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Updated: Apr 7, 2026
Mouse Models Of Helicobacter Infection And Gastric Pathologies
Published on: October 18, 2018
Helicobacter sp. MIT 01-6451 infection during fetal and neonatal life in laboratory mice
Hitoki Yamanaka1, Tai Nakanishi, Toshikazu Takagi
1Division of Comparative Medicine, Center for Frontier Life Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
Abstract:
Helicobacter sp. MIT 01-6451 has been detected in SPF mice kept in Japan. To characterize strain MIT 01-6451, its infection route during fetal and neonatal life and effects on pregnancy were investigated using immunocompetent and immunodeficient mouse strains (BALB/c, C57BL/6, and SCID). MIT 01-6451 was detected in the uterus, vagina, and mammary glands of 50% of infected SCID mice, whereas these tissues were all negative in immunocompetent mice. No fetal infections with MIT 01-6451 were detected at 16-18 days after pregnancy in any mouse strain. In newborn mice, MIT 01-6451 was detected in intestinal tissue of C57BL/6 and SCID mice at 9-11 days after birth, but not in BALB/c mice. The IgA and IgG titers to MIT 01-6451 in sera of C57BL/6 female mice were significantly lower than those of BALB/c mice. Although no significant differences in the number of newborns per litter were observed between MIT 01-6451-infected and MIT 01-6451-free dams, the birth rate was lower in infected SCID mice than in control SCID mice. The present results indicated that MIT 01-6451 infects newborn mice after birth rather than by vertical transmission to the fetus via the placenta and that MIT 01-6451 infection shows opportunistically negative effects on the birth rate. In addition, the maternal immune response may affect infection of newborn mice with MIT 01-6451 through breast milk.
Insights
Helicobacter sp. MIT 01-6451 primarily infects newborn mice post-birth, not fetally. This infection can negatively impact birth rates, particularly in immunodeficient mice, suggesting maternal immunity plays a role.
Area of Science:
- Microbiology
- Immunology
- Animal Health
Background:
- Helicobacter sp. MIT 01-6451 has been identified in specific pathogen-free (SPF) mice in Japan.
- Understanding the transmission routes and effects of this bacterium is crucial for animal health research.
Purpose of the Study:
- To characterize Helicobacter sp. MIT 01-6451 infection.
- To investigate its transmission route during fetal and neonatal stages.
- To determine its impact on pregnancy and birth rate in different mouse models.
Main Methods:
- Infection experiments were conducted using immunocompetent (BALB/c, C57BL/6) and immunodeficient (SCID) mouse strains.
- Maternal and neonatal tissues were analyzed for bacterial presence.
- Pregnancy outcomes, including fetal infection and birth rates, were assessed.
- Serum antibody titers (IgA and IgG) were measured.
Main Results:
- Helicobacter sp. MIT 01-6451 was detected in reproductive tissues of SCID mice but not immunocompetent mice.
- No evidence of fetal infection was found.
- Neonatal intestinal infection occurred in C57BL/6 and SCID mice, but not BALB/c mice.
- Lower antibody titers were observed in C57BL/6 mice compared to BALB/c mice.
- A reduced birth rate was noted in infected SCID mice.
Conclusions:
- Helicobacter sp. MIT 01-6451 transmission occurs postnatally, not vertically via the placenta.
- Infection can negatively affect birth rates, especially in immunodeficient hosts.
- Maternal immune status and potential transmission through breast milk may influence neonatal infection susceptibility.
