Persistent Helicobacter pullorum colonization in C57BL/6NTac mice: a new mouse model for an emerging zoonosis

Area of Science:

• Microbiology
• Immunology
• Veterinary Medicine

Background:

• Helicobacter pullorum is an enterohepatic Helicobacter species linked to human and avian gastroenteritis and hepatobiliary disease.
• A recent outbreak in barrier-maintained rodents highlighted the need to understand H. pullorum infection dynamics in murine models.

Purpose of the Study:

• To evaluate the persistence of H. pullorum infection and the associated serological responses in C57BL/6NTac and C3H/HeNTac mice.
• To assess the efficacy of a novel quantitative PCR (qPCR) assay for detecting H. pullorum.

Main Methods:

• Female C57BL/6NTac and C3H/HeNTac mice were infected with H. pullorum.
• Infection persistence was monitored using PCR and culture of fecal and cecal samples.
• Serological responses were assessed using ELISA, and qPCR was employed to quantify bacterial load.

Main Results:

• C57BL/6NTac mice exhibited chronic H. pullorum infection, primarily in the caecum and colon, with colonization decreasing significantly between 32 and 58 weeks of age.
• Two out of three C3H/HeNTac mice cleared the infection by 26 weeks of age.
• Infected mice developed a serological response (IgG), which declined as bacterial colonization decreased. No gross or histological lesions were observed in the liver or gastrointestinal tract.

Conclusions:

• H. pullorum can establish persistent infections in mice, with varying clearance rates between strains.
• The cdtB-based qPCR assay is a sensitive tool for detecting H. pullorum in various sample types, including animals, food, and environmental sources.
• The findings provide a foundation for future research into the pathogenic mechanisms of H. pullorum, an emerging zoonotic pathogen.