Yersinia pseudotuberculosis
Yersinia pseudotuberculosis is a Gram-negative bacterium which primarily causes disease in animals; humans occasionally get infected zoonotically, most often through the food-borne route.

# Pathogenesis
In animals, Y. pseudotuberculosis can cause tuberculosis-like symptoms, including localized tissue necrosis and granulomas in the spleen, liver, and lymph node.
In humans, symptoms are similar to those of infection with Y. enterocolitica (fever and right-sided abdominal pain), except that the diarrheal component is often absent, which sometimes makes the resulting condition difficult to diagnose. Y. pseudotuberculosis infections can mimic appendicitis, especially in children and younger adults, and, in rare cases the disease may cause skin complaints (erythema nodosum), joint stiffness and pain (reactive arthritis), or spread of bacteria to the blood (bacteremia).
Infection usually becomes apparent 510 days after exposure and typically lasts 13 weeks without treatment. In complex cases or those involving immunocompromised patients, antibiotics may be necessary for resolution; ampicillin, aminoglycosides, tetracycline, chloramphenicol, or a cephalosporin may all be effective.
The recently described syndrome Izumi-fever has been linked to infection with Y.pseudotuberculosis.

# Medical therapy
- 1. Enterocolitis treatment
- Preferred regimen: There is also no evidence that early antimicrobial therapy reduces the frequency or severity of chronic sequelae for either Y. enterocolitica or Y. pseudotuberculosis
- Note: Susceptible to Ampicillin, third generation cephalosporins, aminoglycosides, tetracyclines, and chloramphenicol
- 2. Septicemia treatment
- Preferred regimen: Ceftriaxone 1 g IM/IV q12h
- Note: Pediatric dose: Ceftriaxone 100 mg/kg/day (up to 2 g/day) IM/IV q12h
- Note: There is no duration of treatment established but some Yersinia spp infections have been treat for at least 3 weeks.

# Gallery
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a Hektoen enteric agar (HEK) medium 48hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on SBA 48hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a chocolate agar 24hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on SBA 24hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on chocolate agar medium 24hrs (5x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on chocolate agar medium 24hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a Hektoen enteric agar (HEK) medium agar medium 72hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a MacConkey agar (MAC) medium 24hrs (20x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a MacConkey agar (MAC) medium 24hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a MacConkey agar (MAC) medium 72hrs (5x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on a MacConkey agar (MAC) medium 72hrs (10x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on SBA 24hrs (5x mag). From Public Health Image Library (PHIL). 
- Gram-negative Yersinia pseudotuberculosis bacteria, cultured on SBA 72hrs (10x mag). From Public Health Image Library (PHIL).