EC Dental Science

Genus Yersinia is constituted of rod shaped bacteria configured as Yersinia pestis, Yersinia enterocolitica and Yersinia pseudotuberculosis which are virulent to humans.

 The exceptionally encountered, gram negative bacillus Yersinia pseudotuberculosis induces an enteric illness. Yersinia pseudotuberculosis infection is acquired via consumption of contaminated food and water.

 Yersinia pseudotuberculosis is confined to the soil and accumulates within fresh, farm plants and root vegetables. Besides, innumerable animal reservoirs and wildlife as birds, rodents, rabbits, deer, dogs, cats, and cattle may demonstrate the bacterium. Incubation period of the infection varies from 5 to 10 days with peak disease incidence at 4 days following bacterial ingress [1,2].

 Yersinia pseudotuberculosis infection clinically simulates acute appendicitis or probable occurrence of an abdominal mass. Surgical laparotomy expounds mesenteric lymphadenitis. The self limited condition may be associated with Kawasaki disease [1,2].

 Quantifiably significant inoculum of the entero-pathogen, Yersinia pseudotuberculosis is necessitated to induce human infection. Pre-eminently, a virulence factor, plasmid-encoded protein augments bacterial invasiveness wherein Yersinia pseudotuberculosis may thrive intracellularly [2,3].

 The siderophore-mediated iron scavenging system enmeshed within Yersinia pseudotuberculosis contributes to bacterial virulence. Yersinia pseudotuberculosis may be appropriately discerned by polymerase chain reaction (PCR). Besides, cogent cultures may be employed for diagnosis [2,3].

 Grossly, the infection is associated with inflammation of terminal ileum and cecum [3,4].

 Upon microscopy, lymph node capsule is thickened and oedematous.

 Configured epithelioid cell granuloma is accompanied by centric necrosis and micro-abscess. Immunoblasts and plasma cells appear aggregated within cortex and para-cortical region. Enlarged lymphocytes are confined within lymphatic sinuses. Hyperplasia of germinal centre or lymphoid hyperplasia is observed [4,5].

 Mesenteric lymph nodes and Peyer's patches are imbued with epithelioid cell granulomas. Foci of coagulative necrosis are discerned. During sepsis, granulomatous abscess may occur within hepatic, pulmonary or renal parenchyma, spleen or gastrointestinal tract [4,5].

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 Gram’s stain depicts motile, gram negative, polymorphic, coccoid or ovoid bacteria [6,7].

 Yersinia pseudotuberculosis inhabits and propagates within the gastrointestinal tract as Peyer's patches with consequent dissemination into hepatic parenchyma, spleen, mesenteric lymph nodes or a direct bacterial transmission [6,7].

 Yersinia pseudotuberculosis infection requires segregation from conditions as appendicitis, pancreatitis, inflammatory bowel disease, gastroenteritis, scarlet fever, toxic shock syndrome or leptospirosis [7,8].

 The self-limited Yersinia pseudotuberculosis infection may be associated with toxic symptoms, septic syndrome or severe dehydration [8,9].

 Supportive therapy may be beneficially adopted to treat the bacterial infection. Severe manifestations as sepsis concurring with immunosuppression or chronic liver disease may warrant the commencement of antibiotic therapy [8,9].

 Agents as fluoroquinolones, ampicillin, ceftriaxone, doxycycline and gentamycin may be suitably employed for treating Yersinia pseudotuberculosis infection [8,9].

 Severe gastrointestinal haemorrhage or intestinal obstruction may be suitably managed with surgical manoeuvers as exploratory laparotomy [8,9].

(Figure 1 and 2)

1. Tan Y., et al. “A rare case of Yersinia pseudotuberculosis infection with septic shock and splenic infarction”. Infection and Drug Resistance 18 (2025): 5057-5065.
2. Grygiel-Górniak B. “Current challenges in Yersinia diagnosis and treatment”. Microorganisms 5 (2025): 1133.
3. Brady MF., et al. “Yersinia pseudotuberculosis”. Stat Pearls International. Treasure Island, Florida (2025).
4. Bliska JB., et al. “Role of the Yersinia pseudotuberculosis virulence plasmid in pathogen-phagocyte interactions in mesenteric lymph nodes”. EcoSal Plus2 (2021): eESP00142021.
5. Stanger KJ., et al. “Outbreaks of diarrhoea ('winter scours') in weaned Merino sheep in south-eastern Australia”. Australian Veterinary Journal 5 (2018): 176-183.
6. Yang X., et al. “Type VI secretion systems present new insights on pathogenic Yersinia”. Frontiers in Cellular and Infection Microbiology 8 (2018): 260.
7. Davis KM. “All Yersinia are not created equal: phenotypic adaptation to distinct niches within mammalian tissues”. Frontiers in Cellular and Infection Microbiology 8 (2018): 261.
8. Le Guern AS., et al. “Yersiniosis in France: overview and potential sources of infection”. International Journal of Infectious Diseases 46 (2016): 1-7.
9. Amphlett A. “Far east scarlet-like fever: a review of the epidemiology, symptomatology, and role of superantigenic toxin: Yersinia pseudotuberculosis-derived mitogen A”. Open Forum Infectious Diseases 1 (2016): ofv202.
10. Image 1 Courtesy: Pathology outlines.
11. Image 2 Courtesy: Journal of Infection and Chemotherapy.