title: Helicobacter sp. MIT 01-6451 infection during fetal and neonatal life in laboratory mice.
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.
authors.affiliation: Division of Comparative Medicine, Center for Frontier Life Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Hitoki
authors.initials: H
authors.lastname: Yamanaka
authors.forename: Tai
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Takagi
authors.forename: Makiko
authors.initials: M
authors.lastname: Ohsawa
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kubo
authors.forename: Naoto
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Takahira
authors.initials: T
authors.lastname: Takemoto
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Ohsawa
mesh_terms: D000818:Animals; D000830:Animals, Laboratory / Q000382:microbiology*; D000831:Animals, Newborn / Q000382:microbiology*; D018562:Disease Transmission, Infectious / Q000662:veterinary*; D005260:Female; D005333:Fetus / Q000382:microbiology*; D016998:Helicobacter / Q000302:isolation & purification*; D016481:Helicobacter Infections / Q000382:microbiology* / Q000635:transmission / Q000662:veterinary*; D007121:Immunocompetence; D016867:Immunocompromised Host; D007422:Intestines / Q000382:microbiology; D007564:Japan; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000382:microbiology* / Q000662:veterinary*; D012376:Rodent Diseases / Q000382:microbiology* / Q000635:transmission; D013047:Specific Pathogen-Free Organisms