Yersinia:
Yersinia is a genus of bacteria that includes several species known to cause human illness, such as Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis. These bacteria are facultative anaerobes with a rod-shaped morphology and belong to the Enterobacteriaceae family.

Diseases caused by Yersinia:

Yersinia pestis: Y. pestis is the causative agent of plague, a severe and often deadly infectious disease. Plague has three forms: bubonic, septicemic, and pneumonic. Bubonic plague is characterized by swollen and painful lymph nodes, septicemic plague involves bloodstream infection, and pneumonic plague affects the respiratory system. Plague is primarily transmitted through the bites of infected fleas or through contact with contaminated materials.

Yersinia enterocolitica and Yersinia pseudotuberculosis: These species can cause gastrointestinal infections. Y. enterocolitica is often associated with foodborne illness and can lead to symptoms such as abdominal pain, diarrhea, and fever. Y. pseudotuberculosis can cause a similar range of symptoms but is less commonly reported.

Detection and Diagnosis of Yersinia:
Diagnosing Yersinia infections involves clinical evaluation and laboratory testing. For Y. pestis, cultures from blood, sputum, or lymph node aspirates can be performed. Serological tests, including enzyme-linked immunosorbent assay (ELISA) like the assay available here and agglutination tests, can detect antibodies against Yersinia. Molecular methods, such as PCR, are also used for specific and rapid detection. Prompt diagnosis and treatment are essential, particularly for plague, which requires immediate medical attention to prevent severe outcomes.