YERSINIA

          Enterobacteraceae member

          G (-) coccobacillus

          +/- motile [temperature dependant]

          psychotrophic

    Yersinia enterocolitica

          Ferments glucose, no gas

          Oxidase (-), urease (+)

          Serotypes based on O –cell wall antigens

          Not part of normal flora of humans; normally in frogs, birds, fish, fleas, flies, oysters

          Transmission: Fecal à oral

Clinical course: adherence to mucosa epithelial cells of intestine à diarrhea and appendicitis. 
Can progress to L.N. causing abscess and arthritis

          DX: Culture on special iron media

                  ELISA

          TX: AB

          Prevention: proper cooking of meet, hygiene

Yersinia pestis [Formally Pasteurella pestis]

          G (-) short bacillus with bipolar staining (looks like safety pin)

          Non motile, non sporeformer

          Causative agent of Bubonic plague or Black death

          Plague is endemic in wild rodents

          Tranmitted via flea vector bite or direct by respiratory droplets

          Incubation is 2-5 days

    Clinical Course: Enlarged LN (buboes) à fever à lymphatic organ size increase (splenomegaly)

          Can progress to tachycardia, tachypnea with cough and raspberry syrup sputum and pneumonia and eventual CNS dementia

               Disease course: Bubonic Plague [70% mortality]

                                    Pnemonic Plague [100% mortality]

                                    Black Death (due to DIC) [100% mortality]

          Virulence Factors: LPS

                                      Plasmids

          DX: culture organism from fluids, LN aspirate;  CF  ; IFA

          TX: AB [streptomycin, tetracycline]

          Prevention: Rodent control, flea control