster from earlier in 2020. This method, which does not require specific bioinformatic skills, is now used systematically at the YNRL and proves to display an excellent discriminatory power and is available to the scientific community. IMPORTANCE We describe in here a novel core-genome MLST method that allowed to identify in real time, and for the first time in France, a Y. pseudotuberculosis clonal outbreak that took place during the summer 2020 in Corsica. Our method allows to support epidemiological and microbiological investigations to establish a link between patients infected with closely associated Y. pseudotuberculosis isolates, and to identify the potential source of infection. In addition, we made this method available for the scientific community.

Extraintestinal Manifestation of Yersinia pseudotuberculosis Bacteremia as Acute Hepatitis: Case Report and Review of the Literature

Yersinia pseudotuberculosis is a causative agent of foodborne zoonosis that usually causes self-limiting pseudoappendicitis. Y. pseudotuberculosis infection also causes systemic spread or extraintestinal manifestations in patients with predisposing conditions. Here, we present a case of acute hepatitis with Y. pseudotuberculosis bacteremia in a 30-year-old man. He was previously healthy without significant medical history other than obesity and current smoking. At the time of admission, he presented with high fever accompanied by chills, jaundice, abdominal pain, and watery diarrhea. Laboratory studies revealed leukocytosis and elevated liver function parameters. A stool culture showed no causative pathogens. Empiric antibiotic therapy with ceftriaxone and metronidazole was administered. Y. pseudotuberculosis was later isolated from the initial blood culture performed on the day of admission using MALDI-TOF mass spectrometry. Antibiotic treatment was continued based on the susceptibility testing results from MALDI-TOF MS and VITEk^®2, as well as clinical and laboratory improvements. The patient was discharged on the tenth day of admission and remained healthy with no recurrence during the 12-month follow-up. Here, we review the literature on the systemic infection caused by Y. pseudotuberculosis, including extraintestinal manifestations. This case highlights that Y. pseudotuberculosis may be considered a differential causative organism in patients with acute colitis and hepatitis.

Differential Expression of Yersinia pseudotuberculosis General Porin Genes during Short- and Long-Term Antibiotic Stresses

Here, we investigated general porin regulation in Yersinia pseudotuberculosis 488, the causative agent of Far Eastern scarlet-like fever, in response to sublethal concentrations of antibiotics. We chose four antibiotics of different classes and measured gene expression using qRT-PCR and GFP reporter systems. Our data showed temporal regulation of the general porin genes ompF and ompC caused by antibiotic stress. The porin transcription initially decreased, providing early defensive response of the bacterium, while it returned to that of the untreated cells on prolonged antibiotic exposure. Unlike the major porin genes, the transcription of the alternative porin genes ompX and lamB was increased. Moreover, a short-term ompR- and marA-mediated porin regulation was observed. The main finding was a phenotypic heterogeneity of Y. pseudotuberculosis population manifested in variable porin gene expression under carbenicillin exposure. This may offer adaptive fitness advantages for a particular bacterial subpopulation.

Pan-genomics, drug candidate mining and ADMET profiling of natural product inhibitors screened against Yersinia pseudotuberculosis

Yersinia pseudotuberculosis belongs to the family Enterobacteriaceae and is responsible for scarlatinoid fever, food poisoning, post-infectious complications like erythema nodosum/reactive arthritis as well as pseudoappendicitis in children. Genome sequences of the 23 whole genomes from NCBI were utilized for conducting the pan-genomic analysis. Essential proteins from the core region were obtained and drug targets were identified using a hierarchal in silico approach. Among these, multidrug resistance protein sub-unit mdtC was chosen for further analysis. This protein unit confers resistance to antibiotics upon forming a tripartite complex with units A and B in Escherichia coli. Details of the function have not yet been elucidated experimentally in Yersinia spp. Computational structure modeling and validation were followed by screening against phytochemical libraries of traditional Indian (Ayurveda), North African, and traditional Chinese flora using Molecular Operating Environment software version 2019.0102. ADMET profiling and descriptor study of best docked compounds was studied. Since phytotherapy is the best resort to antibiotic resistance so these compounds should be tested experimentally to further validate the results. The obtained information could aid wet-lab scientists to work on the scaffold of screened drug-like compounds from natural resources. This could be useful in our quest for antibiotic-resistant therapy against Y. pseudotuberculosis.