Far East Scarlet-Like Fever Caused by a Few Related Genotypes of Yersinia pseudotuberculosis, Russia

Complete genome sequence of Yersinia pseudotuberculosis strain SP-1303 from lineage 8, associated with Far East scarlet-like fever

We report the complete genome sequence of Yersinia pseudotuberculosis strain SP-1303, identified as part of lineage 8 and associated with Far East scarlet-like fever. The genome includes the chromosome, the Yersinia-virulence plasmid (pYV) encoding a type III secretion system essential for virulence, the pVM82 plasmid, and two cryptic plasmids.

Yersinia pseudotuberculosis bacteraemia with splenic abscesses: a case report

Introduction

Yersinia pseudotuberculosis has been known to cause a variety of clinical manifestations ranging from mild enteric illness to bacteraemia with septic shock and extraintestinal abscesses. Patients with liver disease and iron overload are at risk of more severe disease manifestations.

Case Report

A middle-aged male with chronic alcohol use disorder presented with confusion and jaundice, with ascites and asterixis noted on examination. His blood work was remarkable for neutrophilic leukocytosis, elevated liver enzymes and lactate. An abdominal computed tomography scan revealed splenic microabscesses and a cirrhotic liver. Yersinia pseudotuberculosis was recovered from his blood cultures and he was treated with ceftriaxone following susceptibility results.

Conclusion

Y. pseudotuberculosis should be considered in the differential diagnosis of splenic or other extraintestinal microabscesses particularly in patients with chronic liver disease.

Adaptation Potential of Three Psychrotolerant Aquatic Bacteria in the Pan-Okhotsk Region

The Pan-Okhotsk region, which is part of the western North Pacific Ocean, is famous for its active volcanoes, which are part of the Pacific Ring of Fire and that enrich the surrounding waters with essential chemicals. Therefore, this region, including the Sea of Okhotsk and the Sea of Japan, is characterized by rich biota. Bacterioplankton plays a significant part in biological communities and is an indicator of ecosystem function. Analyzing the adaptability of three representatives of the microbiota of the Pan-Okhotsk region was the goal of our investigation. Marinomonas primoryensis KMM3633T (MP), Yersinia ruckeri KMM821 (YR), and Yersinia pseudotuberculosis 598 (YP) from the G.B. Elyakov Pacific Institute of Bioorganic Chemistry were studied by means of genomic and bioinformatic methods. The list of membrane translocator proteins, metabolism pathways, and cold shock and antifreeze proteins that were revealed in the genome of MP characterized this bacterium as being adaptable to free living in marine conditions, even at winter temperatures. The genomic potential of YR and YP makes not only survival in the environment of the Pan-Okhotsk region but also pathogenesis in eukaryotic organisms possible. The data obtained will serve as a basis for further ecosystem monitoring with the help of microbiota research.

Listeria monocytogenes Invasion Into Sheep Kidney Epithelial Cells Depends on InlB, and Invasion Efficiency Is Modulated by Phylogenetically Defined InlB Isoforms

The facultative intracellular pathogen Listeria monocytogenes is of major veterinary importance in small ruminants. Nevertheless, details of L. monocytogenes interactions with cells of small ruminants are not fully established. To study the potential of L. monocytogenes to infect sheep cells, we used the finite sheep kidney cell line (shKEC), which was infected with the wild-type L. monocytogenes strain EGDe. The invasion efficiency was 0.015 ± 0.004%. The invasion factor InlB was critically important for invasion, and inlB gene deletion almost prevented L. monocytogenes invasion into shKEC cells. Comparison of the potential of phylogenetically defined InlB isoforms to restore the invasive phenotype of the EGDeΔinlB strain demonstrated that although all InlB isoforms restored invasion of the EGDeΔinlB strain into shKEC cells, the InlB isoforms typical of highly virulent ruminant strains of the clonal complexes CC1 and CC7 were more efficient than isoforms typical of CC2 and CC9 strains (which are less virulent toward ruminants) in supporting invasion. Listeria monocytogenes effectively multiplied with a doubling of time in about 90 min after they entered the sheep cells. Intracellular bacteria moved using the well-known actin polymerization mechanism. Cell-to-cell spreading was restricted to the infection of a few tens of neighboring cells for 7 days. Overall, the obtained results demonstrated that (i) InlB is required for invasion into sheep cells, (ii) InlB isoforms might be important for hypervirulence of certain clonal groups toward ruminants, and (iii) L. monocytogenes effectively multiplies in ovine cells once entered.

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

Pseudotuberculosis in humans until the 1950s was found in different countries of the world as a rare sporadic disease that occurred in the form of acute appendicitis and mesenteric lymphadenitis. In Russia and Japan, the Yersinia pseudotuberculosis (Y. pseudotuberculosis) infection often causes outbreaks of the disease with serious systemic inflammatory symptoms, and this variant of the disease has been known since 1959 as Far Eastern Scarlet-like Fever (FESLF). Russian researchers have proven that the FESLF pathogen is associated with a concrete clonal line of Y. pseudotuberculosis, characterized by a specific plasmid profile (pVM82, pYV 48 MDa), sequence (2ST) and yadA gene allele (1st allele). This review summarized the most important achievements in the study of FESLF since its discovery in the Far East. It has been established that the FESLF causative agent is characterized by a unique phenomenon of psychrophilicity, which consists of its ability to reproduce in the environment with its biologically low and variable temperature (4-12 °C), at which the pathogen multiplies and accumulates while maintaining or increasing its virulence, which ensures the emergence and development of the epidemic process. The key genetic and biochemical mechanisms of Y. pseudotuberculosis adaptation to changing environmental conditions were characterized, and the morphological manifestations of the adaptive variability of these bacteria in different conditions of their habitat were revealed. The main features of the pathogenesis and morphogenesis of FESLF, including those associated with the Y. pseudotuberculosis toxigenicity, were presented. The pathogenetic value of the plasmid PVM82, found only in the FESLF pathogen, was shown.

Genetics and evolution of Yersinia pseudotuberculosis O-specific polysaccharides: a novel pattern of O-antigen diversity

O-antigen polysaccharide is a major immunogenic feature of the lipopolysaccharide of Gram-negative bacteria, and most species produce a large variety of forms that differ substantially from one another. There are 18 known O-antigen forms in the Yersinia pseudotuberculosis complex, which are typical in being composed of multiple copies of a short oligosaccharide called an O unit. The O-antigen gene clusters are located between the hemH and gsk genes, and are atypical as 15 of them are closely related, each having one of five downstream gene modules for alternative main-chain synthesis, and one of seven upstream modules for alternative side-branch sugar synthesis. As a result, many of the genes are in more than one gene cluster. The gene order in each module is such that, in general, the earlier a gene product functions in O-unit synthesis, the closer the gene is to the 5΄ end for side-branch modules or the 3΄ end for main-chain modules. We propose a model whereby natural selection could generate the observed pattern in gene order, a pattern that has also been observed in other species.