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Updated: May 15, 2026
Mouse Models Of Helicobacter Infection And Gastric Pathologies
Published on: October 18, 2018
Resistance of Sprague-Dawley Rats to infection with Helicobacter pullorum
Laura D Cacioppo1, Zeli Shen, Nicola M Parry
1Division of Comparative Medicine Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. cacioppo@mit.edu
Abstract:
Helicobacter pullorum is an enterohepatic Helicobacter spp. known to infect both chickens and humans. H. pullorum infection has recently been reported in both mice and rats. This study was designed to determine whether standard methods of colony health surveillance using exposure to rodent soiled bedding could detect H. pullorum in Sprague-Dawley rats. We exposed 8 Helicobacter-free Sprague-Dawley rats to bedding from H. pullorum-infected Brown Norway rats. Fecal samples were analyzed by PCR every 2 wk for 22 wk. Dirty bedding transfer resulted in intermittent positive fecal PCR results; however, none of the rats became persistently infected with H. pullorum. Select intestinal tissues collected at necropsy analyzed by PCR were negative for H. pullorum. To determine whether the failure to detect H. pullorum in Sprague-Dawley rats receiving contact bedding was due to resistance of Sprague-Dawley rats to H. pullorum colonization, 10 Helicobacter-free Sprague-Dawley rats were orally dosed with H. pullorum. Fecal samples were analyzed by PCR every 2 wk for 12 wk. At 2 wk after infection, 5 of 10 rats were PCR positive for H. pullorum. By 12 wpi, only 2 rats were persistently colonized with H. pullorum according to culture and PCR results. These data contrast with our previous data, which showed a high frequency of both natural and experimental H. pullorum infection in Brown Norway rats. Sprague-Dawley rats are resistant to experimentally induced H. pullorum gastrointestinal colonization when dosed orally with H. pullorum or exposed to bedding from H. pullorum-infected rats.
Insights
Sprague-Dawley rats show resistance to Helicobacter pullorum infection. Standard surveillance methods failed to detect persistent H. pullorum colonization in these rats, contrasting with findings in Brown Norway rats.
Area of Science:
- Veterinary Microbiology
- Infectious Diseases
- Rodent Health Surveillance
Background:
- Enterohepatic Helicobacter species, including Helicobacter pullorum, infect various hosts, with recent reports in mice and rats.
- Standard colony health surveillance relies on detecting infections through methods like soiled bedding exposure.
- Understanding host susceptibility is crucial for accurate disease monitoring in research animals.
Purpose of the Study:
- To evaluate the efficacy of standard soiled bedding exposure for detecting H. pullorum in Sprague-Dawley rats.
- To determine the susceptibility of Sprague-Dawley rats to experimental H. pullorum gastrointestinal colonization.
- To compare H. pullorum infection rates in Sprague-Dawley rats with previously observed rates in Brown Norway rats.
Main Methods:
- Exposure of Helicobacter-free Sprague-Dawley rats to bedding from H. pullorum-infected rats, with fecal PCR analysis every 2 weeks for 22 weeks.
- Oral gavage of H. pullorum into Helicobacter-free Sprague-Dawley rats, followed by fecal PCR and culture analysis every 2 weeks for 12 weeks.
- Necropsy and PCR analysis of intestinal tissues from exposed rats.
Main Results:
- Exposure to contaminated bedding resulted in intermittent positive PCR results, but no persistent H. pullorum infection was established in Sprague-Dawley rats.
- Following oral dosing, only 2 out of 10 Sprague-Dawley rats remained persistently colonized with H. pullorum by 12 weeks post-infection.
- Intestinal tissues from exposed rats were negative for H. pullorum upon necropsy.
- These findings contrast sharply with high infection rates previously observed in Brown Norway rats.
Conclusions:
- Sprague-Dawley rats exhibit significant resistance to experimentally induced gastrointestinal colonization by H. pullorum.
- Standard methods involving soiled bedding exposure are insufficient for reliably detecting H. pullorum in Sprague-Dawley rat colonies.
- The inherent resistance of Sprague-Dawley rats to H. pullorum necessitates alternative surveillance or management strategies if this pathogen is a concern.
