Etiology:  Helicobacters are Gram-negative, microaerophilic spiral motile bacteria.  H. muridarum, H. typhlonius, H. bilis, H. rodentium and H. trogontum are species of Helicobacter that colonize laboratory rats.

Incidence:  The incidence of infection is moderate.

Transmission: The mode of transmission is by the fecal-oral route. Rodent helicobacters normally colonize the lower intestinal tract and can be transmitted to naive rats through contact with feces-laden bedding.

Clinical Signs:  Most rats colonized with helicobacters remain asymptomatic for long periods of time.  Certain rats (athymic nude) may develop a proliferative, inflammatory typhlitis when infected with H. bilis and may show signs of rectal prolapse.

Pathology: Certain rats (athymic nude) will develop a proliferative, inflammatory typhlitis when infected with H. bilis.

Diagnosis: Helicobacters can be detected by PCR testing and histopathology.  PCR of feces is the most sensitive and rapid diagnostic method used for screening rodents for infection.